复合式膜生物反应器的膜污染控制机理

采用常规膜生物反应器(CMBR)和复合式膜生物反应器(HMBR)处理城市生活污水,对HMBR的膜污染控制机理进行了研究。试验结果表明,HMBR能够有效去除胞外多聚物(EPS),反应器内溶解性EPS(S-EPS)、松散附着性EPS(LB-EPS)和紧密附着性EPS(TB-EPS)的含量比CMBR分别降低了42.8%、41.5%和2.1%。附着性EPS(B-EPS)特别是LB-EPS与活性污泥的物理性能密切相关,随着其含量的降低,HMBR中活性污泥的絮凝性能和沉淀性能比CMBR分别提高了24.4%和34.8%。由于滤饼层污泥主要来源于活性污泥,因此随着活性污泥絮凝性能和沉淀性能的提高,HMBR中的滤饼层比阻比CMBR降低了31.1%。作为结果,当跨膜压差(TMP)到达20 kPa时,HMBR运行了143 d,而CMBR仅运行了57 d。

Membrane Fouling Control Mechanism of a Hybrid Membrane Bioreactor

A comparing experiment was done using a conventional membrane bioreactor(CMBR)and a hybrid membrane bioreactor(HMBR)in municipal wastewater treatment in order to study the membrane fouling control mechanism of HMBR.Results showed that HMBR can decrease extracellular polymeric substances(EPS) effectively,the soluble EPS(S-EPS),loosely bond EPS(LB-EPS)and tightly bond EPS(TB-EPS)in which was decreased by 42.8%,41.5% and 2.1% respectively,comparing with CMBR.The bond EPS(B-EPS),especially LB-EPS had a significant correlation with activated sludge characteristics,and with decrease of which,the sludge flocculation and settling ability in HMBR was enhanced by 24.4% and 34.8% respectively,comparing with CMBR.Because the cake layer was mainly derived from activated sludge,therefore with the change of sludge characteristics,the specific resistance to filtration of cake layer in HMBR was decreased by 31.1%,comparing with CMBR.When transmembrane pressure reached to 20 kPa,HMBR could operate for 143 d,while only 57 d for CMBR.