• 환경위생공학
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• 제19권1호
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• pp.37-41
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• 2004

The removal efficiency of cadmium by chitosan complex isolated from Aspersillus oryzae was investigated through laboratory experiments. The results of the study are as follows. The adsorption kinetics of cadmium was reached the adsorption equilibrium in approximately 20 minutes and the removal efficiency was showed 95.8%. The effect of temperature on cadmium adsorption by chitosan complex shows that as the temperature increased, the amount of cadmium adsorption per unit weight of chitosan complex increased. The correlation between amount of cadmium adsorption per unit weight of chitosan complex and temperature was obtained through the coefficient of determination($R^2$). $R^2$ values was 0.854(p<0.05). A linearized Freundlich equation was used to fit the acquired experimental data. As a result, Freundlich constant, the adsorption intensity(1/n) was 0.550, and the measure of adsorption(k) was 2.181. So, it was concluded that adsorption of cadmium by chitosan complex is effective.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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• pp.168-171
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• 2001

Organobentonite modified with hexadecyltrimethylammonium (HDTMA) was used to quantify an adsorption of heavy metals. Based on preliminary experiments, optimal soil/solution ratio, a range of pH, and electrolyte were selected. Adsorption experiments of cadmium and lead were conducted to quantify an adsorption selectivity to bentonite and organobentonite. Adsorption of cadmium and lead to bentonite was increased with increasing a soil/solution ratio. Adsorption of cadmium and lead to bentonite was increased with increasing a soil/solution ratio. Adsorptions of heavy metal to organobentonite were slightly reduced relative to bentonite. This study used the principle of hard-soft-acid-base (HBAB) to interpretate an adsorption mechanism. Because of competition between cadmium and lead. adsorption of cadmium and lead was reduced in mixture of heavy metals. Adsorption selectivity.

• Membrane and Water Treatment
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• 제12권2호
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• pp.51-58
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• 2021

The natural weathered sand of basalt (WSB) has been used for the removal of cadmium from aqueous solution. The influence of various parameters i.e., contact time, pH, weathered sand of basalt dosage, particle size of the weathered sand of basalt, temperature and initial cadmium concentration were analyzed. Cadmium adsorption kinetics was well described by the pseudo second order model. Adsorption equilibrium for cadmium was properly well fitted to Langmuir isotherm model with maximum adsorption capacity 0.50 mg/g. Compared with the other experimental results using various kinds of adsorbents at a low concentration (1.0 mg/L or so) similar to that of this study, the cadmium removal efficiency using weathered sand of basalt was higher. It has been demonstrated that weathered sand of basalt has a available alternative adsorbent for cadmium when its initial concentration is low.

• 펄프종이기술
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• 제47권6호
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• pp.113-122
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• 2015

This study was carried out to investigate the characterization of cadmium adsorption by cellulose hydrogel and aerogel. Hydrogel and aerogel were made from ashless pulp dissolved in alkali hydroxide-urea aqueous solution and manufactured in film and bead types. After regeneration of cellulose, hydrogel went through the process of substitution of organic solvent and freeze-dry in order to make aerogel. SEM was used to analyze the microstructure of hydrogel and aerogel. Experiment was conducted in various concentrations and pH conditions to find out the characteristic of cadmium adsorption. After that, EDS was used to identify existence and distribution of cadmium in hydrogel and aerogel. The result from comparisons of cadmium adsorption shows that bead type aerogel has the maximum cadmium adsorption and film type hydrogel has the minimum cadmium adsorption.

• 한국환경과학회지
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• 제19권9호
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• pp.1177-1185
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• 2010

To examine the potency of biosorbent, the adsorption capacity of Pseudomonas cepacia H42 isolated from fresh water plant root was compared with Saccharomyces cerevisiae SEY2102 on bases of biomass, concentration of heavy metal, presence of light metals, immobilized cell, and ion exchange resin. P. cepacia H42 biomass of 0.05-0.5 g/L increased adsorption and above 1.0 g/L of yeast biomass was the most effective in adsorption. By applying the same amount of biomass, lead showed the highest adsorption on two strains and the adsorption strength was lead>copper>cadmium on both strains. The high heavy metal concentration induced the high adsorption capacity. P. cepacia H42 adsorption was in the order of copper>lead>cadmium and lead>copper>cadmium by yeast in 10 mg/L. Both strain showed same adsorption strength in the order of lead>copper>cadmium in 100 mg/L and 1000 mg/L. The adsorption capacity of both yeast and P. cepacia H42 was decreased in the presence of light metals and the order of cadmium>copper>lead. $Mg^{2+}$ induced the least adsorption while $Na^+$ induced highest adsorption. The adsorption capacity of immobilized yeast and P. cepacia H42 was detected between 200-400 mL in flow volume and decreased in the presence of light metals. Ion exchange containing light metals caused 30-50% adsorption reduction on both strains.

• 한국지하수토양환경학회지:지하수토양환경
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• 제6권3호
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• pp.21-29
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• 2001

양이온성 계면활성제인 HDTMA를 이용하여 치환시킨 유기 벤토나이트의 중금속 흡착능을 알아보았다. 카드뮴과 납의 흡착량은 pH와 흡착제 대 용액 비가 증가함에 따라 증가하였다. 이 실험을 통해 적정 pH 범위와 흡착제 대 용액 비를 결정하였다. 유기 벤토나이로의 중금속 흡착은 벤토나이트에 비해 약간 감소하였으며, 두 가지 중금속이 함께 존재하는 경우 경쟁에 의해 흡착량은 더 감소하였다. 유기 벤토나이트의 경우 카드뮴에 비해 납의 흡착 감소량은 더 두드러지게 나타났다. 이러한 흡착 mechanism을 hard-soft-acid-base (HSAB) 원리를 사용하여 설명하였다.

• 통합자연과학논문집
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• 제4권2호
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• pp.130-136
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• 2011

This study investigated the adsorption characteristics of nickel, zinc and cadmium ions from the aqueous solution onto the alginate bead. Adsorption equilibrium capacities of the heavy metal ions increased with increasing initial pH of the solution. The adsorption equilibrium isotherm of the heavy metal ions was well represented by Langmuir equation. The magnitude of adsorption capacity of the heavy metal ions onto alginate bead was the order of cadmium > zinc > nickel. Kinetic parameters were measured in a batch adsorber to analyze the adsorption rates of the heavy metal ions. The internal diffusion coefficient of the heavy metal ions in the intraparticle were determined by comparing the experimental concentration curves with those predicted from the surface diffusion model (SDM) and pore diffusion model (PDM). The internal diffusion of the heavy metal ions in the intraparticles was explained by PDM.

• 자원리싸이클링
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• 제8권1호
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• pp.37-43
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• 1999

본 연구는 망간단괴와 그로부터 유가금속을 침출한 잔사를 카드뮴 폐수의 흡착제로 이용하는 기초실험으로 초기 카드뮴 농도에 따른 흡착성을 살펴보았다. 또한 이를 Freundlich, Langmuir, Temkin 등온흡착식에 적용하여 각 흡착계를 설명하였다. 카드뮴 이온의 초기농도가 증가함에 따라 흡착량은 증가하였으나 흡착성은 점차로 감소하는 경향을 보였다. 이를 Freundlich, Langmuir 식에 적용한 결과, 선형성을 나타내었다. 그리고 Freundlich 식에서 흡착제의 흡착능력을 평가하는 k값은 망간단괴가 11.72로 제일 컸다. 망간단괴의 경우는 Langmuirtlr의 단분자층을 형성하여 흡착되는 흡착질의 최대흡착량인 $X_m$값또한 0.16으로 침출잔사, 잔사-생단괴 혼합, 활성탄에 비해 큼을 알 수 있었다.

• 한국환경농학회지
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• 제5권2호
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• pp.101-105
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• 1986

폐수중(廢水中) cadmium의 제거(除去)를 위한 목적(目的)으로 천연(天然) Zeolite의 이용가능성(利用可能性)을 조사(調査)한 결과(結果)는 다음과 같았다. Freundlich 흡착상수(吸着常數) $\frac{1}{n}$값이 $0.4{\sim}1.1$인 것으로 보아 천연(天然) zeolite는 효과적(效果的)인 흡착제(吸着劑)였다. 용액중(溶液中) cadmium의 농도(濃度)가 증가(增加)할수록 흡착량(吸着量)은 증가(增加)하였으며 포화(飽和)된 각(各) 양(陽) ion의 종류별(種類別) 흡착량(吸着量)은 Ca-<무처리(無處理)$-<H-{\leqq}Al-<Nazeolite$의 순(順)이었다. 또 천연(天然) Zeolite에 의한 cadmium의 흡착반응(吸着反應) 용액중(溶液中) 공존(共存)하는 Cu와 Zu에 의하여 저해(沮害)되었으며, pH $5{\sim}6$의 범위에서 흡착제거솔(吸着除去率)이 가장 좋았다. 흡착(吸着)된 cadmium을 4종(種)의 염용액(鹽溶液)으로 탈착(脫着)시켜본 결과(結果), 농도(濃度)가 높을수록 많은 양의 cadmium이 탈착(脫着)되었으며, 각(各) 염용액(鹽溶液)의 cadmium 탈착정도(脫着程度)는 $Nacl<CaCl_2<AlCl_3<HCl$의 순(順)이었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.196-201
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• 2000

The influence of adsorption on cadmium toxicity to soil microorganisms in smectite-rich soils and sediments was quantified as a function of solution and sorbent characteristics. Adsorption and surface complexation experiments were conducted to infer Cd sorption mechanisms to a reference smectite and three fractions of a Veritsol soil, and to elucidate the effects of the surface complexation on Cd bioavailability and toxicity in soils and sediments. Cadmium adsorption isotherms conformed to the Langmuir adsorption model, with adsorptive capacities of the different samples dependent on their characteristics. Equilibrium geochemical modeling (MINTEQA2) was used to predict the speciation of Cd in the soil suspensions using Langmuir and Triple Layer surface complexation models. The influence of adsorption and surface complexation on cadmium toxicity to soil microorganisms was assessed indirectly through the relative change in microbial hydrolysis of fluorescein diacetate (FDA) as a function of total Cd concentration and sorbent characteristics. Adsorption decreased the toxicity of Cd to soil microorganisms. Inner-sphere complexation is more effective than outer-sphere complexation in reducing the bioavailability and toxicity of heavy metals in soils and sediments.