• Journal of Sericultural and Entomological Science
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• v.40 no.1
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• pp.17-22
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• 1998

To investigate the detoxificative effect of tea, five kinds of tea(mulberry, anaerobic treated mulberry, green, barly tea and corm tea) were selected and determined their dotoxication activities for Cd and Pb in drinking water. The effect of tea on the removal of Cd and Pb were increased proportionally to the contents of teas. Anaerobic treated mulberry leaf tea showed stronger detoxication activity than the others. In drinking water contaminated with Cd, the removal effect of Cd was high 27% by anaerobic treated mulberry leaf tea and 14% by mulberry leaf tea as compared to green tea. Also, in drinking water with Pb, the removal effect of anaerobic treated mulberry leaf tea was the best among five kinds of tea. Pretreatment method on the removal effect of Cd was better than post-treatment method in the treatment method.

• Journal of Environmental Health Sciences
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• v.21 no.1
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• pp.47-55
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• 1995

Minari(Oenanthe stolonifera DC.) lived in serious polluted water is able to remove chemical elements from batch system. This study attempted to compare the incorporation of cadmium and lead in batch system. Different concentrations of Cd(0.02 0.1 0.5 1.00 5.00 mg/l) and Pb(0.1 0.5 1.0 5.0 10.0 mg/l) were used. Toxic effects were obvious at Cd 1.00 mg/l and Pb 5.00 mg/l. The detrimental effects on minari were chlorosis of leaves and stunted roots and reduction in the number of lateral roots. There was reduction in growth rates exposed above Cd 1.00 mg/l and lead 5.0 mg/l. The minari capacities to remove Cd were 34.1-74.2% and Pb were 53.0~91.5%. The removal rates by minari in Cd and Pb solution were decreased with increased exposure concentration(in Cd r=0.97, in Pb r=0.88). The removal rates by minari in Cd and Pb solution were increased with increased growth rate(in Cd r=0.93 in Pb r=0.92). Recovery rates on minari are 67.3~95.2% in Cd water and 72.6~88.3% in Pb water. The rates are increased with increased growth rates and decreased initial concentrations.

• Journal of Environmental Health Sciences
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• v.21 no.1
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• pp.21-28
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• 1995

The removal of heavy metals from synthetic wastewater containing Pb, Cr, Cd using previously washed and dried exhausted coffee was studied varying cohcentration, pH and temperature. All the heavy metals were removed in 3.0 minutes and the removal efficiency was maximum 80~90% with different pH and temperature conditions. The differences in removal efficiency between exhausted coffee and activated carbon under the same conditions were not seen. The removal efficiency was slightly increased with increasing pH in Cd and increasing temperature in Cr, respectively. The batch adsorption kinetics and adsorption equilibrium were examined and described by a first order reversible reaction and Freundlich isotherm, respectively. And the removal of Pb was found to have the best removal efficiency.

• Mycobiology
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• v.35 no.3
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• pp.135-144
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• 2007

The removal efficiency of the heavy metals Zn, Pb and Cd by the zoosporic fungal species Saprolegnia delica and the terrestrial fungus Trichoderma viride, isolated from polluted water drainages in the Delta of Nile in Egypt, as affected by various ranges of pH values and different temperature degrees, was extensively investigated. The maximum removal efficiency of S. delica for Zn(II) and Cd(II) was obtained at pH 8 and for Pb(II) was at pH 6 whilst the removal efficiency of T. viride was found to be optimum at pH 6 for the three applied heavy metals. Regardless the median lethal doses of the three heavy metals, Zn recorded the highest bioaccumulation potency by S. delica at all pH values except at pH 4, followed by Pb whereas Cd showed the lowest removal potency by the fungal species and vice versa in case of T. viride. The optimum bio-mass dry weight production by S. delica was found when the fungus was grown in the medium treated with the heavy metal Pb at pH 6, followed by Zn at pH 8 and Cd at pH 8. The optimum biomass dry weight yield by T. viride amended with Zn, Pb and Cd was obtained at pH 6 for the three heavy metals with the maximum value at Zn. The highest yield of biomass dry weight was found when T. viride treated with Cd at all different pH values followed by Pb whilst Zn output was the lowest and this result was reversed in case of S. delica. The maximum removal efficiency and the biomass dry weight production for the three tested heavy metals was obtained at the incubation temperature $20^{\circ}C$ in case of S. delica while it was $25^{\circ}C$ for T. viride. Incubation of T. viride at higher temperatures ($30^{\circ}C\;and\;35^{\circ}C$) enhanced the removal efficiency of Pb and Cd than low temperatures ($15^{\circ}C\;and\;20^{\circ}C$) and vice versa in case of Zn removal. At all tested incubation temperatures, the maximum yield of biomass dry weight was attained at Zn treatment by the two tested fungal species. The bioaccumulation potency of S. delica for Zn was higher than that for Pb at all temperature degrees of incubation and Cd bioaccumulation was the lowest whereas T. viride showed the highest removal efficiency for Pb followed by Cd and Zn was the minor of the heavy metals.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.4
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• pp.615-624
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• 2011

last few decades. In this study, the lyophilized cells of Pleurotus eryngii (mushroom) were used as an inexpensive biosorbent for Cd(II) and Pb(II) removal from aqueous solutions. The effect of various physicochemical factors on Cd(II) and Pb(II) biosorption such as pH (2.0-7.0), initial metal concentration ($0.0-300mg\;L^{-1}$), temperature, fungal biomass and contact time (0-120 min) were studied. Optimum pH for removal of Cd(II) and Pb(II) was 6.0, and the contact time was 45 min at room temperature. The nature of biosorbent and metal ion interaction was evaluated by Infrared (IR) spectroscopic technique. IR analysis of mushroom biomass revealed the presence of amino, carboxyl, hydroxyl and methyl groups, which are responsible for biosorption of Cd(II) and Pb(II). The maximum adsorption capacities of P. eryngii for Pb(II) and Cd(II) calculated using Langmuir adsorption isotherm were 82.0 and $16.13mg\;g^{-1}$, respectively. The adsorption isotherms for two biosorbed heavy metals were fitted well with Freundlich isotherm as well as Langmuir model with correlation coefficient ($r^2$>0.99). Thus, this study indicated that the P. eryngii is an efficient biosorbent for the removal of Cd(II) and Pb(II) from aqueous solutions.

• Korean Journal of Food Science and Technology
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• v.18 no.4
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• pp.264-269
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• 1986

This study was undertaken to investigate the removal efficiency of heavy metals (Cd, Pb) in rice and wheat flour by cooking and processing. After four times washing of rice grains with water, the removal ratios of cadmium and lead from artificially-contaminated samples were 39.271 and 34.9%, respectively. In cookingof rice grains washed three-times with water, the residue levels of cadmium and lead decreased to 85.7%, 83.0% in electric rice cooker and 74.51%, 72.6% in pressure rice cooker, respectively. No significant difference was observed in the removal of the metals between naturally-contaminated and artificially contaminated rice samples, and between the electric and pressure rice cookers. In baking of artificially-contaminated wheat flour into cookie and loaf bread, the removal ratios of cadmium and lead were negligible as expected. When knife-cut noodle was made from artificially-contaminated wheat flour and boiled in water, 75% of the metals were found in the noodle solids and only 25% of them were removed into the broth.

• Economic and Environmental Geology
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• v.33 no.1
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• pp.31-40
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• 2000

Sorption characteristics of Pb, Cu, Cd, and Zn onto Ca- and Na-bentonites were investigated by the batch experiments in the condition of various pHs and concentrations of groundwater major anions (${So_4}^{2-}$ and ($HCO_3$), which can form a complex with heavy metals. The sorption removal of heavy metals steadily increases as pH increases. The sorption capability about heavy metals of both Ca-bentonite and Na-bentonite is in the order of Pb>Cu>Zn>Cd. The effect of pH and selectivity of heavy metals of bentonites were explained by the change of surface charge of bentonite and the speciation of heavy metals. Na-bentonite has a little higher sorption ability about heavy metals than that of Ca-bentonite. A high sorption removal of Pb in 0.1M sulfate solution may be attributed to the precipitation of $PbSo_4$(anglesite). However, sulfate has a slight effect on the sorption of CU, Cd and Zn. More than 99% of heavy metals were removed from the 0.1 M bicarbonate solution. However, the efficiency of sorption removal of heavy metals highly decreases in the bicarbonate solution of $10^{-2}$M to $10^{-4}$M. The speciation and saturation index calculated by the WATEQ4F program indicate that the sorption of anionic complexes such as ${Pb(CO_3)_2}^{2-}$, ${Cd(CO_3)_2}^{2-}$, ${Zn(CO_3)_2}^{2-}$, ${Cu(CO_3)_2}^{2-}$ and the precipitation of the solid phases such as $PbCO_3$(cerrusite), $ZnCO_3$(smithsonite), $CdCO_3$(obtavite) are involved in sorption removal of heavy metals in bicarbonate solution. The sorption capability about heavy metals of bentonites in the presence of anions shows the following order: Pb>Cu Cd>Zn.

• KSBB Journal
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• v.14 no.2
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• pp.141-145
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• 1999

The study was conducted for the efficient utilization of biomaterials such as Chestnut shell which was wasted tremendously as an agricultural by-products. This biomaterials were examined for their removal rate of heavy metal ions as adsorbents in wastewater by batch adsorption experiments. In this experiment, the heavy metal ions used were $\Cd^{2+},\;Fe^{2+},\;Cr^{6+},\;Mn^{2+},\;Cu^{2+}$ and $Pb^{2+}$. The range of time for the removal rates of heavy metal ions were observed about 10 min. The range of high pH for the removal rates of $\Cd^{2+},\;Fe^{2+},\;Mn^{2+},\;Cu^{2+}$ and $Pb^{2+}$ ere observed 7.0-9.0. The range of high pH for the removal rate of $Cr_{6+}$ was observed 2. In the case of raw chestnut shell, the removal rates of $\Fe^{2+},\;Mn^{2+},\;Cu^{2+}$ and $Pb^{2+}$ were above 70 percent. The removal rates of heavy metals in formaline pretreated chestnut shells except $Cd_{2+}$ were above 50 percent and in phosphorylating chestnut shells except $Cr_{6+}$ were above 60 percent. Chestnut shells pretreated by formaline and phosphorylating were not so good enough for improvement of removal rates with pH change in mixed heavy metal solution.

• Journal of environmental and Sanitary engineering
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• v.14 no.2
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• pp.46-55
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• 1999

This study compared the adsorption characteristics of heavy metal ions by crab shell, treated crab shell with 2N-HCl, treated crab shell with 4%-NaOH, chitin and chitosan.Using crushed crab shell, the heavy metal ions removal rates of $Cd^{2+}$ and $Zn^{2+}$ were about 70-80% in 45minutes, but the removal rates of $Cu^{2+}$, $Cr^{6+}$ and $Pb^{2+}$ was less than 10%, 10% and 30%, respectively. For the by-products crab shell by 2N-HCl treatment, it was shown that the removal rates of $Cu^{2+}$ and $Pb^{2+}$ were about 70-80% in 45minutes reaction. But, some problems were observed, that the contained protein in crab shell was changed into gel in the mixing solution after a few hours. For the by-products of crab shell by 4%-NaOH treatment, the removal rates of Pb and Zn were about 90% in 45 minutes, and those of capacity of chitin and chitosan powder was better than those of the other by-products. The more adding to the adsorbent dosages increased the removal rates, and the adsorption reaction was rapidly occurred in a few minute. Using 1.0 wt% chitin powder, the heavy metal removal rates were ordered $Cu^{2+}$(94%) > $Zn^{2+}$(89%) > $Cd^{2+}$(88%) > $Pb^{2+}$(77%) > $Cr^{6+}$(58%) in 45 minutes. Using 1.0 wt% chitosan powder, the heavy metal removal rates were ordered $Cu^{2+}$(99%) > $Pb^{2+}$(96%) > $Cd^{2+}$(79%) > $Zn^{2+}$(71%) > $Cr${6+}$(46%) in 45minutes. The degree of degree of deacetylation by prepared chitosan was 91%.The Freundlich adsorption isotherm of $Cu^{2+}$, $Cd^{2+}$ and $Zn^{2+}$, when it was applied to 1.0 wt% chitosan powder in minutes, can be acceptable very strictly. The equation constant (1/n) for $Cu^{2+}$, $Cd^{2+}$ and $Zn^{2+}$ were 0.54 0.41 and 0.23 respectively.

• Journal of the Korean GEO-environmental Society
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• v.12 no.7
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• pp.39-47
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• 2011

The objective of this study is to investigate the removal characteristics of cadmium(Cd) and lead(Pb) by adsorption on red mud and to study the adsorption characteristics of Cd and Pb using red mud activated by acid treatment and calcination. The adsorption of Cd and Pb on red mud was significantly achieved within 1hour and equilibrated after 5 hours. The adsorption capacity of Cd and Pb on red mud increased with increasing pH. The neutralization of red mud by distilled water or acid and the activation of red mud by acid treatment or calcination decreased the adsorption capacity of Cd and Pb on red mud, suggesting that Cd and Pb could be effectively eliminated by adsorption on red mud without any pretreatment or modification. Both Langmuir and Freundlich models were successfully applied to describe the adsorption behavior of Cd and Pb on red mud. The $q_m$ of Langmuir adsorption model and $K_F$ of Freundlich adsorption model were 5.230mg/g and 1.118mg/g for Cd and 22.222mg/g and 7.241mg/g for Pb, respectively.