2 (Langmuir, Freundlich, Elovich, Temkin, and Dubinin-Radushkevich) and 3 (Sips and Redlich-Peterson)-parameter isotherm models were applied to evaluated for the applicability of adsorption of Cu(II) and/or phosphate isotherm using chitosan bead. Non-linear and linear isotherm adsorption were also compared on each parameter with coefficient of determination (R2). Among 2-parameter isotherms, non-linear Langmuir and Freundlich isotherm showed relatively higher R2 and appropriate maximum uptake (qm) than other isotherm equation although linear Dubinin-Radushkevich obtained highest R2. 3-parameter isotherm model demonstrated more reasonable and accuracy results than 2-parmeter isotherm in both non-linear and linear due to the addition of one parameter. The linearization for all of isotherm equation did not increase the applicability of adsorption models when error experiment data was included.

본 연구는 구리 아연 금속합금의 산화 환원 반응과 합성 알루미늄 실리케이트의 흡착 반응을 이용한 폐수 중 중금속 처리에 관한 연구이다. 극세사 형태로 제조된 구리 아연 금속합금이 수용액 중에 서 산화 환원반응에 의해 아연보다 이온화 경향이 작은 중금속은 환원 처리되고, 이온화 된 아연 및 미 반응 중금속은 흡착 처리하여 제거하는 연구이다. 극세사 형태로 제조된 금속합금 물질은 표면적이 커서 1회 처리만으로도 반응 평형에 도달하게 하여 효율이 높은 것으로 나타났다. 크롬(Cr+3)은 redox 반응 1 회 처리만으로도 100.0 % 제거 되었으며, 수은은 98.0 %, 주석 92.0 %, 구리는 91.4 % 정도 제거되었 다. 카드뮴, 니켈, 납도 각각 40.0 %, 50.0 %, 58.0 %가 제거 되었다. 크롬(Cr+3)은 아연과 이온화 경향 차이가 거의 없지만 제거 효율이 높은 것으로 나타났는데 이는 3가 크롬은 이온 상태로 존재하면 redox 반응에서 발생한 OH- 이온과 결합하여 수산화물 침전을 형성하는 것으로 판단된다. Redox 반응 후 증 가한 아연 및 미반응 중금속 농도를 알루미늄실리케이트를 1회 통과하여 거의 100.0 % 제거할 수 있었 다. 이는 합성 알루미늄 실리케이트의 비표면적이 크고 금속 이온의 흡착능력이 우수한 것으로 나타났으 며, 반응 후 알루미늄 이온은 증가하지 않는 것으로 보아 이온 교환이 아닌 흡착으로 아연 및 중금속 이 온들을 제거할 수 있는 것으로 나타났다.

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.

비정질 실리콘 박막 위에 구리용액을 스콘코팅하여 구리이온을 흡착시킨 후 이를 표면 핵생성 site로 이용하는 새로운 저온 결정화 방법에 관하여 연구하였다. 구리 흡착으로 LPCVD비정질 실리콘 박막의 결정화온도를 500˚C까지 낮출 수 있었고 결정화시간도 크게 단축되었다. 530-600˚C에서 어닐링시 구리가 흡착된 비정질 실리콘 막은 나뭇가지 형태의 fractal을 이루며 결정화되었다. 이때 fractal크기는 구리용액의 농도에 따라 30-300μm로 성장하였다. Fractal의 내부는 새 털 모양의 타원형 결정립으로 구성되어 있으며 TEM 에 의한 최종 결정립의 크기는 0.3-0.4μm로 intrinsic 비정질 실리콘 박막을 600˚C에서 어닐링하였을 때화 크기가 비슷하였다. 구리용액의 농도 증가에 따라 핵생성 활성화 에너지와 결정성장 활성화 에너지가 감소하였다. 결과적으로 구리 흡착이 표면에서 우선 핵생성 site를 증가시키고 핵생성 및 fractal 성장에 필요한 활성화 에너지를 모두 낮추어 저온에서도 결정화가 촉진되었음을 알 수 있었다.

The adsorption characteristics of Cu ions were studied using the zeolite Na-A synthesized from Jeju volcanic rocks. The effects of various operating parameters such as initial concentration of Cu ions, contact time, solution pH, and solution temperature were investigated in batch experiments. The adsorption of Cu ions by Na-A zeolite was fitted well by pseudo-second-order kinetics and the Langmuir isotherm model. The maximum adsorption capacity determined using the Langmuir isotherm model was 152.95 mg/g. In addition, the adsorption of Cu ions by zeolite Na-A was primarily controlled by particle diffusion model in comparison with the film diffusion model. As the temperature increased from 303 K to 323 K, ΔG˚ decreased from -2.22 kJ/mol to –3.41 kJ/mol, indicating that the adsorption of Cu ions by Na-A zeolite is spontaneous process.

달성광산 주변 하천에서 채취한 시료를 이용하여 중금속 흡착 특성 평가를 수행하였다. 수용액 내에 존재하는 As, Cu, Cd를 대상으로 산성광산배수 침전물을 이용하여 중금속 제거 실험을 수행하 였다. 중금속 흡착 물질의 주 구성광물은 황갈색(Munsell color 8.75YR 5/10)의 schwertmannite와 흑갈 색의 (Munsell color 2.5YR 3/8) 침철석이다. 흡착 물질에 의한 흡착 제거 효율과 흡착량은 수용액 내 의 중금속의 초기 농도와 흡착물질의 특성에 의해 좌우된다. 달성광산에서 채취한 침전물에 의한 중 금속 흡착 효율은 As > Cu > Cd 순으로 나타낼 수 있다. 저농도일 때 침전물에 의한 흡착 제거 효율 은 As 67.00-85.00%, Cd 26.24-29.08%, Cu 7.67-12.82% 정도이다. Cu의 초기 농도가 1 mg/L와 10 mg/L일 때, 흡착 물질이 schwertmannite인 경우 흡착량은 0.29와 1.29 mg/g이며, 침철석인 경우 0.24-1.97 mg/g으로 초기 농도가 높거나 흡착 물질이 침철석인 경우 흡착량이 더 높게 나타난다.

The removal property of Cu and Zn ions by chemical precipitation and adsorption using zeolite(Z-C1) prepared from coal fly ash(CFA) were evaluated in this study. Adsorption kinetic and equilibrium mechanisms described to analyze parameters and correlation factors with Lagergen 1st and 2nd order model and Langmuir and Freundlich model. Analysis of adsorption kinetics data revealed that the pseudo 2nd order kinetics mechanism was predominant. The equilibrium data in pH 3 - 5 were able to be fitted well to a Langmuir model, by which the maximum adsorption capacities(qmax) were determined at 124.9 - 140.1 mg Cu2+/g and 153.2 - 166.9 mg Zn2+/g, respectively. We found that Z-C1 has a potential application as absorbents in metal ion recovery with low pH.

Various kinds of zeolites, such as analcime (ANA), cancrinite (CAN), Na-P1 and sodalite octahydrate (SOD) could be synthesized from Hwangto by hydrothermal reaction in a high-pressure vessel. The adsorption characteristics of Cu(II) and Cd(II) by Hwangto and its synthetic zeolites were investigated using the chemical and electrochemical surface parameters of these adsorbents. The heavy metal adsorptivity among the adsorbents decreased in the following sequences: Na-P1>SOD>ANA>CAN>Hwangto. This sequence was the same with the values of surface site density (Ns) of these adsorbents and was correlated inversely with the values of pHpzc (pH of the point of zero charge) and the values of Ka2(int) (intrinsic surface deprotonation constant) of the adsorbents for synthetic zeolites, i.e., the adsorbents with higher values of Ns and with lower values of pHpzc and Ka2(int) for synthetic zeolites showed higher heavy metal adsorptivity. With increasing pH, the heavy metal adsorptivity increased greatly between pHpzc and pH 6 or 7 because of the steep increase of negatively charged sites for synthetic zeolites, but for Hwangto, it increased broadly because of slow increase of negatively charged sites based on its lower surface sites.

In this work, the characterization of adsorption of Cu, Zn and Cd on granular activated carbon in water has been studied. The factors that affect adsorption in boundary between activated carbon and wastewater are concentration, temperature, contact time, pH and so on. As the result of this study, the maximum adsorption amount of Cu occurred near pH 7, while that of Zn and Cd was near pH 9.6 and 10, respectively. As contact time and temperature are transformed, such factors as optimum contact time and temperature are taken into consideration in an adsorptive process of heavy metal because an adsorption and a reducing process occur. In isotherm of Freundlich, 1/n values of Cu, Cd capacity were between 0.16 and 0.5.

Removal of Pb(Ⅱ), Cu(Ⅱ), Cr(Ⅲ) and Zn(Ⅱ) ions from aqueous solutions using the adsorption process on domestic loess minerals has been investigated. Variations of contact time, pH, adsorption isotherms and selectivity of coexisting ions and leachate were experimental parameters. YDI, YPT and KRT samples diluted in 1% aquous solution which was adjusted pH 10.8, 8.0 and 6.50, respectively. The result of XRD measurement, Quartz was mainly observed in all samples. In the case of KRT sample, Kaolinite, Feldspar, Chlorite consisting of clay minerals shows almost same pattern with YPT samples. Different properties showed from the YDI sample containing Iillite, remarkably.For all the metals, maximum adsorption was observed at 30min ∼ 60min. Adsorption of metal ions on loess minerals were reached an equilibrium by shaking the solution for about 30min. Removal efficiency of Pb(Ⅱ) ion for KRT, YPT and YDI were 84.7%, 92% and 100%, respectively. The Cu(Ⅱ) and Zn(Ⅱ) adsorptivity on KRT showed the low in various pH solution However, those on YPT and YDI were high than 90% except for the pH 2 solution. The orders of adsorptivities for domestic loess minerals showed as following : YPT>KRT>YDI. The adsorption isotherms of Cu(Ⅱ) and Zn(Ⅱ) ions on clay minerals were fitted to a Freundlich's. Freundlich constants(1/n) of KRT and YPT domestic loess minerals were 0.63, 0.97 and 0.36, 0.25, respectively.