Field testing of a prototype mechanical dry toilet flush

Abstract

A prototype of a non-fluid based mechanical toilet flush was tested in a semi-public, institutional setting and in selected peri-urban households in eThekwini municipality, Republic of South Africa. The mechanism's functionality and users' perception of the flush were assessed. User perception varied depending on background: Users accustomed to porcelain water flush toilets were open to, yet reserved about the idea of using a waterless flush in their homes. Those who commonly use Urine Diversion Dehydration Toilets were far more receptive. The user-centred field trials were complemented by a controlled laboratory experiment, using synthetic urine, -faeces, and -menstrual blood, to systematically assess the efficiency of three swipe materials to clean the rotating bowl of the flush. A silicone rubber with oil-bleed-effect was found to be the best performing material for the swipe. Lubrication of the bowl prior to use further reduced fouling. A mechanical waterless flush that does not require consumables, like plastic wrappers, is a novelty and could – implemented in existing dry toilet systems – improve acceptance and thus the success of waterless sanitation.

Measurement and Modelling of Moisture Sorption Isotherm and Heat of Sorption of Fresh Feces

“…However, it has also contended that this practice could hinder aerobic biodegradation mechanisms in pit latrines [40]. Furthermore, in general, there is a growing recognition of declining freshwater availability at the global and local scales and, as such, waterborne sanitation systems are potentially advantageous in all contexts: low-, middle-, and high-income countries [41,42]. Additionally, the advantages of drying in fecal sludge management include increased pathogen inactivation [43] and the reduction of costs related to transport and treatment of fecal sludge [18].…”

Planning and communicating prototype tests for the Nano Membrane Toilet: A critical review and proposed visual tool

“…At the moment, all sub-products which the NMT comprises are in an iterative phase of building and testing prototypes. The front end has been re-designed as result of field tests involving target users of the NMT (Hennigs et al, 2019). Prototypes of the dryer and combustor (Jurado et al, 2018) have been tested in the lab in several iterations.…”

“…Instead, prototypes of components were developed and tested by the teams working on these components. In the case of the front end, a prototype was developed by one team and then tested by another (Hennigs et al, 2019). It could therefore be possible that the prototype tests to date could have been conducted more effectively had they been planned in a more coordinated manner.…”

“…We have identified three distinct types of prototype tests conducted so far, namely user tests, laboratory tests, and field tests. These types of tests can coincide and overlap: just for one generation of a front-end prototype, Hennigs et al (2019) conducted user surveys and interviews (user tests), photography and image analysis (laboratory tests), and field tests on the material choice of a rubber swipe and the long-term robustness of the prototype (field tests). A fourth type of tests are international standard tests.…”

Sensor-Array Optimization Based on Time-Series Data Analytics for Sanitation-Related Malodor Detection

“…A conventional sewerage infrastructure is prohibitively expensive to build in densely populated emerging countries, therefore novel approaches for decentralized onsite waste treatment are needed. Spearheaded by the Reinvent the Toilet Initiative sponsored by the Bill & Melinda Gates Foundation, transformative sanitation technologies are being developed by several groups [2], [3], including at Duke University [4]- [7].…”