Overview assessment of risk evaluation and treatment technologies for heavy metal pollution of water and soil

Heavy metals are highly toxic elements which are persistent in the natural environment, resulting in magnification throughout the food chain, adversely affecting both human and environmental health. Consequently, heavy metal pollution has received widespread research attention. This review assesses the current progress in heavy metal pollution monitoring, management and mitigations, which show a lack of systematic criteria for risk evaluation. Risk assessment and multivariate analysis methods are also discussed. Assessment of risk evaluation and multivariate statistical analysis are the basic step for the treatment technologies choosing. The technique used is always site-specific, and it often combines different strategies. Only by comprehensively considering the contaminated time, the concentration and nature of the contaminant, the soil/water and site characteristics, the contaminant's availability, and the existence of specific regulations can appropriate restoration and treatment plans be formulated. Combinations of GIS and modeling appear to be most effective for analysis of heavy metal pollution risk. In recent years, many physico, chemical and bio technologies have been used to remove heavy metal pollution from water and soil, each having inherent advantages and limitations. So far, no single method is universally effective for the removal of all heavy metals. Combining different technologies can lead to greater efficiency and may provide a reasonable method to conduct inter-governmental, cross-border heavy-metal prevention and monitoring, for the control of anthropogenic pollution sources. Efficient and commercially viable scaled-up heavy metal treatment technologies will yield large benefits to human and environmental health, as well as economic output. This review provides an overview of the currently available methods, to inform researchers and other stakeholders in the prevention of heavy metal pollution of water and soil.