Volume No. 6 Issue No.: 3 Page No.: 575-581 Jan-Mar 2012

 

OZONE-OXIDATION ASSOCIATED WITH NANOFILTRATION AS A GROUNDBREAKING AND EFFICIENT PROCEDURE IN TREATING DYE EFFLUENTS FROM TEXTILE INDUSTRIES WITH THE HELP OF A BUBBLE COLUMN REACTOR : AN INSIGHTFUL AND FARSIGHTED REVIEW

 

Sukanchan Palit

Department of Chemical Engineering, Rural Engineering College, Bhalki, Bidar, Karnataka (INDIA)

 

Received on : September 20, 2011

 

ABSTRACT

 

Our review will describe and delineate in depth the difficulties and hurdles in these scientific processes. Persistent and recalcitrant chemicals in wastewater cannot be destroyed by primary and secondary wastewater treatments. So the urgent need of tertiary treatment processes such as ozonation or ozone-oxidation . Primary wastewater treatment encompasses flocculation and coagulation while secondary wastewater treatment comprises activated sludge process . Tertiary wastewater treatment process encompasses ozonation, membrane filtration and adsorption. The importance and vision of ozonation as an advanced oxidation process is due to the fact that ozonation process is environmental friendly . Our review and overview will delineate the research work done in the area of ozonation, primarily the ozonation of dye effluent in wastewater from textile industries and also nanofiltration of dyes . The ozone-oxidation method is known to be effective for decomposing organic chemicals containing carbon-carbon double bonds, olefenic double bonds, acetylenic triple bonds, aromatic compounds, phenols, polycyclic aromatics, heterocyclics, carbon-nitrogen double bonds, carbon-hydrogen bonds, sili-con- hydrogen and carbon-metal bonds. Some visionary and exemplary work has been done in the ozonation of reactive dyes in the wastewater effluent of textile industries. Synthetic dyes released to the environment in the form of effluents by textile ,leather and printing industries cause severe ecological and environmental damages. These dyes include several structural varieties of dyes such as acidic, reactive, basic ,azo , diazo, anthraquinone based and metal complex dyes. Due to the inhibitory nature of many compounds for biological oxidation, the need for pretreatment by Advanced Oxidation Process(AOP) has become essential. One of the AOP processes is ozonation or ozone- oxidation , which is versatile, wilfull and environmentally powerful. Ozonation of water is a well known visionary technology and the strong oxidative properties of O3 and its ability to effectively oxidise many organic compounds in aqueous solution have been well documented and well researched . In recent years, ozonation is emerging as a potential process for color removal of dyes, since the chromophore groups with conjugated double bonds, which are responsible for colour can be broken down by ozone either directly or indirectly forming smaller molecules, thereby decreasing the colour of effluents. Due to its high electrochemical potential (2.08 V) , O3 is the strongest oxidant available and applicable as compared to H2 O2 (1.78 V) and can react with several classes of compounds through direct or indirect reaction. Nanofiltration is very effective and the next generation science and technology. Our aim, objective and vision is to delineate and describe the major research work done in the field of ozonation in order to project it as a powerful advanced oxidation process and also describe significant work done in the field of nanofiltration of dyes. The vision of a scientist is wide and unparalled. Our research hardship will lead us to new frontiers of science and technology. Nanofiltration and ozone-oxidation will open up new vistas in the areas of environmental science and technology.

 

Keywords : Persistent, Ozonation, Textile, Dyes, Oxidation, Tertiary Treatment, Primary treatment, Azo, Anthraquinone, Nanofiltration

 

 

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