Abstract:

Facing the drawback of autotrophic denitrification performance driven by a single sulfur base, three groups of complex sulfur substrate packed bed reactors (B1, B2, B3) were constructed by using elemental sulfur (S⁰) and natural iron sulfur ores (FeS, Fe_1-x S, FeS₂) as biological fillers. The deep nitrogen and phosphorus removal effect and microbial community structure characteristics of municipal tailwater were investigated during start-up and stable operation of the reactors. The results indicated that the high denitrification performance were obtained in the three reactors and the \mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{-}-N removal efficiency increased with the extension of the reactor hydraulic retention time (HRT). When the reactor HRT was 12h (B1), 12h (B2) and 9h (B3), 20mg/L \mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{-}-N was completely removed. The \mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{3}-}-P was removed through chemical precipitation with iron ions generated in the denitrification process, and P removal rate was positively correlated with the effect of nitrogen removal. The \mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}-}/\mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{-} of the complex sulfur substrate reactor was lower than that of the single sulfur based autotrophic denitrification system. Also, sulfate production accordingly decreased and the pH was maintained above 6.3 without adding pH buffers. Microbial community structure analysis showed that Thiobacillus and Ferritrophicum were the dominant genera of sulfur autotrophic denitrifying bacteria in the three reactors. The relative abundances of Thiobacillus and Ferritrophicum in B1, B2 and B3 reactors were 16.07% and 31.24%, 30.07% and 50.19%, and 30.20% and 11.62%, respectively. The complex sulfur substrate enhanced the richness and species diversity of microbial communities, which showed better nitrogen and phosphorus removal performance.

Key words: sulfur autotrophic denitrification, complex sulfur substrate packed bed, municipal tailwater, simultaneous nitrogen and phosphorus removal, microbial community analysis

摘要：

针对单一硫基质驱动自养反硝化性能的缺陷，采用单质硫（S⁰）与天然铁硫矿石（FeS、Fe_1-x S、FeS₂）两种矿物作为生物填料，构建3组复合硫基质填充床反应器（B1、B2、B3），探究了启动与稳定运行期间反应器对市政尾水深度脱氮除磷的效果与微生物群落结构的特征。结果表明，3组反应器均表出现较高的脱氮性能，\mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{-}-N去除率均随反应器水力停留时间（HRT）的延长而提高，当反应器HRT分别为1h（B1）、12h（B2）和9h（B3）时，均实现20mg/L \mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{-}-N完全去除。\mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{3}-}-P与脱氮过程中产生的铁离子形成铁磷沉淀物而被去除，且\mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{3}}-P的去除率与脱氮效果呈正相关。复合硫基质反应器的\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}-}/\mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{-}低于单一硫基质自养反硝化系统，硫酸盐产生量相应降低，且pH保持在6.3以上，无需添加pH缓冲剂。微生物群落结构分析表明，Thiobacillus（硫杆菌属）和Ferritrophicum（铁氧化菌属）是3组反应器中硫自养反硝化菌的优势菌属，在B1、B2和B3反应器的相对丰度分别为16.07%和31.24%、30.07%和50.19%以及30.20%和11.62%。复合硫基质提高了微生物群落丰度和物种多样性，从而表现出良好的脱氮除磷效果。

关键词: 硫自养反硝化, 复合硫基质填充床, 市政尾水, 同步脱氮除磷, 微生物群落分析