Treatment of arsenic sludge generated from groundwater treatment plant: A review towards a sustainable solution

摘要

Arsenic contamination above allowable limit in groundwater is universally been identified as a critical threat with a high alarm in the African countries, Western USA and a lot of different developing countries. The increasing numbers of arsenicosis patients with their extremely grave and fatal fates, imposes severe stringency to the treatment strategies. Though numerous types of technologies were adopted regarding the abatement of arsenic from water but as far the generated sludge from arsenic removing groundwater treatment plant is concerned, scanty efforts were put forward towards wise stabilization/capturing/encapsulation of arsenic sludge to provide zero chances of leaching. Thus, arsenic with the ability of leaching back to soil and water while mixing with surface and under-ground water, still stands as a serious and open challenge to the scientific communities for their safe disposal. With an extensive review towards available technologies for safe arsenic sludge disposal, this paper reviews the potential of stabilization of arsenic recalcitrant sludge employing concrete, polymer compounds, fly ash, adding chemicals and by formation of bricks and cement blocks. Such approaches stand out as flexible and economic strategies while permanently capturing stabilized arsenic in solid matrices while sustaining the strength of the building material. Thus, the requirements of coarse aggregate for the formation of concrete blocks could also be reduced. Such a review is expected to initiate influential policies among the research community to combat against the widespread risk of reluctant disposal practices of lethal arsenic sludge generated from arsenic abating water purification methodologies.