Sanitation
4. Disposal or reuse by aircraft and catering, and the remaining volume is produced by other aviation-related businesses. The on-site wastewater treatment plant biologically purifies water to a quality fit for discharge into local waterways. 7
Safely treated poo can be used for energy generation or as fertilizer in food production.
Using safely treated wastewater and waste byproducts in agriculture and other sectors is increasingly considered a method of combining water and nutrient recycling, increasing household food security and improving nutrition for poor households. The growing interest in wastewater use is driven by scarcity of water and nutrients. However, care is needed to mitigate the health and environmental risks.
CASE STUDIES
Biologically purifying wastewater before discharging. The effluent volume from Schiphol Airport, Amsterdam, is comparable to that of a small city with a population of 45,000. About half of the wastewater originates from passengers and businesses at the airport, 25 % is discharged
Decentralized excreta management and local greywater reuse in a peri-urban community: El Alto, Bolivia. The systems installed by the project collect and treat urine and faeces separately, for resource recovery and agricultural reuse. Faeces is composted with worms( vermicomposting), while urine is treated by storage. Greywater from basins and showers is channelled to small constructed wetlands in the household’ s garden, with ornamental and edible plants. Testing found that both water and excreta products were safe to reuse, including for food production. The excreta-derived fertilizers( vermicompost and treated urine) have been found to be even more nutrient-rich than organic fertilizers commonly used in the region( such as cow manure), as evidence by both nutrient testing and crop yields. Potato yields from plants fertilized with human vermicompost and urine were double those of plants fertilized with cow manure. The household systems installed by the project include urine-diverting dry toilets, to minimize water use. The UDDTs have a single vault, in which faeces is collected in 100-litre plastic containers and urine in 20-litre jerry cans. The containers are collected using pickup trucks, and transported to the common treatment plant. Faecal matter is vermicomposted for eight to nine months using red Californian earthworms. 8
Use of wastewater in farming. It is estimated that more than 40,000-60,000 km 2 of land is irrigated with inadequately-treated wastewater or polluted water,
7 UN-Water: World Water Development Report 2017:‘ Wastewater: An untapped resource’: http:// www. unwater. org / publications / publications-detail / en / c / 853650 /
8 Extract from UNEP and SEI( 2016):‘ Sanitation, Wastewater Management and Sustainability’: https:// www. sei-international. org / mediamanager / documents / Publications / SanitationWastewater & Sustainability-Chapter9-Case-studies. pdf
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