采用SBR反应器,系统地研究不同质量浓度Zn(Ⅱ)长期作用对好氧颗粒污泥基本性能和污染物去除功效的影响。试验结果表明:当ρ(Zn(Ⅱ))≤5 mg/L时,Zn(Ⅱ)对好氧颗粒污泥基本性能与污染物去除功效影响较小;当ρ(Zn(Ⅱ))≥10 mg/L时,Zn(Ⅱ)会导致好氧颗粒污染物去除功效降低,混合液悬浮固体(MLSS)质量浓度、沉降速率、污泥粒径与结构发生改变。10 mg/L以上的Zn(Ⅱ)长期作用会导致污泥粒径变小,结构松散,进而导致污泥沉降性能变差,最终引起ρ(MLSS)下降。Zn(Ⅱ)作用76 d后,投加10 mg/L和15 mg/L Zn(Ⅱ)的反应器内NH+4-N、COD去除率分别减低为84.3%和75.1%、90.1%和85.7%;ρ(MLSS)分别降至3 658 mg/L和3 225 mg/L;SVI分别升高至94 m L/g和99 m L/g;颗粒污泥的平均粒径分别降至0.58 mm和0.37 mm,部分颗粒污泥解体。
The long-term effects of Zn( Ⅱ) on the properties and pollutant removal efficiencies of aerobic granular sludge in sequencing batch reactors( SBR) were investigated systematically. The results show that Zn( Ⅱ) with a concentration less than or equal to 5 mg / L has a slight effect on the properties and pollutant removal efficiencies of aerobic granular sludge. When the concentration of Zn( Ⅱ) is greater than or equal to 10 mg / L,the pollutant removal efficiencies of the sludge are reduced,leading to variations of the mass concentration of mixed liquid suspended solids( MLSS) and the sedimentation rate,granular size,and structure of the sludge. Along with the long-term effects of Zn( Ⅱ),the average diameter of granules decreased,the sludge structure loosened,and the sedimentation ability deteriorated,which,finally,resulted in the decrease of the MLSS concentration. After 10 and15 mg / L Zn( Ⅱ) were separately dosed for 76 days,the removal rates decreased to 84. 3% and 75. 1%,respectively,for NH+4-N,and 90. 1% and 85. 7%,respectively,for COD; the MLSS concentration dropped to3 658 and 3 225 mg / L,respectively; the sludge volume index( SVI) increased to 94 and 99 m L / g,respectively;the average particle size decreased to 0. 58 and 0. 37 mm, respectively; and parts of the granular sludge disintegrated.