Removing Cd²⁺from water and wastewater by blowy sand; the effects of total hardness and pH

Abstract

A B S T R A C TIn the present work, blowy sand, as a cheap and available adsorbent, was employed to remove the Cd 2+ from water and obtain the best kinetic and isotherm models for this elimination process. In addition, the effects of total hardness and pH on this process were examined to obtain the best conditions for elimination of Cd 2+ . The calibration of kinetic and isotherm models shows that the model presented by Ho and co-workers is the best kinetic model and Redlich-Peterson model is the best isotherm model for presentation of our results. The pH equal to 5 is the best acidic condition to remove Cd 2+ in all conditions. Moreover, by the increase of total hardness from 0 to 320 (in milligrams of calcium carbonate), the efficiency and capacity of adsorption will decrease, respectively, from 80.4% to 18.7% and from 0.331 to 0.067 mg/g. The reusability of adsorbent without decreasing its efficiency is three times.

Adsorptive removal of cadmium from aqueous solutions using NiFe2O4/hydroxyapatite/graphene quantum dots as a novel nano-adsorbent

“…Cadmium has been shown to cause kidney failure [2]. Due to its hazardous impacts on human healthiness, removing cadmium from water and wastewater is a major environmental problem [3][4][5][6].…”