Water Pollution and Relevant Preventive Measures in the Hechuan Segment of Fujiang River

摘要

Dissolved oxygen (DO), NH 4 + -N, total phosphorus (TP), COD Mn and BOD 5 in water in the Hechuan segmentof Fujing River were monitored to assess water pollution in the river scientifically. Water pollution indexeswere analysed and their pollution load-sharing ratios were calculated by using single pollution index methodand Nemerow comprehensive pollution index method, respectively. Results show that the water quality in25% of the monitored sections can be considered clean and the water quality of 75% of the sections can beconsidered slightly polluted in two water functional zones in the Hechuan segment of Fujiang River withwater quality control targets of Level III and Level IV, respectively. Water quality declines from upstream todownstream. DO does not exceed standards in all the sections. NH 4 + -N significantly contributes to waterpollution in all the sections; as a consequence, NH 4 + -N is a major pollution index in the entire Fujiang River.In some sections, TP, COD Mn and BOD 5 yield high pollution load sharing ratios. The distribution of the mainpollution sources of different sections shows that the pollution indexes exceeding standards are mainlyinfluenced by various pollution factors, such as cultivation, industrial wastewater, urban and rural domesticsewage, and agricultural non-point sources. Therefore, relevant preventive measures and recommendationsare provided as a reference of the comprehensive control of water pollution in the Hechuan segment ofFujiang River.