Adsorption Isotherm and Kinetics of Tannic Acid on to Carbonized Chrome Tanned Leather Solid Waste

Abstract

The disposal of chrome tanned leather shavings (CTLS) waste isa serious concern for the environment due to the presence ofchromium. In this study, an attempt has been made to prepareadsorbent from CTLS through carbonization process.Carbonization of CTLS at temperature 600oC had providedsurface area of 620 m2 g-1 and total pore volume of 0.49 cm3 g-1.The adsorption study is conducted by employing adsorbentprepared from CTLS on adsorbate tannic acid. The effects ofvarious experimental parameters have been investigated using abatch adsorption technique to obtain information on treatingwastewater containing tannic acid. The extent of tannic acidremoval was studied by varying parameters such as pH, contacttime, initial concentration of the tannic acid and amount ofadsorbent. The removal efficiency of tannic acid in aqueoussolution is found to be about 95%. The experimental equilibriumdata for this system has been analyzed using the linearized formsof Langmuir and Freundlich isotherms. The Langmuir isothermwas found to provide the best theoretical correlation of theexperimental data for the adsorption of tannic acid. Theadsorption of tannic acid on adsorbent increased from 57 to 63mg g-1, when the temperature was increased from 30 to 60oC.The adsorption was found to follow pseudo-second orderkinetics. In short, this study provides a greener solution forCTLS and tannin containing wastewater.