Cyanide Removal from Laboratory Wastewater Using Sodium Hypochlorite and Calcium Hypochlorite

Authors

  • Nusara Sinbuathong Scientific Equipment Centre, Kasetsart University Research and Deveolpment Institute (KURDI), Kasetsart University, Bangkok 10900, Thailand
  • Bussarin Kongseri Department of Environmental Science, Thammasart University, Bangkok 12121, Thailand
  • Panadda Plungklang Water Quality Control Division, Provincial Water Works Authority, Bangkok 10210, Thailand
  • Roj Khun-anake Water Quality Control Division, Provincial Water Works Authority, Bangkok 10210, Thailand

Keywords:

cyanide removal, laboratory wastewater, chlorination

Abstract

Removal of cyanide (CN-) from laboratory wastewater using sodium hypochlorite (NaOCl) and calcium hypochlorite (Ca(OCl)2) were performed at the reaction time of 30 minutes. The product of chlorination at an alkaline pH of 12.3 was CNO- which could be oxidized further to N2. Colorimetric method was used to determine the amount of CN- before and after chemical treatments. The optimum doses of chemicals used were determined. It was found that 100% removal of this contaminant could be achieved. The optimum doses and chemical costs of NaOCl and Ca(OCl)2 varied depending on the initial cyanide concentration. The optimum doses of NaOCl and Ca(OCl)2 for 100% CN- removal were Y = 17.3X and Y = 3.32 X, respectively (where X = initial CN- concentration in mg/l, and Y = chemical dose in mg/l). The chemical costs of NaOCl and Ca(OCl)2 were Y = 0.69 X and Y = 0.50X, respectively (where X = initial CN- concentration in mg/l, and Y = cost, baht/m3 of wastewater). Ca(OCl)2 is more effective than NaOCl
considering the cost and dosage used.

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Published

2000-03-31

How to Cite

Sinbuathong, Nusara, Bussarin Kongseri, Panadda Plungklang, and Roj Khun-anake. 2000. “Cyanide Removal from Laboratory Wastewater Using Sodium Hypochlorite and Calcium Hypochlorite”. Agriculture and Natural Resources 34 (1). Bangkok, Thailand:74-78. https://li01.tci-thaijo.org/index.php/anres/article/view/240377.

Issue

Vol. 34 No. 1 (2000): January-March

Section

Research Article

License

online 2452-316X print 2468-1458/Copyright © 2022. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/),
production and hosting by Kasetsart University of Research and Development Institute on behalf of Kasetsart University.