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Wind-induced soil erosion is a major global misfortune, which obliterates nearly one-third of worldwide soil. The windswept sand particles cover large areas including highways, and make the visibility vague. This results in accidents, damaged infrastructure, delayed flights, and various health issues. The erosive impact of the wind can be minimized by enhancing the intactness of the soil surface. There is a prerequisite to adopt viable measures to strengthen soil against wind erosion. There are certain nature-based solutions that can fortify soil against wind erosion and the application of biopolymers is one of them. The objective of this study is to examine the viability of non-toxic biopolymers for stabilizing desert sand by improving its erosion resistance property and strength. In the present experiment, three biopolymers, sodium alginate (SA), pectin (P), and acacia gum (AG), were used with 1, 2, and 3% concentrations for 1 and 0.75 PV as stabilizing agents. The treatment with biopolymers was performed either by surficial treatment (spraying or pouring of solution) or by mixing and compact method based on the viscosity of prepared biopolymer solutions. The biotreated sand samples were tested in a wind tunnel at varying wind speeds of 10, 20, and 30 m/s to assess sand erosion. Surface strengths were assessed by measuring compressive strength using a pocket penetrometer. Crust thickness measurement was performed to check the penetration depth of biopolymer solution and binding of sand particles. All three biopolymers with 1% concentration gave a feasible solution for erosion against wind and binding of particles through SEM analysis. SA and P could not be sprayed for 2 and 3% concentrations due to high viscosity. This solution is also not feasible for the field application. Simultaneously, AG with 2 and 3% concentration was highly soluble, less viscous, and gave more surface strength due to higher percentage of biopolymer concentration. [ABSTRACT FROM AUTHOR]

Penetration test has been a promising technique for characterizing the surface strength of a crusted surface. This paper presents an experimental and numerical investigation of using a flat-ended penetrometer to evaluate the surface strength of mine tailings (MT) treated with biopolymer solutions of different concentrations. The experimental results show that the infiltration depth of biopolymer solution into dry MT decreases with the increase in biopolymer concentration. Biopolymer stabilization effectively increases the surface strength and cracking resistance of MT, and the increase is greater when the biopolymer concentration is higher. To further explore how biopolymer stabilization increases the surface strength and crack resistance of MT, numerical simulations using discrete element method were carried out to study the penetration tests on MT treated with biopolymer solutions of different concentrations. The simulation results show that the inter-particle tensile and shear strengths both increase with higher biopolymer concentration, indicating that more biopolymer induces larger inter-particle bonding and thus increases the surface strength of MT. The simulation results also confirm the delayed formation of cracks on MT after biopolymer stabilization from a microscale perspective, leading to a better understanding of biopolymer stabilization of MT. [ABSTRACT FROM AUTHOR]

Mine tailings, or mill tailings (MTs), are highly susceptible to wind erosion (dust) and have brought about different environmental and safety concerns. Many efforts have been attempted to stabilize MTs for dust control, but all have drawbacks. The current study investigates the feasibility of using two natural and renewable biopolymers, xanthan gum and guar gum, to stabilize MTs for dust control. Moisture retention and wind tunnel tests were performed to evaluate, respectively, the enhancement of water retention capacity and the improvement of resistance to wind dispersal after MTs were treated with biopolymer solutions of different concentrations. Because the resistance to the formation of dust is closely related to how easy the particles can be detached from the surface, a flat-ended cylindrical penetrometer was manufactured and used to evaluate the surface strength (maximum penetration force) of dry MT specimens treated with biopolymer solutions of different concentrations. Scanning electron microscopy imaging was also performed to investigate the evolvement of the microstructure of MTs after biopolymer treatment. The results indicate that both xanthan gum and guar gum are effective in enhancing the moisture retention capacity, improving the dust resistance, and increasing the surface strength of MTs beyond that of water wetting. This is mainly because the biopolymers form coatings on MT particles and create bonding between them. The results also demonstrate that the flat-ended cylindrical penetrometer is a promising technique for characterizing the dust resistance of MTs. [ABSTRACT FROM AUTHOR]