Adsorption and biodegradation in PRB technology

The adsorption and biodegradation processes used in PRB (Permeable Reactive Barrier) Technology are presented in the paper. These processes were selected to assess the possibility of removal of benzene and phenols from groundwater contaminated by a dumping site located in a city in Upper Silesia, Poland. In these processes, a special material called reactive material must be used for efficient treatment of groundwater. To design the PRB properly, a few parameters, called PRB parameters, such as: reactive material parameters, groundwater treatment parameters and geometrical PRB parameters should be determined. Groundwater treatment parameters for GAC (granulated active carbon) as a reactive material in adsorption process were measured with the Freundlich isotherm, and for a mixture of coarse sand and granulated peat in biodegradation process they were determined with the first-order kinetics equation. The results of groundwater treatment parameters for GAC (k_phen = 20.7 1/g; n_phen = 0.51; k_ben = 3.9 1/g; n_ben = 0.48) and for the mixture of coarse sand and granulated peat (λ_phen = 0.0369 1/hr; t_1/2phen = 18-72 hr; λ_ben = 0.0142 1/hr; t_1/2ben = 48.72 hr) show high efficiency of phenols and benzene removal from groundwater. Since high concentration of phenols may be toxic for microorganisms in the case of a biodegradation process, GAC seems to be a better material for designed PRB.