微波辐射对污水处理厂动态流活性污泥性能的影响研究

通过微波辐射对污水处理厂动态流活性污泥性能进行实验研究,考察了微波辐射3min内污泥沉降性能、脱水性能的变化,探讨了微波辐射对污泥挥发性悬浮固体(VSS)溶解率、上清液中COD和污泥微观形态的影响.结果表明,低强度的微波辐射对活性污泥相关性质的影响不显著,没有从根本上改善活性污泥的结构.适宜的微波辐射能显著改善活性污泥的沉降性能和脱水性能,500、700和900W微波辐射的适宜辐射时间分别为180、150和60s,此时,活性污泥的比阻为0.3×109S2·g-1左右,较原活性污泥减小了88%,泥饼含水率由原活性污泥直接抽滤的85.2%降低到70.0%.VSS溶解率和上清液COD都随着辐射功率及辐射时间的增加而升高.适宜的微波辐射能促进污泥的团聚絮凝,过度的辐射会破坏活性污泥结构,使活性污泥颗粒细小化,混合液黏度增大,导致脱水性能变差.通过动态流动下微波辐射对活性污泥性能影响的研究,可为微波辐射在活性污泥处理的实际应用提供理论依据.

Impact on properties of the sewage treatment plant dynamic flow activated sludge by microwave radiation

The dynamic flow activated sludge characteristics of the sewage plant under microwave radiation was studied. With microwave radiation for 3 minutes, the performance indexes of sludge such as the settling characteristics, dewatering performance, dissolution rate of the volatile suspended solids (VSS), supernatant COD and sludge micro morphology were investigated. Results showed that the change of the activated sludge properties was not significant and the improvement of the structure of the activated sludge was small under low intensity microwave, while the suitable microwave radiation could improve the settling characteristics and dewatering performance of the activated sludge significantly. The proper microwave radiation durations of 500 W, 700 W, and 900 W were 180 s, 150 s, and 60 s, respectively. The specific resistance of sludge was 0.3×10⁹ S²·g^-1 which was 88% less than the original activated sludge. The moisture content of the cake reduced from 85.2% to 70%, VSS dissolution rate and supernatant COD increased with the increasing of the radiation intensity and duration. This was because the suitable microwave radiation could promote the agglomeration and flocculation of the sludge, and the excessive radiation could damage the structure of the activated sludge which led to smaller activated sludge particles, so as to increase the viscosity of mixture and result in the degraded dewatering performance.