Effect of vermicompost on some chemical properties of Cd enriched treated municipal waste water in the outlet of soil columns

Municipal wastewater is a potential source for water supplies. Soil organic matter can affect chemical quality of wastewater passing through the soil. This experiment was carried out in order to determine the effects of different levels of vermicompost on change of chemical properties of Cd enriched municipal wastewater of Yasouj station after continuous passing through the soil columns. A completely randomized design was used. Polyethylene columns (80 cm in length and 8 cm in diameter) filled with a clay loam soil during 8 periods of 10 days. Three levels of vermicompost comprising control (V1), 2% (V2) and 4 wt% (V3), were used respectively. At the end of each period, characteristics such as pH, electrical conductivity, phosphate, nitrate, total organic carbon and cadmium concentration were measured in drainage water. Results showed that the effect of both the time and vermicompost was significant on all factors. The average of all factors except for pH of the drainage water, showed a decreasing trend during the experiment. Maximum of EC, P, nitrate and total organic carbon were measured in V3 treatment. Vermicompost exhibited a significant effect on Cd concentration of drainage water. It seems that organic matter has a drastic effect on increasing mobility of Cd as well as on the other studied characteristics, hence soil organic matter content should be considered in the usage management of wastewater.