Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China; Institute of Eco-Chongming, East China Normal University, Shanghai, China.
Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China; Institute of Eco-Chongming, East China Normal University, Shanghai, China.
Sci Total Environ. 2018 Dec 10;644:547-555. doi: 10.1016/j.scitotenv.2018.06.392. Epub 2018 Jul 11.
Chemically enhanced primary sedimentation (CEPS) technology has been widely applied in Hong Kong, exhibiting excellent performance in contaminants removal from sewage. The generated CEPS sludge contains abundance of organics which could be recovered as volatile fatty acids (VFAs) by fermentation for further utilization. In this work, the effect of calcium peroxide (CaO) on the fermentation of FeCl based CEPS sludge was investigated. The feasibility of utilizing the fermentation liquor as substrate for polyhydroxyalkanoates (PHAs) biosynthesis was also evaluated. Results demonstrated that CaO addition facilitated the disintegration of CEPS sludge and enhanced VFAs production. The maximum VFAs yield of 455.8 mg COD/g VSS was obtained with the dosage of 0.1 g CaO/g SS, improving by 44.7% compared with the control sludge. Acetic and propionic acid were the predominant components of the VFAs. Microbial analysis indicated that CaO induced microbial reduction of Fe(III), accelerating the initial disintegration of FeCl based CEPS sludge. Microbial communities with hydrolysis and acidogenesis functions were enriched effectively. CaO treatment had no significant influence on the release of ammonia nitrogen (NH-N), while reduced the concentration of orthophosphate (PO-P) and ferrous (Fe) in fermentation liquor, that was beneficial to the further utilization as substrate for PHAs biosynthesis. The VFA-rich fermentation liquor was proved to be a suitable substrate for PHAs biosynthesis. After cultivation, the PHAs content in activated sludge reached 22.3%, which was comparable to those obtained using waste materials as carbon source. This integrated technology could be a superior alternative of realizing sludge disposal and bioplastic production simultaneously.
化学强化一级沉淀（CEPS）技术已在香港得到广泛应用，在去除污水中的污染物方面表现出优异的性能。所产生的 CEPS 污泥含有丰富的有机物，可通过发酵回收为挥发性脂肪酸（VFAs），以进一步利用。在这项工作中，研究了过碳酸钠（CaO）对基于 FeCl 的 CEPS 污泥发酵的影响。还评估了将发酵液用作聚羟基烷酸（PHA）生物合成基质的可行性。结果表明，CaO 的添加促进了 CEPS 污泥的解体和 VFAs 的产生。当添加量为 0.1 g CaO/g SS 时，最大 VFAs 产率为 455.8 mg COD/g VSS，与对照污泥相比提高了 44.7%。乙酸和丙酸是 VFAs 的主要成分。微生物分析表明，CaO 诱导微生物还原 Fe(III)，加速基于 FeCl 的 CEPS 污泥的初始解体。有效地富集了具有水解和产酸功能的微生物群落。CaO 处理对氨氮（NH-N）的释放没有显著影响，但降低了发酵液中正磷酸盐（PO-P）和亚铁（Fe）的浓度，有利于进一步作为 PHA 生物合成的基质利用。富含 VFA 的发酵液被证明是生物合成 PHA 的合适基质。培养后，活性污泥中的 PHAs 含量达到 22.3%，与使用废物作为碳源获得的含量相当。这种集成技术可以作为一种理想的替代方案，同时实现污泥处理和生物塑料生产。
