A Path Analysis for Chemical Oxygen Demand and Ammonia Nitrogen Discharge from Industrial Sewage in China

The industrial sewage pollution has become a public attention issues with the development of economy. The path analysis is employed to investigate the countermeasures of reducing Chemical Oxygen Demand (COD) and ammonia nitrogen (NH 3 –N) discharge. The result shows that urbanization rate (UR), industrial gross domestic product (IGDP), and environmental investment (EI) co-determine the COD discharge, while UR, IGDP, EI and per capita gross domestic product co-determine the NH 3 −N discharge. UR is the main factor for restraining COD and NH 3 -N discharge, with the total effect of 42.59 and 33.37% respectively. IGDP has a positive direct effect on pollutants discharge.