생물환경연구실

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants in t he soil environment, and considered to be hazardous due to their toxic a nd carcinogenic properties. Intermediates accumulation during PAHs degra dation significantly alters the overall biodegradation rate and toxicity of the soil environment. The biodegradation pathway of phenanthrene, a 3-ring PAH, consisting of14 enzymatic steps was analyzed to determine the release pattern of the intermediates by mathematical calculation of permeability using a membrane transport model. The intermediates with h igh permeability such as 1-hydroxy-2-naphthoic acid were consistent with the compounds frequently observed in laboratory or field in the literat ure.

Stimulatory effects of three different intermediate metabolite (1-hydrox y-2-naphthoate, salicylate, and catechol) as potential inducers on phena nthrene degradation were investigated using two different bacteria (Pseu domonas putida ATCC 17484 and Burkholderia cepacia PB12). The relative i nduction capacity was high in the sequence of 1-hydroxy-2-naphthoate, sa licylate, and catechol inboth strains. The highest of up to 12 times in crease of the induction was obtained by the addition of 1-hydroxy-2-naph thoate inthe strain PB12, compared with the control where no exogenous inducer was added. The induction capacity of the potential inducerswas closely related with the number of oxygenations required per electron e quivalents in one mole of the inducer. ？ The KoreanSociety for Microbi ology and Biotechnology.

Multivariate statistical process control such as principal component ana lysis (PCA) and partial least squares (PLS) has been effectively utilize d to analyze large databases accumulated in industrial plants in order t o improve process performance and productquality. However, because both PCA and PLS are basically linear methods, nonlinearity in most chemical and biological processesis still a significant problem for their pract ical applications. Kernel-based algorithms are potentially very efficien t for monitoring process disturbances and predicting key quality variabl es of nonlinear processes by mapping an original input space into ahigh -dimensional feature space. Nonlinear data structure in the original spa ce is most likely to be linear at the high-dimensional feature space. Ke rnel-based methods essentially require only linear algebra, making them as simple as linear multivariate projection methods, and can handle a w ide range of nonlinearities because of their ability to use different ke rnel functions. In this work, kernel-based algorithms such as kernel PCA (KPCA) and kernel PLS (KPLS) are applied to a full-scale biological ana erobic filter process treating high-strength organic wastewater in a pet rochemical plant. KPCA is applied to detect process disturbances in real -time and KPLS to predict inferentially key process variables in the ana erobic filter process. The proposed kernel-based approaches could effect ively capture the nonlinear relationship in the process variables and sh ow far better performance in process monitoring and prediction of qualit y variables compared to the conventional PCA and PLS methods. ？ 2006 Am erican Chemical Society.

This study describes integrated logic for an artificial neural network (ANN) to control heating devices on a continuous basis. Two ANN-based control logic systems and two conventional rule-based logic systems were developed to control a heating device and the openings of a do uble skin enveloped building. The ANN-based logic controls heating devic es on a continuous basis according to the indoor temperature. The rule-based logic controls heating systems and openings at enve lopes in two-position on/off operation. Control performance for the dev eloped logic was numerically conducted using computer simulations for a small office space with double skin envelopes during the heating season. Analysis results indicate that the ANN-based temperature control log ic resulted in a more stable temperature near the center of the comfort able range with a reduced opening period of the internal envelope. T he reduced number of on/off moments of the heating device and the ope nings inthe ANN-based logic were predicted to save energy and prevent system degradation. The use of ANN-based logic would be effective f or maintaining a stable thermal environment and for system operation. Rule-based logic can be effectively used to improve building energy eff iciency. In this study, two ANN-based logic types were developed for heating devices controlled on acontinuous basis and their per formance was compared with those of rule-based on/off logic. Thus, in order to cover the limitation of this study, further study is warrante d for examining the clear difference achieved by ANN-based vs. rule-bas ed control, when they are applied to control heating output on a contin uous basis. (C) 2014 Elsevier Ltd. All rights reserved.

The fraction in which direct contact occurs between micellar-phase phena nthrene and the bacterial cell surface was estimated by measuring the to xicity of nonionic surfactant (Tween 80 and Triton X-100) solutions to t he phenanthrene-degrading bacterium, Pseudomonas putida P2. Cell viabili ty of completely dissolved phenanthrene decreased by 30% at concentratio ns greater than 0.3 mg L-1, which is equal to approximately one third of its solubility. Both nonionic surfactants had no effect on cell viabili ty up to 5 g L-1. Cell viability increased with increasing surfactant co ncentration at a fixed phenanthrene concentration, due to the decreased concentration of aqueous-pseudophase phenanthrene and the reduced fract ion of direct contact. The fraction of direct contact was c. 20% or more below 3 g L-1 of Triton X-100. The fraction of direct contact for Tween 80 was estimated to be lower than Triton X-100. ？ 2006 Federation of E uropean Microbiological Societies.

The toxicity of solutions containing nonionic surfactants Tween 80, Brij 35 and/or phenanthrene to Pseudomonas putida ATCC 17484 was investigate d. The fraction of direct contact between micellar-phase phenanthrene an d bacterial cell surface was estimated byusing the toxicity data and a mathematical model. The mathematical model was used to calculate phenan threne concentration in the micellar phase and aqueous pseudophase separ ately. The first-order death rate constant increased from 0.088 +/- 0.01 6 to 0.25 +/- 0.067 h(-1) when the phenanthrene concentration was increa sed from 0 to 5.17 x 10(-6) M (equals water solubility). The intrinsic t oxicity of surfactant was higher in Brij 35 than in Tween 80. When phena nthrene concentration was increased to 9.7 x 10(-5) M in surfactant solu tions, the death rate constant increased to 1.8 +/- 0.024 and 0.41 +/- 0 .088 h(-1) for 8.4 x 10(-4) M Brij 35 and 7.6 x 10(-4) M Tween 80. The d irect-contact fraction was 0.083 and 0.044 for Brij 35 and Tween 80, res pectively, under these conditions using exponential model. The toxicity increased with increasing phenanthrene concentration at a fixed surfact ant concentration. The toxicity decreased with increasing the surfactant concentration at a fixed phenanthrene concentration due to decreased co ntact of bacteria with phenanthrene present in the interior of surfactan t micelles. (c) 2007 Elsevier B.V All rights reserved.

Selective adsorption of a hazardous hydrophobic organic compound (HOC) b y activated carbon as a means of recovering surfactants after a soil was hing process was investigated. As a model system, phenanthrene was selec ted as a representative HOC and Triton X-100 as a nonionic surfactant. T hree activated carbons that differed in size (Darco 20-40 (D20), 12-20 ( D12) and 4-12 (D4) mesh sizes) were used in adsorption experiments. Adso rption of surfactant onto activated carbon showed a constant maximum abo ve the critical micelle concentration, which were 0.30, 0.23, 0.15 g g(- 1) for D20, D12, and D4, respectively. Selectivity for phenanthreneto T riton X-100 was much higher than I over a wide range of activated carbon doses (0-6 g l(-1)) and initial phenanthrene concentrations (10-110 mg l(-1)). Selectivity generally increased with decreasing particle size, increasing activated carbon dose, and decreasing initial concentration of phenanthrene. The highest selectivity was 74.9, 57.3, and 38.3 for D 20, D12, and D4, respectively, at the initial conditions of 10 mg l(-1) phenanthrene, 5 g l(-1) Triton X-100 and 1g l(-1) activated carbon. In the case of D20 at the same conditions, 86.5% of the initial phenanthre ne was removed by sorption and 93.6% of the initial Triton X-100 remaine d in the solution following the selective adsorption process. The result s suggest that the selective adsorption by activated carbon is a good al ternative for surfactant recovery ill a soil washing process. (C) 2007 E lsevier Ltd. All rights reserved.

The performance of activated carbon in soil washing and subsequent selec tive adsorption for surfactant recovery from the washed solution was inv estigated. Sandy loam soil contaminated with phenanthrene at 200 mg kg-1 was washed with four different nonionic surfactants: Tween 40, Tween 80 , Brij 30 and Brij 35. The efficiency of soil washing was highest when u sing Brij 30 with the highest solubilizing ability for phenanthrene and low adsorption onto soil. In the selective adsorption step, surfactant recovery was quite effective for all surfactants ranging from 85.0 to 8 9.0% at 1 g L-1 of activated carbon (Darco 20-40 mesh). Phenanthrene rem oval from the solution washed with Brij 30 was only 33.9%, even though i t was 54.1-56.4% with other surfactants. The selectivity was larger than 7.02 except for Brij 30 (3.60). The overall performance considering bot h the washing and surfactant recoverystep was effective when using Twee n 80 and Brij 35. The results suggest that higher solubilizing ability o f surfactants is a requirement for soil washing but causes negative effe cts on phenanthrene removal in the selective adsorption. Therefore, if a surfactant recovery process by selective adsorption is included in soil remediation by washing, the overall performance including the two steps should be considered for properly choosing the surfactant. ? 2007 Elsev ier B.V. All rights reserved.

The adsorption of cadmium ions on granular activated carbon treated with nitric acid (NGAC), and untreated regular granulatedactivated carbon (RGAC) is reported in the absence and presence of mixtures o f anionic (sodium dodecyl sulfate, SDS) andnonionic (Triton X-100, TX100) surfactants. In the absence of surfactants, NGAC adsorbed 8.7 times more Cd (0.165 mmol/g) than did RGAC (0.019 mmol/g). In RG AC suspensions, the amount of Cd sorbed increased significantly wit h increasing dose of SDS, to a maximum of 0.112 mmol/g. This incre ase was due to increased binding of Cd with sorbed SDS. However, in NGAC suspension, the amount of Cd sorbed was not increased further by the addition of SDS. It suggested that addition of SDS blocked the availability of surface functional groups in the microporous s tructure of NGAC. (C) 2009 Elsevier B.V. Allrights reserved.

Three different bacteria capable of degrading phenanthrene were isolated from sludge of a pulp wastewater treatment plantand identified as Acinetobacter baumannii, Klebsiella oxytoca, an d Stenotrophomonas maltophilia. Phenanthrene degradation effici encies by different combinations (consortia) of these bacteria were inv estigated and their population dynamics during phenanthrene degradation were monitored using capillary electrophoresis-based single-strand conformation polymorphism (CE-SSCP). When a single microorgan ism was used, phenanthrene degradation efficiency was very low (48.0, 11.0, and 9.0% for A baumannii, K. oxytoca, and S. maltophilia respecti vely, after 360h cultivation). All consortia that included S. malto philia degraded similar to 80.0% of phenanthrene and reduced lag tim e to 48 h compared to the 168 h of pure A. baumannii culture. CE-SSCP a nalysis showed that S. maltophilia was the predominant species during phenanthrene degradation in the mixed culture. The results in dicate that mixed cultures of microorganisms may effectively degrade target chemicals, even if the microorganisms show low degradation ac tivity in pure culture. (C) 2009 Elsevier B.V. All rights reserved.

The effect of impregnation of chitosan (CS) beads with cetyl trimethyl ammonium bromide (CTAB), a cationic surfactant, on the structural organization of the beads was investigated using various techniqu es such as infrared spectroscopy, zeta potential, X-ray diffraction, transmission electron microscopy and scanning electron microscopy equipped with energy dispersive X-ray. Impregnation of chitosan b eads with this surfactant (CTAB) significantly increased adsorption ca pacity from 178.32 (0 wt% CTAB) to 373.29 mg/g (0.05 wt% CTAB) for adsor ption of congo red (CR) from an initial concentration of 1000 mg/l. The results of zeta potential analysis of CS beads impregnated with v arious CTAB concentrations indicated that zeta potential was not signifi cantly increased by CTAB impregnation up to 0.1%. Based on different characterization results, enhanced adsorption of CR onto CTAB-impregnated CS beads not only involves electrostati c interactions between CR molecules, and multiple functional groups of CS and positively charged head group of CTAB molecules, but al so involves significant hydrophobic interactions between the hydrop hobic tail of CTAB and hydrophobic moieties of CR molecules. (C) 2009 Elsevier B.V. All rights reserved.

The adsorption performance of chitosan (CS) hydrogel beads was investigated after multiwalled carbon nanotubes (MWCNTs) impre gnation for the removal of congo red (CR) as an anionic dye. The study of the adsorption capacity of CS/CNT beads as a function of the CNT concentration indicated that 0.01% CNT impregnation was the most useful for enhancing the adsorption capacity. The sulfur (%) in th e CS/CNT beads measured by energy dispersive X-ray (EDX) was 2.5 tim es higher than thatof normal CS beads after CR adsorption. Equilibri um adsorption isotherm data of the CS/CNT beads exhibited bett er fitto the Langmuir isotherm model than to the Freundlich isotherm model, and the heterogeneity factor (n) value of the CS/CNT beads calc ulated from the Sips isotherm model was close to unity (0.98). The maxi mum adsorption capacity of CS/CNT beadsobtained from the Langm uir model was 450.4 mg g(-1). (C) 2009 Elsevier Ltd. All rights reser ved.

Surfactant enhanced soil washing is an efficient remediation process for sites contaminated with hazardous hydrophobic organiccompound (HOC). To reduce the cost of the process, the used surfactant shou ld be recovered. This paper presents investigation of selective adsorpti on of HOC in nonionic-anionic surfactant mixtures by activated carbon as a means of recovering surfactants, using phenanthrene (PHE) as an HO C, Triton X-100 (TX100) as a nonionic surfactant, and sodium dodecyl sulfate (SDS) as an anionic surfactant. The sorbed amount of TX10 0 on activated carbon decreased from 0.433 to 0.227 mmol/g as SOS dose increased. However the sorbed amount of PHE increased from 0.125 to 0.178 mmol/g as SOS dose increased because molar solubilization ratio of the surfactant mixtures decreased. As a result, selectivity for PHE sorption that represents the ratio of PHE partitioning to surf actant partitioning increased with increase in the proportion of SOS in the surfactant mixture.Selectivity for PHE to surfactant was muc h higher than 1 over a wide range of surfactant composition. The highe st selectivity, 95.97 +/- 49.94 at 5.61 x 10(-2) mmol-PHE/L, was obtained in the solution containing only SDS. These results suggest th at addition of anionic surfactant may improve surfactant recover y when selective adsorption for surfactant recovery is included in s oil remediation by surfactant enhanced soil washing. (C) 2009 Els evier B.V. All rights reserved.

The effect of sorbed surfactant on the distribution of hydrophobic organic compounds (HOCs) during soil washing was investigated usin g a mathematical model. Phenanthrene (PHE) as an HOC and Triton X-100 (TX100) as a nonionic surfactant were used with two soils with lo w (SS) and high (BS) organic matter contents. The available carbon fract ion (f(A, soil) ) after surfactant sorption was determined from surfa ctant coverage by measuring soil surface area using a methylene blue me thod. The sorbed surfactant was greatly effective as a sorbent for PHE, with an effectiveness factor (epsilon(soil)) in the range of 10.9-117. 2 for SS and 39.7-121.3 for BS. Surface molar solubilization ratio (MSR s) and epsilon(soil) decreased with increasing TX100 dose.The MSRs decr ement was lower for BS than for SS probably due to stronger affinity of PHE on organic matter in BS than in SS,which cause lower efficiency of soil washing than estimated by intrinsic sorption of PHE. These results suggest that soil washing in the field using surfactant for soi ls with high organic matter contents may give much lower efficiency tha n expected due to additional adsorption of HOC onto sorbed surfac tant. (C) 2010 Elsevier B.V. All rights reserved.

Surfactants in their impregnated forms in chitosan beads (CBs) were used for sorption of naphthalene (NAP) from aqueous solutions. Thre e different surfactants, Triton X-100 (TX100), cetyltrimethyl ammoniu m bromide (CTAB) and sodium dodecyl sulfate(SDS), were selected for this study. The results showed that surfactant-impregnated CS beads (SI CBs) in the form of a separatephase surfactant were very effective for NAP sorption. The calculated molar sorption ratio (MSRB mol NAP/mol surfactant) of the surfactant impregnated into SICBs was much g reater than the intrinsic molar solubilization ratio (MSR) in liquid p hase. The high MSRB value could be explained by favorable configurati ons of surfactants in beads, such as micelles in sorbed form. The equi librium isotherm did not follow Langmuir or Freundlich models, but foll owed Chapman sigmoidal equation, indicating co-operative sorption of solutes. Using SICBs as a separate phase surfactant may be a va luable tool for remediation of groundwater contaminated with hydrophob ic organic compounds. (C) 2010 Elsevier Ltd. All rights reserved.

A new type of chitosan hydrogel beads (CSB) with a core-shell membrane structure was generated by sodium dodecyl sulfate (SOS) gelation process. CSB exhibited higher mechanical strength and acid stabi lity than chitosan hydrogel beads (CB) formed by alkali gelation. The effect of SDS concentration variation during gelation on the adsorption capacity of CSB for congored (CR) as a model anionic dye showed that CSB formed by 4 g l(-1) SDS gelation had the highest adsorption capacity.The maximum adsorption capacity of CSB (208.3 mg g(-1 )) obtained from the Sips model was found slightly higher than tha t of CB (200.0 mg g(-1)). Membrane materials of CSB obtained after sque ezing core water from the beads showed approximately 25 times higher volumetric adsorption capacity than CB. (C) 2009 Elsevier Ltd. All rights reserved.

In this paper, a new steering system for a self-balancing electric scoot er is proposed with an intuitive steering command input method, where th e steering command is generated from the rider’s motion of shifting bod y to move the center of gravity toward the rotational direction. For the purpose, weight distributions on the rider’s feet are measured using f orce sensors placed beneath the rider’s feet, and the difference is app lied to a steering control system. Stability of the steering system and resultantradius of gyration is investigated by modeling the steering s ystem in consideration of the rider’s motion and centrifugal force.The proposed steering system is applied to experiments, and the results are presented to prove the validity of the proposed method.

The performances of aqueous mixtures of the model nonionic surfactant Triton X-100 (TX100) and chitosan (CS) for the solubilization of the hydrophobic organic compound phenanthrene (PHE) were evaluated by varying mixture compositions. The addition of minute amounts of C S into TX100 solutions above the critical micelle concentration signific antly increased PHE solubility.The PHE solubility was maximized at cer tain optimal concentrations of CS increasing in proportion to the TX10 0 concentrations, which were 2, 10, and 20 mg/L CS for 5, 10, and 2 0 g/L TX100, respectively. At each optimal concentration of CS, PHE solubility was increased by 46%, 39%, and 43% for the 5, 10, and 20 g/L TX100 solutions, respectively. The enhanced solubilization o f PHE by the addition of CS to TX100 solutions may be attributable to multiple factors, such as an increase of micellar size and hydrophobi city as well as to the formation of variously configured micelle-pol ymer aggregates. (C) 2010 Elsevier B.V. All rights reserved.

Chitosan hydrogel beads (CSB) formed by sodium dodecyl sulphate (SDS) gelation were used for the removal of a cationic dye, methylene blue (MB), from aqueous solutions. The adsorption capacity of chitosan be ads (CB) formed by alkali gelation was low because of charge repulsions between the chitosan (CS) and the MB. The adsorption capacity of CS B (4 g/L SDS gelation) for MB (100 mg/L) was 129.44 mg/g, and it decreas ed significantly with increasing SDS concentration during gelation. Th is decrease was a result of increased density of the CSB membrane materials. The CSB membrane materials formed with the 4 g/L SD S gelation showed the highest volumetric adsorption capacity. Th e MB adsorption on to CB and CSB increased with increasing values f or the initial pH of solution. Data from both CB and CSB showed good fit to Sips isotherm models, and the maximum adsorption capacity of CSB (226.24 mg/g) was higher than that of CB (99.01 mg/g).

The structural organization of chitosan hydrogel beads (CSBs) formed by various anionic surfactants, sodium dodecyl sulfate (SDS), sodium decyl sulfate (DS), dodecyl benzenesulfonic acid sodium salt (SDBS), and dioctyl sulfosuccinate sodium salt (DSS),and their applications a s adsorbents for environmental purifications were investigated using Congo red (CR) as a modeldye. The adsorption capacities of CSB as a function of surfactant concentration revealed that CSBs formed by 5g/L anionic surfactant were the most effective for CR adsorption. The structure of CSBs and their adsorption capacities for CR depend o n the nature of anionic surfactants. The maximum adsorption capacities of CSBSDS, CSBDS, CSBSDBS, and CSBDSS obtained from the Langmuir is otherm model were 186.02, 209.28, 207.25, and 113.83mg/g, respectively, indicating that CSBDS was the best adsorbent for CR.

The adsorption capacity of chitosan hydrogel beads generated by alkali (CB) and sodium dodecyl sulphate (CSB) gelation was investigated after polyethyleneimine (PEI) grafting for adsorption of Reactive Black 5 (RB5) from aqueous solutions. The adsorption capacities of PEI-grafted CB (PEI-CB) and CSB (PEI-CSB) were varied with the amount of PEI used during grafting. The maximum adsorption capacity values of PEI-CB (709.27 mg/g) and PEI-CSB (413.23 mg/g) obtained from the Langmuir isotherm model were higher than those of CB (201.90 mg/g) and CSB (168.07 mg/g), indicating that the adsorption performance of CB and CSB could be highly enhanced by PEI grafting. All of the adsorption systems showed better fits to the Langmuir isotherm model than the Freundlich isotherm model, except PEI-CSB. The kinetic data of the adsorption systems showed better fits to a pseudo-first-order rate model than a pseudo-second-order model. (C) 2010 Elsevier B.V. All rights reserved.

The adsorption performance of chitosan (CS) hydrogel beads (CSBs) generated by sodium dodecyl sulfate (SOS) gelation with multi-wal led carbon nanotube (CNT) impregnation was investigated for Congo red removal as a model anionic dye. CNT-impregnated CSBs were prepare d by four different strategies for dispersing CNTs: (a) in CS solution (CSBN1), (b) in SOS solution (CSBN2), (c) in CS solution containi ng cetyltrimethylammonium bromide (CTAB) (CSBN3), and (d) in SDS sol ution for gelation with CTAB-containing CS solution (CSBN4). It was obs erved from FE-SEM study that depending on nature of CNT dispersion, CNT s were found on the outer surface of CSBN2 and CSBN4 only. The adsorptio n capacity of the CSBs varied with the strategy used for CNT impregnation, and CSBN4 exhibited the highest maximum adso rption capacity (375.94 mg/g) from the Sips model. The lowest Sip s maximum adsorption capacity by CSBN3 (121.07 mg/g) suggested signi ficant blocking of bindingsites of CS by CNT impregnation. (C) 2 011 Elsevier Ltd. All rights reserved.

The solubility of solid phenanthrene (PHE) powder in aqueous solutions of surfactant and chitosan (CS) was evaluated by varying the composition of aqueous mixtures. Cetyltrimethyl ammoniumbrom ide (CTAB) and sodium dodecyl sulfate (SDS) were used as model cationic and anionic surfactants, respectively. CS at a particular concen tration in the mixture especially above the CMC value of the anionic su rfactant exhibited somewhat higher PHE solubility values than surfact ant itself. CS (20 mg/l)-SDS (20 g/l) solution showed higher PHE solubil ity (422.05 mg/l) than that of 20 g/l SDS (377.92 mg/g). However, CS-CTA B didnot show any additional enhancing effect on PHE solubilization, and CS (5 mg/l)-CTAB (10 g/l) solution showed almost similar PHE solu bility (867.23 mg/l) of 10 g/l CTAB (865.25 mg/g). The maximum inc rease in absorbance value of a 20 ml CS solution (5, 20 and 100 mg/l ) at 540 nm with stepwise addition of SDS (10 g/l) was found at a SDS c oncentration much less than its CMC value (2.33 g/l) in the mixture, ind icating strong complex formation between CS and SDS because of oppo sitely charged molecules in the experimental conditions.

Two-stage upflow anaerobic sludge blanket (UASB) process was investigated as an efficient process configuration optionfo r the treatment of purified terephthalic acid (PTA) wastewater. To study its feasibility in a defined condition, synthetic wastewater con taining only the major pollutants (i.e., acetate, benzoate, terephth alate and p-toluate) was used. By focusing the role of the second stag e on the p-toluate degradation, improved overall COD and p-toluate re moval capacities of 4.18 and 1.35 g-thCOD/L. day could be achieved together with a complete COD removal efficiency. In this situation, a ll the pollutants except p-toluate were completely degraded in the first stage while 38 and 62% of p-toluate originally present inthe was tewater were consecutively degraded in the individual stages. The concom itant methane production rate in each stage was 0.91 and 0.35 L/L . day respectively, and the methane yield on p-toluate was determ ined to be 0.12 L/g-thCOD. Batch tests using the granules obtained fro m each stage revealed that the acidogenic microorganisms enriched in bot h stages had a universal ability to degrade all aromatic pollutants pres ent in the PTA wastewater. Moreover, image analysis using scanning ele ctron microscope and confocal laser scanning microscopy combined with fluorescence in situ hybridization technique elucidated th at the distribution of acidogens and methanogens within the granu le was varied in each stage, which influenced the mass transfer regime r esulting in the different pollutant degradation rates during the batch tests. (C) 2012 ElsevierLtd. All rights reserved.

Eco-design is an essential way to reduce the environmental impacts and economic cost of processes and systems, as well as products. Until now , the majority of eco-design approaches have employed multi-objective optimization methods to balance between environmental and economic performances. However, the methods have limitations because multi-objective optimization requires decision makers to su bjectively assign weighting factors for objectives, i.e., environmenta l impacts and economic cost. This implies that, depending on decision makers' preference and knowledge, different design solutions can be engendered for the same design problem. Thus, this study proposes an e co-design method which can generate a single design solution by devel oping mathematical optimization models with a single-objective fu nction for environmental impacts and economic cost. For the formulatio n of the single-objective function, environmental impacts are moneti zed to external cost by using the Environmental Priority Strategie s. This enables the tradeoffs between environmental impacts and eco nomic cost in the same unit, i.e., monetary unit. As a case study, the proposed method is applied to the eco-design of a water reuse system in an industrial plant. This study can contribute to improving th e eco-efficiency of various products, processes, and systems. (C) 2012 Elsevier Ltd. All rights reserved.

Soybean oil was used as a biodegradable extracting agent for the removal of sorbed phenanthrene (PHE) in sandy soil. In this stud y, several methods of forming emulsions using soybean oil and their extraction properties were investigated. The stable and homogene ous oil emulsions were formed more effectively by ultrasonication (U1) t han by homogenization (H1). Moreover, homogenization before ultrasonica tion (HU1) established more stable emulsions than U1 alone. The mean diameter of oil droplets in U1 or HU1 was reduced to the nanome ter range (approximately 70 nm) by U1 with 750 W using a high-power sonic tip operated at 33% amplitude and 20 kHz frequency for 5 min. T he extraction efficiency of sorbed PHE from soil by oil emulsions increased with decreasing size of droplets of oil emulsions; t he maximum extraction of PHE was achieved with HU1. Thus, nano-em ulsions of vegetable oil made by U1 could be an environmentally benign alternative for effectively washing soil.

The degradation, kinetics and biotransformation of Direct Red 80 and chemical oxygen demand (COD) were examined under a sulfate reducing environment. Complete color and sulfate removal with more than 87% COD removal were obtained in the batch experiments at different dye (5 0-800 mg/l) and sulfate (100-5000 mg/l) concentrations. Dye degradation, COD and sulfate removal followed first order kinetics. An increase in dye concentration from 0 to 800 mg L-1 decreased the rate constant (k (1)) for dye, COD and sulfate removal from 0.0843 to 0.035 h(-1), 0.01 9 to 0.009 h(-1) and 0.108 to 0.075 h(-1), respectively. In particular , the sulfate concentration had no significant effect on dye degradatio n. Unlike other anaerobic cultures, the sulfate-reducing bacteria cu lture showed excellent dye mineralization and desulfonation ability. Fo urier transform infrared spectroscopy andgas chromatography-mass spectrometry revealed aniline and 1,4-diamino benzene to be the resulting metabolites after the decolorization of Direct Re d 80. (C) 2013 Elsevier B.V. All rights reserved.

Lignin is the major source of polyphenolic compounds available from natural biomass. Although most commercial lignin productshave been supplied from wood biomass, the residues from bioethanol production processes could be an additional potential source. About 75% of lig nin inherent in corn stover and rice straw was recoverable from the residues of bioethanol producing processes. Chemical structures and thermolysis features of the lignin residues from corn stover an d rice straw obtained through acid-alkali pretreatments were character ized. Due to inherent structural differences, the corn stover- and ri cestraw lignin were more reactive and had less thermal stability than t he wood-based Kraft lignin. The corn stover lignin showed the lowe st maximum degradation temperature with the highest mass loss rate in the primary pyrolysis reaction and it was mainly pyrolyzed into mon omers of lignin building blocks with a higher phenol content (10%), unli ke the other lignin samples (<6%). (C) 2014 Elsevier B.V. All ri ghts reserved.

Light-weight magnesium metal is used to displace heavy-weight steel and iron in automobiles and decrease CO2 emissions in the vehicle operation stage. This benefit is, however, significantly offset by CO2 emissions from high energy consumption in the magnesium production process. Thus , this study presents and assesses CO2 reduction strategies to mitigate the drawbacks of magnesium metal, based on the concepts of industrial ecology: industrial symbiosis with cement plant to utilize waste slag from magnesium production; industrial and urban symbiosis to utilize waste energy from urban area; and environmental supply chain managem ent to purchase a feedstock with lower carbon footprint. These strategie s can be used to reduce the embodied CO2 of magnesiummetal by 5%, 31% , and 9%, respectively, compared to that of an existing magnesium meta l. The industrial ecology-based strategies can be applied to produce low-carbon products and mitigate climate change. (C) 2015 Elsevie r B.V. All rights reserved.

As a result of the continuous release of new electronic devices, existing electronic devices are quickly made obsolete andrapidl y become electronic waste (e-waste). Because e-waste contains a va riety of metals, information about those metalswith the potential for substantial environmental impact should be provided to manufactu rers, recyclers, and disposers to proactively reduce this impact. This study assesses the resource and toxicity (i.e., cancer, noncancer, and ecotoxicity) potentials of various heavy metals commonly found i n e-waste from laptop computers, liquid-crystal display (LCD) moni tors, LCD TVs, plasma TVs, color cathode ray tube (CRT) TVs, and cell phones and then evaluates such potentials using life cycleimpact-base d methods. Resource potentials derive primarily from Cu, Sb, Ag, and Pb. Toxicity potentials derive primarily from Pb, Ni, and Hg for c ancer toxicity; from Pb, Hg, Zn, and As for noncancer toxicity; and from Cu, Pb, Hg, and Zn for ecotoxicity. Therefore, managing these hea vy metals should be a high priority in the design, recycling, and dispo sal stages of electronic devices. Integr Environ Assess Manag 2016;12:36 4-370. (c) 2015 SETAC

Lignin pyrolysis has a significant opportunity of producing commodityphenolic chemicals from natural biomass resources or industrial byproducts. Bio-oil production of lignin pyroly sis in a fixed-bed system was systematically characterized by respo nse surface methodology (RSM) to optimize operating variables such as temperature, heating rate, and loadingmass. According to the mathemat ical model of RSM, the predicted maximum bio-oil yield of 30.1% and the actual bio-oil yield of 29.3% were obtained under the optimum co ndition: 669 degrees C temperature, 15 degrees C/min heating rate, and 6.97 g loading mass. Temperature significantly influenced both t he yield and the chemical composition of lignin bio-oils becausepyrol ytic decomposition of lignin consisted of temperature-dependen t stepwise reactions. The bio-oil under the optimum condition produc ed not only the higher yield but also the higher content (43.2%) of t he primary product (i.e., 2-methoxyphenol). (C) 2016 Elsevier B.V. A ll rights reserved.

The objectives of the study were to (i) investigate whether short term mineralization varies to a greater extent by charring organic matter (OM) or by exposure to different mineral surfaces, (ii) examine the effect of clay mineralogy on mineralization of either charred or uncharred OM and (iii) quantify these differences in mineralizat ion in the context of C evolution during charring. Mineralization of di fferent combinations of OM types (corn stover, cellulose, glucose, ligni n and arginine)or their corresponding pyrogenic organic matter (PyOM) with minerals (quartz, corundum, goethite, kaolinite and kaolinite mi xed with goethite) were assessed in incubation experiments at 30 deg rees C for 196 days. All PyOM materials showed lower mineralization ext ent (3.8-7.5% of initial C) than uncharred OM (7.6-89% of initial C) . Charring decreased mineralization to a greater extent (by 4.7-95 %) than differences in the minerals (by 3.7-70%). The relative standard deviation of C mineralization of individual charred OM material s caused by differences in mineralogy was smaller (8.7-16%) than that of uncharred OM (8.7-65%). For the ratio of C remaining after both mineralization and charring to mineralization of uncharred biom ass, the relative standard deviation was higher for different OM types ( 51-84%) than mineral types (1.1-47%), suggesting thatmineralogy was le ss important than OM properties. Therefore, the importance of mine ralogy was lower for charred than uncharred OM and the type of PyOM mo re strongly controlled mineralization than the type of mineral dur ing the initial decomposition process. (C) 2016 Elsevier Ltd. All right s reserved.

Biochar was produced from Korean cabbage (KC), rice straw (RS) and wood chip (WC) and the use as alternative adsorbents to activated carbon (AC) in wastewater treatment was investigated. Congo red (CR) and crystal violet (CV) were used as a model anionic and cationic dye , respectively. Initial solution pH had little effect on CR and CV adsorption onto all biochars except for AC on CR. The isotherm m odels and kinetic data showed that adsorption of CR and CV onto all bi ochars were dominantly by chemisorption. All biochars had lower adsorpt ion capacity for CR than AC. KC showed higher Langmuir maximum adsor ption capacity (1304 mg/g) than AC (271.0 mg/g), RS (620.3 mg/g) and W C (195.6 mg/g) for CV. KC may be a good alternative to conventiona l AC as cheap, superb and industrially viable adsorbent for removal of c ationic dyes in wastewater. (C) 2016 Elsevier Ltd. All rights reserved.

The impregnation of Triton X-100 (TX100) in chitosan capsules (TCC) via an anionic surfactant gelation method was investigated for the sorption of naphthalene (NAP) from aqueous solutions. Impregnation with TX100 enhanced NAP sorption at all tested concentrations of TX100, ranging from 0.1 to 10 g/l. The highest NAP sorption capacity (68.7 mg/g) wa s obtained at 2 g/l of TX100, a capacity 5.1-fold higher than that of chitosan capsules without TX100 impregnation (CC) (13.4 mg/g). The highest molar sorption ratio of capsule (MSRC) was 12.23 mol NAP/m ol TX100 at 0.1 g/l, which was much higher than the MSRB for beads (0 .70) and the MSRW for the aqueous phase (0.11). Thus, when a nonionic surfactant is present in a hydrogel capsule, the ability of the surfactant to solubilize organic chemicals can be significantly increased compared to the surfactant in water or in hydrogel be ads. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsev ier B.V. All rights reserved.

The potential of activating terrestrial biomass (spent mushroom substrate, SMS) with ash-laden marine biomass [kelp seaweed, KE ] via co-pyrolysis in the field of adsorption was first investigated. KE biochar (KBC), SMS biochar (SMSBC), biochar (SK10BC) from 10%-K E added SMS, and biochar (ESBC) from KE-extract added SMS were used for the adsorption of cationic dye crystal violet (CV). ESBC had highes t fixed carbon content (70.60%) and biochar yield (31.6%). SK10BC exhib ited high ash content, abundant functional groups, coarser surface morphology and Langmuir maximum adsorptive capacity (610.1 mg /g),which is 2.2 times higher than that of SMSBC (282.9 mg/g). Biochar activated by a small amount of high ash-containing biomass such as sea weed via co-pyrolysis can serve as viable alternative adsorbent for c ationic dye removal.

ds showed a maximum adsorption capacity of 175.95 mg/g at an initial str ontium concentration of 10 g/L at 35 degrees C and pH 7. Furthermor e, they showed a good selectivity toward strontium ions in the prese nce of competing ions such as Al3+, Mg2+, and K+. The effects of di fferent operating conditions like flow rate and initial strontium co ncentration were investigated in the fixed-bed column reactor. The Thoma s, Adams-Bohart, and Yoon-Nelson models were applied to the exp erimental data to predict thebreakthrough curves using non-linear reg ression. Both the Thomas and the Yoon-Nelson models were appropriate for describing entire breakthrough curves under different opera ting conditions. Overall, RSBC beads demonstrate great potential as efficient adsorbents for the treatment of wastewater pollut ed with strontium in a continuous operation mode. (C)2017 Elsevier B.V. All rights reserved.

The presence of acetaminophen (also known as paracetamol; PRC) micropollutant in water can cause some potential health risks for human. In this study, commercial activated carbon (CAC), which has been oxidized with HNO3 by supplier to increase the oxygen-functional groups, was applied to remove PRC from water. Results demonstrated that CAC is a dominantly mesoporous material (accounting for 76.3%) with large surface area (S-BET = 1284 m(2)/g) and high total pore volume (V-Total = 0.680 cm(3)/g). CAC possessed abundantly oxygencontaining functionalities and low pH(PZC) (4.95). Raman spectrum of CAC indicated that CAC possessed a more disordered structure with a high intensity ratio of D band and G band (I-D/I-G = 2.011). Adsorption study showed that the adsorption capacity of CAC towards PRC was less affected by solution pH value (2.0-10), and ionic strength (0-1.0 M NaCl), and different water matrixes (distilled water, tap water, coastal water, wastewater from water treatment plant, groundwater, and wastewater from beauty salon). The adsorption process occurred rapidly, with around 52% of PRC in solution (similar to 517 mg/L) being removed within 5 min of contact. The Langmuir maximum adsorption capacity of CAC was 221 mg/g under 1.0 g/L of CAC, pH 7.0, 25 degrees C, and initial concentration of paracetamol (similar to 100-1200 mg/L). The pore-filling was the most important mechanism. The SBET and V-Total of CAC after adsorption decreased (by approximately 96% for both) to 45.6 m(2)/g and 0.039 cm(3)/g, respectively. The second important mechanism involved in n-pi interaction was established by a remarkably decrease in the band intensity (the FTIR spectrum after adsorption) at 1630 cm(-1) (the C=O group). Weak pi-pi interaction was confirmed a significant decrease in the ID/IG ratio from 2.011 to 1.947 after adsorption. Hydrogen bonding formations were recommended by decreasing band intensity in FTIR spectrum at 3448 cm(-1) (O-H) and 1045 cm(-1) (C-O). Weak van der Waals force was identified through the study of effect of solution temperature and desorption. Consequently, oxidized CAC can serve as a promising and potential material for efficiently eliminating PRC from water environments.

Sewage sludge biochar (SBC) was used as adsorbent to study the adsorption behavior of triarylmethane dyes, malachite green (MG; diaminotriphenylmethane), and crystal violet (CV; triaminotriphenylmethane). SBC exhibited high content (g/kg) of Al (65.8), P (64.6), Ca (57.3), and Fe (44.6). The Langmuir model showed that the affinity of MG for the surface of SBC was 22.6-times that of CVs (K-L=0.0053l/mg); maximum Langmuir monolayer adsorption capacity of 69.5 mg/g for MG and 49.0 mg/g for CV. Similar functional groups and adsorption mechanisms like hydrogen bonding, pi-pi interaction, electrostatic interactions, and ion exchanges governed both MG and CV adsorption onto SBC. Both physisorption and chemisorption were involved in both dyes adsorption (Redlich-Peterson model: R-2> 0.900) Leachability tests showed a dependency of leached metallic ions on the type of dye employed, where ion exchange was dominated by P, Al, Ca, K for MG, and Na, K, Ca for CV. Interestingly, although minimal, the standalone contribution of biochar-free ions on MG and CV decolorization was, respectively, 13% and 7.7% (Fe), 6.7% and 2.3% (K), 2.9% and 0% (Ca), and 0% and 0.8% (Mg), which showed that some adsorption-unrelated mechanism may have also contributed to decolorization of CV and MG.

Microbial electrosynthesis (MES) is a potential sustainable biotechnology for the efficient conversion of carbon dioxide/bicarbonate into useful chemical commodities. To date, acetate has been the main MES product; selective electrosynthesis to produce other multi-carbon molecules, which have a higher commercial value, remains a major challenge. In this study, the conventional carbon felt (CF) was modified with inexpensive nickel ferrite (NiFe2O4@CF) to realize enhanced butyrate production owing to the advantages of improved electrical conductivity, charge transfer efficiency, and microbial-electrode interactions with the selective microbial enrichment. Experimental results show that the modified electrode yielded 1.2 times the butyrate production and 2.7 times the cathodic current production of the CF cathode; product selectivity was greatly improved (from 37% to 95%) in comparison with CF. Microbial community analyses suggest that selective microbial enrichment was promoted as Proteobacteria and Thermotogae (butyrate-producing phyla) were dominant in the NiFe2O4@CE biofilm (similar to 78%). These results demonstrate that electrode modification with NiFe2O4 can help realize greater selective carboxylate production with improved MES performance. Hence, this technology is expected to be greatly useful in future reactor designs for scaled-up technologies.

In this study, chitosan/hematite nano-composite hydrogel capsules (HC-H) was developed via anionic surfactant gelation occurring simultaneously with immobilization and impregnation of alpha-Fe2O3 nanoparticles (HNPs) within the gel matrix. The nanocomposite adsorbent was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), inductively coupled plasma optical emission spectrometry (ICP-OES), Xray diffractometry (XRD) and elemental analyzer. The HC-H was successfully used for the removal of Congo red (CR) from aqueous solution. The CR adsorption isotherm data fitted to the non-linear forms of the Langmuir, Freundlich and Redlich-Peterson isotherm models indicated that both physisorption and chemisorption were essential in the overall adsorption process. The maximum Langmuir adsorption capacity of HC-H was 4705.6 mg/ g (26.7 times more that of the pristine chitosan hydrogel capsule (176.5 mg/g)). The adsorption kinetics data were fitted with the non-linear forms of pseudo first-order and pseudo second-order and intraparticle diffusion models. The overall adsorption process was pH dependent. The HC-H represents a chitosan-based nano-composite adsorbent with stupendous affinity for CR dye molecules and thus, has huge prospect to be considered in wastewater treatment.

The effects of utilizing goethite (5%, 10%, and 20%) in co-pyrolysis with low-lignin macroalgae, Saccharina japon-ica, on the carbon sequestration potential, magnetic, physicochemical, and dye (basic blue 41, BB41) removal properties of the resulting biochar were investigated. Biochars exhibited more aromaticity, better magnetic prop-erties, and insignificant alterations to their point of zero charges (11.07 +/- 0.03 to 10.59 +/- 0.01) with goethite increment. Optimum conditions for high organic matter conversion and carbon preservation occurred using 5% goethite. Adsorption experiments showed that BB41 adsorption was highly pH-dependent, equilibrated later (from 12 h to 24 h) after goethite modification, and was best fitted to the pseudo-second-order model (higher R-2 and lower SSE values). Langmuir monolayer adsorption capacity for BB41 was the highest amongst carbona-ceous adsorbents in the literature [1494 mg/g (pristine); 1216 mg/g (5% goethite)]; initial BB41 concentration of 2000 mg/L at 30 degrees C and pH 8. The main governing mechanisms involved ion exchanges, hydrogen bonding, pi-pi interaction and pore-filling. Overall, low goethite amount (5%), co-pyrolyzed with macroalgae, offers an econom-ically and environmentally effective way to produce magnetic biochar with enhanced carbon sequestration po-tential and superb cationic dye removal performance for environmental remediation applications. (C) 2021 Elsevier B.V. All rights reserved.

Goethite impregnated chitosan hydrogel capsules (GS5) were treated with an alkali solution and the effect of alkali treatment on the adsorption performance of the treated capsules for Congo red (CR), and the changes in physico-chemical properties, morphology, and mechanical stability of the capsules were studied. The goethite particles were synthesized via the co-precipitation method from ferric chloride hexahydrate solution and NaOH. The as-obtained goethite nanoparticles were successfully impregnated into chitosan capsules via an anionic surfactant gelation approach. The alkali treatment of GS5 with 0.02 N alkali solution (GSN5) increased adsorption capacity from 1040.54 mg/g (GS5) to 1641.96 mg/g as obtained by Langmuir adsorption isotherm. The goethite impregnated chitosan capsules more closely followed the Freundlich adsorption isotherm than the Langmuir adsorption isotherm model suggesting heterogeneous adsorption sites on the capsules, and both va-rieties of the capsules showed a better fit to first-order-kinetic rate model. Elemental analysis, inductively coupled plasma optical emission spectroscopy (ICP-OES), and energy dispersive X-ray (EDX) spectroscopy clearly indicated that alkali treatment completely removed SDS from the capsules and also, caused some morphological changes in the structural network of capsules as obtained by scanning electron microscopy (SEM). The me-chanical stability study indicated that alkali treatment caused slightly more weight loss of the capsules under mechanical agitation.

Hydrogen is a sustainable energy resource. However, H-2 is mainly produced by steam reforming of fossil fuels, emitting greenhouse gases. H-2 production from macroalgae is a promising alternative to fossil fuels because of the carbon neutrality of the marine biomass. In this study, we investigated the steam reforming of liquefied oil derived from Saccharina japonica over metal titanate-based Ni catalysts (Ni/K2TixOy, Ni/CaTiO3, Ni/SrTiO3, and Ni/BaTiO3). CO temperature-programmed reduction (CO-TPR), and O-2 temperature-programmed desorption (O-2-TPD) characterizations showed that the reducibility of lattice oxygen on metal titanates depended on metal cation species and was much higher than on the inert Al2O3. SrTiO3 exhibited the highest reducible oxygen content among the metal titanates. Catalytic evaluations showed that Ni/MTixOy catalysts exhibited higher H2 selectivity and catalytic stability than Ni/Al2O3. Ni/Al2O3 exhibited an H2/CO ratio of 1.1, while other Ni/MTixOy catalysts exhibited higher values (2.3-4.4); especially, Ni/SrTiO3 showed the highest H2 selectivity (55.8%) and H-2/CO ratio (4.4). The H2 selectivity could be correlated with the amount of reactive lattice oxygen, as quantified by CO-TPR and O2-TPD. Furthermore, reactive oxygen species inhibited coke deposition on Ni/MTixOy catalysts. Overall, the Ni/MTixOy catalysts exhibited a high potential for H2 production by the steam reforming of bio-oil from macroalgae.

This study developed a green and novel magnetic biochar via the co-pyrolysis of firwood biomass pre-treated with 10% (w/w) of either solid-phase (admixing; G10BC(A)) or liquid-phase (impregnation; G10BC(I)) goethitemineral (alpha-FeOOH). Newly fabricated magnetic biochars were characterized by inductively coupled plasma-optical emission spectroscopy (ICP-OES), Brunauer-Emmett-Teller (BET) equipment, X-ray powder diffractometry (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), proximate and elemental analyzer, and vibrating sample magnetometry. The effects of magnetic precursor, iron loading, and aqua-treatments on recoverability, magnetic property, and stability (resistance to alpha-FeOOH reconstructive crystallization/dissolution reactions) were explored and compared to those of magnetic biochar derived from conventional ferric chloride precursor (F10BC(I)). Results confirmed a direct correlation between biochar yields and ash contents with iron loading, irrespective of the used types of magnetic precursors (alpha-FeOOH or FeCl3). Although FeCl3 can generate magnetic biochar (F10BC(I)) with higher total carbon content (83.6%) and surface area (299 m(2)/g), alpha-FeOOH proved to be more effective at yieldingmagnetic biochars with nanostructured surfaces, lower water extractable components ( thus green; G10BC(A) = 0.21 mg/mL and G10BCI = 0.16 mg/mL), higher magnetic saturation (G10BC(A) = 10.0 emu/g and G10BC(I) = 20.8 emu/g), higher ferromagnetic susceptibility, and excellent recoverability. alpha-FeOOH was undetected on the surface of G10BC(A), post-aqua-treatments (over 30 days), and this demonstrated its stability in the face of demagnetization via alpha-FeOOH reformation reactions. Consequently, this study demonstrated that the admixing solid-phase alpha-FeOOH (10%) with firwood biomass offered a green, facile, and efficient way to thermochemically produce magnetic biochar. The produced biochar exhibited a superb stability to alpha-FeOOH reconstructive crystallization/dissolution reactions in aquatic (aqua) media, green attributes, good magnetic properties, and great potential applications in many areas of the economy. (c) 2020 Published by Elsevier B.V.

In this study, we developed an innovative spherical biochar with high porosity and excellent paracetamol (PRC) adsorption capacity. The optimal pyrolysis temperatures for the preparation of spherical biochar (derived from pure glucose) and non-spherical biochar (from pomelo peel wastes) were obtained at 900 degrees C and 700 degrees C, respectively. Various advanced techniques were applied to characterize the prepared biochars. Spherical and non-spherical biochars exhibited large specific surface area (1292 and 1033 m(2)/g) and high total pore volume (0.704 and 1.074 cm(3)/g), respectively. The adsorption behavior of PRC onto two biochars was conducted utilizing batch experiments. Results demonstrated that the adsorption process was slightly affected by the change of solution pH (2-11) and addition of NaCl (0.05-1.0 M) and was able to achieve fast equilibrium (similar to 120 min). The maximum adsorption capacity of spherical biochar (286 mg/g) for PRC was approximately double that of non-spherical biochar (147 mg/g). The signal of thermodynamic parameters was negative Delta G degrees and Delta H degrees values, but positive Delta S degrees value. The adsorption mechanism consisted of pore-filling, hydrogen bonding formations, n-pi and pi-pi interactions, and van der Waals force. The adsorption capacities of two biochars were insignificantly dependent on different real water samples containing PRC. Consequently, the biochars can serve as a green and promising material for efficiently removing PRC from water.

In this study, a magnetic titanium carbide (Ti3C2Tx) MXene was synthesized through a one-step chemical co-precipitation method using ammonium bifluoride as a mild etchant and was investigated for photocatalytic degradation of diclofenac (DCF) via the ultraviolet (UV)/chlorine process. The DCF degradation was enhanced by the generation of active radicals such as the hydroxyl radical and reactive chlorine species compared with that resulting from UV and chlorination treatment alone as well as UV/H2O2 processes at pH 7. The first-order rate constant of the UV/chlorine process was 0.1025 min(-1), which is 12.7 and 6.8 times higher than those of the only UV and UV/H2O2 processes, respectively. Magnetic nanoparticles on the surfaces of Ti3C2Tx sheets not only enhanced the adsorption capacity of the synthesized composite but also increased the rate of electron transfer in solution. In addition, the effects of different operating conditions such as magnetic Ti3C2Tx dose, pH, and initial chlorine concentration on DCF degradation were investigated. Magnetic Ti3C2Tx, showed high stability and photodegradation efficiency during seven consecutive degradation reaction cycles. The derivatives of DCF during the photocatalytic degradation process were also investigated based on the observed intermediate products and a degradation pathway was proposed. Thus the synthesized magnetic Ti3C2Tx, is a simple and affordable photocatalyst, which can significantly enhance DCF degradation in the UV/chlorine advanced oxidation process.

Deep saline reservoirs have the capacity to hold large volumes of CO2. However, apart from the high brine salinity, which poses an injectivity challenge, a high percentage of saline reservoirs are also fractured. The mechanisms of drying and salt precipitation and the resulting impact on CO2 injection are unique in fractured reservoirs. Analytical models were developed to investigate the impact of salt precipitation on CO2 injectivity and storage capacity. Two types of fractured saline reservoirs were considered: type I fractured reservoirs, where storage capacity and injectivity are contributed by only fractures, and type II fractured reservoirs, where both fractures and the adjacent rock matrix blocks contribute to CO2 storage and injectivity. We found that, depending on the initial brine salinity, salt precipitation could severely impair CO2 injectivity and reduce storage capacity. Salt precipitation had a fourfold impact on CO2 injectivity compared to storage capacity. Type I reservoirs with high irreducible brine saturation were less susceptible to salt clogging in the fractures. The results also suggest that fractures with rectangular aperture were less likely to be plugged by salt compared to elliptical fractures. Contrary to previous reports, some fractured deep saline reservoirs may not be suitable for CO2 storage. Generally, type II fractured reservoirs were found to be more suitable for CO2 storage in terms of susceptibility to salt clogging. The findings provide valuable understanding of the mechanisms and effect of drying and salt precipitation on CO2 storage potential, making a strong case for CO2 storage in naturally fractured deep saline reservoirs.

ObjectivesSodium dodecyl sulfate (SDS)-chitosan hydrogels have been employed for adsorption of anionic dyes and metallic substances. Two mutant forms of Thermoanaerobacter ethanolicus alcohol dehydrogenase (TeSADH) were used as model enzymes to develop a novel enzyme immobilization technique employing newly formulated porous chitosan hydrogels. Results The enzyme immobilized on chitosan hydrogel capsules formed by 5 g/l SDS gelation and subsequent treatment with 0.05 M NaOH was 28-35% higher in NADPH production than that formed by 20 g/l SDS gelation only under the same conditions. A 48-h asymmetric biphasic reduction of acetophenone with immobilized TeSADH enzyme at 50 degrees C showed 68% increase in (R)-1-phenylethanol production than the free enzyme. Compared to the free enzyme which denatured and lost its activity at 80 degrees C, the immobilized enzyme retained about 25% of its initial activity after 2-h incubation. Conclusion In contrast to the conventional chitosan hydrogel which suffers thermal and operational stability, the newly formulated porous chitosan hydrogel capsules have excellent enzyme loading efficiency and stable at harsh temperatures. Especially, this newly developed enzyme immobilization method would be applicable for food processing.

In this study, chitosan (an abundant natural biopolymer) was used as a polysaccharide source to synthesize multi-membrane hydrogel capsules (MHC) using a novel approach. The MHC material was formed in a single step self-assembly approach by an in-situ immobilization of goethite nanoparticles (GNP) during the chitosananionic surfactant complex formation reaction. The pivotal role of GNP in the formation of multi-membrane was thoroughly discussed herein. Some important factors effecting the formation and property of MHC were explored. The results of adsorption study (Co 1000 mg/L, 30 C, and pH 7.0) demonstrated that MHC (1321 35.6 mg/g) exhibited excellent adsorptive capacity for Congo red dye compared to HC (244 35.6 mg/g) and GNP (91.1 19.6 mg/g). Therefore, the unique characteristics of multi-membranes structures breeds an exciting prospect of application in diverse fields, especially wastewater treatment because of its excellent adsorption capacity for dye contaminants.

The alginate-kelp biochar composite hydrogel bead (Alg-KBC) was successfully developed via physical crosslinking with Ca2+. The composite material was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), inductively coupled plasma optical emission spectrometry (ICP-OES), and elemental analyzer. The Alg-KBC showed high removal capacity for crystal violet (CV), from aqueous solution (33.8% more than that of the pristine alginate bead). The adsorption isotherm data were fitted to the nonlinear forms of the Langmuir, Freundlich, and Redlich-Peterson isotherm models. Also, the adsorption kinetics data were analyzed with the nonlinear forms of the pseudo-first-order, pseudo-second-order, and intra-particle diffusion models. Both chemisorption and physisorption with an indispensable role of external mass transfer and stagewise pore diffusion were essential in the adsorption process. Thus, by impregnating biochar powder in alginate, a bio-platform, a composite hydrogel bead which has higher affinity for cationic dye in aqueous medium and also eliminates the onerous task of separating biochar powder from the adsorbate solution, was obtained. Hence, the Alg-KBC can be considered for efficient dye removal in the wastewater treatment process.

The effect of bentonite-mineral co-pyrolysis in amounts of 5%, 10%, and 20% with macroalgae (Saccharina japonica; kelp) on the physicochemical property changes and dye adsorption of the bentonite/biochar composite was investigated. Mathematical relations to assess the contribution of mineral and biochar components of the bentonite/biochar composite on cationic, crystal violet (CV) and anionic, Congo red (CR) dye uptake were first developed via comparison with bentonite/biochar blends from stand-alone pyrolysis of kelp and bentonite. Results demonstrated that bentonite was successfully loaded into the biochar matrix, increased mesoporosity (2.67-12.7 nm), and simultaneously enhanced bio-oil (by 7.4%-35%) and biochar yields (by 6.0%-13.6%). The carbon sequestration potential increased by 27% on co-pyrolysis with 5% bentonite with an adsorption capacity value amongst the highest for CV (1275 mg/g); dominated by chemisorption. Mathematical derivations and calculations showed that co-pyrolysis enhanced adsorption capacity contribution of bentonite (f(q,PyB,co) > 0) on both dyes. Synergy comparison (r(q.co/sp)) between bentonite/biochar composites from the co-pyrolysis and stand-alone pyrolysis were comparable on CR and CV with 20% bentonite but superior for co-pyrolysis (r(q.co/sp)=1.79), on CR adsorption with 10% bentonite. Bentonite/biochar composite thus harbor potential as an effective wastewater treatment and carbon sequestration tool. (C) 2019 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

The effects of water washing pretreatment process on the property and adsorption capacity of biochar were investigated at different biochar/water ratios from 1:5 to 1:100 (w/v). Saccharine japonica macroalgae-derived biochars (B300, B450, and B600) were prepared at 300 degrees C, 450 degrees C, and 600 degrees C, respectively. The optimal biochar/water ratio was obtained at 1:10. The results indicated that the washing pretreatment can contribute to dramatically increasing the specific surface area of biochars, but slightly increasing their porosity. The washed biochars were carbonaceous microporous materials (67-80% micropore volume), with their specific surface area and porosity being B600 (543 m(2)/g and 86%), B450 (521 m(2)/g and 75%), and B300 (188 m(2)/g and 80%), respectively. The unwashed biochars exhibited a significantly higher ash content (59%-65%) than washed biochars (26%-35%). Equilibrium adsorption study demonstrated that the Langmuir maximum adsorption capacity (Q(max)(o)) of crystal violet cationic dye decreased in the following order: unwashed-B450 (1719 mg/g) > washed-B450 (1277 mg/g) > commercial activated carbon (492 mg/g). The washing pretreatment can remove solute-inorganic minerals to prevent their release from biochar during the dye adsorption. The washed biochar with its excellent adsorption capacity can serve as a highly sustainable and industrially viable adsorbent for the removal of cationic dyes from waste bodies.

The feasibility of producing biochar and its steam-activated counterpart in a large scale (1000 kg) from spent mushroom substrate (SMS) and their usage as effective environmental remediation tools to augment current SMS management strategies were explored. Steam-activated SMS biochar exhibited enhanced surface area (332 m(2)/g), pore volume (0.29 cm(3)/g), and porosity (77.1%). The effectiveness of activation was higher on the cationic dye, crystal violet (CV) by 4.1 times increase from 255 mg/g to 1057 mg/g. The biochar and its steam-activated counterpart, respectively exhibited high COD and color removal efficiencies of 49.6% and 40.1%, and 67.7 and 99.6% for CV-spiked real wastewater. Reusability studies confirmed the dominant role of chemisorption in the adsorption process. The lower production cost coupled with the superior physicochemical properties and adsorption performances rendered the biochar with/without steam activation, as a promising alternative adsorbent to serve as a green, viable and effective environmental remediation tool.

This study investigated the effect of steam and air flowrate combinations on the syngas efflux, physico-chemical properties and adsorption performances (on congo red, CR and crystal violet, CV removal) of waste char by-product from the industrial gasification of solid refuse fuel from municipal solid waste. The BET surface area (11.4 m(2)/g), porosity (74.7%), fixed carbon content (25.8 wt%) and hydrophilicity (0.09) were enhanced with lower steam rate and higher air supply rate combination (MSWC-L) than for the higher steam rate and lower air supply rate combination (MSWC-H). Adsorption performances were higher for MSWC-L than MSWC-H on both CR (35.7-49.7 mg/g) and CV (235 to 356 mg/g) removal, suggesting that, higher air supply rate (214 Nm(3)/h; at 0.36 equivalence ratio) with lower steam rate (37 kg/h) were more effective gasification process conditions. Results showed that, syngas efflux was more sensitive to air supply rate than steam supply rate. Reactions in the combustion zone were not only limited to the pyrolysis gas vapours but to the char also. In conclusion, the waste chars from municipal solid waste gasification showed good potential as adsorbents in wastewater treatment. (C) 2019 Elsevier Ltd. All rights reserved.

An attempt has been made in this review to provide some insights into the possible adsorption mechanisms of hexavalent chromium onto layered double hydroxides-based adsorbents by critically examining the past and present literature. Layered double hydroxides (LDH) nanomaterials are typical dual-electronic adsorbents because they exhibit positively charged external surfaces and abundant interlayer anions. A high positive zeta potential value indicates that LDH has a high affinity to Cr(VI) anions in solution through electrostatic attraction. The host interlayer anions (i.e., Cl-, NO3-, SO42-, and CO32-) provide a high anion exchange capacity (53-520 meq/100 g) which is expected to have an excellent exchangeable capacity to Cr(VI) oxyanions in water. Regarding the adsorption-coupled reduction mechanism, when Cr(VI) anions make contact with the electrondonor groups in the LDH, they are partly reduced to Cr(III) cations. The reduced Cr(III) cations are then adsorbed by LDH via numerous interactions, such as isomorphic substitution and complexation. Nonetheless, the adsorption-coupled reduction mechanism is greatly dependent on: (1) the nature of divalent and trivalent salts utilized in LDH preparation, and the types of interlayer anions (i.e., guest intercalated organic anions), and (3) the adsorption experiment conditions. The low Brunauer-Emmett-Teller specific surface area of LDH (1.80-179 m(2)/g) suggests that pore filling played an insignificant role in Cr(VI) adsorption. The Langmuir maximum adsorption capacity of LDH (Q(max)(o)) toward Cr(VI) was significantly affected by the natures of used inorganic salts and synthetic methods of LDH. The Q(max)(o)values range from 16.3 mg/g to 726 mg/g. Almost all adsorption processes of Cr(VI) by LDH-based adsorbent occur spontaneously (Delta G degrees < 0) and endothermically (SW > 0) and increase the randomness (Delta S degrees > 0) in the system. Thus, LDH has much potential as a promising material that can effectively remove anion pollutants, especially Cr(VI) anions in industrial wastewater.

Contaminants in water bodies cause potential health risks for humans and great environmental threats. Therefore, the development and exploration of low-cost, promising adsorbents to remove contaminants from water resources as a sustainable option is one focus of the scientific community. Here, we conducted a critical review regarding the application of pristine and modified/treated biosorbents derived from leaves for the removal of various contaminants. These include potentially toxic cationic and oxyanionic metal ions, radioactive metal ions, rare earth elements, organic cationic and anionic dyes, phosphate, ammonium, and fluoride from water media. Similar to lignocellulose-based biosorbents, leaf-based biosorbents exhibit a low specific surface area and total pore volume but have abundant surface functional groups, high concentrations of light metals, and a high net surface charge density. The maximum adsorption capacity of biosorbents strongly depends on the operation conditions, experiment types, and adsorbate nature. The absorption mechanism of contaminants onto biosorbents is complex; therefore, typical experiments used to identify the primary mechanism of the adsorption of contaminants onto biosorbents were thoroughly discussed. It was concluded that byproduct leaves are renewable, biodegradable, and promising biosorbents which have the potential to be used as a low-cost green alternative to commercial activated carbon for effective removal of various contaminants from the water environment in the real-scale plants.

Two-dimensional (2-D) titanium carbide MXene core (Ti3C2Tx) shell aerogel spheres (MX-SA) for mercuric ion removal were designed and fabricated with varying concentrations of Ti3C2Tx MXene and sodium alginate (SA) using a facile method. Owing to their unique inside structures, high porosities, large specific surface areas, oxygenated functional groups of MXene nanosheets, and available active binding sites, the synthesized microspheres constitute a unique adsorbent for heavy metals removal in water. The MX-SA(4:20) spheres exhibit an exceptional adsorption capacity of 932.84 mg/g for Hg2+, which is among the highest value reported for adsorbents. The adsorbent exhibits high single-and multi-component removal efficiencies, with 100% efficiency for Hg2+ and > 90% efficiency for five heavy metal ions. The synthesized materials are highly efficient for Hg2+ removal under extreme pH conditions (0.5-1.0 M HNO3) and have additional excellent reproducible properties. The micro-size and spherical shape of MX-SA(4:20) also allow it to be used in column-packed devices.

HOCs(hydrophobic organic chemicals)로 오염된 토양을 복원하기 위해 적용한 토양세척 공정에서 발생한 계면활성제 용액을 재사용하는 기 核�활성탄을 사용하였으며 이때 계면활성제와 HOCs 의 분배를 예측 할 수 있는 모델을 개 발하였다. 모델은 활성탄이 주입된 계면활성제/HOC 계에서 평형 상태의 농도 분배를 바탕으로 하였다. 본 연구에서 사용한 계면활성제는 Triton X-100, H OC는 phenanthrene, 활성탄은 Darco 20-40, 12-20, 4-12 메쉬 이다. 개발된 모델을 통해 계면활성제의 농도, HOC의 농도, 활성탄 주입량 그리고 활성탄 입자의 크기에醯�영향을 살펴보았다. 전산 모사를 통해 각 물질들의 분배 결과를 얻었으며 이를 바탕으로 계산된 선택도는 활성탄을 이용한 계면활성제 재사용 기술의 평가에 사용되었다. 본 모델의 전산모사 결과 CMC(s)를 전후 하여 서로 다른 분배 양상을 보였으며 모든 경우에서 선택도 값이 1보다 커서 활성탄을 이용한 기술이 적절한 방법임을 알 수 있었다. 모델은 계면활성제 를 재사용하기 위한 복잡한 실험 이전 단계에서 간단한 전산 모사를 통해 공 정의 성능을 평가할 수 있는 모델로 활용할 수 있을 것이다.

다환방향족 탄화수소는 화석연료의 사용 등으로 자연계에 유출되며, 매우 낮 은 용해도로 인해 토양과 강한 결합을 형성하여 장기적으로 영 袖�준다. 이 러한 PAHs로 오염된 토양을 복원하기 위해 계면활성제를 사용한 토양세척 공 법을 사용하게 되며, 공정 시 계면활성제의 사용으로 전체 복원 비용이 증가 하게 된다. 이에 토양복원 시 사용된 계면활성제의 재사용을 위한 연구들이 많이 진행되고 있다. 본 연구에서는 활성탄을 이용한 계면활성제 재사용 기 술을 개발하였다. 활성탄으로는 원료물질과 활성방법이 같고 입자 크기가 다 른 세 가지 GAC(Darco 4-12, 12-20, 20-40 메쉬)를 사용하였으며, PAH로는 ph enanthrene을 계면활성제로는 Triton X-100을 사용하여 회분식으로 실험을 수 행하였다. 이때 Triton X-100 용액에서 phenanthrene의 선택적 흡착정도를 보 기위해 선택도를 사용하였다. 실험결과 입자 크기가 작을수록,舟Ⅸ湧馨�기 공 부피가 클수록 높은 선택도를 나타내었다. 선택도는 세 활성탄 모두 1보다 높아 Triton X-100 용액으로부터 phenanthrene이 효과적으로 분리됨을 알 수 있었다. 본 연구의 결과, PAHs와 같은 소수성물질로 오염된 토양의 세척시 발생하는 계면활성제 용액을 적절한 특성을 가진 활성탄을 이용하면 오염물 질을 선택적으로 제거시킬 수 있음을 알 수 있다. 따라서 활성탄을 이용한 선 택적 흡착을 이淪玖�토양 세척시 계면활성제 사용량을 줄이게 되어 복원 비 용을 절감하는 효과를 가져올 것으로 예상된다.

오염 토양 세척 공정에서의 계면활성제 비용을 줄이기 위해 활성탄을 이용한 선택적 흡착을 통해 계면활성제의 회수와 재이용 공정을 제안 臼눼� 본 연 구에서는 토양 세척 공정, 계면활성제 회수 공정, 계면활성제 재이용에 의한 토양 재세척 공정으로 구성된 전체 공정에 대한 전산모사를 수행하여 운전변 수에 대한 영향을 분석하였다. 계면활성제 첨가량은 미셀 생성 농도의 6-10배 정도가 최적이었으며, 활성탄첨가량이 너무 많을 경우 계면활성제 재이용 효율이 감소하는 결과를 얻었다. 토양 흡착 효율 인자는 세척 공정에 크게 영향을 미치지 않는 반면, 활성탄 흡착 효율 인자는 회수 공정에 큰 영향을 미칠 수 있었다. 계면활성제 회수 및 재이용 공정을 적용할 경우 기존 세척 공정에 비해 계면활성제 요구량을 20-30% 수준으로 줄일 수 있을 것으로 보 이며 발생하는 폐수에서의 오염도도 크게 줄일 수 있을 것으로 기逾홱� 본 연구에서 개발된 모델을 통해 실제 복잡한 실험 이전 단계에서 전체 공정의 성능을 예측할 수 있으며 다양한 운전조건을 모사臼�최적의 운전조건을 도 출하기 위한 기본적인 자료로 활용될 수 있을 것으로 판단된다.

계면활성제를 사용하는 토양 세척공정에서 발생하는 세척수에서 계면활성제를 재사용하고자 활성탄 흡착 공정을 적용하였으며 이때 오염물 珦�흡착분배를 평가하기 위해 수학적 모델을 적용하여 해석하였다. 오염물질로는 phenanthr ene을 계면활성제로는 Triton X-100을 사용하였다. Phenanthrene을 200 mg/kg 으로 오염시킨 토양을 10 g/L의 계면활성제 용액으로 세척을 수행하였으며 이 세척액을 대상으로 다양한농도의 입상 활성탄을 첨가하여 선택적 흡착을 수 행하였다. 활성탄의 주입량이 2.5 g/L에서 99.3%의 phenanthrene이 흡착 제거 되었으며�때 액상에 존재하여 재이용 가능한 계면활성제의 회수율은 88.9% 였다. 활성탄 흡착 평형에서 오염물질의 흡착량은 단일 성분 표준 모델에서 예상할 수 있는 양보다 훨씬 많은 양이 선택적으로 흡착되었으며 이는 활성 탄에 흡착된 계면활성제 미셀에 의한 표면 용해 현상에 의�것으로 해석할 수 있었다. 이러한 현상으로 인해 흡착 계면활성제의 흡착 효율 인자는 1보 다 매우 큰 값을 나타내었고 흡착 몰 당 오염물질 용해 비가 액상 값보다 훨 씬 높은 결과를 나타내었다. 이러한 결과는 활성탄 흡착에 의한 계면활성제 재이용 시 이론적 분배보다 더 우수한 효율로 오염물질의 선택적 분리가 가 능함을 제시한다고 할 수 있다.

Zero-valent iron (ZVI) particles were synthesized by the aqueous phase borohydride reduction method, and the synthesized ZVI particles were used for the reductive degradation of Reactive Black 5 (RB5) dye in aqueous solution. The sizes of the synthesized ZVI particles were i n the microscale range, with an average diameter of 13.57 mu m. To st udy the efficiency of surfactant-treated ZVI particles for the decolorization of RB5 solution, three different surfactant s, triton X-100 (TX100, non-ionic surfactant), cetyl trimethyl ammon ium bromide (CTAB, cationic surfactant), and sodium dodecyl sulfate (S DS, anionic surfactant) were selected for the treatment of ZVI. The no rmalized residual concentration after decolorization of 500 mg/l RB 5 by ZVI for 3 h was 0.236, while ZVI particles treated with TX100 (0.5 g/l), CTAB (1.0 g/l). and SDS (2.5 g/l) exhibited normalized residual concentration of 0.172, 0.154, and 0.393, respectively, af ter 3 h. The color removal efficiency was found to be increased with de crease in initial pH of dye solution, and ZVI exhibited good color r emoval efficiency at acidic pH. Decolorization kinetics by pseudo -first-order rate equation showed that removal rate was increased after treatment with TX100 as well as CTAB, while that was reduced after S DS treatment. (C) 2010 Elsevier B.V. All rights reserved.

The coagulation of soil particles from a soil-washing solution containing the nonionic surfactant Triton X-100 (TX100) was investigated using various coagulants, such as chitosan (CS), polyacrylamide (PAA), and polyaluminum chloride (PAC). Soil contaminated with phenanthrene (PHE) was washed with aqueous TX100 solutions at concentrations ranging from 0.1 to 20 g/L. The effectiveness of CS (5 mg/L) as a coagulant in the system was compared with PAA (50mg/L) and PAC (50 mg/L), and the results indicated that the system with CS exhibited a more effective separation of soil than those with PAA and PAC. The removal efficiency of PHE (Rj=81.7%) and the selective separation factor (SSF=14.2) at 10 g/L TX100 were the highest for the system with CS (5 mg/L), indicating that the selection of CS as a coagulant in surfactant-mediated soil washing marke dly improved both PHE removal and soil separation.

바이오차는 바이오매스를 이용하여 산소가 없는 환경에서 열분해할 때 만들어지는 탄소함량이 높은 고체 물질이다. 바이오차의 탄소 賻� 재 생 에너지, 폐기물 관리, 농업 생산성 개선, 환경복원 관점에서의 중요한 기능으로 인해 최근에 크게 주목을 받고 있다. 바이오차는 토양에서 수천 년간 안정적으로 보존될 수 있기 때문에, 결국에는 분해될 수 밖에 없어 탄소중립이라 불리는 바이오매스 에너지와는 달리 탄소 네가티브의 특징을 가지고 있다. 게다가 바이오차를 토양에 적용하면 바이오차의 높은 pH와 물 및 영양분�우수한 보유능으로 인해 농업 생산성이 크게 개선될 수 있다. 본 논문은 바이오차의 탄소격리 원리와 물리화학적 특징, 농업 및 환경에의 적용과 관련된 최근의 연구 동향을 총설하여 기술하고자 한다.

Field cultivation of corn and microbial cell viability tests using Pseudomonas putida K-5 were performed to assess the toxiceffect o f kelp seaweed biochar (KBC) and fir wood biochar (FBC) produced by pyrolysis. After 63 days growth, FBC increased corn growth by 4.9 % without fertilizer and by 7.6% with fertilizer, while KBC decreas ed it by 20.2% without fertilizer and by 27.9% with fertilizer. Physico-chemical characterization of the biochars such as ICP, CHON, and proximate analyses showed that KBC contained large am ount of metals and ashes which could be responsible for its inhibition t o corn growth. Upon exposure of K-5 cells for 1 h to biochar extracts, t he cell viability in KBC extracts was 48.2% and quite lowerthan that (78.6%) in FBC. Washed KBC biochar with water at 1:10 w/v % increased the cell viability to 54.0%. The results indicated that seaweed biochar may be careful t o be used for plant growing additives due to its high concentra tions of metals and ashes. This toxic effect could be reduced by proper washing method with water.

ESG는 환경(environment), 사회(social), 지배구조(governance)의 영어단어 머리글자의 조어로 2003년 유엔 환경계획 금융이니셔티브(UNEP FI)에서 처음 사용되었다[1]. ESG의 세 가지 영역 중 환경은 기업이 환경에 미치는 영향을 말한다. 환경요인은 기후변화 정책과 배출, 폐기물 그리고 자연자원 소비의 감축 시도 등을 다룬다. 사회요인은 기업이 조직 자체 및 기업과 직간접적으로 상호작용하는 이해관계자-직원, 고객, 지역사회, 정부 등-간의 사회적 영향을 개선할 수 있는 방향을 이야기한다.지배구조요인은 기업의 주요의사결정을 하는 주주, 이사회 구성과 이들의 다양성과 독립성, 그리고 의사결정에 대한 한계와기대를 설정하는 내부정책 등을 말한다. ESG 경영과 관련된 연구는 기업의 사회적 책임, 지속가능성, 기업 또는 재무적 성과그리고 사회적 책임투자 등에 대한 부분이며 사례연구, 데이터 기반의 실증연구를 통하여 ESG 경영기업은 전기한 분야 대부분에서 정(+)의 결과가 나왔음을 확인할 수 있었다. 본 논문은 ESG의 역사, 도입배경 그리고 경영성과에 미치는 영향 등을 국내·외 연구의 문헌분석을 통해 재무, 인사, 마케팅, 생산전략은 장기적으로 재무적인 요소뿐만 아니라 비재무적 요소 등에서도 ESG를 도입·운영하는 회사들이 강한 시장의 매력요인 창출을 통하여 기업의 지속가능성을 높이며 회사의 성장에 직접적인 영향을 주는 강력한 경쟁전략임 확인하여 이론적, 실무적 시사점을 제시하였다.