Lignocellulose-Based Biosorbents for the Removal of Contaminants of Emerging Concern (CECs) from Water: A Review

Abstract

Contaminants of emerging concern (CECs) are chemicals or materials that are not under current regulation but there are increasing concerns about their possible occurrence in the environment because of their potential threat to human and environmental health, with wastewater perceived as their primary source. Although various techniques for their removal from water have been studied, it should be emphasized that the choice should also consider the use of resources and energy within the removal processes, which must be minimized to avoid additional carbon footprints and environmental impact. In this context, the use of biomass-based sorbents might represent a cost-effective and environmentally friendly approach for the removal of CECs from water because they are based on preferably local renewable resources with lower negative impacts on the global carbon cycle through greenhouse gas emissions than the conventional nonrenewable ones. This paper provides an overview of the studies dealing with the application of such so-called biosorbents for the removal of CECs from water and discusses the use of their different forms: sorbents after a minimal pretreatment of the original lignocellulosic biomass; sorbents extracted from lignocellulosic biomass and/or modified; and biochar-based sorbents obtained after thermochemical conversion of biomass. It explains possible modifications of biosorbents and discusses the efficiency of various biosorbents for the removal of selected emerging compounds that belong to the classes of pharmaceuticals, personal care products, and pesticides and compares the adsorption capacities, kinetic models, and mechanisms reported in the relevant literature. Biochar-based sorption has been studied more often if compared to other considered biosorbents. In some cases, removal efficiencies of contaminants greater than 90% were achieved, but nonetheless a wide range of efficiencies for different CECs indicates that for successful simultaneous multicompound removal, a combination of different processes seems to be a more appropriate approach than the stand-alone use of biosorbents. Finally, this review discusses the reasons behind the limited commercial application of the considered biosorbents and provides directions for possible further research, in particular the use of spent biosorbents from a perspective of circular systems.

Mesoporous activated carbon prepared from waste fibers and their application on removing iron (II) ions from aqueous solution: Adsorption isotherm, kinetics, and thermodynamic studies

“…Various biosorbents derived from agricultural wastes such as Coconut Coir [14], Banana Peels [15], sugarcane bagasse [16], sorghum brewing waste [17], creeping Launea leaf [18], and rice husk [19], activated residual Dodonaea Viscosa [20]. Using raw biomass materials directly without any treatment to remove metals usually does not have a high sorption capacity for metals owing to their low BET surface area [21], [22]. Alias et al prepared activated carbon of Moringa oleifera (ACMO) by chemical activation with phosphoric acid for iron removal in an aqueous solution.…”

“…The world currently uses around 400 million tonnes of paper per year [31]. The use of waste paper as an alternative source for the production of activated carbon is very attractive [21], [32]. Moyib et al (2017) applied waste printing paper after treatment with hydrogen peroxide (H2O2) for removal of heavy metal (Ni(II), Cd(II), Pb(II), Cu(II)) ions from aqueous solutions.…”

Biosorption of Technologically Valuable Metal Ions on Algae Wastes: Laboratory Studies and Applicability

“…Numerous agricultural wastes (such as fruit peels, cereal straw and shells, peanut shells, etc.) [16][17][18], aquatic and terrestrial plant residues (like micro and macroalgae, leaves of plants or trees, plant stems, tree bark, etc.) [19,20], or agri-food industrial waste and byproducts (such as tea and coffee waste, fermentation waste, sugar waste, etc.)…”

Ecofriendly Application of Calabrese Broccoli Stalk Waste as a Biosorbent for the Removal of Pb(II) Ions from Aqueous Media

“…The use of ecofriendly biomaterials for sorption processes applied in the cleaning of waters contaminated by heavy metals, such as lead, has gained huge attention [12]. The ideal sorbent for wide application needs to be inexpensive, available in large quantities, non-toxic, with little or no processing, and with known kinetic parameters and good sorption characteristics [13]. In recent years, these studies have been focused on the use of waste materials, especially those obtained from food and agricultural waste as citrus peel, olive stone, groundnut shell, potato or cucumber peels, barley straw, cranberry kernel shell, tea waste, potato, strawberry or canola stems, among others [2,7,[14][15][16][17][18][19][20].…”