Evaluation of Greywater Treatment System by Aerobic Method in Planning Urban Ecology and Green Space Development

Contamination in sewage systems and dumping them in the environment is amongst the biggest concerns for the World Community for which some solutions have been proposed. In this paper, a greywater treatment system in a Shiraz residential building using the aerobic method was evaluated and 10 intake and exhaust samples were acquired under normal lab conditions. Sampling was done in approximately four-month period in 5-day intervals. The results revealed that output values for pH, Turbidity, COD, BOD5, Nitrate, Total Coliform, and Fecal Coliform were 6.88, 26.5, 111.6, 29.7, 5.65, 184.9 and 670.2 respectively. All the amounts are within the legal limits of Ministry of Health and Medical Education’s Article 5 of Code of Water Pollution. This technology is able to purify turbidity up to 99.11 percent, COD up to 93.92 percent, BOD5 up to 96.23 percent and nitrate up to 99.96 percent. Therefore, scientific and principled treatment of greywater can reduce more than 90% of pollutants in wastewater and set the level of pollution to the standard of use in agriculture and irrigation. The use of this valuable water source can be useful in the development of urban green space and the promotion of the urban ecosystem.