Eawag: Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; ETH Zürich, Institute of Environmental Engineering, 8093 Zürich, Switzerland.
Eawag: Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; EPFL Lausanne, Environmental Chemistry Laboratory, 1015 Lausanne, Switzerland.
Water Res. 2018 Nov 1;144:752-762. doi: 10.1016/j.watres.2018.07.005. Epub 2018 Jul 4.
On-site biological hand washing water treatment can improve global access to safe hand washing water, but requires a thorough understanding of the chemical composition of the water to be treated, and an effective treatment strategy. This study first presents a detailed characterization of the individual inputs to hand washing water. We demonstrate (i) that soap is likely the most significant input in hand washing water, representing ∼90% of mass loading, and (ii) that inputs to hand washing water have low concentrations of biologically-essential macro- and micro-nutrients (nitrogen, phosphorus, potassium, copper, zinc, molybdenum and cobalt) with respect to carbon, which may impair biological carbon removal. This study next formulates a recipe that recreates a representative composition of hand washing water and develops a procedure to identify and supplement nutrients in which this recipe is estimated to be deficient. Batch testing of the nutrient-supplemented hand washing water with an inoculum of planktonic bacteria demonstrated improved assimilable organic carbon removal (99% vs. 86% removal) and produced lower final dissolved organic carbon concentrations (1.7 mg/L vs. 3.5 mg/L) compared to realistic (nutrient-deficient) washing water. Supplementing nutrients did promote cell growth (50x higher final total cell count). Full-scale testing in a biologically activated membrane bioreactor (BAMBi) system treating 75 L/day of nutrient-supplemented hand washing water showed that long-term operation (100 days) can deliver effective carbon removal (95%) without detrimental fouling or other disruptions caused by cell growth. This work demonstrates that biological treatment in a BAMBi system, operated with appropriate nutrient-balancing offers an effective solution for decentralized treatment of light greywater.
现场生物洗手水的处理可以改善全球获得安全洗手水的机会，但需要彻底了解待处理水的化学成分，并采用有效的处理策略。本研究首先详细描述了洗手水的各个输入物。我们证明了(i)肥皂是洗手水中最主要的输入物，约占质量负荷的 90%，以及(ii)洗手水中的输入物中含有低浓度的生物必需的宏量和微量营养素（氮、磷、钾、铜、锌、钼和钴），相对于碳而言，这可能会损害生物碳去除。本研究接下来制定了一个配方，重现了洗手水的代表性组成，并开发了一种识别和补充营养物质的方法，该配方估计在这些营养物质中存在不足。用浮游细菌接种物对添加营养物质的洗手水进行批量测试，结果表明，可生物利用的有机碳去除率提高（99%对 86%的去除率），最终溶解有机碳浓度降低（1.7 mg/L 对 3.5 mg/L），与实际的（营养缺乏的）洗手水相比。补充营养物质确实促进了细胞生长（最终总细胞计数增加了 50 倍）。在处理 75 L/天添加营养物质的洗手水的生物激活膜生物反应器（BAMBi）系统中进行的全规模测试表明，长期运行（100 天）可以有效地去除碳（95%），而不会因细胞生长而导致有害的结垢或其他干扰。这项工作表明，在 BAMBi 系统中进行生物处理，并进行适当的营养平衡，为分散式处理轻度灰水提供了一种有效的解决方案。
