Abstract

Hossein Hassanpour Darvishi, Mohammad Manshouri and Hossein Aliabadi Farahani

The rapid population growth in many municipalities in the arid and semiarid of world continues to place increased demands on limited fresh water supplies. Many cities and districts are struggling to balance water use among municipal, industrial, agricultural, and recreational users. The population increase has not only increased the fresh water demand but also increased the volume of waste water generated. Treated or recycled waste water (RWW) appears to be the only water resource that is increasing as other sources are dwindling. Use of RWW for irrigating landscapes is often viewed as one of the approaches to maximize the existing water resources and stretch current urban water supplies (USEPA, 1992). Sewage, often untreated, is used to irrigate 10% of the world’s crops, according to the first ever global survey of waste water irrigation. This is a largely hidden practice and is outlawed in many countries. However, many farmers, especially those in urban areas, use sewage
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