Effluent Quality Parameters for Safe use in Agriculture

Abstract

“When the well is dry, we know the worth of water.” Benjamin Franklin, (1706-1790), Poor Richard's Almanac, 1746 Fast depletion of groundwater reserves, coupled with severe water pollution, has put governments all over the world in a difficult position to provide sufficient fresh water for our daily use. Ismail Serageldin vice president of World Bank in 1995 predicted that “if the wars of this century were fought over oil, the wars of the next century will be fought for water”. Thus it signifies the role water is going to play in the current century we live in. At the same time, the need for sustained food production to feed the hungry mouths of the ever increasing population is apparent. In many arid and semi-arid countries since water is becoming increasingly scarce resource and planners are forced to consider alternate sources of water which might be used economically and effectively. The use of wastewater (WW) for crop irrigation as an alternative for effluent water disposal and for freshwater (FW) usage is common worldwide in countries in which water is scarce. Disposal of wastewater is also a problem of increasing importance throughout the world including India. Both the need to conserve fresh water and to safe and economically dispose of wastewater makes its use in agriculture a very feasible option. Furthermore, wastewater reuse may reduce fertilizer rates in addition to low cost source of irrigation water. In many parts of the world, treated municipal wastewater and raw sewage wastewater and even industrial wastewater has been successfully used for the irrigation of various crops (Asano and Tchobanoglous 1987, Adriel et al., 2007; Tak et al., 2010). It is well known that the enteric diseases, anaemia and gastrointestinal illnesses are high among sewage wastewater farmers. In addition, the consumers of vegetable crops which are eaten uncooked and grown without any treatment are also at risk. This chapter particularly envisages the review on the safe and quality parameters of wastewater for sustainable use in agriculture. The use of sewage effluents for agricultural irrigation is an old and popular practice in agriculture (Feigin et al., 1984). Irrigation with wastewater has been used for three purposes: i. complementary treatment method for wastewater (Bouwer & Chaney, 1974); ii. use of marginal water as an available water source for agriculture (Al-Jaloud et al., 1995; Tanji, 1997) – a sector demanding ~ 70% of the consumptive water use.