Rapid barrier materials for organic contaminated soils via epoxy resin-modified bentonite with a network structure

Bentonite is extensively employed in the construction of soil barrier walls at contaminated sites to inhibit the migration of pollutants. However, conventional bentonite barrier material often suffers from insufficient strength and requires prolonged periods to develop satisfactory properties. Herein, a novel self-hardening slurry composing of epoxy resin and bentonite (B-EP) was proposed, with the composition optimized through ratio adjustments. The rapid hardening and chemical compatibility of the bentonite-epoxy resin composite material were investigated by assessing its compressive strength and permeability coefficient . Compared to traditional bentonite slurry, the addition of 20 wt% epoxy resin to the material resulted in a twofold increase in the maximum unconfined compressive strength and a reduction in the permeability coefficient to two-thirds of its original value, achieving the desired strength and permeability coefficient within 24 hours. This improvement was attributed to the dense three-dimensional (3D) cross-linked network structure by the reaction between the epoxy resin and the curing agent . The 3D network structure effectively filled the pores of bentonite, resulting in the formation of a robust soil skeleton that significantly improved the strength and impermeability of the B-EP. Additionally, the barrier performance of the novel material against pollutants was evaluated, demonstrating its effective capacity to block pollutant migration . This study offers valuable insights into the feasibility of applying bentonite-epoxy composite slurry in soil barrier technology. • Achieve the required strength and permeability indicators within 24 hours. • Significant enhancement of chemical compatibility at high solute concentrations. • Bentonite skeleton fixed by three dimensional network cross-linking structure. • Effective barrier for high concentration organic polluted soil.