TREATMENT OF WASTEWATER FROM NON-POINT SOURCE IN RURAL AREAS WITH HIGH-RATE ALGAL POND( HRAP)

Currently，the annual emission load of rural domestic sewage is increasing steadily in China，while the treatment of them is not optimistic that in 96% of the villages drainage and sewage treatment systems hadn t been built，bringing about severe environmental contamination in rural areas． To research the rural non-point source domestic sewage，a pilot apparatus for high rate algal pond ( HrAP) was used to treat the artificial rural non-point source domestic sewage and the optimum operational conditions，impact factors and reaction mechanism were systematically investigated during the process． Based on the optimal culture medium for the algae，the optimum conditions for nitrogen and phosphorus were given: the maximum removal rate of NH + 4 － N，TP and COD exceeded 95%，60% and 90% respectively in the HrAP under the optimal operational conditions of full aeration，temperature of 24 ～ 35 ℃，light intensity of 4 000 Lux，pH 7. 5 and algae concentration of 8 × 105 /mL．