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Field testing of an onsite sanitation system on apartment building blackwater using biological treatment and electrochemical disinfection

Varigala, Siva Kumar and Hegarty-Craver, Meghan and Krishnaswamy, Srinivas and Madhavan, Prakash and Basil, Milan and Rosario, Praveen and Raj, Antony and Barani, Viswa and Cid, Clément A. and Grego, Sonia and Luettgen, Michael (2020) Field testing of an onsite sanitation system on apartment building blackwater using biological treatment and electrochemical disinfection. Environmental Science: Water Research & Technology, 6 (5). pp. 1400-1411. ISSN 2053-1400. doi:10.1039/c9ew01106d.

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The Closed Loop Advanced Sanitation System (CLASS) was designed to treat, disinfect, and recycle toilet blackwater from existing flush toilets in a multi-story apartment building. Two systems were tested at two unique sites in Coimbatore, India for a combined 7500+ treatment hours resulting in more than 180 000 L of treated water. The CLASS prototypes used a combination of biological pretreatment and electrochemical oxidation processes to produce treated water that nearly met the stringent requirements outlined in the standard ISO 30500. The nutrient and organic loading from the toilet blackwater was predominantly reduced by over 85–95% and 80–87%, respectively, through biological processes that were achieved using either a sequencing batch reactor (SBR, site A) or an anaerobic–aerobic biodigester (EcoSan, site B). Complete disinfection of E. coli with nil CFU per ml was achieved using electrochemical processes that also served to remove the remaining organic and nutrient loading to over 90–96%. The treated water was reused for flushing by the residents of the apartment building for 89 days.

Item Type:Article
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URLURL TypeDescription Information
Varigala, Siva Kumar0000-0002-6783-7652
Hegarty-Craver, Meghan0000-0002-0919-6906
Cid, Clément A.0000-0002-7293-035X
Grego, Sonia0000-0003-1734-2157
Luettgen, Michael0000-0001-8930-0381
Additional Information:© 2020 The Royal Society of Chemistry. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Submitted 13 Dec 2019; Accepted 24 Feb 2020; First published 16 Mar 2020. This work was supported by the Bill & Melinda Gates Foundation under contract service agreement ID 43951 (STeP project) and grants OPP1170650 (Kohler), OPP1111246 and OPP1192374 (California Institute of Technology). SKV, PM, MB, PR, AR, and VB were the field researchers supporting the operations and data collection activities; CAC, SKV, and ML conceived the design and validated it; MHC, SG, CAC, and SKV performed the data analysis; SK and CAC assisted in the writing of the manuscript. We gratefully acknowledge the PSG Institute of Medical Sciences and Research (IMSR), Coimbatore for supporting the test site installation and operation on their campus. We gratefully acknowledge the management of Serene Idigarai Private Limited for supporting the installation and operation in one of their residential apartment buildings in Coimbatore. We thank Dr. Sudha Ramalingam and the PSG IMSR Center for Molecular Medicine and Therapeutics for their contribution on sample analysis and logistical support. There are no conflicts to declare.
Funding AgencyGrant Number
Bill and Melinda Gates FoundationOPP1170650
Bill and Melinda Gates FoundationOPP1111246
Bill and Melinda Gates FoundationOPP1192374
Issue or Number:5
Record Number:CaltechAUTHORS:20200320-094911094
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Official Citation:Field testing of an onsite sanitation system on apartment building blackwater using biological treatment and electrochemical disinfection. Environ. Sci.: Water Res. Technol., 2020, 6, 1400-1411; doi: 10.1039/c9ew01106d
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:102021
Deposited By: Tony Diaz
Deposited On:20 Mar 2020 18:36
Last Modified:16 Nov 2021 18:08

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