سيده ثريا شجاعيان

This study aimed to determine the effectiveness of wood-rotting fungus on bioremediation of soils contaminated with deltamethrin as a model pesticide. After eva‎luating and confirming the ability of a wood-rotting fungus to consume deltamethrin as a carbon source in the liquid phase, biodegradation of deltamethrin in the soil phase at concentrations of 25, 50 and 75 (mg/kg dry soil) contaminants, two types of nitrogen sources, ammonium nitrogen and urea, at a constant ratio of C/N = 10 was investigated. In the next step two types of nitrogen sources with three molar ratios of C/N equal to 10, 20 and 30 at deltamethrin concentration of 50 (mg/kg dry soil) were examined. All soil tests were done at 12% humidity and 30°C in two small laboratory column systems with aeration capability of 0.25 l/min intermittently every 24 hours and in glass jars with micro-aeration conditions for 50 days. At the end of the trials, the results of the kinetic analysis indicated that the growth rate was more significant at higher concentrations, which could be due to better access of microbes to the contaminant and higher the concentration could increase the rate of biodegradation. Thus, with increasing the initial concentration of deltamethrin, the bioremediation rate constants for the micro-aeration system increased from 0.027 to 0.058 day-1 and for the intermittent aeration system from 0.027 to 0.12 day-1. Also, the optimal C/N ratio for the micro-aeration system was equal to 30 with bioremediation of 81% and for the intermittent aeration system equal to 20 with 90% biodegradation. The results of these experiments illustrated the positive effect of inoculation of microorganisms on the biodegradation of deltamethrin in soil and also the high ability of the wood-rotting fungus used in the decomposition of this type of contaminant.

حشره كش هاي پيروتروئيدي , دلتامترين , زيست پالايي , فاز خاك , قارچ پوساننده چوب

Pyrethroid insecticides , Deltamethrin , Bioremediation , Soil phase , Wood-rotting fungus

Seyede Soraya Shojaeyan

Dr. Parisa Hejazi