Environmental Erosion Research

fa مدیریت همزمان فرسایش خاک و آلودگی محیطی با بهره‌گیری از گیاه بومی اشنان در حذف رنگ کریستال ویوله از پساب Integrated Management of Soil Erosion and Environmental Pollution Using the Native Desert Plant, Seidlitzia rosmarinus, for Crystal Violet Dye Removal from Wastewater مدیریت و کنترل اثرات فرسایش محیطی پژوهشي Research <a name="_Hlk217987791">افزایش جمعیت، توسعه فعالیت‌های صنعتی و تغییرات شتابان محیطی در دهه‌های اخیر، منجر به افزایش تولید پساب‌های آلاینده و تشدید فشار بر منابع آب و خاک شده است که این روند به‌ویژه در مناطق خشک و نیمه‌خشک، با تخریب خاک و تشدید فرسایش همراه است. پساب‌های حاوی رنگ‌های آلی پایدار، علاوه بر آلودگی منابع آب، در صورت نفوذ یا استفاده ناصحیح، می‌توانند کیفیت فیزیکی و شیمیایی خاک را کاهش داده، نفوذپذیری و پایداری خاکدانه‌ها را مختل کرده و فرآیندهای فرسایشی را تشدید کنند. در این چارچوب، تصفیه پساب و امکان بازچرخانی ایمن آن، به‌عنوان راهبردی مؤثر در مدیریت پایدار منابع آب و حفاظت خاک مطرح است. هدف این پژوهش، بررسی قابلیت گیاه بومی و بیابانی اشنان به‌عنوان یک جاذب زیستی طبیعی و سازگار با محیط‌زیست در حذف رنگ کریستال ویوله از محلول‌های آبی و تبیین نقش بالقوه این رویکرد در حمایت از برنامه‌های مدیریت فرسایش خاک است. آزمایش‌های جذب به‌صورت ناپیوسته انجام شد و اثر پارامترهای </a>pH، غلظت اولیه رنگ، زمان تماس و مقدار جاذب بررسی گردید و داده‌ها با استفاده از مدل‌های سینتیکی شبه‌مرتبه اول و شبه‌مرتبه دوم و ایزوترم‌های لانگمویر، فروندلیش، تمکین و دوبینین–رادوشکویچ تحلیل شدند. نتایج نشان داد، بیشترین راندمان حذف رنگ در pH برابر 7 حاصل شد و فرآیند جذب با مدل سینتیکی شبه‌مرتبه دوم تطابق بیشتری دارد؛ همچنین ایزوترم دوبینین–رادوشکویچ بهترین انطباق را با داده‌های تجربی نشان داد، به‌طوری که ظرفیت جذب 41/35 میلی‌گرم بر گرم و حداکثر راندمان حذف 25/96 درصد به‌دست آمد. بر اساس نتایج، استفاده از گیاه بومی اشنان در تصفیه پساب، علاوه بر کاهش آلودگی‌های محیطی، می‌تواند زمینه بازچرخانی کنترل‌شده آب را برای تقویت پوشش گیاهی فراهم سازد که از طریق افزایش رطوبت خاک، بهبود پایداری ساختاری خاک و کاهش رواناب، به‌طور غیرمستقیم در کنترل و مدیریت فرسایش خاک مؤثر است. این رویکرد تلفیقی، ظرفیت بالایی برای به‌کارگیری در برنامه‌های حفاظت خاک و مدیریت پایدار اکوسیستم‌های مستعد فرسایش دارد.   Extended Abstract 1. Introduction Rapid population growth, industrial development, and unsustainable environmental exploitation have imposed increasing pressures on water and soil systems worldwide. Discharge of industrial effluents into surface and groundwater not only threatens aquatic ecosystems but also indirectly impacts soil quality. Organic dyes, such as crystal violet, are particularly concerning due to their chemical stability, toxicity, and resistance to biodegradation. When these pollutants infiltrate soils, they can alter physical and chemical properties, reduce infiltration, disrupt microbial activity, and weaken aggregate stability, increasing soil susceptibility to both water and wind erosion. These effects are especially pronounced in arid and semi-arid regions with sparse vegetation cover.Cleaner production and sustainable resource management strategies aim to minimize environmental contamination through reduced resource consumption, elimination of toxic chemicals from production processes, and decreased effluent generation. In this context, natural, biodegradable, and low-cost biosorbents have gained attention as effective tools for removing organic pollutants from wastewater. Plant-derived materials are particularly promising because they are readily available, environmentally friendly, and do not generate secondary pollution. Furthermore, integrating biosorbent-based wastewater treatment with controlled water reuse can enhance soil moisture, support vegetation growth, and indirectly contribute to soil conservation and erosion control.This study focuses on evaluating Seidlitzia rosmarinus, a native desert plant, as a biosorbent for removing crystal violet from aqueous solutions. The research aims to develop an effective, economical, and environmentally compatible treatment approach, which simultaneously improves aquatic ecosystem health, enables controlled water reuse, and indirectly reduces soil vulnerability to erosion.Crystal violet, a synthetic cationic triphenylmethane dye with molecular weight of 407.98 g/mol and chemical formula C25H30N3Cl, is widely used in textile, medical, and laboratory applications. Its structural stability and covalent bonding make it highly resistant to light, heat, and microbial degradation. Conventional wastewater treatment methods—including chemical oxidation, coagulation-flocculation, membrane filtration, photocatalysis, ion exchange, electrochemical processes, and aerobic or anaerobic treatments—often involve high costs, complex operations, or secondary pollutant formation. Adsorption, due to its simplicity, high efficiency, and scalability, remains a practical method for dye removal. However, common adsorbents like activated carbon face limitations related to production cost, regeneration difficulty, and environmental impact. Consequently, research has shifted toward unconventional natural biosorbents, including agricultural residues and desert plants, for their affordability, biodegradability, and capability for safe water reuse. 2. Methodology Seidlitzia rosmarinus biomass was collected from desert regions in Yazd Province, Iran. Samples were washed, dried, ground, and sieved to produce fine powder. Crystal violet solutions with concentrations ranging from 40 to 90 mg/L were prepared using distilled water. Batch adsorption experiments were conducted to evaluate the influence of pH, biosorbent dosage, contact time, and initial dye concentration. Solution pH was adjusted with 0.1 M HCl or NaOH.The point of zero charge (pHpzc) of the biosorbent was determined using the pH drift method, providing insight into surface charge behavior under different pH conditions. Dye concentrations were measured using UV–Vis spectrophotometry at 558 nm. Adsorption capacity (qe) and removal efficiency (%) were calculated through standard mass balance equations. Kinetic studies were performed using pseudo-first-order and pseudo-second-order models, while equilibrium data were fitted to Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherms. Thermodynamic parameters (ΔG°, ΔH°, ΔS°) were estimated at multiple temperatures. Reusability was assessed over five consecutive adsorption–desorption cycles 3. Results FTIR analysis revealed the presence of hydroxyl, carbonyl, carboxyl, aromatic, and amine groups on the biosorbent surface, suggesting the potential for hydrogen bonding, electrostatic interactions, and π–π interactions with crystal violet molecules. The pHpzc was found to be 7.1, indicating that the biosorbent surface carries a negative charge under neutral to slightly alkaline conditions, favoring adsorption of the cationic dye.Maximum dye removal occurred at pH 7. Contact time experiments showed rapid adsorption, reaching equilibrium within 15 minutes. Increasing biosorbent dosage enhanced removal efficiency until a saturation point was reached. Higher initial dye concentrations led to decreased removal percentages due to competition for limited adsorption sites.Kinetic analysis showed that adsorption followed the pseudo-second-order model more accurately than the pseudo-first-order model, indicating that chemisorption on active sites dominated the process. Equilibrium data fitted best to the Dubinin–Radushkevich isotherm, with a maximum adsorption capacity (qm) of 35.41 mg/g. Thermodynamic analysis indicated spontaneous adsorption (negative ΔG°), endothermic behavior, and reduced system disorder (negative ΔS°). Reusability tests demonstrated acceptable adsorption efficiency over multiple cycles, confirming the practical applicability of S. rosmarinus as a sustainable biosorbent. 4. Discussion & Conclusions The results confirm that Seidlitzia rosmarinus is an effective and sustainable biosorbent for crystal violet removal, combining high adsorption capacity, rapid kinetics, and favorable thermodynamics. The pseudo-second-order kinetic model and Dubinin–Radushkevich isotherm suggest that adsorption is governed by chemical interactions on active sites and micro-pore diffusion mechanisms.Beyond its efficiency in dye removal, using S. rosmarinus supports controlled reuse of treated wastewater, which can enhance soil moisture content, promote vegetation establishment, and stabilize soil aggregates. These indirect effects are particularly valuable for mitigating soil erosion in arid and semi-arid regions. By improving water availability and maintaining vegetation cover, this approach contributes to sustainable soil management and erosion control.Utilizing native, plant-based biosorbents aligns with cleaner production and integrated environmental management strategies. It reduces reliance on costly synthetic adsorbents, minimizes secondary pollution, and facilitates eco-friendly wastewater treatment practices. Moreover, this approach provides a dual benefit: protecting aquatic ecosystems by removing persistent dyes and supporting terrestrial ecosystems by indirectly improving soil structure and resilience to erosion.In conclusion, Seidlitzia rosmarinus represents a low-cost, environmentally compatible, and technically feasible biosorbent for industrial dye removal. Its application supports sustainable wastewater treatment, enables controlled water reuse, and contributes indirectly to soil conservation and erosion mitigation. These findings highlight the potential of combining biosorption technology with ecosystem-based management strategies to address water and soil challenges in arid and semi-arid landscapes. Future research should explore field-scale applications and integration with land management practices to maximize environmental benefits.   بازچرخانی آب؛ تصفیه پساب؛ جذب زیستی؛ حفاظت خاک؛ فرسایش خاک؛ گیاه بیابانی؛ مدیریت پایدار سرزمین. Water reuse, Wastewater treatment, Biosorption, Soil conservation, Soil erosion, desert plants, Sustainable land management. 160 179 http://magazine.hormozgan.ac.ir/browse.php?a_code=A-10-73-4&slc_lang=fa&sid=1 mahdi tazeh مهدی تازه mehditazeh@gmail.com 100319475328460010146 100319475328460010146 Yes Department of Nature Engineering, Faculty of Agriculture & Natural Resources, Ardakan University, P.O. Box 184, Ardakan, Iran گروه طبیعت، دانشکده کشاورزی و منابع طبیعی، دانشگاه اردکان، اردکان، یزد، ایران. saeideh kalantari سعیده کلانتری skalantari@ardakan.ac.ir 100319475328460010147 100319475328460010147 No Department of Nature Engineering, Faculty of Agriculture & Natural Resources, Ardakan University, P.O. Box 184, Ardakan, Iran گروه طبیعت، دانشکده کشاورزی و منابع طبیعی، دانشگاه اردکان، اردکان، یزد، ایران.