Volume No. 12 Issue No.: 3 Page No.: 305-311 January-March 2018

 

THERMAL TREATMENT OF MERCURY CONTAMINA-TED WASTE GENERATED BY MAHSHHAR PETRO-CHEMICAL CHLOR-ALKALI UNIT WITH MgCl2 AT REDUCED TEMPERATURE

 

Yashar Rezaei Sabzevar* and Fereydoun Ghazban

Department of Environmental Engineering, Faculty of Environment, University of Tehran, Tehran (IRAN)

 

Received on : September 29, 2017

 

ABSTRACT

 

There are several methods for treatment of various mercury bearing waste materials as hazardous wastes. Among these methods, thermal treatment is a promising technology for remediation of these wastes; however, the method requires an enormous amount of energy to reach the temperature above 600C required for the treatment. In this investigation, a method for thermal treatment with the facilitation of MgCl2.6H2O was carried out on mercury contaminated waste produced by a chlor-alkali unit in a major petrochemical complex in southern Iran. The results showed that treatment of the waste for a period of 1 hour treatment at temperature of 400C, removed only 2.12% of the mercury from the waste and reduced the mercury content in Toxicity Characterization Leaching Procedure (TCLP) test above limitations. Adding MgCl2.6H2O to the waste before treatment under similar time and temperature (i.e. 1h at 400C) resulted in a further reduction of the total mercury content in the waste and TCLP test in permissible concentration. Based on the results MgCl2.6H2 O/Hgmolar ratio of 270:1 in the waste was the optimum dosage, while at this dosage, the residual mercury and TCLP reduced up to about 66% and 0.2 mg/l respectively. Therefore, it appears that adding Cl agent to the waste before treatment helps thermal treatment to decrease the mercury content, and make the final waste suitable for disposal in landfills.

 

Keywords : Thermal treatment, Hazardous waste, Chlor-alkali, Mercury, MgCl2.6H2O

 

 

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