As one of the most significant factors influencing the settling properties of the activated sludge, the effects of various salinities and their changes on sludge bulking were investigated by applying wastewaters containing different kinds of salinity in a sequencing batch reactor (SBR). The influences of salinities induced by NaCl, Na2SO4 and Na3PO4 on the removal efficiency of pollutants and the settleability of the activated sludge were analyzed by utilizing sodium acetate as sole carbon source. The performances of the SBR fed with NaCl salinity (increased gradually from 0 to 30 g/L) when the dissolved oxygen (DO) concentration was 3 mg/L were as follows:the sludge volume index (SVI) dropped from 135 mL/g to 71 mL/g;the removal efficiency of the total nitrogen (TN) dropped from 80%to 60%;The extracellular polymeric substance (EPS) increased from 521 to 917 mg/L;And the sludge showed a good settleability. When the Na2SO4 salinity increased gradually from 0 to 30 g/L, the SVI dropped from 135 to 73 mL/g, the TN removal efficiency dropped from 81% to 60% and the EPS increased from 523 to 896 mg/L. By comparison, when the Na3PO4 salinity increased gradually from 0 to 8 g/L, SVI increased from 135 to 198 mL/g, the removal efficiency of TN dropped from 80% to 60% and the EPS increased from 549 to 674 mg/L, which led to sludge bulking. It demonstrated that when the NaCl and Na2SO4 salinity increased, the removal efficiency of TN decreased, while the sludge settleability was improved and the EPS concentration increased. For system fed with increasing Na3PO4 salinity, the sludge settleability and the removal efficiency of TN decreased, while the EPS concentration increased. Meanwhile, with the decreasing salinity of NaCl (30~0 g/L), Na2SO4 (30~0 g/L) and Na3PO4 (8~0 g/L), SVI increased from 71 to 298 mL/g, 73 to 291 mL/g and 198 to 241mL/g, respectively, the respective TN removal efficiency dropped from 62% to 43%, 65%to 44%and 70%to 35%and the EPS concentration increased from 917 to 1 092 mg/L, 896 to 1 078 mg/L and 674 to 759 mg/L, respectively. It indicated that when the salinity of NaCl, Na2SO4 and Na3PO4 reduced from high values to low values, the sludge settleability and the removal efficiency of TN decreased, while the correponding EPS concentration continued to increase, which finally led to sludge bulking. In conclusions, when the NaCl and the Na2SO4 salinity experiences a gradual ascending trend, the settleability of the activated sludge will be improved, while the nitrogen removal efficiency will decline;Filamentous sludge bulking is induced when these two salinities undergo a descending trend. Meanwhile, both the increase and decrease of Na3PO4 salinity will result in non-filamentous sludge bulking.%为了研究盐度对污泥膨胀的影响，采用序批式生物反应器（sequencing batch reactor，SBR）处理含盐废水，考察NaCl、Na2SO4和Na3PO4盐度变化对污泥沉降性和污染物去除效果的影响。结果表明，当NaCl和Na2SO4盐度由0升高至30 g/L时，污泥容积指数（sludge volume index，SVI）由135 mL/g下降至71～73 mL/g，总氮（total nitrigen，TN）去除率由80%下降到60%，胞外聚合物（extracellular polymeric substance，EPS）质量浓度由521～523 mg/L升高到896～917 mg/L，污泥沉降性良好；当Na3PO4盐度由0升高至8 g/L时，SVI由135 mL/g升高至198 mL/g，TN去除率由80%下降至60%，EPS质量浓度由549 mg/L升高到674 mg/L，发生污泥膨胀。随着NaCl和 Na2SO4盐度的提高，污泥沉降性能提高，TN 去除率下降，EPS 质量浓度升高。随着 Na3PO4盐度的提高，污泥沉降性能和TN去除率均下降，EPS质量浓度升高。然而，随着NaCl（30～0 g/L）、Na2SO4（30～0 g/L）和Na3PO4（8～0 g/L）盐度的降低，SVI值分别由71 mL/g升高至298 mL/g，73 mL/g升高至291 mL/g和198 mL/g升高至241 mL/g，TN去除率分别由62%下降至43%，65%下降至44%，70%下降至35%，EPS质量浓度分别由917 mg/L升高至1092 mg/L，896 mg/L升高至1078 mg/L，674 mg/L升高至759 mg/L。随着NaCl、Na2SO4和Na3PO4盐度由高降低后，污泥沉降性能和TN去除率均下降，EPS质量浓度继续升高，盐度降低后发生了污泥膨胀。
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