Occurrence and temporal-spatial distribution of fecal indicator microorganisms in three rivers of the Haihe River Basin

Abstract

The current monitoring, research and treatment of river pollution in China pay little attention to the microorganism index, thus the microbial pollution in most Chinese rivers is yet unknown. Therefore, in order to acquire the occurrence of fecal indicators and their temporal-spatial distribution in Haihe River Basin, Fecal Coliform, Escherichia coli, Enterococcus, Somatic Coliphages were selected and monitored as microbial indicators in three typical rivers of this watershed for one year. The results show that besides the organic pollution and the eutrophication, three typical rivers also faced with serious microbial contamination. Average concentrations of Enterococcus, Escherichia coli, Fecal Coliform and Somatic Coliphages in these three rivers generally ranged from 1.039×10³ to 9.168×10⁵ CFU·L^-1, 10 to 1.870×10⁶ CFU·L^-1, 1.43×10² to 8.105×10⁶ CFU·L^-1, 0 to 4.77×10⁶ PFU·L^-1, respectively. The temporal-spatial distribution of the four fecal indicator microorganisms were analyzed by Mann-Whitney U test, which shows that the four fecal indicators microorganisms did not change significantly seasonally. But the spatial distribution was obvious. Wenyu River suffered the worst microbial pollution among three rivers. Although the organic pollution of Yongding River in the upper stream was less polluted, the microbial pollution was severe due to the contamination of animal feces. In order to protect the public health security and groundwater safety, the animal manure treatment in the upper stream and the effluent from the sewage treatment plant in the middle reach should be paid more attention.