Large scale study on influence of biopolymer to mitigate wind induced sand erosion with durability analysis

Abstract

The desertification is a serious threat that affects the sustainable agriculture, ecosystem, and economic progress of society. There is an urgent need for an environment friendly, cost-effective, durable, and practical approach to mitigate wind induced erosion. The present study introduces a novel approach through large scale testing using biopolymer, including durability analysis. The research investigates the influence of biopolymer namely Acacia gum (AG) to mitigate wind induced sand erosion. For the experimental setup, rectangular trays (180 cm × 60 cm × 15 cm) containing 11 erosion pins (three rows along the length, in a staggered way at equal spacing) have been filled with desert sand. Solutions have been prepared using biopolymer concentrations (1%, 2%, and 3%) mixed with water. The prepared solution was sprayed onto specimens and the treated samples were then left for air drying (7 and 28 days curing period). The study has been performed on summer days with an average temperature of 40 °C. After biotreatment, the specimens were examined in a wind tunnel at variable wind speeds of 6, 10, and 15 m/s to measure sand loss rate (SLR) for different wind intervals (i.e., 1, 2, 3, 4, and 5 min). Surface strengths were assessed using a pocket penetrometer. To check the durability of biotreated sand samples, 28 days curing period samples, with all biopolymer percentages have gone through 5 wetting and drying cycles (WDC). After the last WDC, samples were left again for 28 days and then experienced all tests. The minimum and maximum SLR for desert sand ranged from 17 kg/m² at 6 m/s and 1 min duration to 123 kg/m² at 15 m/s and 5 min duration respectively. Instead biotreated sand samples presented negligible SLR. Surface strength increased with increasing biopolymer concentration and a curing period. The maximum surface strength was 334.47 kPa recorded at 3% concentration during the curing period of 28 days. Further analysis involving SEM, EDX, and PXRD, confirmed sand particle bonding. For surface strength, 3% biopolymer concentration consistently produced positive outcomes, even after undergoing 5 WDC.