Monitoring And Analysis Of Main Water Quality Indexes Of A Sewage Treatment Plant In Anhui Province

Water is the source of human life. The water areas such as river, lake, and reservoir have been polluted in different levels and the overall trend of water pollution is growing worse in our country. It has become a main factor which restricts the development of the cities in our country. In this paper, the main water quality indexes of annual influent and effluent have been monitored of a sewage treatment plant in Anhui province. The varies of concentration, removal rate and reduction have been compared. The seasonal variation characteristics of main water quality indexes were analyzed.The main results are as follows:1. The range and removal rate of main water quality indexes of effluent. Range: pH:7.1-7.9 SS:5.3-8.9 mg/L BODs:6.4-8.7 mg/L COD:23.5-42.9 mg/L NH3-N:2.3-4.2 mg/L TN:9.8-11.4 mg/L TP:0.2-0.5 mg/L Removal rate (%): SS:94-96 BOD5:89-94 COD:79-84 NH3-N:86-90 TN:75-81 TP:77-892. The seasonal variation characteristics of main water quality indexes.(1) The reduction of COD is the highest in winter. The main reason is that the concentration of COD in winter is higher than it is in the other seasons. In the condition of the same sewage treatment capacity, the higher influent concentration, the higher reduction of COD.(2) The reduction of BODs is the highest in winter. There are various influencing factors when monitoring BOD5 and temperature has an obvious influence on biochemical reaction. Generally speaking, the rate of biochemical reaction speeds up when the temperature rises. Then the rate of oxidation speed up and the consumption of DO changes. The usual temperature of biochemical reaction is 20 ℃ and the water temperature in winter is far below which effluent the monitoring results.(3) NH3-N reduction of autumn and winter is higher than that of summer. The main reason is in autumn and winter, the influent concentration is high, in the same amount of sewage treatment, the concentration of the influent high reductions greater.(4) TN reduction decrease in summer for the consumption of dissolved oxygen in water quickly increased because of rainfall and water consumption increased, a large number of domestic sewage, industrial wastewater, irrigation water into the water, then organic nitrogen and inorganic nitrogen content increased, coupled with the high temperature.(5) TP emission reduction was lowest in summer. Rainfall and water consumption increased in summer, many comprehensive phosphate (pyrophosphate, metaphosphate and phosphate) and organic combination of phosphorus in water, dissolved oxygen consumption of water, coupled with the high temperature, the content of dissolved oxygen in water decreased rapidly, resulting in TP reduction of low.