Reuse of Industrial Effluent Water - Prospect and Opportunities in Agricultural Perspectives

Abstract

Fresh water is a retreating resource worldwide. To tide over the crisis, limiting its allocation is vivid in every water use sectors. Irrigation occupies a major share of available fresh water to provide food, feed, fodder, fuel and maintaining green space. Only 40% of the total cultivated area is under irrigation and rests are rain-fed. Irrigation water can meet timely water requirement of crop and assure production even during water stress situation. Therefore with growing crisis of freshwater there is a need to provide an alternate source, which could support and sustain production in proportion with growing demand of burgeoning population. Water quality varies depending on purpose of water – use in various sectors. Agriculture is the major user of water and can accept marginal quality water without apparent loss of productivity or degrading soil and water qualities. A large number of effluent waters are coming out from various industries that could be utilized as per their suitability for agricultural perspectives, which are otherwise reported to defile natural resources and degrading the health of natural ecosystem. Reuse of wastewater for irrigating crops is in vogue since centuries. Due to rapid development and unparallel growth in every sector more and more number of farmers depend on its use especially in developing countries. Most of the effluent reuse practices are not reported to escape the complexities associated with effluent use norms. However the study would help to understand the nature of industrial effluent waters, assess the quality of effluent, locate the applicability of effluent and could promote the use of certain kind of effluent during fresh water crisis for irrigating crops. This has enhanced the scope of using effluent more judiciously in different circumstances to countenance fresh water shortage in agriculture. Keeping this in view a variety of effluents generating from all the major and medium level industries were collected, characterized and investigated for use in irrigation. This bulletin provides comprehensive information about various characters of industrial effluents, merits and demerits and probability of their use in crop production. It has unearthed agricultural potential of certain effluent and their probable use as irrigation source during fresh water scarcity. On consideration of relevant soil characteristics and prevalent land uses, the effort also revealed that how and in what contexts even a chemically sound industrial effluent water could be used for irrigating crops. Following this the paper mill and distillery spent wash had been used to grow crops at varied situations. Use of them for irrigation in specific soil type appeared to improve crop yield, nutrient uptakes and soil fertility attributes. Evaluation of effluent water from diverse perspectives thus helps to understand their potential and consequently indicate the place of use of individual effluent in specific circumstances. In effluent use practice, periodical regulation of effluent water quality is prerequisite to ensure quality of produce and restore purity of the environment. Selection of effluent quality indicators has thus revealed the state–of–the art to analyze, scrutinize and condense the characteristics to indicating properties. Estimation of these indicators only could reflect the character of effluent when use for irrigation and could save energy, cost and time to a great extent. It also indicates about the necessary measures to be undertaken to secure soil and crop qualities as well. Development of this environs – friendly package thus provides effluent water reuse techniques and information for promoting its reasonable use in farming.