Study of the benzene removal in solution for the immobilized carriers using dead Bacillus sp. and polysulfone

Abstract

Batch and column experiments for the biosorption of benzene from aqueous solution by using dead biomass have been performed. The immobilized bio-carrier with dead Bacillus drentensis and polysulfone was manufactured as the biosorbent. From results of the sorption experiments, more than 98.0 % of the initial benzene was removed from 50 ㎖ solution by using 2 g of immobilized bio-carriers containing 5 % biomass, suggesting that the biosorption process using the immobilized bio-carrier is very useful to clean up benzene-contaminated water. Batch sorption experiments with different reaction times were conducted to determine the optimal reaction time for the maximum removal efficiency of benzene. More than 94.6 % of initial benzene in solution was sorbed on the bio-carriers within 5 minutes of reaction time and the biosorption reached in equilibrium within 2 hours of the reaction. Experiments were carried out to assess the effect of temperature on the biosorption of benzene. Benzene removal efficiency slightly increased (96.1 to 96.7 %) as the temperature increased from 20 to 35 ℃, suggesting that the temperature rarely affects on the removal efficiency. The sorption ability change under the different initial benzene concentration in solution was also investigated. The removal efficiency increased with the increase of the initial benzene concentration (0.001 to 10 ㎎/ℓ). More than 99.0 % was removed from the solution when the initial benzene concentration ranged from 1 to 10 ㎎/ℓ. From results of fitting process for sorption data to Langmuir and Freundlich isotherms, it was recognized that the biosorption isotherms of benzene were more well fitted to Freundlich model (r2=0.9242) rather than Langmuir model (r2=0.7453). From the column experiment, the benzene removal efficiency maintained over 82.1 % until 126 pore volumes of benzene solution (1 ㎎/ℓ) were injected in the column packed with bio-carriers. Results investigated that the immobilized carrier containing Bacillus drentensis and polysulfone is the outstanding biosorbent for the removal of benzene from contaminated solution.