Removal of heavy metals from industrial wastewater by use of Cyclopentane - Clathrate Hydrate formation technology

Abstract

In this research, the experimental system was built up for treatment of wastewater containing substantial metal particles by the hydrate-based technique. The whole experimental system comprises of five fundamental methodologies: hydrate formation, hydrate separation, hydrate dissociation, centrifugal separation, and characterization. Many technologies were being utilized to remove substantial metal particles; however these frameworks had special prerequisites for raw wastewater, such as pH, temperature, contamination type and amount. Consequently, there is a evolving requirement for elective techniques for treating wastewater containing heavy metals, for which hydrate-based separation seems promising. The removal of the heavy metal ion Cu2+, Ni2+, Zn2+ and Cr3+by the hydrate-based method gives an enhancement to the ordinary wastewater treatment innovation. Aqueous solutions of the wastewater were synthesized by adding a certain amount of each salt such as copper sulfate anhydrous (CuSO4•5H2O), nickel sulfate (NiSO4), Zinc chloride (Zncl2) and tri-chloro chromium (CrCl3) to the distilled water. Cyclopentane was employed to form hydrate in this research on account of its immiscibility with water, non-toxicity, and thermodynamic stability. Clathrate for ternary systems (cyclopentane, water and ionic salt) were formed at different types and concentrations of salts in the liquid state at temperature below 7 °C and normal atmospheric pressure. An effect of the cyclopentane-heavy metal solution volume ratio and concentration of the heavy metal on removal efficiency of heavy metal ions, the enrichment factor and a yield of the dissociated water are discussed. The results show that the technology has higher removal efficiency upon changing the volume ratio from 1/2 to 1/6, and achieve wastewater minimization, but lower enrichment factor and yield of dissociated water. This work gives thoughts into low-energy, serious treatment of wastewater.