Detection and remediation of heavy metal pollution in seawater using instrumentation and nanomaterials

Abstract

This study explores methodologies for removing heavy metal elements such as nickel (Ni), copper (Cu), cadmium (Cd), and lead (Pb) from diverse aquatic environments, including rivers, lakes, and oceans. Nanosized montmorillonite (MON) was used as the raw material and was subjected to organic chemical modification through silanization using cetyltrimethylammonium bromide and grafting of amino groups to produce amino-functionalized nanomontmorillonite composite (NH2-MON). The removal effectiveness of NH2-MON on heavy metal elements in water bodies was evaluated. Experiments involving adsorption were conducted to evaluate the impact of nanomaterial concentration and solution pH on the entrapment of heavy metal ions. The results indicated that an increased nanomaterial adsorbent dosage precipitated water coagulation, which subsequently altered the accessibility of adsorption sites for heavy metal ions, thereby significantly affecting the heavy metal removal effectiveness of the nanomaterial. The ideal nanomaterial dosage was determined to be 2.5 g/L, yielding the maximum unit adsorption capacity and removal rate. The acidity or alkalinity of the solution was instrumental in the adsorption of heavy metal ions such as Ni, Cu, Cd, and Pb using nanomaterials, establishing solution pH as a pivotal determinant in the adsorption process. As the solution pH increased, the electronegativity of the nanomaterial increased, thus encouraging its interaction with positively charged heavy metal ions, including Ni, Cu, Cd, and Pb. The ideal solution pH range was found to be 4–5.