The investigation and designing of an onsite grey water treatment systems at Hazrat-e-Masoumeh University, Qom, IRAN

摘要

Limited water supplies remind the environmental ethics of recovery and reuse of limited resources. One of the interesting options in this context is Grey water. Grey water is wastewater originating from showers, baths, bathroom sinks, kitchen sinks and laundries. It does not include toilet or garbage wastes, or wastewater contaminated by soiled diapers. Despite the fact that it may include a complex mixture of organic matter, suspended solids, bacteria and common household chemicals, when used wisely and in a manner that is protective of public health and the environment, it can help preserve limited water supplies. Qom Province is located in the central part of Iran, at the Latitude and the Longitude of 34° 38' 24 N and 50° 52' 35 E respectively. The city of Qom is the 7th most populated city of Iran. With an altitude of 933 meters above the sea level and a location adjacent to two great deserts Qom has a very hot and dry weather. The salt lake (Daryacheh-ye Namak) in the east of the city has caused the ground to be usually arid and parched. Due to proximity to desert region, the climatic changes and the low value of precipitation, water resources are under pressure, and under such harsh conditions, water is very precious. The onsite wastewater treatment systems can reduce the water crisis. To this end the Hazrat-e-Masoumeh University was selected as a pilot to investigate the feasibility of reusing the produced grey water. Based on studies undertaken to propose a grey water treatment system, the Hazrat-e-Masoumeh University has recommended the application of trickling filters with suspended plastic media. In this method, waste particles (if existing) are first removed from the system by a 1cm mesh screen. Then the grey water is conducted to a buried septic tank and the resulting water is pumped to a trickling filter containing suspended plastic media and the sludge, amounting to thrice the discharge of the pumped water is returned to the septic tank. After passing through the tricklmg filter, water is led to the settling tank, where the produced sludge is settled. Finally a chlorination system is used to disinfect the treated effluent. It should be noted that the kitchen effluent needs to be pre-treated to remove fat and 4. Furthermore, this project is the first report of designing an onsite grey water treatment system in a university in Iran.