基于反硝化脱氮的硫铁复合填料除磷机制

Phosphorus Removal Mechanism of Sulfur/Sponge Iron Composite Fillers Based on Denitrification

为提高硫铁复合填料反硝化脱氮同步除磷效果,对比研究了不同填料和耦合微生物后的除磷效果,分析了微生物耦合硫铁复合填料反硝化脱氮同步实现除磷的机制.结果表明与单纯海绵铁填料比较,硫磺与海绵铁复合填料除磷效率提高30%,达到95%以上,出水磷含量可降至0.1 mg·L^(-1)以下.X射线衍射(XRD)和总铁浓度分析表明,硫铁复合填料除磷系统反应产物主要为FeOOH、FeS和Fe_4(PO_4)_3(OH)_3固体物质和溶解性铁离子,产生于海绵铁的腐蚀和除磷过程;腐蚀产生的Fe^(2+)及Fe^(3+)的水解产物FeOOH和Fe S通过吸附沉淀作用将PO_4^(3-)转化为Fe_4(PO_4)_3(OH)_3去除.微生物耦合硫铁炭复合填料反应器运行稳定后,TN、TP去除率分别在90%左右和83%以上;硫自养反硝化产生的H^+和生物铁作用也可以促进海绵铁腐蚀和除磷过程,体系将"异养协同自养"复合反硝化与化学除磷有机结合,实现了城市污水处理厂尾水高效反硝化脱氮同步除磷的目的.

In order to improve the phosphorus removal effect in the denitrification and phosphorus synchronous removal process by sulfur / sponge iron composite fillers,the phosphorus removal effect by different fillers with the coupling microorganisms was studied to analyze the denitrifying phosphorus removal mechanism of the microbial coupling sulfur / sponge iron composite fillers. The research result showed that the phosphorus removal ratio of sponge iron / sulfur composite fillers was over 95%,which was increased by 30% as compared to only sponge iron filler. In addition,the effluent TP concentration was reduced to less than 0. 1 mg·L- 1. The analysis of X-ray diffraction（ XRD） and total iron concentration indicated that the main phosphorus removal system products which were produced in the corrosion and phosphorus removal process of sponge iron were Fe OOH,Fe S and Fe4（ PO4）3（ OH）3deposits and dissolved iron ions; Fe S and Fe OOH which were the hydrolysis products of Fe^2＋and Fe^3＋ converted PO4^3-to Fe4（ PO4）3（ OH）3by adsorption and deposition so that phosphorus removal could be achieved. After the reactor of microbial coupling sulfur / sponge iron carbon composite fillers became stable,the removal efficiency of TN and TP could reach 90% and more than 83%,respectively; Corrosion of sponge iron and phosphorus removal process could also be promoted by biological iron and H＋that was produced in the sulfur autotrophic denitrification process,the system could realize the combination of ＂heterotrophic synergy autotrophic＂composite denitrification and chemical phosphorus removal,and efficient denitrifying denitrification synchronous phosphorus removal process could be achieved in the urban sewage treatment plant.