Determination of the Efficacy of Eggshell as a Low-Cost Adsorbent for the Treatment of Metal Laden Effluents

Abstract

Excessive release of metals and metalloids into the environment is a major global environmental concern and there is need for environmentally friendly and cost-effective methods for their removal. The present study investigated the adsorptive removal of zinc, lead, copper, and nickel ions from synthetic aqueous solutions and various metals from three acid mine drainage (AMD) sites using chicken eggshells. Process parameters, including the initial metal concentration, were evaluated and the optimum conditions obtained were pH 7, adsorbent dose of 7 g, and contact time of 360 min (for the removal of 100 ppm metal ions). Under these conditions, the percentage adsorptions were 97% for lead, 95% for copper, 94% for nickel, and 80% for zinc. Aluminium, iron, potassium, nickel, and zinc ions all had percentage adsorptions above 75% in AMD sample 1. Potassium had a 98.78% adsorption, while magnesium, strontium, and zinc had 72.33, 68.75, and 53.07% adsorption, respectively, in sample 2. Arsenic, chromium, copper, iron, antimony, and tellurium ions were above 75% for sample 3. The study demonstrated the efficacy of chicken eggshells and presents it as a viable low-cost adsorbent for bioremediation.