Archive | 2019

An environmentally friendly soil improvement technology for sand and dust storms control

 
 
 
 
 

Abstract


Background: Dust storms occur when unchecked, strong, or turbulent winds combine with exposed \nloose and dried soil surfaces. Sand and dust storms have a significant impact on society, economy, and \nenvironment at local, regional, and global levels. The environmental and health hazards of such storms \ncannot be permanently reduced, however, by taking appropriate measures, its impact can be reduced. \nThe present study aimed to investigate the effects of microbial precipitation of calcium carbonate \n(CaCO3) as a biocompatible agent on soil stabilization and control of dust storms using ureaseproducing \nbacteria (UPB) as a biological improvement technique, which were isolated, identified, \nsprayed on the soil surface. \nMethods: For this purpose, the erosion of bio-cemented soil samples was investigated experimentally \nin a wind tunnel under the condition of wind velocity of 0 to 98 km.h-1 in two soil types with sandy and \nsilty texture in a completely randomized design with three replicates. \nResults: The investigation of the threshold wind velocity of soil particles showed that soil particles \nbegan to move at velocity of 8 and 10 km.h-1 in silty and sandy soils, respectively, but in all biological \nsamples (MICP), particles did not move until the wind speed reached 97 km.h-1. It was also revealed \nthat the weight loss of all MICP-treated samples at different wind velocities was significantly reduced \ncompared to the control group. Differences in the amount of soil loss among bio-cemented samples \nand control treatments were even superior at higher velocities, so that at velocities more than 57 km.h-1, \nsoil losses increased significantly in the control group, while in soils treated with bacteria, soil loss was \nvery low (about 2.5 kg.m-2.h-1). Comparison of the bacteria used in this study also showed that Bacillus \ninfantis and Paenibacillus sp3 had high efficiency in controlling dust storms. \nConclusion: The formation of abrasion-resistant surface layers on soil samples treated by biocementation \nshowed that cementation by biological methods could be an effective way to stabilize \nsurface particles and control sand and dust storms. \nKeywords: Urease, Dust storms, Bio cement, Soil loss flux

Volume 6
Pages 63-71
DOI 10.15171/EHEM.2019.07
Language English
Journal None

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