Institute of Sustainable Processes, Dr. Mergelina, s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina. s/n, 47011 Valladolid, Spain.
Institute of Sustainable Processes, Dr. Mergelina, s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina. s/n, 47011 Valladolid, Spain.
Water Res. 2024 Jan 1;248:120834. doi: 10.1016/j.watres.2023.120834. Epub 2023 Nov 4.
Anaerobic and microalgae-based technologies for municipal wastewater treatment have emerged as sustainable alternatives to activated sludge systems. However, viruses are a major sanitary concern for reuse applications of liquid and solid byproducts from these technologies. To assess their capacity to reduce viruses during secondary wastewater treatment, enveloped Phi6 and nonenveloped MS2 bacteriophages, typically used as surrogates of several types of wastewater viruses, were spiked into batch bioreactors treating synthetic municipal wastewater (SMWW). The decay of Phi6 and MS2 in anaerobic and microalgae-based reactors was compared with the decay in activated sludge batch reactors for 96 h (Phi6) and 144 h (MS2). In each reactor, bacteriophages in the soluble and solids fractions were titered, allowing the assessment of virus partitioning to biomass over time. Moreover, the influence of abiotic conditions such as agitation, oxygen absence and light excess in activated sludge, anaerobic and microalgae reactors, respectively, was assessed using dedicated SMWW control reactors. All technologies showed Phi6 and MS2 reductions. Phi6 was reduced in at least 4.7 to 6.5 log units, with 0 h concentrations ranging from 5.0 to 6.5 log PFU mL. Similarly, reductions achieved for MS2 were of at least 3.9 to 7.2 log units, from starting concentrations of 8.0 to 8.6 log PFU mL. Log-logistic models adjusted to bacteriophages' decay indicated T values in activated sludge and microalgae reactors of 2.2 and 7.9 h for Phi6 and of 1.0 and 11.5 h for MS2, respectively, all within typical hydraulic retention times (HRT) of full-scale operation. In the case of the microalgae technology, T values for Phi6 and MS2 of 12.7 h and 13.6 h were also lower than typical operating HRTs (2-10 d), while activated sludge and anaerobic treatment achieved less than 99 % of Phi6 and 50 % of MS2 inactivation within 12 h of typical HRT, respectively. Thus, the microalgae-based treatment exhibited a higher potential to reduce the disinfection requirements of treated wastewater.
厌氧和微藻基技术已成为活性污泥系统的可持续替代方法，用于处理城市废水。然而，病毒是这些技术产生的液体和固体副产物再利用的主要卫生关注点。为了评估它们在二级废水处理过程中减少病毒的能力，将包膜的 Phi6 和非包膜的 MS2 噬菌体作为几种废水病毒的替代物，加入到处理合成城市废水（SMWW）的批量生物反应器中。比较了厌氧和微藻基反应器中 Phi6 和 MS2 的衰减情况，与活性污泥批量反应器中 96 小时（Phi6）和 144 小时（MS2）的衰减情况进行了比较。在每个反应器中，测定了可溶部分和固体部分的噬菌体效价，从而可以评估随时间推移病毒与生物量的分配情况。此外，还使用专门的 SMWW 对照反应器评估了搅拌、缺氧和光照过量等非生物条件对活性污泥、厌氧和微藻反应器的影响。所有技术都显示出 Phi6 和 MS2 的减少。Phi6 的减少至少为 4.7 到 6.5 个对数单位，起始浓度范围为 5.0 到 6.5 log PFU mL。同样，MS2 的减少至少为 3.9 到 7.2 个对数单位，起始浓度为 8.0 到 8.6 log PFU mL。调整为噬菌体衰减的对数逻辑模型表明，在活性污泥和微藻反应器中，Phi6 的 T 值分别为 2.2 和 7.9 小时，MS2 的 T 值分别为 1.0 和 11.5 小时，均在全规模运行的典型水力停留时间（HRT）范围内。就微藻技术而言，Phi6 和 MS2 的 T 值分别为 12.7 小时和 13.6 小时，也低于典型的操作 HRT（2-10 天），而活性污泥和厌氧处理在典型 HRT 为 12 小时内，对 Phi6 的灭活率均低于 99%，对 MS2 的灭活率则低于 50%。因此，基于微藻的处理方法具有更高的潜力来降低处理后废水的消毒要求。
