木屑-硫磺填充床反硝化生物滤池强化硝酸盐去除

针对污水处理厂二级出水深度脱氮的需求，设计了以木屑与硫磺颗粒为填料（质量比1:1）的反硝化生物滤池，对碳氮比失衡的污水处理厂二级出水进行深度脱氮处理。结果表明，木屑释放碳源速率在10 d之后趋于稳定，COD中（40.6±10.0）%是反硝化菌可直接利用的VFA。反硝化生物滤池运行的最佳HRT为10 h，在此条件下，进水硝酸盐（以N计）浓度为30 mg·L-1时，出水硝酸盐浓度最低为11.5 mg·L-1，亚硝酸盐（以N计）浓度最低为1.4 mg·L-1，反硝化生物滤池内未发生硝酸盐异化还原（DNRA）作用，出水无氨氮积累。出水SO42-浓度最高为73.8 mg·L-1。反硝化生物滤池运行稳定后，出水中COD未超过30 mg·L-1，木屑释放的碳源与异养反硝化过程消耗的碳源持平，经反硝化生物滤池深度处理的出水中无过量残留有机物。出水pH稳定在6.9~7.4范围内，反硝化生物滤池无需外加碱类物质。

Woodchip-sulfur packed denitrification biofilter for enhanced nitrate removal

The results indicated the rate of the released carbon from woodchip tended to be stable after 10 d and (40.6±10.0)% of COD was volatile fatty acid, an available carbon source directly utilized by denitrifier. Under the condition of the optimal HRT (10 h) with thenitrate concentration (nitrate nitrogen value) of 30 mg·L-1 in influent, the concentration of nitrate, nitrite (nitrite nitrogen value) and sulfate in the effluent could reach 11.5, 1.4 and 73.8 mg·L-1, respectively. It was worth to mention that the accumulation of ammonia and dissimilatory nitrate reduction to ammonium were not occurred. In addition, no residual organic material was escaped from woodchip to the effluent, verified by the low COD in effluent (-1). The range of pH in effluent maintained at 6.9 to 7.4 and there no additional alkaline compounds was required.