黑碳吸附/解吸对微生物降解苯酚的影响

本文以黑碳为吸附介质,苯酚为吸附质,研究了黑碳上吸附的苯酚以及液相中的苯酚对微生物降解的影响。苯酚降解微生物选择假单胞菌,它能够以苯酚为唯一碳源和能源。通过实验得出,Freundlich吸附模型能够较好地描述苯酚在黑碳上的吸附;在实验浓度和时间条件下,假单胞杆菌降解苯酚呈现零级反应,在有黑碳的体系中,苯酚降解速度为5.77 mg.L-1.h-1,在无黑碳的体系中,苯酚降解速度为2.67 mg.L-1.h-1,黑碳促进了细菌降解苯酚,加大苯酚的降解速度。实验在有黑碳的体系中可以得出黑碳上苯酚的脱附速率跟不上细菌的降解速率,当液相中的苯酚降解完成后,黑碳的苯酚脱附是细菌降解苯酚的限制条件。

THE EFFECT OF ADSORPTION/DESORPTION ON PHENOL MICROBIAL DEGRADATION

In this paper, black carbon and phenol were used as the adsorption medium and adsorbate, respectively. The effect of phenol on black carbon and phenol in liquid to bacteria degradation was studied. The bacteria capable of using phenol as the sole source of carbon and energy were used in the experiments. The results show that Freundlich adsorption model could describe phenol adsorption on black carbon very well; Under the experimental condi- tions of time and phenol concentration, zero order reaction can describe phenol degradation by Pseudomonas; in the system with black carbon, the phenol degradation rate is 5.77 mg. L-1. h-l, however, in the system without black carbon, the phenol degradation rate is 2.67 mg.L- 1.h-1. A plausible explanation for enhanced degradation rate is that black carbon can accel- erate bacteria degrading phenol. The experiment shows that in the system with black carbon, the desorption rate of phenol is lower than the degradation rate of bacteria, but when there is no phenol in liquid, phenol desorped by black carbon is the limited condition to bacteria.