Arnepalli Siva Kesav Kumar, Gondu Venkata Ramana, Chinthala Sumanth
Department of Civil Engineering, National Institute of Technology Warangal, Warangal, 506004, India.
Department of Civil Engineering, Vasavi College of Engineering, Hyderabad, 500091, India.
Environ Sci Pollut Res Int. 2025 Jan 4. doi: 10.1007/s11356-024-35781-7.
Granite sludge dust (GSD), a significant byproduct of granite processing globally, poses severe environmental and public health challenges, with India alone generating 200 million tons annually. The conventional use of GSD in soil stabilization and construction materials is limited to 20-30%, underscoring the urgent need for sustainable repurposing solutions within the circular economy catering to broader bulk utilization. Unlike traditional techniques, repurposing granite dust using microbially induced calcite precipitation (MICP) offers a sustainable low-impact and eco-friendly ground improvement solution. It also reduces waste and associated environmental pollution. MICP leverages bacterial enzymes to catalyze urea hydrolysis, leading to calcite (CaCO) precipitation stabilizing the solids matrix. This study evaluates the efficacy of MICP in strength enhancement of GSD enabling its repurposing in low-volume roads. To assess this, unconfined compressive strength (UCS), wetting and drying (WD) durability, and X-ray diffraction (XRD) tests were conducted. Additionally, to assess the efficacy of MICP in mitigation of both wind and rainfall-induced erosion of GSD from waste containments, percentage weight loss in wind tunnel tests along with air quality parameters PM, PM, and drip erosion tests were conducted respectively. MICP treatment with Bacillus megaterium resulted in significant strength gain of up to 1355 kPa UCS, suitable for low-volume pavement subbases, enhanced durability up to two wetting and drying cycles, substantial reductions in PM and PM levels due to wind erosion, and improved resistance to rainfall-induced erosion sustaining the 10-min test. This low-carbon-intensive technique endorses circular economy goals by transforming GSD into a sustainable construction material addressing waste management, infrastructure resilience, and environmental sustainability. Further, the surficial application of MICP contributes to eco-friendly infrastructure and pollution control of GSD storage facilities.
花岗岩污泥粉尘（GSD）是全球花岗岩加工过程中产生的一种重要副产品，对环境和公众健康构成严峻挑战，仅印度每年就产生2亿吨。GSD在土壤稳定和建筑材料中的传统用途仅占20%-30%，这凸显了在循环经济中迫切需要可持续的再利用解决方案，以实现更广泛的大规模利用。与传统技术不同，利用微生物诱导碳酸钙沉淀（MICP）对花岗岩粉尘进行再利用，提供了一种可持续的、低影响且环保的地基改良解决方案。它还减少了废物及相关环境污染。MICP利用细菌酶催化尿素水解，导致方解石（CaCO）沉淀，从而稳定固体基质。本研究评估了MICP在增强GSD强度方面的效果，使其能够用于低流量道路。为了评估这一点，进行了无侧限抗压强度（UCS）、干湿循环（WD）耐久性和X射线衍射（XRD）测试。此外，为了评估MICP在减轻风蚀和降雨对GSD废物填埋场侵蚀方面的效果，分别进行了风洞试验中的重量损失百分比测试以及空气质量参数PM、PM测试和滴蚀试验。用巨大芽孢杆菌进行MICP处理后，UCS显著提高，最高可达1355 kPa，适用于低流量路面基层，耐久性提高至两个干湿循环，风蚀导致的PM和PM水平大幅降低，并且在10分钟的降雨侵蚀试验中抗侵蚀能力增强。这种低碳密集型技术通过将GSD转化为可持续的建筑材料，实现了循环经济目标，解决了废物管理、基础设施弹性和环境可持续性问题。此外，MICP的表面应用有助于实现生态友好型基础设施建设以及GSD储存设施的污染控制。
