Environmental Engineering Research Centre, Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China; Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen, China.
Environmental Engineering Research Centre, Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China.
Water Res. 2019 Jun 15;157:145-154. doi: 10.1016/j.watres.2019.03.075. Epub 2019 Mar 28.
Iron (Fe)-based chemically enhanced primary sedimentation (CEPS) is an effective process used to remove organic and phosphorus (P) pollutants from wastewater into sludge. In this study, electro-fermentation (EF) technology was developed to treat the organic- and P-rich Fe-sludge for the purposes of sludge reduction and resource recovery. Using a two-chamber bioreactor with a cation exchange membrane and an exterior voltage (0.5-1.0 V) for sludge treatment, the EF system enabled product accumulation and separation during the fermentation process. Compared with the conventional fermentation in a single-chamber reactor, the EF treatment of Fe-sludge significantly improved the efficiency of P dissolution from the sludge from 8% to 56% after 4 d. Meanwhile, about 70% of released ammonium ions and 50% of Fe in the sludge were driven by the current from the sludge suspension into the cathode chamber for potential recovery. With a similar yield of volatile fatty acids (VFAs) but less ammonium remaining, the COD/N of the sludge supernatant from the EF reactor could reach 67.7, much higher than that from the single-chamber fermenter at 13.0. The protease activity was effectively promoted by the EF treatment, suggesting that both electrochemical and biological hydrolysis effects contributed to the increased P release from the sludge. Microbial community analysis showed that the electrical stimulation increased the relative abundance of Firmicutes and facilitated the growth of Acidobacteria. Overall, electro-fermentation was developed as an effective biotechnology for processing Fe-based CEPS sludge with the benefits of recovering organics, phosphorus, ammonium and iron resources.
铁（Fe）基化学强化一级沉淀（CEPS）是一种从废水中去除有机和磷（P）污染物到污泥中的有效工艺。在这项研究中，开发了电发酵（EF）技术来处理富含有机物和 P 的 Fe 污泥，以实现污泥减量和资源回收。使用带有阳离子交换膜和外部电压（0.5-1.0 V）的两室生物反应器进行污泥处理，EF 系统在发酵过程中实现了产物的积累和分离。与在单室反应器中的传统发酵相比，EF 处理 Fe 污泥可将污泥中 P 的溶解效率从 4 d 后的 8%显著提高到 56%。同时，约 70%的释放出的铵离子和 50%的污泥中的 Fe 被电流从污泥悬浮液驱入阴极室，以进行潜在的回收。EF 反应器中污泥上清液的 COD/N 可达到 67.7，与单室发酵器中的 13.0 相比，具有相似的挥发性脂肪酸（VFAs）产量，但剩余的铵更少。EF 处理有效地促进了蛋白酶活性，表明电化学和生物水解作用都有助于增加污泥中的 P 释放。微生物群落分析表明，电刺激增加了厚壁菌门的相对丰度，并促进了酸杆菌的生长。总的来说，电发酵被开发为一种有效的生物技术，用于处理 Fe 基 CEPS 污泥，具有回收有机物、磷、铵和铁资源的优势。
