用于合成PHA活性污泥的驯化培养

Enhanced acclimating strategies for polyhydroxyalkanoateproduction conventional activated sludge

摘要:

活性污泥用于可降解塑料聚羟基烷酸酯(polyhydroxyalkanoate,PHA)生产前需进行驯化培养,以增强其合成能力．为提高PHA产量,对比考察了单阶段驯化和双阶段驯化两种模式对底物利用、活性污泥性质以及合成PHA的影响．结果表明:单阶段模式下乙酸利用速率为88 mg／(L·min),活性污泥质量浓度为2 000 mg／L左右,PHA单位乙酸合成效率为019 g／g,PHA含量在进水后90 min时达到最大值;双阶段模式下各项指标均有提高,利用率为273 mg／(L·min),活性污泥质量浓度为4 500 mg／L左右,PHA单位乙酸合成效率提高到024 g／g,PHA含量在进水后30 min时达到最大值．因此,双阶段模式比单阶段模式更适于培养具有高PHA合成能力的活性污泥．

Abstract:

The polyhydroxyalkanoate (PHA) accumulation ability of raw Conventional activated sludge (CAS) can be improved with proper acclimating method, which is necessary for high PHA yield. This study compared two acclimating strategies: onestep acclimation and twostep acclimation. The comparison was based on the PHA production activity, substrate utilization rate and sludge characteristics. The onestep acclimation performed a PHA yield of 019 g／g acetate acid and an acetate acid utilization rate of 88 mg／(L·min). The PHA maximum content was obtained 90 min later after substrate feeding accomplished. The final biomass concentration (MLVSS) was around 2 000 mg／L. The data of these three criteria for the twostep acclimation were 024 g／g acetate acid, 273 mg／(L·min), 30 min and 4 500 mg／L, respectively,which were all increased. Our study indicated that the twostep acclimating strategy was more suitable to cultivate PHAproduction CAS.