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.

Investigation was carried out to observe the dominant bacteria and the effect of metals(Cd & Zn) and its nitrate compound on growth of bacteria isolated from the three tributaries and lower reach of the Nakdong River. Mean CFU(log10) level was highest in Kumho River(8.30 CFU), Nam River, Hwang River, and Mulgum followed. Staphylococcus xylosus, Staph. lentus, Pasteurella pneumotropica, Aeromonas hydrophilla were dominant species in each study site. Cadmium powder and Zinc powder showed strong effect to inhibit the growth of Micrococcus spp., Pasteurella pneumotropica, Aeromonas hydrophilla. But, nitrate compounds of Cd and Zn(Cd(NO3)24H2O, Zn(NO3)26H2O) did not clearly show the strong effect to inhibit the growth of dominants.

Surface complexation models(SCMs) have been performed to predict metal ion adsorption behavior onto the mineral surface. Application of SCMs, however, requires a self-consistent approach to determine model parameter values. In this paper, in order to determine the metal ion adsorption parameters for the triple layer model(TLM) version of the SCM, we used the zeta potential data for Zeolite and Kaolinite, and the metal ion adsorption data for Pb(Ⅱ) and Cd(Ⅱ). Fitting parameters determined for the modeling were as follows ; total site concentration, site density, specific surface area, surface acidity constants, etc. Zeta potential as a new approach other than the acidic-alkalimetric titration method was adopted for simulation of adsorption phenomena. Some fitting parameters were determined by the trial and error method. Modeling approach was successful in quantitatively simulating adsorption behavior under various geochemical conditions.

Heavy metal ions in water were removed using algal biomass as adsorbents. Absorbents were dried for 3 days, ground them by 40∼60 mesh and then were swelled in a buffer solution for 1hr. After being packed in the column, commercially available standard solution of Cd(Ⅱ) and Pb(Ⅱ) ions were diluted to get the suitable concentration and then it was eluted with the rate of 1 ㎖/min. Heavy metals on the adsorbents were recovered with nitric acid. More amounts of Cd(Ⅱ) or Pb(Ⅱ) ions in green algae, Ulva pertusa, than in brown algae, Sargassum hornerl, were adsorbed. Pb(Ⅱ) ion was adsorbed more than Cd(Ⅱ) ion in both algae. The pH effect of adsorbed amounts of Cd(Ⅱ), Pb(Ⅱ) ions on the biomass was shown the following order ; pH 10.5 > 8.5 > 7.0 > 5.5 > 3.5. Recovery ratio of metal ions from algae is shown higher in acidic or neural conditions than It in alkalis ones. Pb(Ⅱ) ion is recovered relatively more than Cd(Ⅱ) ion in our system.

Cation exchange distribution coefficients of poly(dithiocarbamate) were presented for Cd^2+, Cr^3+, and Pb^2+ in HCl. The distribution coefficients were determined by using the batch method. Based on these distribution data, the separation possibilities of the heavy metal ions were discussed. The distribution coefficients of three heavy metal ions on dithiocarbamate resin were decreased as HCl concentrations were increased. The selective separation of Cr^3+ and Cd^2+ was possible by using 0.1 M HCl in dithiocarbamate resin and the reproducibility test showed that the average absorptivity of resin was 90% in the case of Cd^2+ ion by the column method.