Feature: Recycling household wastewater
Los Banos, Laguna (5 February) -- Each member of an urban household uses at least 100 liters of water for drinking, washing and bathing. Of this volume, about 90 percent is disposed off as wastewater ("grey water") into the environment.
The efficient reuse or recycling of "grey water" can significantly reduce water consumption, produce food like vegetable and fish, and minimize environmental pollution.
To reduce the use of potable water at the household, the flushing of toilets with laundry wastewater can be done. One toilet flush requires 20-40 liters of water. Laundry wastewater applied at 1.28 liters per cubic meter per day was found to be a good liquid fertilizer for tilapia production (0.87 kg/m2 per day) in a backyard pond by Aquatic Biosystems (ABS), a private R&D firm, monitored by the PCAMRD-DOST.
In studies conducted by the ABS on the use of human urine and kitchen wastewater for vegetable production, results showed that fertilization of petchay (Brassica compensis) with 10% tap water gave a higher yield compared to that of the control (tap water only). The use of kitchen wastewater only and a combination of kitchen wastewater (90%) and human urine (10%) had a similar and better yield that ha of the control respectively, for sweet potato vegetation after a month of culture in pots.
Household or domestic wastewater is a major pollutant of freshwater bodies (lakes and rivers) in areas of the country that lack adequate wastewater treatment facilities. The reuse or recycling of "grey water" will not only minimize aquatic pollution but also enhance food production and reduce the consumption of potable water in households. (RD Guerrero III) [top]