A review on coal fly ash-based adsorbents for mercury and arsenic removal

Treatment of environmental contamination using sepiolite: current approaches and future potential

“…Emissions and accumulation of fly ash not only occupy land, but also cause serious pollution to the environment and poses a disposal challenge (Ochedi et al 2020 ). However, fly ash is also a resource that can be widely applied in the fields of construction materials, road sub-base, mine backfill etc.…”

“…However, fly ash is also a resource that can be widely applied in the fields of construction materials, road sub-base, mine backfill etc. (Ahmaruzzaman 2010 ), and fly ash also shows a promising ability as a heterogeneous catalyst to oxidize aqueous Na 2 S solution (Mallik and Chaudhuri 1999 ) or sorbent to remove various air pollution (Ahmaruzzaman and Gupta 2012 ; Ochedi et al 2020 ). Fly ash is utilized as a constituent of mixtures for solidification/stabilization technologies because of its low-cost, good pozzolanic properties, which helps with solid waste disposal and coping with potential stress of its large generation and accumulation in an economically beneficial way (Terzano et al 2005 ).…”

Iron oxide coated hollow poly(methylmethacrylate) as an efficient adsorption media for removal of arsenic from water

“…[27][28][29] Except for adsorption which is an effective and economical method, other methods have high operational cost and less efficient for arsenic removal. 30,31 Several studies on the adsorption of arsenic(III) have been carried out using various adsorbents, such as y ashes, [32][33][34] natural and synthetic clay materials, 35,36 ion-exchange resins, 21,37,38 carbon nanotubes 39,40 and metal oxides. 1,41,42 Additionally, polymeric adsorbents in the form of hollow microspheres possess advantages such as low density, high surface area with a size range of about 1 to 1000 mm, and can readily be synthesized using various polymerization techniques.…”

“…Therefore, these adsorbents are used for the removal of a wide variety of contaminants from drinking water. [30][31][32][33][34] Arsenite, As(III), and arsenate, As(V) are the predominant oxidation states of arsenic found in water, under reduced and oxygenated conditions respectively, 25,44 and are potentially harmful to health. Trace amounts of methylated arsenic species are typically found in drinking water, and higher levels are found in biological systems.…”

Removal of arsenate using graphene oxide-iron modified clinoptilolite-based composites: adsorption kinetic and column study

“…Among these methods, adsorption has attracted more attention due to its ease of operation, low cost, sustainability, efficiency, low waste generation and low energy requirement (Weerasundara et al 2021;Amen et al 2020). Many different natural and synthetic adsorbents have been tried to remove arsenic from water including industrial and agricultural wastes (Mohan and Pittman Jr 2007), Fe-Mn binary oxides (Zheng et al 2020), fly ash (Ochedi et al 2020), chitosan (Kloster et al 2020), activated carbon (Hashim et al 2019), and activated alumina (Tripathy and Raichur 2008). In recent years, zeolites have been used to remove many pollutants such as arsenic from water and wastewater due to their high surface area, easy availability, and low cost (Figueiredo and Quintelas 2014;Asere et al 2019).…”