Pod razor (Ensis siliqua) shell powder as cost-effective biomineral for removal of nickel(II), copper(II) and zinc(II) from artificially contaminated industrial wastewater

Abstract

The removal of Ni(II), Cu(II) and Zn(II) from aqueous model solutions and real wastewater samples by using pod razor (Ensis siliqua) shell powder has been investigated under several conditions such as heavy metal concentrations, pH, contact time, powder dosage. It was found that the removal of heavy metals was dependent on the dose of the biomineral and contact time. The results showed that this low-cost material can be fruitfully used for the removal of heavy metal ions such as Ni(II), Cu(II) and Zn(II) below concentration of 200 mg/L applying a shell powder dose of 1.2–4 g/L. The minimal dose for removal of Cu(II) and Zn(II) from industrial wastewater was found to be 1.2 g/L, while for Ni this value amounted to 1.6 g/L. The contact time necessary for quantitative removal was found to be 30–60 min and the optimum initial pH range was between 4 and 5.