The Effect of Cyanide on Bio-Kinetic Parameters

Cyanide is frequently produced in many major industrial processes including steel mill, chemical, petrochemical and explosive production. Wide variation in industrial wastewater flow and characteristics make the biological treatment more difficult in comparison with municipal wastewater. A literature survey showed that there is a lack of quantitative information on the impacts of cyanide on biokinetic parameters. The objective of this study were:1) To determine the impacts of cyanide on biokinetic parameters (K,Ks,Y and Kd).2) To determine which microorganisms are resistant to cyanide and capable of biodegrading it.Both synthetic and actual wastewater were used in this research. Also this study demonstrated that the biodegradation is the major mechanisms in removal of cyanide in wastewater effluent. Further biotreatment studies showed that cyanide is converted to ammonia (NH3) in first stage and then to nitrate (NO3) in the second stage under optimum operating conditions. The batch study indicated that cyanide removal followed first order kinetic reaction. The reaction rate constant (K) was obtained in a range of 0.038- 0.092 per hour.Also the primary experimental results showed that the estimated biokinetic parameters K, Ks, Y and Kd ranges were 0.2-0.4 day-1, 100-200 mg/l, 44-110mg/mg and 0.4-0.7day-1 respectively.