黄铁矿-硫自养反硝化生物滤池同步脱氮除磷

Simultaneous Denitrification of Nitrogen and Phosphorus by Pyrite-Sulfur Autotrophic Denitrification Biological Filter

基于黄铁矿的自养反硝化(PAD)工艺具有成本低,产泥量少等优点,是一种具有前景的低C、N比废水脱氮除磷技术。然而,与其他硫基自养反硝化(SAD)工艺相比,PAD的动力学较慢,限制了其工程应用。为此,构建了黄铁矿、硫单质为填料的自养反硝化生物滤池(PSAD-BF)和黄铁矿为填料的硫化钠驱动的自养反硝化生物滤池(SAD-BF),PSAD-BF的硝酸盐去除负荷和去除率均高于SAD-BF,FeS_(2)和S^(0)之间的相互作用加速了反硝化过程并维持了酸碱平衡,减少了硫酸盐的产生,同时通过生成FePO_(4)和Fe_(3)(PO_(4))_(2)(OH)_(2)去除磷酸盐。长期运行结果表明:在HRT为3~12 h时,PSAD-BF对总氮和磷酸盐的去除率达到90%~100%,最高反硝化速率可达600 mg/(L·d)。PSAD-BF是一种很有前途的实现铁硫耦合自养反硝化除磷的工艺。

The autotrophic denitration and phosphorus removal technology based on pyrrhotite(PAD)has the advantages of low cost and low sludge production,making it a promising low C/N ratio wastewater treatment method.However,compared to other sulfur-based autotrophic denitration(SAD)processes,PAD has slower kinetics,limiting its engineering application.In this experiment,a self-autotrophic denitration biofilter using pyrrhotite and elemental sulfur as fillers(PSAD-BF)and a self-autotrophic denitration biofilter using pyrrhotite as filler and sodium sulfide as the driving agent(SAD-BF)were constructed.The nitrate removal load and efficiency of PSAD-BF were higher than that of SAD-BF.The interaction between FeS_(2) and S^(0) accelerated the denitration process and maintained acid-base balance,reducing sulfate production.Moreover,phosphate removal was achieved through the formation of FePO_(4) and Fe_(3)(PO_(4))_(2)(OH)_(2).Long-term operation results showed that PSAD-BF achieved a removal efficiency of 90%~100%for total nitrogen and phosphates at a hydraulic retention time(HRT)of 3~12 h,with a maximum denitration rate of 600 mg/(L·d).PSAD-BF is a promising process for iron-sulfur coupled autotrophic denitration and phosphorus removal.