Content and change pattern of bacteria in typical recycling water

Objective:To analyze content and change pattern of bacteria in typical recycling water of 3 sewage treatment plants in Beijing.Methods:Refer to national "Standard Test Method of Drinking Water"(GB5750-85.37),"National Standards of PRC"(GB/T4789.32-2002) as well as "detection and count of total bacteria,total coliform and heat-resistant E.coli in Microbiological Examination of Food Hygiene" to complete this test.Results:In the samples of effluent and reclaimed water of three typical wastewater treatment plant,the total number of bacteria is 57～2.4×106 cfu/ml;the total E.coli MPN with the orders of magnitude ranged from 103～107 cfu/100 ml;heat-resistant E.coli ranged from102～105 cfu/100 ml of magnitude.The number of total bacteria,total coliform and heat-resistant E.coli were found no difference in effluent and reclaimed water of the three plants.Monthly changes of bacteria at outlet were not obvious.Conclusion:In reclaimed water,with the presence of risks to environment and public health,the microbial detection indicators of reclaimed water should be added.