Emerging sustainable technologies for remediation of soils and groundwater in a municipal solid waste landfill site -- A review.

Remediation of soils and groundwater in a municipal solid wastes (MSW) landfill site emerges as a global challenge to the living environment on earth with significant market potential. Unlike contaminants in an industry or agricultural site, contaminants from MSW landfills are diverse, primarily consisting of chemical oxygen demand (COD), inorganic matter (ammonia-nitrogen, nitrate-nitrogen, total phosphorus) and heavy metals. This renders new challenges to remediation contaminants of different characters altogether. A status quo of existing technologies, including permeable reactive barriers, electrokinetic remediation, microbial remediation, and injection of either solubilizing agents or micro or nanobubbles were thoroughly reviewed, with an emphasis on removal efficiency based on existing projects at lab, pilot or field scales. A design chart tailored for the remediation of a landfill contaminated site was developed, verified by a few case studies, which supplement the chart. Future trends of technical innovation (such as multi-layer permeable reactive barriers (PRBs)) and challenges (such as flow pattern) were identified.