Reinvent the Toilet Challenge – Round 1
Grant ID# 1037498: Data and design – mineralisation of sanitation wastes from community ablution blocks
June 2011 – September 2012
Partner Organisations: eThekwini Water and Sanitation; Envirosan; Hering SA
Project Description:
The Reinvent the Toilet Challenge (RTTC) project at the University of KwaZulu-Natal (UKZN) aimed to ground the research work in the real-world context of informal settlement community ablution blocks. The characterisation of human excreta samples from these settings provides the basis for producing the data necessary to design excreta-processing systems suitable for operation in these contexts.
A decision was made to separate excreta waste streams at source, to facilitate downstream processing. To achieve this, a new source-separation pedestal was developed and two prototype versions of it manufactured.
The concept design for a three-stage processing system for the drying and combustion of the faecal and non-faecal solids was developed and the first stage (extruder-separator) prototyped – see below.
TOILET PEDESTAL: THREE-STREAM SOURCE SEPARATION (A) DIVERSION OF USED HAND- WASHING WATER TO RINSE TOILET PEDESTAL (B) URINE SEPARATION SECTION (C) – (D) MECHANISM FOR CONTAMINATED WASHWATER DIVERSION
Theoretical models were developed for the handling and treatment of urine, faecal matter and washwater. In order to develop the prototype and the models, an extensive sampling and analyses programme was undertaken to generate data on faecal matter. However at the end of this Phase, the final design could not be manufactured.
The thought process behind the design is provided in the following schematic:
GENERAL PROCESS FLOW DIAGRAM OF THE TOILET SYSTEM
Main outcomes:
The main outcomes from Phase 1 highlighted the strengths of the UKZN team (through the PRG) and the importance of collaboration with EWS. This includes:
- Access to various on-site sanitation systems to obtain different excreta streams
- Sampling of these on-site systems
- Laboratory analysis to determine mechanical, chemical and biological properties of the various excreta streams
- Undertaking detailed investigations into the processing of segregated streams
Phase 2 of the project, therefore aims to build on the lessons learnt, knowledge, strengths and experience gained by the team during Phase I implementation.
Documents: