Department of Energy, Building and Environment, Mälardalen University, SE-721 23, Västerås, Sweden.
Department of Energy, Building and Environment, Mälardalen University, SE-721 23, Västerås, Sweden.
Water Res. 2016 Mar 15;91:277-84. doi: 10.1016/j.watres.2016.01.027. Epub 2016 Jan 14.
Integration of the microalgae and activated sludge (MAAS) process in municipal wastewater treatment and biogas production from recovered MAAS was investigated by studying the hydraulic retention time (HRT) of semi-continuous photo-bioreactors. An average total nitrogen (TN) removal efficiency (RE) of maximum 81.5 ± 5.1 and 64.6 ± 16.2% was achieved at 6 and 4 days HRT. RE of total phosphorous (TP) increased slightly at 6 days (80 ± 12%) HRT and stabilized at 4 days (56 ± 5%) and 2 days (55.5 ± 5.5%) HRT due to the fluctuations in COD and N/P mass ratio of the periodic wastewater. COD and organic carbon were removed efficiently and a rapidly settleable MAAS with a sludge volume index (SVI_10) of less than 117 mL g(-1) was observed at all HRTs. The anaerobic digestion of the untreated MAAS showed a higher biogas yield of 349 ± 10 mL g VS(-1) with 2 days HRT due to a low solids retention time (SRT). Thermal pretreatment of the MAAS (120 °C, 120 min) did not show any improvement with biogas production at 6 days (269 ± 3 (untreated) and 266 ± 16 (treated) mL gVS(-1)), 4 days (258 ± 11(untreated) and 263 ± 10 (treated) mL gVS(-1)) and 2 days (308 ± 19 mL (treated) gVS(-1)) HRT. Hence, the biogas potential tests showed that the untreated MAAS was a feasible substrate for biogas production. Results from this proof of concept support the application of MAAS in wastewater treatment for Swedish conditions to reduce aeration, precipitation chemicals and CO2 emissions.
通过研究半连续光生物反应器的水力停留时间 (HRT)，研究了将微藻和活性污泥 (MAAS) 工艺集成到城市污水处理厂并从回收的 MAAS 中生产沼气。在 6 天和 4 天 HRT 时，实现了最大总氮 (TN) 去除效率 (RE) 分别为 81.5 ± 5.1%和 64.6 ± 16.2%。由于周期性废水中 COD 和 N/P 质量比的波动，在 6 天 HRT 时，总磷 (TP) 的 RE 略有增加（80 ± 12%），并在 4 天（56 ± 5%）和 2 天（55.5 ± 5.5%）HRT 时稳定下来。COD 和有机碳被有效地去除，并且在所有 HRT 下观察到具有小于 117 mL g(-1) 的污泥体积指数 (SVI_10) 的快速沉降 MAAS。未经处理的 MAAS 的厌氧消化由于低固体停留时间 (SRT)，在 2 天 HRT 时显示出较高的沼气产量 349 ± 10 mL g VS(-1)。MAAS 的热预处理（120°C，120 分钟）在 6 天（269 ± 3（未处理）和 266 ± 16（处理）mL gVS(-1)）、4 天（258 ± 11（未处理）和 263 ± 10（处理）mL gVS(-1)）和 2 天（308 ± 19 mL（处理）gVS(-1)）HRT 时，没有显示出任何提高沼气产量的效果。因此，沼气潜力测试表明，未经处理的 MAAS 是一种可行的沼气生产底物。这一概念验证的结果支持将 MAAS 应用于瑞典条件下的污水处理厂，以减少曝气、沉淀化学品和 CO2 排放。
