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 환경영 향성이 낮기 때문에 보다 안전하고 안정적인 유해조류의 제어 방식이 될 것이다.

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.

The activated carbon produced from rubber wood sawdust by chemical activation using phosphoric acid have been utilized as an adsorbent for the removal of Cu(II) from aqueous solution in the concentration range 5-40 mg/l. Adsorption experiments were carried out in a batch process and various experimental parameters such as effect of contact time, initial copper ion concentration, carbon dosage, and pH on percentage removal have been studied. Adsorption results obtained for activated carbon from rubber wood sawdust were compared with the results of commercial activated carbon (CAC). The adsorption on activated carbon samples increased with contact time and attained maximum value at 3 h for CAC and 4 h for PAC. The adsorption results show that the copper uptake increased with increasing pH, the optimum efficiency being attained at pH 6. The precipitation of copper hydroxide occurred when pH of the adsorbate solution was greater than 6. The equilibrium data were fitted using Langmuir and Freundlich adsorption isotherm equation. The kinetics of sorption of the copper ion has been analyzed by two kinetic models, namely, the pseudo first order and pseudo second order kinetic model. The adsorption constants and rate constants for the models have been determined. The process follows pseudo second order kinetics and the results indicated that the Langmuir model gave a better fit to the experimental data than the Freundlich model. It was concluded that activated carbon produced using phosphoric acid has higher adsorption capacity when compared to CAC.

The rapid development of some industries generates a huge amount of useless biowastes. Recently, biosorption, which can use biowastes as biosorbents, has attracted attention as an environmentally friendly method for the removal of ionic pollutants from wastewaters. For this reason, many researchers have investigated the biosorption capacities of various biowastes. In this study, fermentation waste (Escherichia coli) was used as a biosorbent for the removal of various organic and inorganic pollutants: i.e., cationic dye (methylene blue (MB)), anionic dye (Reactive Red 4 (RR4)), cationic metal (cadmium (II)), and anionic metal (arsenic (V)). The uptake of the cationic pollutants by the biosorbent increased as solution pH was increased. The RR4 uptake increased with a decrease in solution pH. In the case of the anionic metal (As (V)), it was not well removed in the range of pH 2-7. To examine adsorption rates and mechanisms, kinetic and isotherm experiments were conducted, and various kinetic and isotherm models were used to fit the experimental data. The maximum adsorption capacities of MB and RR4 were predicted to be 231.3 mg/g and 257.6 mg/g, respectively. In conclusion, fermentation waste (E. coli) is a cheap and abundant resource for the manufacture of effective biosorbents capable of removing both cationic and anionic (in) organic pollutants from wastewaters.

This study was performed to find the effect of Enteromorpha prolifera as a biosorbent on the removal of heavy metals such as lead, copper, zinc and cadmium from the synthetic wastewater. The biosorption experiment was conducted using biomass of dried Enteromorpha prolifera, which has caused environmental pollution issues in oceans and lakes. To find the physico-chemical characteristics and adsorption capacity, parameters such as biosorbent dosage, initial heavy metal concentration, pH value of solution, contact time which influence the effects on heavy metals removal were changed and the optimum values were found through batch test. The experimental results showed that the sequence for adsorption capacity of heavy metals by Enteromorpha prolifera was Pb2+> Cu2+> Cd2+> Zn2+. The optimum conditions of pH, contact time and dosage of biosorbent were pH 5.0, 60 min. and 0.5 g/L, respectively. As initial heavy metal concentration increased, the adsorption capacity increased up to 17.53 mg/g for Pb with 98% removal efficiency. From the adsorption thermodynamic and kinetic analysis, the biosorption pattern of Pb, Cu, Zn and Cd was well described using Freundlich and Langmuir sorption isotherm with their R2 values of 0.99 and 0.97, respectively. The sorption kinetics followed pseudosecond order kinetic models and thus supported chemical sorption rather than internal diffusion. The work clearly indicates the potential of using Enteromorpha prolifera as an excellent adsorbent for heavy metal removal in industrial wastewater.

This research investigated the feasibility of rice husk (RH) as a biosorbent for the removal of anions from aqueoussolution. RH-g-GMA-Am biosorbent, which possesses anionic exchangeable function, was prepared through graftpolymerization of glycidyl methacrylate (GMA) in the presence of N,N'-methylene-bis-acrylamide as a cross-linker usingpotassium peroxydisulphate as a redox initiator and subsequent amination reaction using ethylenediamine (EDA),diethylenetriamine (DETA), dimethylamine (DMA) and trimethylamine (TMA) as a amine source. Fourier transforminfrared (FTIR) and scanning electron microscopy (SEM) analysis as well as the sorption capacity for anions verifiedthe presence of grafted GMA polymers and amine groups on the RH surface. The zero point of surface potential ofaminated RH-g-GMA-Am sorbent was 6.4, which facilitated the sorption of anions on the positively charged sorbent atpH<6.4. The sorption capacity of RH-g-GMA-Am depending on the amination chemicals increased in the order:DETA≥EDA>DMA>TMA, i.e., primary amine>secondary amine>tertiary amine. The sorption selectivity of RH-g-GMA-Am sorbent aminated with DETA and EDA in the presence of equimolar anions and at pH 4.7 increased in theorder: SO4>PO4>NO3>F. Furthermore, their sorption capacities for PO4 were much higher than those of commercialanion-exchange resins. The results obtained suggest that the RH-g-GMA-Am biosorbent prepared by the GMA graftcopolymerization and subsequent amination can be used as an effective anion-exchanger comparable to commercial anion-exchange resins.

This research investigated the feasibility of rice husk as a biosorbent for removal of ammonium ion from aqueous solutions. To improve the sorption functionality of rice husk, the carboxyl groups were chemically bound to the surface of the rice husk by graft polymerization of acrylic acid using potassium peroxydisulphate as a redox initiator. The removal of ammonium ion by rice husk grafted with acrylic acid (RH-g-AA) was studied in a batch mode and fixed bed columns. The kinetic and equilibrium data obtained from batch experiments follow the second-order kinetics and fit well with the Langmuir isotherm model. The sorption energy determined from D-R model was 8.61 kJ/mol indicating an ion-exchange process as the primary sorption mechanism. To determine the characteristic parameters of the column useful for process design, four mathematical models; Bed Depth Service Time (BDST), Bohart-Adams, Clark and Wolborska models were applied to experimental data obtained from the fixed bed columns with varying bed heights. All models were found to be suitable for simulating the whole or a definite part of breakthrough curves, but the Wolborska model was the best. The fixed bed sorption capacity determined from the Wolborska model was in the range 33.3 ~ 40.5 mg/g close to the value determined in the batch process. The thickness of mass-transfer zone was calculated to be approximately 40 mm from DBST model. The RH-g-AA sorbent could be regenerated by a simple acid washing process without a serious lowering the sorption capacity or physical durability.

This research investigated the feasibility of rice husk as a biosorbent for the removal of heavy metals from aqueous solutions. The carboxyl groups were chemically bound to the surface of the rice husk by graft polymerization of acrylic acid using potassium peroxydisulphate as a redox initiator. The Pb sorption capacity and FT-IR spectra confirmed the presence of carboxyl groups on the structural units of the acrylic acid-grafted rice husk (RH-g-AA). The sorption selectivity of the RH-g-AA for cations under competition with each other was high in the following order: Pb > Cu > Cd ≥ Fe > Mn > Zn > Ni > Mg > K > Cr > Ca. Sorption equilibrium of Pb on RH-g-AA was better described by the Fruendlich isotherm model than the Langmuir isotherm model. The sorption energy obtained from D-R model was 13.13 kJ/mol indicating an ion-exchange process as the primary sorption mechanism. Sorption kinetic data fitted with the pseudosecond- order kinetic model and indicated that both external and intraparticle diffusion took part in sorption processes. The RH-g-AA sorbent could be regenerated for more than 5 times by the washing process with 0.1 M HCl without a serious lowering the sorption capacity.