Application of Modified Biochar in the Treatment of Pesticide Wastewater by Constructed Wetland

Abstract

To explore the synergistic effects of modified biochar in the purification of herbicide-containing wastewater, the effect of biochar addition on the removal effect of the herbicide atrazine in wastewater was verified by the addition of biochar bags in a small reed bed-constructed wetland in the laboratory. The results showed that the addition of sulfuric acid-modified biochar could increase the removal rate of atrazine in wastewater from 50% to 70%, and the COD elimination rate in wastewater was from 66.7% to 86.7%. The addition of biochar to the constructed reed bed wetland improved the removal efficiency of total nitrogen and total phosphorus in the wastewater, and the outlet water from the constructed wetland reached the Class III level of China’s surface water quality standard (the inlet water was inferior to Class V). The experimental design met the requirements of low-cost, generalized atrazine-containing wastewater treatment and thus could have the potential for wide application. The results reflected the application potential of modified biochar as a synergist in the treatment of herbicide wastewater in constructed wetlands.