Greywater Management in Low and Middle-Income Countries - SSWM

As explained earlier, ponds are not recommended as primary treatment of
greywater for households or neighbourhoods due to mosquito breeding and bad odour.
Ponds may be considered for larger scale applications (e.g. for treating greywater
maintenance of the system can be performed by skilled staff. Mara (2003) provides
good guidance on how to design, operate and maintain pond systems for treatment
of domestic wastewater in low and middle-income countries.
Currently, polishing ponds are mainly used in household or neighbourhood
greywater management systems after a chain of treatment comprising primary and
Costa Rica). Polishing ponds can be located quite close to
residential areas provided they are well-designed and implemented.
A pond system for household greywater treatment
was implemented in Skåne, Sweden. The system
consists of a series of ponds with an impermeable
bottom and permeable shore zones, porous enough
for water to pass through. The shore zone between
zone until it is taken out from the reception well with
a small wind pump and continually pumped back to
the inlet tank. The water is thus recycled several times
through the system, thereby increasing the system’s
for domestic (non-potable) purposes.
Compact, commercially available in-house greywater treatment systems are
increasingly applied. The systems sold comprise rotating biological contactors and
osmosis. These systems are technically complex, expensive (compared to lowtech
systems) and require skilled labour to install and maintain. Given the limited
experience with such systems, they cannot be recommended yet for application
in low and middle-income countries. An overview of compact greywater treatment
systems available on the German market is presented by the German Association
Fachvereinigung Betriebs- und Regenwassernutzung (see www.fbr.de/publikation/
marktuebersicht_gw.pdf). Activated sludge systems, widely applied for municipal
wastewater treatment in Western countries, have hardly been used for greywater
likely to be low on account of the low nutrient content in greywater.
Greywater Management in Low and Middle-Income Countries
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