• Carbon letters
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• 제10권1호
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• pp.23-32
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• 2009

The adsorption of phenolic compound resorcinol on activated carbons prepared from Moringa oleifera (Drumstick bark) has been investigated. Activated carbon was prepared by impregnating Moringa oleifera with 50% phosphoric acid in the ratio of 1:1 and 1:2(w/w), designated as MOAC1 and MOAC2. Equilibrium and isotherm studies were carried out. The influences of variables such as contact time, initial concentration of resorcinol, carbon dosage in the solution on percentage adsorption and adsorption capacity of the bark have been analysed. The equilibration time was found to be 4 h. Kinetics of resorcinol onto activated carbons was checked for pseudo first order and pseudo second order model. It was found that the adsorption of resorcinol follows pseudo second order kinetics for both MOAC1 and MOAC2. The isotherm data were correlated with isotherm models, namely Langmuir and Freundlich. Adsorption isotherms were satisfactorily fitted by both the Langmuir and Freundlich model for MOAC1 and MOAC2.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제2권1호
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• pp.1-8
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• 1998

Biomass of non-living brown seaweed Sargassum fluitans pretreated by different methods is capable of taking up more than $10\%$ (11 meq/g) of its dry weight in aluminum at a pH of 4.5. It is indicated that the biomass sequestered the aluminum in the form of polynuclear aluminum species. The fraction of $Al(OH)_3$ Precipitated in the aluminum nitrate solution without biomass at pH 4.5 increased as the Al concentration increased. Aluminum-alginate complex precipitated in the solution as alginate was partially released from the biomass. External colloidal precipitate occurring in native and protonated S. fluitans biomass sorption systems caused a significant difference in Al sorption isotherms determined by standard and desorption methods, respectively, Sodium ions added for pH adjustment were not sorbed at all in the presence of aluminum ions.

• 한국환경과학회지
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• 제7권5호
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• pp.653-658
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• 1998

Marine algaes are capable of binding a large quantity of heavy metals. We have investigated the uptake capacity of Pb and Cu by using 22 species of marine algae. collected from Korean coast. Among a variety of different marine algae types for biosorbent potential. Kjellmaniella crassifolia showed the highest uptake capacity of Pb. Metal uptake of Pb and Cu by Kjellmaniella crassifolia increase as the initial concentration rises, as long as binding sites are remained. The metal uptake parameters for Pb and Cu had been determined according to Langmuir and Freundlich model. By increasing pH, Pb uptake was increased and Cu uptake was constant. The maximum uptake capacity of Pb and Cu by Kjellmaniella crassifolia was 437 mg/g and 129 mg/g, respectively.

• Journal of Microbiology and Biotechnology
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• 제11권5호
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• pp.781-787
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• 2001

The binding of heavy metals by a biosorbent with binary functional groups was mathematically modeled. An FT-IR spectrophotometer analysis was employed to determine the stoichiometry between the protons in the functional groups of alginic acid and lead ions as a model system. The results calculated using an equilibrium constant agreed well with the experimental results obtained under various operating conditions, such as pH and metal ion concentration. It was also shown that the overall adsorption phenomenon of alginic acid was mainly due to its carboxyl groups. The equilibrium constants for each functional group successfully predicted the lead adsorption of ${\alpha}$-cellulose. Furthermore, the biosorption model could predict the adsorption phenomena of two metal ions, lead ions and calcium ions, relatively.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.29-34
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• 2004

Biosorption technology is recognized as an economically feasible alternative for the removal and/or recovery of metal ions from industrial wastewater sources. However, the structure of biosorbents is quite complex when compared with synthetic ion-exchange resins, which makes it difficult to quantify the ion-binding sites. Accordingly, this report describes a well-defined method to characterize the pK values and numbers of biomass functional groups from potentiometric titration data. When the proposed method was applied to Sargassum polycystum biomass as a model biosorbent, it was found that the biomass contained three types of functional groups. In addition, the carboxyl group (pK=$3.7{\pm}0.09$) was found to be the major binding sites ($2.57{\pm}0.06 mmol/g$) for positively-charged heavy-metal ions.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권1호
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• pp.67-71
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• 2006

This paper compares regression and neural network modeling approaches to predict competitive biosorption equilibrium data. The regression approach is based on the fitting of modified Langmuir-type isotherm models to experimental data. Neural networks, on the other hand, are non-parametric statistical estimators capable of identifying patterns in data and correlations between input and output. Our results show that the neural network approach outperforms traditional regression-based modeling in correlating and predicting the simultaneous uptake of copper and cadmium by a microbial biosorbent. The neural network is capable of accurately predicting unseen data when provided with limited amounts of data for training. Because neural networks are purely data-driven models, they are more suitable for obtaining accurate predictions than for probing the physical nature of the biosorption process.

• KSBB Journal
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• 제13권4호
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• pp.444-448
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• 1998

Biosorption of Pb and Cu was evaluated for 23 species of marine algae collected from a Korean coast. Among a variety of species for biosorbent potential, Hypnea charoides showed the highest capacity for Pb. An adsorption equilibrium was reached in about 2 hr for Pb and 30 min for Cu. The uptake capacity was 192.8 mg Pb/g biomass and 256 mg Cu/g biomass, respectively. The adsorption parameters for Pb and Cu were determined according to Langmuir model. With an increase in pH value, more negative sites are becoming avaliable for adsorption of pH and Cu, thus the removal of Pb and Cu increases at alkaline conditions. The selectivity of mixture solution shows the uptake order of Pb>Cu>Cr>Cd. When Ca concentration increases in Pb solution, Pb was selectively adsorbed.

• Nuclear Engineering and Technology
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• 제49권3호
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• pp.534-540
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• 2017

The adsorption of uranium (VI) by calcium alginate beads was examined by batch experiments. The effects of environmental conditions on U (VI) adsorption were studied, including contact time, pH, initial concentration of U (VI), and temperature. The alginate beads were characterized by using scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. Fourier transform infrared spectra indicated that hydroxyl and alkoxy groups are present at the surface of the beads. The experimental results showed that the adsorption of U (VI) by alginate beads was strongly dependent on pH, the adsorption increased at pH 3~7, then decreased at pH 7~9. The adsorption reached equilibrium within 2 minutes. The adsorption kinetics of U (VI) onto alginate beads can be described by a pseudo first-order kinetic model. The adsorption isotherm can be described by the Redlich-Peterson model, and the maximum adsorption capacity was 237.15 mg/g. The sorption process is spontaneous and has an exothermic reaction.

• 한국환경농학회지
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• 제28권2호
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• pp.158-164
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• 2009

왕겨와 톱밥 3종(미송, 참나무, 포플러)을 sodium hydroxide(NaOH)와 tartaric acid($C_4H_6O_6$)를 처리한 후 중금속 흡착특성을 평가한 결과 모든 소재에서 중금속 선택성은 Pb > Cu > Cd > Zn 순으로 나타났다. 참나무 톱밥(NaOH로 개질)은 Pb(19.36 mg $g^{-1}$)과 Cu(13.47 mg $g^{-1}$)에 대해 그리고 왕겨(tartaric acid로 개질)는 Cd(5.37 mg $g^{-1}$)과 Zn(2.24 mg $g^{-1}$)에 대해 뛰어난 흡착능을 나타내었다. SEM 분석결과 4가지 소재에서 모두 NaOH 개질 후에 표면의 불순물이 제거됨이 확인되었고 흡착표면이 매끄럽게 안정화 된 것을 관찰할 수 있었다. FT-IR 분석결과 왕겨는 1080 $cm^{-1}$에서 carbonyl group, hydroxyl group 등의 관능기가 존재함을 확인하였고 tartaric acid로 개질한 경우 1184 $cm^{-1}$와 1735 $cm^{-1}$에서 carboxylate group, carboxyl group, methylene group 등의 새로운 관능기가 생성됨을 확인하였다. 3종의 톱밥(미송, 참나무, 포플러)에 대한 FT-IR 분석결과 왕겨와 유사한 peak가 관찰되었는데 1030 $cm^{-1}$에서 carbonyl group과 hydroxyl group, 1200 $cm^{-1}$과 1700 $cm^{-1}$ 사이에서 carboxylate group, carboxyl group, methylene group 등이 이에 해당하였다. 한편 NaOH로 개질한 경우 peak에서 큰 변화를 나타내지 않았으나 흡착량이 증가한 것은 표면개질로 새로운 관능기가 생성되지는 않았으나 표면의 불순물이 제거.안정화됨으로써 흡착 표면적이 증가되었기 때문인 것으로 판단되었다.

• 환경생물
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• 제37권4호
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• pp.741-748
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• 2019

본 연구에서는 바이오매스 폐기물인 Corynebacterium glutamium을 Alg를 이용한 고정화와 PEI 표면개질 과정을 통하여 유해 미세조류인 Microcystis aeruginosa를 제거할 수 있는 흡착소재인 PEI-AlgBF를 개발하였다. 녹조의 발생단계에 상관없이 PEI-AlgBF는 수계로부터 M. aeruginosa를 성공적으로 제거할 수 있었으며 유해조류 제거과정에서 M. aeruginosa 세포의 파괴를 유발하지 않았다. 흡착소재의 표면적은 M. aeruginosa의 제거효율에 매우 큰 영향을 주는 주요인자로 확인할 수 있었다. PEI-AlgBF를 사용한 M. aeruginosa 흡착/제거 방식은 기존 기술에 비하여 환경영향성이 낮기 때문에 보다 안전하고 안정적인 유해조류의 제어 방식이 될 것이다.