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

Abstract

To evaluate the potential of sepiolite-based materials to resolve environmental pollution problems, a study is needed which looks at the whole life cycle of material application, including the residual value of material classified as waste from the exploitation of sepiolite deposits in the region or from its processing and purification. This would also maximize value from the exploitation process and provide new potential for local waste management. We review the geographical distribution of sepiolite, its application in the treatment of potentially toxic elements in soil and across the wider landscape, an assessment of modification and compositional variation of sepiolite-based applications within site remediation and wastewater treatment. The potential of sepiolite-based technologies is widespread and a number of processes utilize sepiolite-derived materials. Along with its intrinsic characteristics, both the long-term durability and the cost-effectiveness of the application need to be considered, making it possible to design ready-to-use products with good market acceptance. From a critical analysis of the literature, the most frequently associated terms associated with sepiolite powder are the use of lime and bentonite, while fly ash ranked in the top ten of the most frequently used material with sepiolite. These add improved performance for the inclusion as a soil or wastewater treatment options, alone or applied in combination with other treatment methods. This approach needs an integrated assessment to establish economic viability and environmental performance. Applications are not commonly evaluated from a cost–benefit perspective, in particular in relation to case studies within geographical regions hosting primary sepiolite deposits and wastes that have the potential for beneficial reuse.

The Usability of Sorbents in Restoring Enzymatic Activity in Soils Polluted with Petroleum-Derived Products

“…Computed values demonstrated that soil pollution through DO caused greater disorders in the metabolic profile of LS and SL than soil pollution through P. Presumably, DO represents a better source of nutrients to microorganisms, which in the present study could affect enzyme biosynthesis [ 91 ]. Soil polluted with petroleum may modify the structure of a bacterial community [ 127 ], whereas petroleum itself can act as a substrate for certain bacteria, facilitating soil transformation and reclamation [ 111 , 128 ].…”

“…A holistic approach should be implemented while discussing the disorders of soil metabolism. Special attention should be paid to the feasibility of restoring homeostasis in the ecosystem [ 128 ]. The present study results indicate that the biochemical activity of soil should be taken into account when planning the remediation measures undertaken to restore its productivity.…”

“…In the present study, all sorbents stimulated the enzymatic activity in LS polluted with DO, whereas in SL, this effect was triggered by the molecular sieve, Ikasorb and expanded clay. Sorbents had no significant effect on the enzymatic activity of the soils polluted with P, which could be due to the chemical composition of both the petroleum-derived products and sorbents themselves [ 128 , 135 ].…”

Experimental Study on Shear Behavior of Rock Composite Material under Normal Unloading Conditions

“…As the weak plane in rock mass, the joint is usually the key factor in the stability of instances of rock mass engineering such as slopes, dam foundations and underground chambers [ 1 , 2 , 3 ], thus further affecting human life and property as well as the environment [ 4 , 5 , 6 ]. Research on the deformation and strength characteristics of joints aims to provide a basis for the evaluation and utilization of rock mass stability [ 7 , 8 ].…”

Synthesis of a polymeric nanocomposite based on magnetic sepiolite functionalized with an ionic liquid for the adsorption of aromatic pollutants from aqueous solution

“…The powerful sorbent properties of SP and its ability to adsorb organic or inorganic ions are related to the alternating blocks and tunnels growing along the microfibers. 15,16 To improve pollutant adsorption onto the surface of SP, some modification methods have been used including acid treatment, thermal treatment, acidthermal treatment, magnetic modification, and organic modification. [17][18][19][20] It has been observed that acid activation enhances the surface area as the proton (H + ) of acids is replaced by some of the Mg 2+ ions located in the octahedral sheets.…”