Study On The Biological-Chemical Process For The Nightsoil Wastewater Treatment

In this paper,based on the character of nightsoil wastewater—containing both highly concentrated nitrogen and organic matters,applying microbiology-chemical process to treat it and study on the efficiency of the combination system. Through the effects of organic load,temperature to removal in anaerobic process,the steady treatment is proved. Based on high ammonia content(500~600mg/L),biodegradability(BOD5/COD=0.2)in effluent from anaerobic process,the effects of organic load,ammonia content and water temperature to nitrogen removal in aerobic process is discussed. Besides,about the bio-refractory organic compounds,chroma and phosphor of effluent from aerobic process,comparisons and decision of choosing lime to remove phosphor and activated carbon absorption to remove the bio- refractory organic compounds,chroma were made.①using the anaerobic sludge of Chongqing Tangjiaqiao wastewater treatment plant,start-up from low load,controlling the start load is 0.5 kgCOD/m3·d and the sludge concentration is about 25gVSS/L,through the 30d,the start-up is succeed and removal rate of COD is 95% in anaerobic process.②On the different influent,the anaerobic process for the nightsoil treatment had good and steady removal. the experiment proved on the designing load rate and the low load rate or high load rate the removal was steady.③In anaerobic process, removal rate was high and steady in different temperature through the whole year. The effection of temperature to anaerobic process was low. The COD & NH4+-N removal in aerobic process on the different temperature in winter and summer was steady. The removal of temperature to aerobic process had effection, but the effction was low.④The COD removal in aerobic process was low, COD was high(above 100mg/L) in effluent,removal rate of COD was less than 50%. The reason was that the biochemical treatment effluent remained the undegradable COD. The removal in aerobic process was steady.⑤Because the pH was low, using saleratus to improve alkalinity was to solve the problem about shortage of alkalinity. On the high pH,the NH4+-N removal was high and steady, the NH4+-N of the effluent less than 15 mg/L, meeting the national standards.⑥the flocculate can't remove the bio-refractory organic compounds because the...