CaltechAUTHORS
  A Caltech Library Service

Membrane-separated electrochemical latrine wastewater treatment

Yang, Yang and Lin, Lin and Katebian Tse, Leda and Dong, Heng and Yu, Shaokun and Hoffmann, Michael R. (2019) Membrane-separated electrochemical latrine wastewater treatment. Environmental Science: Water Research & Technology, 5 (1). pp. 51-59. ISSN 2053-1400. http://resolver.caltech.edu/CaltechAUTHORS:20181120-095849847

[img] PDF - Supplemental Material
See Usage Policy.

982Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20181120-095849847

Abstract

Electrolysis is demonstrated to be useful for onsite latrine wastewater treatment. Improved wastewater treatment efficiencies are achieved through the use of a combination of cation and anion exchange membranes (CEM/AEM) in electrochemical reactors. Compared to a membrane-free electrolysis cell, the separation of anodic and cathodic chambers using a CEM separator is shown to reduce energy consumption by 51% for COD removal and 87% for NH_4+ removal. Furthermore, 51% of the initial [NH_4+]_0 is recovered via electrodialysis. CEM-separated electrolysis is shown to produce 39% less ClO_3− and 92% less chlorinated organic by-products than in a membrane-free reactor. Helminth (Ascaris suum) eggs, which yield parasitic worms, are very resistant to conventional disinfection methods. Membrane-free electrolysis only inactivates 15% of the dosed helminth eggs (100 eggs per mL). In CEM-separated electrolysis, a combination of low pH and in situ chlorine production in the anodic chamber results in 85% inactivation of helminth eggs. In addition, H_2, which is produced in the cathodic chamber of the CEM-separated reactor, is directly converted to electricity using a hydrogen–air fuel cell. The hydrogen energy produced during electrolysis is estimated to reduce the overall energy cost of operation by 20%. Recovery of 85% of the initial [PO_4^3−]_0 and pH neutralization are achieved by treating the acidic effluent of a CEM-separated electrolysis cell in an AEM-separated electrolysis cell. A one-month continuous operation demonstrates the potential of using both the CEM and AEM during electrolysis to achieve more efficient wastewater treatment while, at the same time, recovering NH_4+ and PO_4^3−, for eventual use as agricultural fertilizers.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1039/c8ew00698aDOIArticle
http://www.rsc.org/suppdata/c8/ew/c8ew00698a/c8ew00698a1.pdfPublisherSupplementary Information
ORCID:
AuthorORCID
Yang, Yang0000-0003-3767-8029
Hoffmann, Michael R.0000-0002-0432-6564
Additional Information:© 2018 The Royal Society of Chemistry. The article was received on 07 Oct 2018, accepted on 08 Nov 2018 and first published on 20 Nov 2018. This research was supported by the Bill and Melinda Gates Foundation (BMGF RTTC Grants OPP1111246 and OPP1149755). There are no conflicts to declare.
Funders:
Funding AgencyGrant Number
Bill and Melinda Gates FoundationOPP1111246
Bill and Melinda Gates FoundationOPP1149755
Record Number:CaltechAUTHORS:20181120-095849847
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20181120-095849847
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:91066
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:20 Nov 2018 18:28
Last Modified:05 Apr 2019 21:56

Repository Staff Only: item control page