Loading...

Experimental Study of Biological Removal of Cyanides in the Effluent of Coke Oven of Esfhan Steel Company

Mirizadeh, Shabnam | 2012

496 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 43427 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Yaghmaei, Soheila
  7. Abstract:
  8. The presence of highly toxic cyanides in the effluent of coke oven of steel industries is considered as a critical problem. Owing to high levels of toxicity, control and removal of cyanide are of great importance in this industry. Biological removal of cyanides by indigenous microorganisms offers inexpensive, safe and environmentally compatible option in comparison with chemical and physical methods. The present study primarily focused on the isolation and purification of the microorganisms which utilize cyanide as the sole source of Nitrogen in alkaline conditions. The isolated bacterial strains were investigated through variety of bacteriological and biochemical reactions as well as standard tests such as gram stain and colony morphology. The performance of each microorganism for the decomposition of cyanide was investigated. The experiments were carried out at the temperature of 30 ℃ and pH=9.5-10 and with an agitation rate at 150 rpm. Our results indicate that microorganism (S2) was the best strain which tolerates 500 ppm and decomposes 200 ppm cyanide completely within four days. RSM and Design Expert software were utilized to analyze the experimental data. Thirty tests were designed to optimize four parameters, namely pH, Temperature, concentration of carbon source (glucose) and agitation rate. After analyzing data, the quadratic model to predict the concentration of cyanide was derived. The optimum parameters to achieve maximum removal of cyanide are as follows: pH 10.30, glucose concentration 0.44 g/l, agitation rate 144.6 rpm and Temperature 34.23. The optimum point suggested through software was examined tentatively and the obtained cyanide concentration was 26 ppm.
  9. Keywords:
  10. Biological Removal ; Microorganisms ; Optimization ; Cyanide

 Digital Object List

  • محتواي پايان نامه
  •   view

 Bookmark

No TOC