Investigation of removal of some pesticides by Ralstonia eutropha

In this study, biodegradation of the pesticides with R. eutropha was investigated in a batch stirred reactor. Glucose was used as carbon source in addition to pesticides. The effects of initial pH, temperature and initial pesticides concentrations on the substrate removal and specific growth rates and yields were investigated and results were compared. Optimum initial pH values were obtanied as 7 for fenvalerate and 6 for lambda c. which optimum temperature as 20°C and 2 mg/L respectively. In this optimum conditions, the maximum microorganism?s spesific growth and pesticide removal rates were determined as 0,088 h-1 and 0,0483 mg/g.dm.o.h for fenvalarete and 0,0878 h-1 and 0,0408 mg/g.dm.o.h for lambda c., respectively. At higher pesticide concentrations (>2 mg/L), substrate inhibition was observed. At experiments, where substrate inhibition was not obsered, microorganism?s specific growth was implied with Monod Equality depending on substrate concentration. In these conditions, microorganisms inhibition constant values were determined as Ks= 1,371 mg/L for fenvalerate and Ks= 0,8540 for lambda c., respectively. The results show that the growth of R. eutropha was not effective for biodegration of both pesticides. Keywords: R.eutropha, Fenvalerate, Lambda c., Biodegradation, pH, Temperature, Initial pesticide concentration.