短程硫黄/硫铁矿自养反硝化脱氮性能研究

Study of nitrogen removal performance of short-cut sulfur/pyrite autotrophic denitrification

为了解决异养反硝化处理低n(C)/n(N)废水需外加有机碳源和硫黄自养反硝化硫酸盐产量较高的问题,启动了短程硫黄/硫铁矿自养反硝化反应器并探究其脱氮性能,通过批式试验考察了n(S)/n(N)、初始pH、硫铁矿和石灰石等因素对脱氮性能的影响.结果表明,短程硫黄自养反硝化总氮(TN)去除率稳定在96%以上,比完全硫黄自养反硝化的实际硫酸盐产量减少大约40%.在氮容积负荷(以NO_(2)^(-)-N计)为0.40 kg/(m^(3)·d)时,短程硫铁矿自养反硝化的TN去除率高达98%,进一步解决了以S^(0)为电子供体时硫酸盐产量较高的问题.短程硫黄自养反硝化在n(S)/n(N)=2.5、初始pH=8时脱氮效果较好;FeS_(2)+NaHCO_(3)组合脱氮效果最好;CaCO_(3)在减少出水中硫酸盐产量和碱度缓释方面具有优势.Thiobacillus是硫自养反硝化反应器的主要功能菌属,相对丰度在13.2%以上.

To solve the problems that the heterotrophic denitrification requires additional organic carbon resource in treating low n(C)/n(N)wastewater and the sulfur autotrophic denitrification has a high sulfate production,a short-cut sulfur/pyrite autotrophic denitrification reactor is started and its nitrogen removal performance is investigated.The effects of n(S)/n(N),initial pH,pyrite and limestone on nitrogen removal performance are examined by batch experiments.The results show that the total nitrogen(TN)removal rate of the short-cut sulfur autotrophic denitrification is stable at over 96%,whose practical sulfate production is about 40%less than that of the complete sulfur autotrophic denitrification.Furthermore,when nitrogen volume load(in terms of NO_(2)^(-)-N)is 0.40 kg/(m^(3)·d),the TN removal rate of the short-cut pyrite autotrophic denitrification is as high as 98%,which further solves the problem of high sulfate production when S^(0)is used as electron donor.The short-cut sulfur autotrophic denitrification has a better nitrogen removal effect when n(S)/n(N)=2.5 and initial pH=8.The combination of FeS_(2)+NaHCO_(3)displays the best nitrogen removal effect.CaCO_(3)shows the advantages in reducing sulfate production in effluent and alkaline slow-release.Thiobacillus is the main functional bacteria of sulfur autotrophic denitrification reactor,with a relative abundance of over 13.2%.