(395ax) A Review On Adsorption Process for the Removal of Dyes From Textile Industry Effluent

There is a constant threat to the environment in terms of the pollution which is enhancing day by day. The impact of the pollution in the atmosphere, lithosphere and hydrosphere cannot be ignored. A lot of man made activities such as domestic, industrial, agriculture, shipping, radio-active, aquaculture waste activities are developing the negative impact on the water body by enhancing the contaminants present in the water. Textile industries are one of the type which are being counted as the top polluting industry. There are a number of harmful dyes which are present in the effluents from the textile industries and should not be discharged directly to the water body. These effluents are required to be treated for the removal of all the harmful dyes available in it before discharging it to the outer water body.

There are a number of processes available for the removal of textile dyes from the effluents such as such as trickling filtration, activated sludge process, oxidation ditch, oxidation pond, electrolytic precipitation & foam fractionation, membrane separation, ion exchange method, adsorption, etc. These processes can be further characterized into primary, secondary and tertiary category on the basis of the severity and effectiveness of the process. The processes other than adsorption are effective but are non co-operative in one or the other situation. Some are not effective at higher temperature, while others are not suitable at low temperature. Some processes are effective in cold conditions while others are more effective in hot environments. Adsorption is proven to be an efficient and cost effective method for the harmful dye removal. Adsorption is the only effective process which can work in a vast range of dye concentration. There are various adsorbents available for the dye removal such as fly ash, activated neem bark, china clay, silica, peat, etc. There be a requirement of developing a low cost adsorbent which will help in making the adsorption process more economical.