مروری تحلیلی بر کاربرد فناوری رسوب‌گذاری کربنات القاشده توسط آنزیم در تثبیت خاک و کنترل گردوغبار

Background and Objectives: Fugitive dust emissions and dust storms represent a critical environmental and land-management problem in arid and semi-arid regions, where sparse vegetation, surface disturbance, drought, and salinity accelerate wind erosion and soil degradation. Conventional dust suppression and stabilization practices often face limitations such as short service life, high water consumption, recurring maintenance, or ecological incompatibility. Enzyme-Induced Carbonate Precipitation (EICP) has emerged as a bio-mediated alternative that can improve soil structure through calcium carbonate bonding without the operational complexity of handling living microorganisms. This study aims to (i) explain the fundamental mechanism of EICP and its relevance to dust control, (ii) identify the key operational and soil-related parameters governing treatment efficiency, (iii) assess the suitability of different urease sources—particularly plant-derived urease—for large-scale applications, and (iv) summarize the principal technical, environmental, and research challenges that must be addressed to enable reliable field deployment in critical dust hotspots.
Methodology: An analytical narrative review was conducted by synthesizing research on urease-driven carbonate precipitation, EICP-based soil improvement, and surface stabilization for wind erosion mitigation. The literature was examined with emphasis on: reaction chemistry (urea hydrolysis and carbonate generation), precipitation behavior (CaCO₃ content, crystal morphology, and spatial distribution), treatment implementation (spraying, percolation, shallow injection, and multi-cycle application), and field-relevant performance indicators (crust formation, strength improvement, permeability variation, and erosion resistance). The review also compared urease sources (commercial/purified, microbial, and plant-derived) in terms of availability, cost, activity stability, and environmental compatibility, and compiled reported limitations including non-uniform cementation, pore clogging risk, by-product management, and durability under weathering.
Results: The reviewed evidence indicates that EICP can significantly enhance near-surface cohesion by precipitating calcium carbonate within pore spaces and at grain contacts, thereby promoting interparticle bonding and forming a protective crust. Such crusting can increase surface resistance to aerodynamic forces and reduce particle detachment, supporting the potential use of EICP as a dust suppression measure in loose sandy and silty soils commonly associated with active dust sources. Treatment performance is strongly controlled by temperature and pH (which affect urease kinetics and carbonate availability), enzyme activity and dosage, urea and calcium concentrations and their molar balance, and the choice of calcium salt. Soil texture and pore structure influence reagent transport and precipitation uniformity; coarse materials may allow deeper penetration but require repeated cycles to achieve adequate crust integrity, whereas finer materials can produce stronger surface sealing but may exhibit localized clogging and heterogeneity. Application strategy is likewise decisive: surface spraying is practical for large areas but tends to create depth gradients in CaCO₃, while percolation or shallow injection can improve penetration at the cost of higher operational complexity. Plant-derived urease is highlighted as a promising route for scaling EICP, since it may reduce costs and improve accessibility for extensive treatment in remote drylands; however, variability in extraction protocols, enzyme stability, and activity quantification can limit reproducibility unless standardized procedures are adopted. Across studies, persistent constraints include uneven precipitation distribution, uncertain long-term performance under wetting–drying and salt cycles, and environmental concerns related to ammonium generation and potential salinity impacts.
Conclusion: EICP is a developing yet highly promising technology for environmentally compatible soil stabilization and dust control. By enabling carbonate-based cementation without reliance on viable microbial cultures, it offers practical advantages for deployment under harsh field conditions. The literature supports its capacity to form erosion-resistant surface crusts and improve mechanical properties relevant to wind erosion mitigation, but translation to routine field practice requires targeted optimization. Future progress depends on establishing performance-based design criteria linked to dust-control outcomes, improving treatment uniformity through refined delivery protocols, standardizing plant-urease extraction and activity reporting, and implementing effective management strategies for ammonium and salinity risks. Well-designed pilot and long-term field trials in representative dust hotspots are essential to validate durability, quantify environmental trade-offs, and define robust guidelines for large-scale application.