Research Progress of Permeable Reactive Barrier in the Remediation of Nitrate Pollution in Groundwater

The principle of permeable reactive barrier (PRB) and its application status in the process of groundwater nitrate pollution remediation were reviewed. Four frequently-used types of PRB, including reducing, absorbing, precipitating and degradable PRBs, were reviewed, and the effect of PRB technique on nitrate pollution in groundwater was discussed. The impact of organic carbon sources types and microorganism species which were added to the degradable PRB on the remediation effect of ground water nitrate pollution was especially discussed, and the problems existing in the operation and the future possible development direction of PRB was analyzed. Problems that should be noticed when applying PRB technology to groundwater nitrate pollution remediation, such as the secondary pollution caused by the employ of carbon sources and bacteria, the filter medium clogging in the repairing process, the uncontrollability of carbon source release rate, and the nitrate deposition to the bottom of the PRB that was difficult to remove, were pointed out. On the basis of strengthening reaction mechanism research, combining phytoremediation with PRB technology could solve the above problems.