Research on the Advanced Treatment of Coking Wastewater Using Constructed Wetland of Combined Substrate and the Degradation of Organic Matter

The manganese sand-gravel constructed wetland and gravel wetland were used to the advanced treatment of coking wastewater. Results showed that when the HRT was shortened from 5 days to 3 days, COD, iron, manganese in effluent was less than 60mg/L, 0.3mg/L, 0.1mg/L respectively, which meets the standard of “The reuse of urban recycling water ―Water quality standard for industrial uses”. Removal of pollutants was affected by HRT and different combination of substrates. The manganese sand and gravel wetland has better treatment results and the variety and number of organic compound in effluent were greatly reduced. (Abstract)