以红薯浸泡液为碳源的生物反硝化

为选择低碳氮比污水生物脱氮中合适的碳源,以搅拌罐浸泡淀粉类物质释放碳源,在确定利用红薯浸泡液为碳源后,以浸没式生物滤池为反应器进行生物反硝化实验。实验结果表明:20 g红薯置于2 L自来水中,采用250 r/m in的搅拌速度,搅拌频率为每搅拌3 h停1 h,2 d后得到的浸泡液COD浓度平均为5 921 mg/L,最高可超过7 000 mg/L;将此红薯浸泡液和污水以1∶50的流量比例,采用分别投加的方式进入反应器,污水中总氮、硝酸盐氮、亚硝酸盐氮及氨氮的平均去除率分别为88.6%、91.6%、88.2%和54.8%,出水COD平均在30 mg/L以下;在红薯浸泡液COD浓度为5 700 mg/L左右时,进水中亚硝酸盐氮浓度与硝酸盐氮浓度比为3∶2时总氮去除率为95.3%,当该比例为2∶3时总氮去除率为88.2%。研究表明,红薯浸泡液是一种经济合适的碳源,采用红薯浸泡液作为低碳氮比污水生物处理中反硝化的碳源是可行的。

Biodenitrification with sweet potato lixivium as carbon source

In order to choose the appropriate carbon source in the biological nitrogen removal of low C/Nratio wastewater,a stirred tank was used to soak the starch matter to release carbon source,and the experiment of biodenitrification with sweet potato lixivium as the carbon source in a submerged biological filter was carried out.The experimental results showed that when 20 g sweet potato was added into 2 L water with stirring at 250 r/min for 3 h and without stirring for 1 h.the average concentration of released COD of the lixivium was 5 921 mg/L and the highest concentration was above 7 000 mg/L after 2 d.The average removal rates of total nitrogen,nitrate-nitrogen,nitrite-nitrogen and ammonia-nitrogen achieved 88.6%,91.6%,88.2%,54.8%respectively and the effluent COD concentration average was maintained below 30 mg/L,when the sweet potato lixivium and the wastewater were separately pumped into the reactor with the flow ratio of 1:50.When the COD concentration of the sweet potato lixivium was about 5 700 mg/L,the remoral rate of total nitrogen was 95.3% when the nitrite-nitrogen to nitrate-nitrogen concentration ratio was 3:2.while the removal rate of total nitrogen was 88.2% when the nitrite-nitrogen to nitrate-nitrogen concentration ratio was 2:3.The research indicated that the sweet potato lixivium was a kind of economical and suitable carbon source.and it was feasible to use the sweet potato lixivium in the biodenitrification for the treatment of low C/N ratio wastewater.