Fixed Bed Column Adsorption Studies of selected Phenols and Dyes using Low-cost adsorbents. A mini Review

Abstract

Consumption of water contaminated with dyes and phenolic compounds is detrimental to human and animal wellbeing even at permissible limits. Therefore, their decontamination from water is important for the safety of consumers. Conventional water treatment techniques such as ozonation, ion exchange among others are expensive and ineffective. Adsorption as an emerging technique has gained research interest because of its ease in design, environmentally friendly and availability of materials as adsorbents in large quantities. The application of various adsorbents have extensively been reported for decontamination of dyes and phenolic compounds in wastewater such as 4-chlorophenol, Metanil Yellow (MY) dye, Phenol, Methyl green dye, Bromothymol Blue dye, Crystal violet, Methylene blue and Direct Blue 71. It has also been reported that adsorption by column continuous processes are more efficient than batch as it can be used continuously under high effluent flow rates in many pollution control processes in an industrial set up. The fixed bed column adsorption data is analyzed at different column conditions of bed height, pH, particle size, concentration and flow rate using different kinetic models such as Bohart-Adams, Thomas, Yoon-Nelson, Clark, Bed depth service time and Wolborska models amongst others to determine the column performance. The present paper involves a mini review of dynamics of fixed-bed column studies for removal of selected dyes and phenolics from a synthetic media.