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Highlights Two field tests in Switzerland and one in South Africa. Short-term stabilization and evaporation resulted in 98% nitrogen recovery. During long-term field tests nitrogen recovery decreased to 20%. Evaporation rates were governed by the relative humidity of the ambient air. Low resource consumption resulted in costs as low as 0.05 EUR pers −1 d −1 .

In the informal settlements of eThekwini municipality, South Africa, laundry activities are typically undertaken at local standpipes and washbasins of community ablution blocks (CABs), and are characterised by high levels of water consumption and greywater production. Since greywater contains a high pollution load, including sodium tripolyphosphate, it poses a significant environmental and public health risk. The overall objective of this study was to develop and test a water-efficient laundry system designed for informal settlements. Initial fieldwork at a standpipe and CAB in eThekwini municipality showed respectively 56 and 58% of users were in favour of a water-efficient laundry system based upon sharing washing water. Subsequent laboratory work assessed crosscurrent and countercurrent cascades for washing clothes. Under optimised washing conditions at a detergent dose of 5 g/kg water, specific water consumption of 5 kg water/kg clothes and three rinsing phases it was determined that the countercurrent method wasted 33% less water. Thus the countercurrent cascade has great potential for minimising greywater production in South African informal settlements. Future work should concentrate on evaluating greywater production, detergent usage and social acceptability in the field