厌氧氨氧化颗粒污泥胞外聚合物金属元素特性

Characteristics of metal elements in anammox granular sludge extracellular polymeric substances.

为探究厌氧氨氧化颗粒污泥胞外金属元素特性,将厌氧氨氧化颗粒污泥根据粒径筛分为0.5~1.4mm、1.4~2.8mm、>2.8mm 3组,提取不同粒径厌氧氨氧化颗粒污泥胞外聚合物(EPS),研究EPS金属元素特性.结果表明,蛋白质(PN)是厌氧氨氧化颗粒污泥EPS的主要成分,占EPS含量的84.2%以上.随着粒径的增大,EPS中Na、K、Ca、Mg元素含量均增多,且与EPS中蛋白质含量变化一致.EPS中K、Ca、Mg元素的离子形式占比分别为68.6%、56.2%、94.7%.EPS经过阳离子交换树脂(CER)处理后,0.5~1.4mm、1.4~2.8mm、>2.8mm组EPS Zeta电位分别减小了4.7,7.2,9.1mV,EPS中的金属离子可通过压缩双电层作用促进颗粒污泥的聚集,金属离子对大粒径颗粒污泥EPS Zeta电位的影响幅度更大.

In order to explore the impacts of extracellular metal elements on anammox granular sludge,anammox granular sludge was divided into three groups based on its sizes(0.5~1.4mm,1.4~2.8mm and>2.8mm).Then,the extracellular polymeric substrances(EPS)of the anxmmox granular sludge were extracted.Results show that proteins(PN)accounted for more than 84.2%of the EPS content,showing that PN were the main components of EPS.The anammox granular sludge EPS mainly contained four metal elements,K,Na,Ca,and Mg.In addition,above four metals were arranged in a descending order based on their concentration.With the increase in particle size,more metals and PN were found in EPS.The ionic forms of K,Ca,and Mg in the EPS accounted for 68.6%,56.2%,and 94.7%,respectively.When the EPS were treated with cation exchange resin,the Zeta potential of the EPS of the 0.5~1.4mm,1.4~2.8mm,>2.8mm groups decreased by 4.7mV,7.2mV,and 9.1mV,respectively.Furthermore,the metal ions in EPS could promote the aggregation of granular sludge by compressing the electric double layer,and the effect of metal ions was more significant on larger-size granular sludge in Zeta potential.