Fe^3+和Na^+共存对缺氧污泥脱氮除磷效率和胞内外聚合物的影响  

Effects of coexisting Fe^3+ and Na^+ on nitrogen and phosphorus removal, intracellular polymeric substances and extracellular polymeric substances of anoxic sludge

作　　者：张兰河[1,2] 徐英 陈子成 张小雨[2] 关晓辉 张海丰[1] 徐平[1] Zhang Lanhe;Xu Ying;Chen Zicheng;Zhang Xiaoyu;Guan Xiaohui;Zhang Haifeng;Xu Ping(School of Chemical Engineering,Northeast Electric Power University,Jilin 132012,China;Key Laboratory of Songliao Aquatic Environment,Ministry of Education,Jilin Jianzhu University,Changchun 130118,China)

机构地区：[1]东北电力大学化学工程学院,吉林132012 [2]吉林建筑大学松辽流域水环境教育部重点实验室,长春130118

出　　处：《农业工程学报》2020年第8期197-205,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金(51678119,51808254);吉林省科技发展计划项目(20180201016SF)。

摘　　要：为了提高多种金属离子共存的含盐废水脱氮除磷效率和生物絮凝性,考察Fe^3+和Na^+共存对A2O工艺缺氧区污染物去除率的影响,研究缺氧区胞内聚合物(Intracellular Polymeric Substances,IPS)和胞外聚合物(Extracellular Polymeric Substances,EPS)的变化,采用气相色谱法与蒽酮比色法分析IPS中聚-β-羟丁酸(Poly-β-hydroxybutyrate,PHB)和糖原含量的变化,结合三维荧光光谱(Three-dimensional Excitation Emission Matrix Fluorescence Spectroscopy,3D-EEM)与傅里叶变换红外光谱(Fourier Transform Infrared Spectroscopy,FTIR)探索EPS组成结构的变化,以期揭示共存的Fe^3+和Na^+、IPS及EPS与污泥絮凝性的关系。结果表明:1)单一Fe^3+的加入有助于提高COD、TN和TP的去除率,增加碱性磷酸酶与酸性磷酸酶活性,IPS和EPS总量增多。2)在Fe^3+和Na^+共存的条件下,当Fe^3+浓度为10 mg/L、Na^+浓度为0.5 g/L时,低浓度的Na^+提高了COD、TN和TP去除率,增强了碱性磷酸酶与酸性磷酸酶活性,增加了IPS总量,但是抑制了微生物EPS的分泌,EPS总量下降;当Fe^3+为10 mg/L,Na^+浓度(>1 g/L)继续升高时,高浓度的Na^+导致COD、TN和TP去除率下降,IPS总量降低,但是促进了微生物EPS的分泌,EPS总量增加。3)由FTIR分析可知,Fe^3+和Na^+浓度的变化并未导致松散结合型胞外聚合物(Loosely Bound Extracellular Polymeric Substances,LB-EPS)和紧密结合型胞外聚合物(Tightly Bound Extracellular Polymeric Substances,TB-EPS)的官能团发生明显变化,主要成分始终为蛋白质(Protein,PN)和多糖(Polysaccharide,PS);由3D-EEM分析可知,Fe^3+的加入使三维荧光光谱中出现了可见区类色氨酸峰,Na^+的加入使色氨酸、腐殖酸类物质降解,EPS的成分改变。4)IPS和EPS之间存在竞争生长,IPS/EPS比值较高时,IPS占主导作用,污泥絮凝性能好。Salty wastewater from seawater toilet-flushing in coastal cities can dramatically change the bioactivation and bioflocculation of activated sludge in sewage treatment system, particularly on extracellular osmotic pressure of microorganisms for the separation of cytodermand and cytoplasm. In order to improve bioflocculation for the removal of nitrogen and phosphorus, this study aims to investigate the effects of Fe^3+ and Na^+ on the removal of pollutants in activated sludge, and the evolution reaction mechanism of intracellular polymeric substances(IPS) and extracellular polymeric substances(EPS) in the anoxic zone of a A2 O process. The contents of poly-β-hydroxybutyrate(PHB) and glycogen in IPS under multiple metal ions were analyzed using gas chromatography and anthrone colorimetry. The compositions and structures of EPS were characterized using three-dimensional excitation emission matrix(3 D-EEM) fluorescence spectroscopy and fourier transform infrared spectroscopy(FTIR), in order to reveal the relationship between Fe^3+/Na^+, IPS, EPS and sludge flocculation. The results showed that the addition of single Fe^3+ can contribute to the removal of COD, TN and TP, the activity of alkaline phosphatase and acid phosphatase, and the total IPS and EPS. More substances were accumulated on the surface of microbial cells under the flocculation of Fe^3+. Compared with the addition of Fe^3+ alone, the combination of Fe^3+(10 mg/L) and Na^+(0.5 g/L) can increase the removal of COD, TN and TP from 42%, 41% and 45% to 45%, 43% and 49%, respectively. Low concentration of Na^+ can promote the respiration of microorganisms to save the generation time of cells, and thereby enhance the removal of organic compounds in activated sludge system. Although the increase in the total IPS and the activity of alkaline phosphatase and acid phosphatase, the low concentration of Na^+ can inhibit the secretion of EPS to result in the decrease of the total EPS. The removal of COD, TN and TP decreased when Fe^3+ was 10 mg/L and Na^+ was higher

关 键 词：金属离子 废水 缺氧污泥 胞内聚合物 胞外聚合物 絮凝性 

分 类 号：X703[环境科学与工程—环境工程]