Recovery of Groundwater Contaminated by Tannery Effluents Using Nanomaterials

Urbanization, driven largely by economic factors, also leads to significant environmental issues, including groundwater contamination. This focuses on the Pallavaram area in Chennai, India, where groundwater is affected by rapid urbanization, industrial effluents, sewage seepage, and improper solid-waste disposal. This situation poses a serious health hazard, as the area relies entirely on groundwater. The levels of BOD, COD, nitrates, chlorides, total dissolved solids (TDS), hardness, heavy metals, and pathogenic bacteria are substantially elevated, resulting in chemical and microbiological contamination. This study examines the causes, extent, and nature of groundwater contamination in Pallavaram by assessing key water-quality parameters and comparing them with the drinking-water standards (IS 10500:2012). It also evaluates sustainable treatment technologies, such as permeable reactive barriers (PRBs) incorporating multi-layered biochar, potassium permanganate, limestone, wood chips, zero-valent iron (ZVI), coarse aggregate, sand, and multi-walled carbon nanotubes (MWCNTs), as well as chlorination. The study highlights the importance of restoring water quality to protect public health and concludes that low-cost, eco-friendly remedial measures, such as PRBs combined with oxidative processes, can be applied to treat groundwater in Pallavaram.