Spectrophotometric study of Solvent extraction of Pb (II) and Cd (II) by aminooctyldiphosphonic acid

Abstract

This study has investigated the solvent extraction of cadmium and lead ions from an aqueous solution in nitrate medium using aminooctyldiphosphonic acid (AODPA) as extractant in chloroform. In order to establish spectrophotometrically the concentration of metal ion in the aqueous phase before and after extraction, the Arsenazo III method was used. The effects of several extraction parameters on the extraction of these metals ions including volume ratio between the aqueous and organic phases (1–5), extraction kinetic time (0–30 min), molar ratio Q (1–5), addition of HNO3 (pH =2–6), addition of KNO3 (0.01 – 1M), temperature (10–40°C) and the synergetic effect by adding TOPO (solvating agent) were evaluated. Thermodynamic parameters including the Gibbs free energy (ΔG0),enthalpy (ΔH0), and entropy (ΔS0) were calculated. Performed experiments showed that Pb (II) can be extracted till 73% when Cd (II) can be recovered completely after two cycles. The extraction of both metallic ions was spontaneous, endothermic and with a slight randomness. Positive synergetic effect was observed at a chelating agent/TOPO ratio of 3. It is a very encouraging result which can lead us to recover cadmium and lower the concentration of lead from wastewater.

Preparation and characterization of green adsorbent on functionalized and nonfunctionalized ALOE VERA: A combined experimental and DFT calculations

“…The parameter of the Temkin model Fig. 8(c) was studied using equations (10) and (11). Temkin is characterized by the uniform distribution of binding energies.…”

“…Due to their hazardous effects on the environment and human health, it is important to develop a simple and sensitive analytical method in order to improve the quality of the environment and human life. Several industrial wastewater treatment methods for the removal of these cations have been reported in the literature [10].…”