The Effect and Mechanism of Cement-Soil Using for Sewage Purification

Cement-soil samples were made from composite cement (25%), red clay (75%) and proper amount of ultra-pure water. The samples were used to treat sewage water in the experiment of anaerobic reaction and aerobic reaction respectively. The raw sewage was collected from the inflow path of a wastewater treatment plan and it mainly consisted of domestic sewage. Results showed that the effect of ion exchange and pollutants adsorption by cement-soil were weak and the purification effect was mainly depended on the biodegradation of microorganisms on the surface of cement-soil. From the result we can also see that the sewage water can be effectively treated by cement-soil when oxygen got abundantly supplied. Temperature heavily affected the efficiency of the sewage water treatment in aerobic reactions. Pollutants removal efficiencies under 30°C temperature were much better than that under 10°C temperature. It was concluded that the mechanism of sewage water purification by cement-soil samples were similar to that by porous eco-concrete. However, the cost of the former is lower than the latter. Moreover, cement-soil could be easily crushed to be cultivated soil and doesn´t need to worry about its durability after being abandoned. Cement-soil is thought to be more beneficial to environment protection than ordinary eco-concrete.