氮对藻类生长与污水净化的影响

EFFECTS OF NITROGEN ON ALGAE GROWTH AND SEWAGE PURIFICATION

在室内模拟生物氧化槽中比较研究了污水中不同氮含量及氮磷比例对藻类生长与污水净化的影响。原污水中磷含量约为7毫克/升,氮含量分别为13.5、24.8、44.4和77.4毫克/升,结果发现:原污水中N/P=44.4/7.0毫克/升时,氧化槽内藻类生长状况、产氧量及污水净化效果最好。

An experiment on the effects of nitrogen content on artificial sewage purification in modelling stabilization pond systems has been carried out in laboratory during spring to summer in 1988 and 1989. The results obtained indicate that when TP concentrations are kept at 7mg/l and TN concentrations are varied from 77.4, 44.4, 24.8 to 13.5 mg/l in raw sewage, the removal rates of TP, BOD and LAS in the stabilization pond are decreased with TN concentration increasing, but the removal rates of TN appear an opposite tendency (Table 4). The N/P = 44.4/7.0 mg/l in the raw sewage is the optimum concentration and ratio for sewage purification. It is related to the species composition, biomass and oxygen production of algae in sewage. The algal production is obviously decreased with the nitrogen concentration decreasing in the raw sewage (Table 5). The N/P = 44.4/7.0 mg/l in raw sewage is the optimum concentration and ratio for algae growth and oxygen producing. When the TN is less than 25mg/l in raw sewage, it becomes a limiting factor for algae growth in the stabilization pond system and cause a low purification rate of sewage. Under this experimental con-dition,the BOD:N:P= 350:44.4:0.7mg/l or 50:6:1 is the optimum concentration and ratio for algae growth, oxygen producing and sewage purification.