Study Of Nitrogen Pollution Conyrol In Soilless Culture Used Biogas Slurry As Fertilizer

With the rapid development of Protected Agriculture in recent year, the soil salinization problem, with nitrate as the main characteristics, is becoming more serious. Research has shown that, biogas slurry as fertilizer can reduce the accumulation of nitrate, the technology will be widely used with the rapid development of biogas plants. In this article, nitrogen pollution controll in soilless culture used biogas slurry as fertilizer was studied. Main result consists of:Nitrogen pollution characteristics in soilless culture used biogas slurry as fertilizer was studied. The results showed that:NO3--N was dominating in total nitrogen of effluent water, which concentration increased with the influent concentration of NH4+-N, NO2--N, NH4+-N and COD kept in low level.Rotten wood was choosed as carbon sources in Hydrolysis-Denitrifying bioreactor for denitrification. At room temperature of 25±1℃, NO3--N concentration of 30mg-L-1, hydraulic retention time of 12h, the nitrate removal rate can reach 95%, and the reactor could run 46 days with 80% removal effect.Nitrogen pollution control used rotten wood as carbon source was studied. The results showed that:After adding carbon source, intermittent water (4 times·d-1, 0.75L·times-1, 30min-times-1), under the conditions of plant Gynura, NH4+-N concentration of 120mg·L-1, the N in effluent water achieved "national urban wastewater treatment plant emission standards" (GB 18918-2002) 1A standard, COD could reach 2 standards.