An overview of in-situ remediation for nitrate in groundwater

Faced with the increasing nitrate pollution in groundwater, in-situ remediation has been widely studied and applied on field-scale as an efficient, economical and less disturbing remediation technology. In this review, we discussed various in-situ remediation for nitrate in groundwater and elaborate on biostimulation, phytoremediation, electrokinetic remediation, permeable reactive barrier and combined remediation. This review described principles of each in-situ remediation, application, the latest progress, problems and challenges on field-scale. Factors affecting the efficiency of in-situ remediation for nitrate in groundwater are also summarized. Finally, this review presented the prospect of in-situ remediation for nitrate pollution in groundwater. The objective of this review is to examine the state of knowledge on in-situ remediation for nitrate in groundwater and critically evaluate factors which affect the up-scaling of laboratory and bench-scale research to field-scale application. This helps to better understand the control mechanisms of various in-situ remediation for nitrate pollution in groundwater and the design options available for application to the field-scale.