Removal of lead from aqueous solution using Dead Sea mud

Abstract

This study aimed to investigate the performance of the (DSM) as an adsorbent for removing of lead from aqueous solution. Batch adsorption experiments were conducted using dried and burned (DSM) at different temperatures. The impact of the main parameters that affect the adsorption process; namely the pH, contact time, initial lead concentration, dose of (DSM), solution temperature and the burning temperature of the (DSM) were investigated.The result revealed that 100 % removal of lead ions was achieved at pH 7, room temperature, a dose of 2g of dried (DSM) with a mixing speed of 15 rpm, for 3 h contact time and initial concentration of lead in the solution of 100 mg/l. The adsorption capacity reached: 39.84 mg/g, 39.74 mg/g, 39.1 mg/g, 39.12 mg/g, and 34.45 mg/g for dry samples, and burned samples at 200, 500, 800, and 1000 °C respectively. Kinetic models showed that the pseudo-second-order kinetic model was better (R2 = 0.99) than the othere used models to describe the adsorption process.Regarding the isothermal models, it was found that the D-R is the best fit for lead adsorption, with (R2) of 0.90 indicating physicochemical adsorption mechanism. Thermodynamic studies found that at the adsorption process occurs spontaneously and is exothermic in nature with ΔHo value of −49.419 kJ mol− 1 and ΔSo = −13.558 kJ mol− 1 and ΔGo value at 25 °C = −45.31KJmol-1. It can be concluded that high removal efficiency of (Pb+2) can be achieved by using (DSM) as adsorbent which considered as a low cost, naturally existing material.

Keywords

• Heavy metal
• Lead
• (DSM)
• Isothermal adsorption
• Thermodynamics adsorption