Electrochemical disinfection of repeatedly recycled blackwater in a free-standing, additive-free toilet.

Journal Article (Journal Article)

Decentralized, energy-efficient waste water treatment technologies enabling water reuse are needed to sustainably address sanitation needs in water- and energy-scarce environments. Here, we describe the effects of repeated recycling of disinfected blackwater (as flush liquid) on the energy required to achieve full disinfection with an electrochemical process in a prototype toilet system. The recycled liquid rapidly reached a steady state with total solids reliably ranging between 0.50 and 0.65% and conductivity between 20 and 23 mS/cm through many flush cycles over 15 weeks. The increase in accumulated solids was associated with increased energy demand and wide variation in the free chlorine contact time required to achieve complete disinfection. Further studies on the system at steady state revealed that running at higher voltage modestly improves energy efficiency, and established running parameters that reliably achieve disinfection at fixed run times. These results will guide prototype testing in the field.

Full Text

Duke Authors

Cited Authors

  • Hawkins, BT; Sellgren, KL; Klem, EJD; Piascik, JR; Stoner, BR

Published Date

  • November 2017

Published In

Volume / Issue

  • 31 / 4

Start / End Page

  • 545 - 551

PubMed ID

  • 29242713

Pubmed Central ID

  • PMC5724497

Electronic International Standard Serial Number (EISSN)

  • 1747-6593

International Standard Serial Number (ISSN)

  • 1747-6585

Digital Object Identifier (DOI)

  • 10.1111/wej.12277


  • eng