State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, China.
Water Sci Technol. 2012;66(6):1203-11. doi: 10.2166/wst.2012.301.
This study highlighted the inorganic fractions in the extracellular polymeric substance (EPS) extract from two activated sludges and one biofilm. Nine EPS extraction methods (centrifugation, sonication, cation exchange resin (CER) + sonication, CER, heating, formaldehyde + heating, formaldehyde + NaOH, ethanol and EDTA) were used in the study. The EPS extracts had large inorganic fractions, which ranged from 28% to 94% of the EPS dry weight. The EPS inorganic fraction was dependent on the source of the sludge and wastewater, the kinds of bacteria and the extraction method. The EPS extracts obtained by heating and sonication had smaller inorganic fractions than those obtained by centrifugation. The compositions of the inorganic fraction of EPS extracts obtained with CER and sonication + CER showed similar trends. The chemical extraction methods could contaminate the inorganic composition of EPS extracts by impurities, carrying over of the extractant itself or by changing the pH of the solution. Ethanol was the most effective extractant for obtaining inorganic ions.
本研究强调了两种活性污泥和一种生物膜中细胞外聚合物（EPS）提取物中的无机部分。研究中使用了九种 EPS 提取方法（离心、超声、阳离子交换树脂（CER）+超声、CER、加热、甲醛+加热、甲醛+NaOH、乙醇和 EDTA）。EPS 提取物含有大量的无机部分，占 EPS 干重的 28%至 94%。EPS 无机部分取决于污泥和废水的来源、细菌种类和提取方法。通过加热和超声获得的 EPS 提取物的无机部分比通过离心获得的提取物的无机部分小。通过 CER 和超声+CER 获得的 EPS 提取物的无机部分的组成表现出相似的趋势。化学萃取方法可能会通过杂质、萃取剂本身的夹带或改变溶液的 pH 值来污染 EPS 提取物的无机成分。乙醇是获得无机离子最有效的萃取剂。
