| Ca2+对污泥硝化活性和絮凝沉降性能的影响 |
| 摘要点击 2861 全文点击 908 投稿时间：2019-01-12 修订日期：2019-04-04 |
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| 中文关键词 硝化活性 胞外聚合物(EPS) 沉降性 絮凝性 金属离子 |
| 英文关键词 nitrification activity extracellular polymeric substances (EPS) sedimentation flocculation metal ion |
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| 中文摘要 |
| Ca2+是微生物重要的生长因子，影响污泥的活性和絮凝沉降性能.为了研究Ca2+在活性污泥体系中的作用，采用比耗氧速率（SOURAOB和SOURNOB）分析硝化菌和亚硝化菌活性的变化，利用傅里叶变换红外光谱（Fourier transform infrared spectroscopy，FTIR）和三维荧光光谱（three-dimensional excitation emission matrix fluorescence spectroscopy，3D-EEM）分析胞外聚合物（extracellular polymeric substances，EPS）组分和结构的变化，考察Ca2+对污泥硝化活性和代谢产物的影响.结果表明，当Ca2+浓度由0.45 mmol·L-1逐渐提高至3 mmol·L-1时，SOURAOB和SOURNOB分别由6.3 mg·（g·h）-1和2.3 mg·（g·h）-1升高至10.4 mg·（g·h）-1和3.7 mg·（g·h）-1，EPS总量由68 mg·g-1增加至93 mg·g-1，污泥重絮凝能力（FA）增强.当Ca2+>3 mmol·L-1时，SOURAOB和SOURNOB均下降，FA维持在30%左右，污泥粒径持续增大.随着Ca2+浓度的增加，由FTIR分析可知，LB-EPS和TB-EPS的主要组成基团均未发生明显变化，以氨基、酰胺Ⅰ和羧基为主；由EEM分析可知，LB-EPS组成未发生变化，在低硝化速率下，TB-EPS中存在腐殖酸类物质.低浓度的Ca2+促进污泥硝化活性和絮凝性，高浓度的Ca2+导致污泥硝化活性降低. |
| 英文摘要 |
| Ca2+ is an important microbial growth factor that can affect the activity, flocculation, and sedimentation of activated sludge. In order to study the roles of Ca2+ in the activated sludge system, the activity changes of ammonium oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) were analyzed using the specific oxygen uptake rates (SOURAOB and SOURNOB). The changes in composition and structure of extracellular polymeric substances (EPS) were analyzed using Fourier transform infrared spectroscopy (FTIR) and three-dimensional excitation emission fluorescence spectroscopy (3D-EEM). The effects of Ca2+on the nitrification activity and microbial metabolites were investigated. The results showed that when the Ca2+concentration increased from 0.45 mmol·L-1 to 3 mmol·L-1, SOURAOB and SOURNOB increased from 6.3 mg·(g·h)-1 to 10.4 mg·(g·h)-1 and from 2.3 mg·(g·h)-1 to 3.7 mg·(g·h)-1, respectively. The EPS concentrations increased from 68 mg·g-1 to 93 mg·g-1, and the flocculation ability (FA) of the sludge was improved. When the Ca2+ concentration was higher than 3 mmol·L-1, SOURAOB and SOURNOBboth decreased. The FA was maintained at about 30%, and the particle size of the sludge continued to increase. Based on FTIR analysis, the main components of EPS were always amino, amide Ⅰ, and carboxyl with an increase in Ca2+ concentration. Based on EEM analysis, the composition of loosely-bound (LB)-EPS did not change, and humic acid substances appeared in the tightly-bound (TB)-EPS at low nitrification rates. Low concentrations of Ca2+ promoted nitrification activity and flocculation of the sludge. However, high concentrations of Ca2+ led to a decline in the sludge nitrification activity. |
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