The Tongaat WWTW is home to the Latrine Dehydration and Pasteurisation (LaDePa) machine to process sludge from Ventilated Improved Pit Latrines (VIPs) to produce pellets. The machine was developed by eThekwini Water and Sanitation in conjunction with their technology partner Particle Separation Systems (PSS). The machine won the IWA development award in 2011.
Capacity 2 500 kg/day at 70% solids (8 h/d)
Services population of 62 000 (8 h/d, 365 d/y)
Diesel consumption 100 l/d
i.e. 1 l diesel /25 kg dried sludge (70% solids)
0,6 l diesel/person/annum
LaDePa is a machine that provides a containerised method of producing a nutrient rich soil conditioner that is workable and improves sustainability on a number of fronts, by removing the detritus, and pasteurising and drying the sludge to beyond the sticky phase. Due to its use of low technology, LaDePa relates well to the social environment where pit latrines are usually encountered in the developing world urban areas as it provides both business and work opportunities for the poorly skilled.
Further LaDePa machines are being commissioned for use at other Wastewater Treatment Works within eThekwini.
The PRG is home to two laboratory scale LaDePa machines which are used to provide research support to EWS in terms of optimisation of the process.