Optimization of reed-specific degrading bacteria by re-sponse surfaces for remediation of crude oil-polluted soil in Xinjiang, China

This paper discussed the optimization of conditions for remediation of crude oil-polluted soil based on pot experiment by applying reed-specific degrading bacteria,and using response surfaces methodology.We took the initial crude oil concentration,the amount of inoculation,the ratio of nitrogen and phosphorus,and the use of surfactant(Tween-80)as independent variables(factors),and the degrading ratio of crude oil as the dependent variable(response)after a 90-day experiment.The experiment explored the impacts of each independent variable and their interactions on the bioremediation of crude oil-polluted soil using the Box-Behnken design.Working with a simulated forecasting model the study obtained optimization values for the treatment parameters of 200 g/kg of the reed+specific degrading bacteria,a nitrogen to phosphorus ratio of about 6.0,and 0.2% surfactant.Under experimental conditions,for crude oil concentrations of 10,30 and 50 g/kg,the optimal effects of the treatments achieved 71.87%,66.61% and 54.52% degradation of the crude oil,respectively.The results can provide a basis for the technical development of plant-microorganism combined bioremediation of crude oil-polluted soil.