摘要
This study investigated the feasibility of using some natural clay minerals available in Egypt like kaolinite, bentonite, also using of iron oxide, rock phosphate and mixture of these types to minimize the rate of Ni, Cu, Zn and Mn desorption from sewage soils and to evaluate the effect of these mixtures on Zn equivalent constant values before and after remediation. The obtained results indicated that all mixtures used were minimizing the rate of potential toxic elements （PTE＇s） release from sewage soils compared to control treatment. According to the decreasing order of different treatments, data indicated that application of the mixture treatment of bentonite, kaolinite and rock phosphate （RP） in sewage soils becomes the best treatment compared to other treatments used. However, the lowest and save Zn equivalent constant value which represents the hazard indicator in the study was observed in sewage soil treated with the mixture of bentonite and RP. The kinetic constants of Elovich, modified Freundlich and Hoerl equations, the best fitted models, were significantly decreased compared to control treatments with different percent of minimization according to type of pollutants and remediation material used. To understand the mechanisms of PTE＇s retained in treated sewage soil, distribution study was applied which showed that different pollutants studied were removed to hardly available form different mechanisms of PTE＇s undergo in treated sewage soils were discussed in the study.
