摘要
短程反硝化作为厌氧氨氧化反应基质亚硝酸盐(NO_(2)^(-)-N)获取的新途径,近年来受到广泛关注.短程反硝化与厌氧氨氧化耦合的污水脱氮工艺具有重要应用潜力.然而,城市污水基质浓度较低且波动频繁,有效实现厌氧氨氧化菌持留与富集是该工艺稳定脱氮的关键.针对上述问题,构建了基于生物膜的短程反硝化耦合厌氧氨氧化工艺,采用2种结构不同的生物填料为载体,对比系统长期脱氮性能,重点考察氮负荷降低过程中系统氮素转化规律及菌群活性变化,深入分析生物膜胞外聚合物(extracellular polymeric substances,EPS)产生特性.结果表明,以含氨氮(NH_(4)^(+)-N)与硝酸盐氮(NO_(3)^(-)-N)废水为处理对象,乙酸钠为有机碳源,分别采用聚氨酯海绵填料(R1)和聚乙烯空心环填料(R2)成功构建了短程反硝化耦合厌氧氨氧化生物膜系统.进水NH_(4)^(+)-N与NO_(3)^(-)-N由150 mg/L逐渐降低至50 mg/L、氮负荷由0.6 kg/(m^(3)·d)降为0.2 kg/(m^(3)·d)时,R1和R2维持高效稳定脱氮,低负荷阶段平均总氮(TN)去除率分别为87.6%和83.6%.厌氧氨氧化作用始终为主要脱氮途径,其占两系统TN去除的贡献率分别高达98.2%和97.4%.生物膜短程反硝化速率随氮负荷减少而降低,但高NO_(2)^(-)-N积累特性未受影响,R1系统NO_(2)^(-)-N积累效率达到95.1%且高于R2(89.8%),其厌氧氨氧化活性降低程度小于R2,表明聚氨酯填料更适合低负荷下该工艺长期运行.低负荷下微生物分泌更多EPS,蛋白质含量增加有助于系统应对氮负荷变化.综上,短程反硝化耦合厌氧氨氧化生物膜工艺处理低基质废水时具有稳定高效的重要优势,为解决厌氧氨氧化应用的瓶颈问题提供了新方法,具有研究意义和应用价值.
Partial-denitrification has received wide attention as a new approach for nitrite(NO_(2)^(-)-N)generation.The novel nitrogen removal process coupling partial-denitrification and anammox has great potential in application.However,considering the low substrate concentration and frequent fluctuation of municipal wastewater,efficient retention and enrichment of anammox bacteria appears to be a crucial issue for this technology.Taking this into consideration,this study established a process in biofilm systems using two types of carriers for partial denitrification coupling with anammox,and aimed to compare the long-term nitrogen removal performance,and mainly investigated the nitrogen transformation and microbial activities variation under decreasing nitrogen loading rates,as well as an in-depth analysis of extracellular polymeric substance(EPS).Result showed that,feeding with wastewater contained NH_(4)^(+)-N and NO_(3)^(-)-N,using acetate as organic carbon source,partial denitrification coupling with anammx systems with fixed biocarriers of polymeric sponges(R1)and polyethylene hollow rings(R2)were established successfully.When the influent of NH_(4)^(+)-N and NO_(3)^(-)-N gradually decreasing from about 150 mg/L to 50 mg/L,corresponding to the nitrogen loading rates(NLR)declining from 0.61 to 0.21 kg/(m^(3)·d),both of the systems maintained the stably high nitrogen removal performance,and the average total nitrogen(TN)removal efficiencies in low NLR phase were 87.6% and 83.6%,respectively.Anammox were the dominant pathways of nitrogen removal,accounting for as high as 98.2% and 97.4%,respectively.The decreasing NLR resulted in the reduced rates of partial denitrification,while it had little impact on the NO_(2)^(-)-N accumulation efficiency,which achieved 95.1%in R1 and was higher than R2(89.8%),and it showed a less decrease in anammox activities than R2,indicating that the polymeric sponges was more suitable for long-term operation of this process under low NLR.More EPS were secreted and increasing protein would benefit for coping with varying NLR.Overall,the partial-denitrification coupling with anammox process holds significant advantage in treating low-strength wastewater,providing a new solution for bottleneck in applying anammox process,with great significance of research and values of practical application.
作者
彭永臻
王锦程
李翔晨
杜睿
刘莹
PENG Yongzhen;WANG Jincheng;LI Xiangchen;DU Rui;LIU Ying(National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology,Beijing University of Technology,Beijing 100124,China;Zhongshan Public Utilities Water Co.Ltd.,Zhongshan 528400,Guangdong,China)
出处
《北京工业大学学报》
CAS
CSCD
北大核心
2021年第12期1367-1376,共10页
Journal of Beijing University of Technology
基金
北京市自然科学基金资助项目(8204056)。
