In this study, to stabilize the heavy metal in the contaminated soils, the column leaching test based on rainfall and pH value was performed by using coal mine drainage sludge(CMDS): which was generated during electrical purification of abandoned coal mine wastewater. Four types of testing column were used in this study. That were the CMDS and the heavy metal contaminated soils well mixed in 0 wt%, 1 wt%, 3 wt% and 3 wt% layered column. According to the investigation, when the influent pH was 5.5∼6.2, there were no heavy metal elution at all conditions, and when the influent pH was 3∼3.3, the order of Cu, Zn, Pb, Cr elution concentration was 3 wt% M(mixed)＜3 wt% S(separation)＜1 wt% M＜0 wt% and the average elution concentration was quite low, the value was 0.005 mg/L. Therefore, CMDS can used as new stabilizer of the heavy metal in the contaminated soils.

This study was performed to investigate the possible uses of waste sludge for the removal of heavy metal ions. The adsorption experiments were conducted with wastes such as sewage treatment sludge, water treatment sludge and oyster shell to evaluate their sorption characteristics. Heavy metals selected were cadmium, copper and lead. In the sorption experiments on the sewage treatment sludge, water treatment sludge, oyster shell and soil, sorption occurred in the beginning and it reached equilibrium after 40 minutes on the oyster shell and 4 hour on the sewage treatment sludge and water treatment sludge. Results of Freundlich isotherms indicated that sewage treatment sludge could be properly used as an adsorbent for heavy metals and sorption strength of heavy metals was in the order of Pb > Cu > Cd. In the influence of pH on the adsorbents, sorption rate was more than 80% in pH 4 and most of heavy metals were adsorbed in pH 9. Adsorption rate of Cd decreased with decreasing pH and then adsorption rate of Cu was lower in soil.

The biosorption of dye, Rhodamine B(Rh-B), onto waste activated sludge was investigated. The biosorption capacity and contact time were shown as a simulation of dye adsorption equilibrium and kinetics models. We observed that biosorption of Rh-B occurred rapidly less than 4hr. These experimental data could be better fitted by a pseudo-second-order rate equation than a pseudo-first-order rate equation. The equilibrium dependence between biosorption capacity and initial concentration of Rh-B was estimated and it was found that the equilibrium data of biosorption were fitted by four kinds of model such as Langmuir, Freundlich, Redlich- Peterson, and Koble-Corrigan model. The average percentage errors, ε(%), observed between experimental and predicted values by above each model were 21.19%, 9.97%, 10.10% and 11.76%, respectively, indicating that Freundlich and Redlich-Peterson model could be fitted more accrately than other models.

Waste sludge may be used to recovery wastewater contaminated with heavy metals. The waste sludge is an inexpensive readily available source of biomass for biosorption with metal-bearing wastewater. The biosorption of heavy metals such as Pb(II), Cu(II), Cr(II), and Cd(II) onto waste sludge was investigated in batch experiments and waste sludge loaded heavy metals was separated by dissolved air flotation. The biosorption equibria of heavy metals could be described by Langmuir and Freundich isotherms. The adsorption capacity for waste sludge was in the sequence of Pb(II)>Cr(II)>Cu(II)>Cd(II). The system attained equilibrium about 20 min. The Langmuir and Freundlich adsorption model effectively described the biosorption equilibrium of Cu(II) and Cr(II) ions on waste sludge. Maximum adsorption capacity of Cu(II) and Cr(II) were 196.08 and 158.73 mg/g, respectively. Solid-liquid separation efficiencies were kept above 95% on waste sludge loaded heavy metals, and were decreased with pH increasing.

The properties of biosorption of dye(Rhodmine B) was investigated to figure out the effects of temperature as a function of dye concentration and sludge concentration by the Langmuir and Lagergen adsorption model. It was found that the uptake capacity of biosorption was increased at low temperature. The Langmuir adsorption model was found suitable for describing the biosorption of the dye. The experimental results indicated that the dye uptake process followed the pseudo-first-order kinetics.