Retention of the zinc present in wastewater through a non-conventional adsorbent developed fron industrial waste

Abstract

The removal of zinc by brine mud (industrial waste) and sawdust (agricultural waste) was investigated by means of simple batch tests. Brine mud is mainly made up of NaCl (halite) and CaCO3 (calcite), the main cation exchangers being sodium (659.4 cmol+/kg) followed by calcium (12.1 cmol+/kg). The adsorption isotherms adjusted very well to the Langmuir model and the mixture presented maximum fixation values of 2,29 and 5.59 (mg/g) for the ratio adsorbent/ solution 1:20 and 1:40, respectively. The main mechanism involved in the zinc removal in both materials is the ion exchange between sodium and calcium ions present in the brine mud and between H+ present in functional groups of sawdust.