Zeolite for Treatment of Distillery Wastewater in Fluidized Bed Systems

Abstract

AbstractDistillery wastewater is among the most polluting industrial effluent because it contains high organic load and significant amount of inorganic pollutants such as phosphates, sulphates, nitrates, chloride, calcium and potassium. Normally biological treatment is applied as the initial treatment step for the degradation of the biodegradable organic compounds. This is complemented by integrating with other treatment methods downstream such as chemical oxidation and physico-chemical processes for further removal of inorganic pollutants and biorecalcitrant organic compounds. Zeolite has favourable adsorption capacity and can be beneficial in improving the performance of integrated biological, chemical and physico-chemical process used in treating distillery wastewater. This work gives an elaborate review on the application of zeolite as a biomass support material in anaerobic digestion and as a catalyst support in photocatalytic treatment of distillery wastewater in fluidized bed reactors. An increase in biomass retention time of 8.5-folds and a low biomass detachment rate of 0.038 d−1 has been reported with organic load reduction of above 90% when zeolite is used in anaerobic digesters. Zeolite in anaerobic digester favours the growth of methanogens in the order Methanococcaceae, Methanosarcina and Methanosaeta, respectively. Further to this, factors such as catalyst-to-zeolite ratio and terminal velocity of zeolite particles are significant in the performance of a photocatalytic reactor. This work provides significant information on the use of zeolite to enhance biological and advanced chemical oxidation processes as an integrated approach for the treatment of distillery wastewater.KeywordsZeoliteDistillery wastewaterAdsorptionAnaerobic digestionAdvanced oxidation processes