膜生物反应器PVDF膜和尼龙膜污染特性

分别采用PVDF膜（第1~219d）和尼龙（Nylon）膜（第220~360d）长期运行膜生物反应器（MBR），分析MBR系统的脱氮性能和膜污染特性.结果表明，反应器最终在进水NH₄⁺-N和NO₂^--N浓度分别为400~740mg/L和460~790mg/L的条件下稳定运行112d，总氮去除率（TNRE）维持在86%左右，总氮去除负荷（NRR）为0.61~1.08kg N/（m³·d）.经过263d的运行，反应器中混合液悬浮固体浓度（MLSS）从4918mg/L增至7230mg/L，混合液挥发性悬浮固体浓度（MLVSS）从2585mg/L增加至4455mg/L，比厌氧氨氧化活性（SAA）最高达0.46g N/（d·gVSS）.无论是PVDF膜还是尼龙膜，Anammox-MBR系统在一个膜污染周期结束时，都是泥饼层阻力占主导，但二者的膜污染机制不同.与相同水力停留时间（HRT）下运行的PVDF膜相比，尼龙膜的膜污染发展速度显著减小.结合脱氮性能和膜污染情况，本实验条件下，MBR系统优先采用尼龙膜在HRT=1.5d运行.

Membrane fouling characteristics of PVDF membrane and nylon mesh in Anammox-MBRs

PVDF membrane was used in the early operation period (1~129d) and nylon mesh was used in the later operation period (220~360d) to analyze the nitrogen removal performance and membrane fouling characteristics of the two kind of membrane bioreactor (MBR) system. The MBR system was operated stably for 112d with the influent NH₄⁺-N and NO₂^--N concentrations of 400~740mg/L and 460~790mg/L, respectively. During this period, the total nitrogen removal efficiency (TNRE) maintained at about 86%, and the nitrogen removal rate (NRR) was 0.61~1.08kg N/(m³·d). After 263days' operation, mixed liquid suspended solids (MLSS) in the reactor increased from 4918mg/L to 7230mg/L, and the corresponding mixed liquor suspended solids (MLVSS) increased from 2585mg/L to 4455mg/L, the highest special anammox activity (SAA) was 0.46g N/(d·g VSS). For both PVDF membrane or nylon mesh, the cake layer resistance dominates at the end of a membrane fouling cycle, but their fouling mechanisms was different. Compared with that of PVDF membrane system, nylon mesh maintained good anti-fouling performance, even operated under the same HRT to PVDF membrane. Considering the nitrogen removal performance and the membrane fouling cycle, nylon mesh with HRT=1.5h was preferred in this experiment.