Chemical composition, nutrient-balancing and biological treatment of hand washing greywater

WATER RESEARCH

卷:144

Article

Ziemba, Christopher^1,2  Larive, Odile^1,3  Reynaert, Eva^1,2  Morgenroth, Eberhard^1,2 

[1] Eawag Swiss Fed Inst Aquat Sci & Technol, CH-8600 Dubendorf, Switzerland

[2] Swiss Fed Inst Technol, Inst Environm Engn, CH-8093 Zurich, Switzerland

[3] EPFL Lausanne, Environm Chem Lab, CH-1015 Lausanne, Switzerland

关键词: Soap;    Nitrogen;    Micro-nutrients;    Biologically activated membrane bioreactor (BAMBi);    Gravity-driven membrane (GDM);    Handwashing;   

DOI  :  10.1016/j.watres.2018.07.005

来源: Elsevier

【 摘 要 】

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 similar to 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(c)/L vs. 3.5 mg(c)/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. (C) 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license.

【 授权许可】

Free