engleski

Fixed bed natural zeolite as a permeable reactive barrier for zinc uptake and prevention of soil contamination

Permeable reactive barrier (PBR) filled with natural zeolite has a role of a reactive membrane for prevention of soil pollution due to the spreading of ground and underground polluted waters. In this paper, experiments of the zinc removal into fixed bed of natural zeolite have been used for evaluation of zinc concentration pattern through zeolite barrier in wastewater remediation. Evaluation of parameters necessary for prediction of PBR concentration profile assumes experimental performance in a fixed bed column filled with different bed depths of natural zeolite (40, 80, 120 mm), where simulated wastewater containing zinc ions of different initial concentrations (0.725-1.787 mmol/l) and flow rates (1-3 ml/min), passed through column in down flow mode. Breakthrough curves shows that volume of treated solution is extended at higher bed depths at lower initial concentration and at lower flow rates Based on the column experimental results, the hydrodynamic dispersion coefficient DL, retarded coefficient Rd and retarded hydrodynamic dispersion coefficient DLR were estimated by means of the Brigham method. Values of retarded coefficient indicate ability of the zeolite barrier to retain contaminate. Based on the calculated values of retarded hydrodynamic dispersion, the transport of zinc from the point source through the barrier can be analysed by a simple analytical pulse model, for different assumed distances of the barrier at examined experimental conditions. Results have been presented by graphical dependences of zinc concentrations through the barrier versus retardation time. The results indicate that certain dimension of barrier is required to ensure adequate contact time between the contaminants and the zeolite, which depends on the groundwater velocity and the initial concentration of the contaminants.

reactive membrane, permeable reactive barrier, column method, Brigham method

nije evidentirano