不同碳源对低温投加氧化还原介体污水生物反硝化脱氮过程的影响

Effects of different carbon sources on biological denitrification of wastewater at low temperature with adding redox mediator

低温污水生物反硝化脱氮效果差,投加氧化还原介体有利于反硝化过程,不同碳源对反硝化脱氮过程有不同影响。本文考察了不同碳源(丙酸钠、甲醇、乙醇及乙酸钠)对低温投加氧化还原介体1,2-萘醌-4-磺酸盐(NQS)污水生物反硝化脱氮过程的影响。以硝态氮、总氮、亚硝态氮浓度、去除率和脱氮速率、化学需氧量(COD)、氧化还原电位(ORP)的变化对不同碳源的影响进行了表征,发现丙酸钠为碳源时的反硝化速率最高,最高为7mg NOx–-N/(g VSS·h),分别是甲醇[0.88mg NOx–-N/(g VSS·h)]、乙醇[2.72mg NOx–-N/(g VSS·h)]和乙酸钠[1.97mg NOx–-N/(g VSS·h)]为碳源时的8倍、2.6倍和3.6倍;硝态氮的最大去除率为61.5%,分别是甲醇(8.9%)、乙醇(6.6%)和乙酸钠(15.3%)为碳源时的6.9倍、9.3倍和4倍;总氮的最大去除率为47.4%,分别是甲醇(9.1%)、乙醇(10.3%)和乙酸钠(10.3%)为碳源时的5.2倍、4.6倍和4.6倍。

The effect of denitrification of low temperature sewage is poor. It is found that the redox mediator in low temperature is beneficial to denitrification process. Different carbon sources have different effects on denitrifying nitrogen removal. The effect of different carbon sources（sodium propionate,methanol,ethanol and sodium acetate） on the biological denitrification of wastewater at low temperature with adding redox mediator 1,2-naphthoquine-4-sulfonic acid（NQS）were investigated. The effects of concentration of nitrate,total nitrogen and nitrite,removal efficiency and denitrification rate,chemical oxygen demand（COD）and redox potential（ORP）on the different carbon sources were characterized. The results showed that the highest denitrification rate was obtained when sodium propionate was used as carbon source,up to 7 mg NOx–-N/（g VSS·h）,and it is 8 times,2.6 times and 3.6 times of methanol [0.88 mg NOx–-N/（g VSS·h）],ethanol [2.72 mg NOx–-N/（g VSS·h）] and sodium acetate [1.97 mg NOx–-N/（g VSS·h）] as carbon source,respectively. The maximum removal efficiency of nitrate was 61.5%,which was about 6.9 times,9.3 times and 4 times higher than that of methanol（8.9%）,ethanol（6.6%）and sodium acetate（15.3%）as carbon source. The maximum removal efficiency of total nitrogen was 47.4%,which was about 5.2 times,4.6 times and 4.6 times that of methanol（9.1%）,ethanol（10.3%）and sodium acetate（10.3%）as carbon source.