低有机负荷下不同载体对好氧污泥颗粒化的影响

针对活性污泥在低有机负荷下难以实现颗粒化的现状，通过在不同序批式活性污泥（sequencing batch reactor activated sludge process，SBR）反应器中微生物生长的对数期分别投加聚合硫酸铁、硫酸铝和硅藻土来强化好氧颗粒污泥的形成，并对比分析了不同载体的强化造粒机制。结果表明：投加聚合硫酸铁、硅藻土和硫酸铝后，污泥特性得到明显提高，污泥颗粒化所需时间分别提前了11d、7d和4d，而且与对照组的提前解体相比，载体强化后所形成颗粒污泥的结构更为密实，均具有良好的稳定性。而不同于聚合硫酸铁和硅藻土，投加硫酸铝后，污泥胞外聚合物（extracellular polymeric substances，EPS）含量明显增加，由之前的171.31mg/gMLVSS升高至223.47mg/gMLVSS，蛋白（PN）可达205.69mg/gMLVSS，且蛋白（PN）/多糖（PS）可达10以上，这就说明通过刺激污泥EPS的分泌来促进微生物聚集也是硫酸铝强化颗粒污泥形成的作用方式之一。另外，三维荧光光谱分析结果显示，载体的投加能够对污泥EPS的结构产生影响，这也可能在一定程度上促进了污泥的颗粒化进程。

Effects of different carriers on the process of aerobic activated sludge granulation with low-strength wastewater

Based on difficult situation of granulation of activated sludge in low-strength wastewater, and in order to promote the formation of granular sludge and investigate the mechanism of different carriers in the process of aerobic activated sludge granulation in low-strength wastewater, the polymeric ferric sulfate, aluminum sulfate and diatomite were dosed respectively into different sequencing batch reactor activated sludge process (SBR) reactors during the logarithmic phase of microorganisms. According to the results, with a dose of ferrous sulphate, diatomite, and aluminum sulfate, the characteristics of sludge have been significantly improved. Also, the required time of sludge granulation was decreased by 11d, 7d, and 4d, respectively. Compared with the control group broking up due to the presence of filamentous bacteria, the structure of granules cultivated with carriers was more compact with good stability. Different to ferrous sulphate and diatomite, after dosing aluminum sulfate, the total amount of extracellular polymeric substances (EPS) was significantly increased from 171.31mg/gMLVSS to 223.47mg/gMLVSS. The amount of PN reached 205.69mg/gMLVSS, and PN/PS could reach over 10, indicating that promoting the secretion of EPS is one of the important ways of aluminum sulfate to enhance the microorganism aggregate. In addition, the fluorescence spectra parameters of EPS from granular sludge showed that the carriers can affect the composition of the EPS, and it probably promotes the process of granular sludge to a certain extent.