Quality of Sewage Water and Phytorid Technology for its Reuse in Agriculture

Abstract

Water requirement in India in the year 2025 is assessed at 1027 BCM as against the requirement of 525 BCM in the year 1990 showing an increase of 86 percent. Besides, India need to produce 380 MT of food grain per annum in 2025, against the present 242 MT, to feed 1.4 billion expected population under resource constraints. The scope for increase in production through horizontal expansion of area is negligible and due to competition from other mere paying sectors of economy, the fresh water availability is bound to decrease for agriculture. According to the estimates, wastewater generated through irrigation, water supply, industry and energy sectors is expected likely to be 556 BCM by 2025 in India (Gupta, 2003). Thus utilization of water resources is crucial to agricultural production for meeting the ever-increasing demand of irrigation water in agriculture. Since natural water resources are limited and a large gap exists between available water supply and the amount required for intensive cropping, appropriate use of wastewater of domestic origin can help in meeting a part of the increased demand of water. Wastewater reuse for agriculture presents not only a low cost appropriate disposal medium but also an opportunity to manage wastes with minimum adverse environmental effects, as the treatment requirements prior to land application are less rigid than those for disposal into water bodies. It has been observed that in states, such as Haryana, the NO3 concentration has exceeded the permissible limits (Maria 2003). Application of sewage, sludge and municipal wastewater on land has been practiced since time immemorial. The challenge is to utilize the physical, chemical, and biological properties of soils as an acceptor with minimum adverse effects on crops to be grown, soil characteristics and ground and surface water quality (Gupta et al.1998). Such practice of sewage irrigation continues for longer period, without knowing pollutant load, this may lead to chemical degradation of lands and possible entry of pollutants / toxicants in the food chain of people and animal consuming the farm produce of these lands Oswald (1989). In view of this, it is necessary to assess and monitor the sewage water and treated sewage water used for irrigation of the agricultural crops otherwise there will be health hazards