Groundwater is a valuable natural resource for various human activities (Prasad and Narayana, 2004). Natural contaminants such as fluoride, nitrate, and chloride salts are increasing in ground water of Rajasthan making it unfit for drinking and posing risk to health. Apart from the problem of water shortage, the huge amount of wastewaters discharged in the environment by the ever-growing industrial activities of the last century, has raised serious environmental concerns about water pollution. In light of this, the recycle of properly treated industrial effluents at the “end of pipe” would be extremely desired. A great number of industries such as textile, paper and pulp, printing, pharmaceuticals consume large volumes of water and organic based chemicals (Buitron et al., 2004; Mohan et al., 2007). iron-steel, petroleum, pesticide, paint, solvent Textiles are among the basic needs of human being. These industries therefore have great economic significance by virtue of its contribution to overall industrial output and employment generation. With the increased demand for textile products, the textile industry and its wastewaters have been increasing proportionally, making it one of the main sources of severe pollution problems worldwide (Enayatzamir et al., 2010). Textile industry is a water intensive industry, requiring large volumes of water at various steps (Porter et al., 1990; Sharma et al., 1999) The volume of waste water released from them is large and of highly polluting nature. Textile wastewaters display a great chemical Introductoin complexity and variability in terms of quantities and pollution load, type of dyes, pH, and temperature (Hai et al., 2007). Waste water generated by different production steps of a textile mill have high pH, temperature, detergents, oil, suspended and dissolved solids, dispersants, leveling agents, toxic and non-biodegradable matter, color and alkalinity (Kumar et al., 2007). Effluents from these industries also contain undesirable quantities of pollutants showing a vast difference in composition, molecular weight, toxicity etc. and need to be treated (Aksu, 2005). Important pollutants in textile effluent are mainly recalcitrant organics, color, toxicants and surfactants, chlorinated compounds (AOX). The textile wastewaters are characterized by extreme fluctuations in many parameters such as chemical oxygen demand (COD), biochemical oxygen demand (BOD), pH, colour and salinity (Talarposhti et al., 2001). (Table 1.1) describes the composition of waste from a cotton textile mill. Table 1.1:
Further reading PhD theisis Dr Nidhi Joshi