Chitosan-calcite from shrimp residues: A low-cost adsorbent for three triazines removal from aqueous media

Abstract

Abstract The low-cost adsorbents with high adsorption capacity and eco-friendly properties are a new economical way to adsorption process. Alternative materials can be used as sorbents, such as chitosan-calcite that is a cheap and green option. In this study, chitosan-calcite from shrimp residues was evaluated as a low-cost adsorbent in order to remove triazine herbicides from aqueous media. The adsorption properties of the chitosan-calcite for prometryn, metribuzin, and terbuthylazine were investigated in a batch system as a function of the amount of adsorbent (10−100\u2009mg), initial triazine concentration (1−100\u2009mg/L), solution pH (3–11), and contact time (0−120\u2009min). The adsorption process of the chitosan-calcite was compared with a commercial chitosan provided by Sigma-Aldrich. The experimental results proved that chitosan-calcite and Sigma-Aldrich chitosan were well modeled with the Freundlich isotherm model, and the sorption process followed the pseudo-second-order kinetic equation. The adsorption capacity calculated was similar for both adsorbents. Based on the results, chitosan-calcite, which can be easily obtained with a simple method, is an efficient, novel, and inexpensive alternative for the removal of triazine from aqueous solution.