Department of Civil and Environmental Engineering, University of Alberta, 7-263 Donadeo Innovation Centre for Engineering, Edmonton, Alberta, T6G 1H9, Canada.
Department of Civil and Environmental Engineering, University of Alberta, 7-263 Donadeo Innovation Centre for Engineering, Edmonton, Alberta, T6G 1H9, Canada.
J Hazard Mater. 2019 Mar 5;365:44-52. doi: 10.1016/j.jhazmat.2018.10.055. Epub 2018 Oct 25.
Source-diverted blackwater (toilet wastewater) contains most of the organic energy in domestic wastewater and can be treated anaerobically to maximize energy recovery. Blackwater collected from toilets of different water saving options (e.g., conventional, dual and vacuum toilets) represents different characteristics, but their digestibility has not been discussed. In the present study, blackwater collected from different toilet flushing systems were characterized and compared in terms of chemical composition, digestibility and microbial population development during biochemical methane potential (BMP) tests. Interestingly, the highest BMP (48%) was achieved for conventional/dual flush toilet (5-9 L water/flush) blackwaters, whereas vacuum toilet (0.5-1.2 L water/flush) blackwater BMP was only 34%. Elevated free ammonia (FA) concentration (>205 mg L) appeared to contribute to the reduced digestibility of high-water saving toilet (< 1.5 L water/flush) blackwaters. Methanogenesis was the major FA inhibition step in anaerobic digestion as evident by batch kinetics studies; where Methanosarcina methanogens predominate in all blackwater, but ammonia-tolerance methanogens Methanoculleus and Methanomicrobiales were also predominant in blackwater collected from vacuum toilets. This work underlines that overall measures of sustainability also need to consider blackwater characteristics when designing resource recovery based source-diverted sanitary treatment systems.
源分离黑水（厕所污水）含有家庭污水中大部分有机能量，可进行厌氧处理以实现最大能量回收。从不同节水选项（如常规、双冲和真空马桶）的马桶中收集的黑水具有不同的特性，但它们的可消化性尚未得到讨论。在本研究中，对来自不同马桶冲洗系统的黑水进行了特性描述，并在生化甲烷潜能（BMP）测试中就其化学组成、可消化性和微生物种群发展进行了比较。有趣的是，常规/双冲马桶（5-9 L 水/冲）黑水的 BMP 最高（48%），而真空马桶（0.5-1.2 L 水/冲）黑水的 BMP 仅为 34%。高游离氨（FA）浓度（>205 mg/L）似乎导致高节水马桶（<1.5 L 水/冲）黑水的可消化性降低。甲烷生成作用是厌氧消化中 FA 抑制的主要步骤，这从批处理动力学研究中显而易见；所有黑水中都以 Methanosarcina 产甲烷菌为主，但也以氨耐受产甲烷菌 Methanoculleus 和 Methanomicrobiales 为主，这些产甲烷菌来自真空马桶黑水。这项工作强调，在设计基于源分离的卫生处理系统以实现资源回收时，可持续性的整体措施还需要考虑黑水的特性。
