Abstract
Polycyclic aromatic hydrocarbons are a large group of chemicals that represent an important concern due to their widespread distribution in the environment and their harmful effects. The current study is aimed to accelerate the process of water clarification using successive stages of adsorption and biodegradation. For the optimized degradation of anthracene by isolate Bacillus sp., different parameters were examined such as pH, temperature, inoculum size and different concentration of anthracene. An integrated system of two separated columns was used to speed up the adsorption and biodegradation of anthracene. The HPLC results of anthracene adsorption showed that the free graphite powder succeeded to eliminate 43.9% of the water existing anthracene followed by 39.6% for the first and second columns, respectively. The sum of these percentages indicates the ability of both columns to remove 83.5% of the initial anthracene concentration (70 mg/L). The anthracene molecules that were adsorbed to both graphite forms were submitted to the biodegradation process using Bacillus sp. in separate tanks. After 24 h of incubation, Bacillus sp. was able to biodegrade 62.7% and 82.6% of anthracene adsorbed to free and immobilized graphite powders, respectively.