Enhance Soil Quality Research Articles

Precision Agriculture Based on Machine Learning and Remote Sensing Techniques

In today's agricultural landscape, precision is crucial, utilizing advanced technologies like IoT, AI, aircraft, and satellite systems. Smart agriculture aims to revolutionize production by monitoring soil quality and employing data analytics through machine learning. This study enhances soil quality assessment in Saudi Arabia's Aljouf region using remote sensing technology. Leveraging UAVs, remote sensing provides crucial data and imagery for olive cultivation. Cloud platforms with satellite data offer invaluable information, aiding public and private decision-making. Proposing an AI-powered application combined with remote sensing, this paper develops predictive models for soil moisture and time-series satellite image analysis. Experimental results show a 91% accuracy with decision tree and extra trees regressor models, highlighting their effectiveness. This research transforms agricultural productivity through advanced technology and data-driven methodologies.

Chitosan-Coated Alginate Matrices with Protein-Based Biostimulants: A Controlled-Release System for Sustainable Agriculture

Developing biodegradable complex fertilizers is crucial for sustainable agriculture to reduce the environmental impact of mineral fertilizers and enhance soil quality. This study evaluated chitosan-based hydrogel coatings for sodium alginate matrices encapsulating amino acid hydrolysates from mealworm larvae, known for their plant growth-promoting properties. The research aims to identify the potential of biopolymer matrices for producing biodegradable slow-release fertilizers and to outline future development pathways necessary for this technology to be usable in the fertilizer industry. Chitosan coatings prepared with citric acid and crosslinked with ascorbic acid optimized plant growth, while those using acetic acid negatively affected it. Water absorption and nutrient release tests showed that chitosan coatings reduced water uptake and slowed initial nutrient release compared to uncoated samples. Leaching assays confirmed controlled-release behavior, with an initial burst followed by stability, driven by alginate–chitosan interactions and ion exchange. The X-ray diffraction (XRD) analysis revealed that adding hydrolysate and chitosan increased amorphousness and reduced porosity, improving structural properties. Thermogravimetric analysis (TGA) and Fourier-transform infrared (FTIR) spectroscopy demonstrated enhanced homogeneity and the presence of chemical interactions, which led to improvements in the material’s thermal stability and chemical characteristics. Biodegradation tests indicated greater durability of chitosan-coated composites, although hydrolysate incorporation accelerated decomposition due to its acidic pH. Germination tests confirmed no phytotoxicity and highlighted the potential of biopolymeric matrices for slow nutrient release. These findings indicate the possibilities of chitosan-coated alginate matrices as sustainable fertilizers, emphasizing the importance of adjusting coating composition and hydrolysate pH for enhanced efficacy and environmental benefits. The main recommendation for future research focuses on optimizing the chitosan coating process by exploring whether adding hydrolysate to the chitosan solution can reduce diffusional losses. Additionally, investigating the use of glycerol in the alginate matrix to minimize pore size and subsequent losses during coating is suggested. Future studies should prioritize analyzing percentage losses during the crosslinking of the alginate matrix, chitosan coating, and final shell crosslinking. This pioneering research highlights the potential for encapsulating liquid fertilizers in biopolymer matrices, offering promising applications in modern sustainable agriculture, which has not been studied in other publications.

Impact of Conservation Agriculture on Soil Quality and Cotton–Maize System Yield in Semi-Arid India

Intensive agriculture is the chief cause of soil degradation, particularly in regions with low soil organic carbon status, such as semi-arid southern India. In the quest to attain sustainable yield and improved soil quality, conservation agriculture (CA) is being advocated and adopted globally, including in India. In this experiment, CA was implemented to investigate the synergistic impacts of tillage and weed management on soil quality index and system yield and to identify a remunerative treatment combination that can sustain system yield and enhance soil quality. Contrasting tillage practices (main plots) included the T1: conventional tillage with cotton–conventional tillage with maize–fallow, i.e., no Sesbania rostrata (Farmers’ practice), T2: conventional tillage with cotton–zero tillage with maize–zero tillage with Sesbania rostrata and T3: zero tillage with cotton + Sesbania rostrata residues–zero tillage with maize + cotton residues–zero tillage with Sesbania rostrata + maize stubbles. Weed management tactics (sub-plots) were W1: chemical weed control, W2: herbicide rotation, W3: integrated weed management and W4: single hand-weeded control in a split-plot design with cotton–maize–Sesbania cropping system over 3 years, in a split-plot design. Principal component analysis (PCA) was performed using the soil quality index (SQI)-CAL Version 1.0 software tool to extract minimum datasets from measured soil properties. A total of 40 soil variables were analyzed at 60 DAS and after the maize harvest, then subjected to principal component analysis (PCA) and subjected to PCA in soil quality index (SQI)-CAL software as to choose variables, minimum dataset and obtain soil quality index. The following soil properties, soil organic carbon (SOC), silt fraction, available soil zinc (Zn), iron (Fe), potassium (K), nitrogen (N), pH, electrical conductivity (EC), soil carbon to nitrogen (C:N) and cation exchange capacity (CEC), were selected as indicators based on correlations, calculated PCA and adept opinions on texture and lime concretions of experimental soil. The soil quality index improved by 23.34% in the T3W4 compared to T1W1. The system yield was 51.79% higher with the adoption of T3W3 compared to T3W4 combinations. Therefore, considering both system yield and soil quality index, T3 and W3 were remunerative and the best treatment combination among all others to sustain both soil and crop productivity in this region.

Fabrication of Functional Polymers with Gradual Release of a Bioactive Precursor for Agricultural Applications

Biodegradable and biocompatible polymeric materials and stimulus-responsive hydrogels are widely used in the pharmaceutical, agricultural, biomedical, and consumer sectors. The effectiveness of these formulations depends significantly on the appropriate selection of polymer support. Through chemical or enzymatic hydrolysis, these materials can gradually release bioactive agents, enabling controlled drug release. The objective of this work is to synthesize, characterize, and apply two controlled-release polymeric systems, focusing on the release of a phyto-pharmaceutical agent (herbicide) at varying pH levels. The copolymers were synthesized via free radical polymerization in solution, utilizing tetrahydrofuran (THF) as the organic solvent and benzoyl peroxide (BPO) as the initiator, without the use of a cross-linking agent. Initially, the herbicide was grafted onto the polymeric chains, and its release was subsequently tested across different pH environments in a heterogeneous phase using an ultrafiltration (UF) system. The development of these two controlled-release polymer systems aimed to measure the herbicide’s release across different pH levels. The goal is to adapt these materials for agricultural use, enhancing soil quality and promoting efficient water usage in farming practices. The results indicate that the release of the herbicide from the conjugate systems exceeded 90% of the bioactive compound after 8 days at pH 10 for both systems. Furthermore, the two polymeric systems demonstrated first-order kinetics for herbicide release in aqueous solutions at different pH levels. The kinetic constant was found to be higher at pH 7 and 10 compared to pH 3. These synthetic hydrogels are recognized as functional polymers suitable for the sustained release of herbicides in agricultural applications.

Approaches to Sustainable Agriculture: A Retrospective Analysis for Soil Health Improvement

Gaining insight into farmers' viewpoints is essential for attaining Sustainable Development Goals in agriculture. By actively involving farmers and integrating their perspectives, it is possible to foster novel strategies that enhance soil quality and bolster the agricultural ecosystem. It is possible to improve soil health and reduce reliance on outside inputs by using regenerative farming methods that are based on agroecological principles and precision farming technologies. Engaging in collaboration with researchers, policymakers, and agricultural communities is crucial to jointly developing creative artificial intelligence (AI), which has the potential to enhance economic expansion, reduce inefficiencies, and provide nutrients directly to plant roots. This transformation revolves around the recognition of solutions that effectively tackle the Sustainable Development Goals (SDGs) and advance the improvement of soil health. The study regenerated previous understanding and recommended that farmers investigate the intricate correlation between bacteria and nutrients to discover more effective approaches to soil management. Several natural alternatives include cyanobacteria, biofertilizers, plant growth-promoting rhizobacteria (PGPR), and livestock manure. Optimal soil health is crucial for the overall functioning and sustainability of entire ecosystems. The study emphasized the significance of prioritizing farmers' practices and adopting their perspectives to comprehend the real-time decision-making process. Furthermore, the study suggested some effective recommendations that farmers should receive to practice land tilling, smart farming adoption, residue management, and weed management. These potential strategies significantly enhance agricultural productivity.

Effect of Nutrient Management on Ricebean [Vigna umbellata (Thunb.) Ohwi and Ohashi]- linseed (Linum usitatissimum L.)

Background: Soil fertility depletion is a major constraint on agricultural production, necessitating a balanced application of inorganic and organic nutrients while effective crop residue management post-harvest enhances soil quality and structure, mitigates evaporation and aids carbon fixation. In Nagaland, agriculture faces challenges like nutrient loss from erosion and minimal use of external inputs while sustainable agriculture requires a viable cropping system and effective crop management; technological advancements in agro-techniques, particularly in cropping systems and nutrient management, are crucial for improving productivity in a ricebean-based linseed cropping system. Methods: A field experiment was conducted to focus on green manuring followed by cultivating a legume crop, rice bean and subsequently linseed in 2019-2021, the investigation would carry out to study the growth, yield and quality parameter and the study was laid in randomized block design with three replications and nine treatments with sources of organic manures and inorganic fertilizers. Result: The study revealed substantial influence of growth and yield which included a combination of poultry manure at 0.7 tons ha-1 along with 100% RDF exhibited superior performance in ricebean, a similar trend was also observed in the subsequent crop, which was linseed and also yielded promising results in terms of plant height, nodules, pods plant-1, seeds pods-1 and yield and concluded to achieve higher seed yield, improve seed quality, preserve soil quality.

Sugarcane biomass-derived biochar for soil quality enhancement in sugarcane-growing soil

This study explored the barrel technique for biochar production, comparing it with laboratory-prepared biochar by evaluating the effect on sugarcane-growing soil quality. Different sugarcane biomass (bagasse, trash, and mini mill waste) derived biochar was prepared using a muffle furnace at three different temperatures (300, 450, and 600 °C) and with the barrel technique. Biochar was characterized by yield, pH, electrical conductivity (EC), proximate and ultimate analysis, scanning electron microscopy (SEM) analysis, and Fourier-transform infrared spectroscopy (FT-IR) characterization. A pot experiment was conducted with soil amendments with biochar (bagasse biochar pyrolyzed at 450 °C–BBC-450 and bagasse biochar prepared from barrel technique–BBC-BT) at a 2.5% (w/w) rate. The initial, 45-day, and 90-day soil samples were analyzed by selected soil chemical and physical parameters. The soil quality index of the 90-day soil samples was determined. Sugarcane biomass-derived biochar was rich in carbon content (64.68%–85.43%). Biochar amendment led to significant enhancements in soil pH, EC, organic carbon (OC), water holding capacity, total N, available P and Zn, and exchangeable K, Ca, and Mg. The results of the 90-day soil samples indicated an increase in soil OC by 1.22% due to both biochar amendments relative to the controls. Available P increased by 2.59% in BBC-BT amended soil and by 23.05% in BBC-450 amended soil. The EC increment due to soil amendments with BBC-BT and BBC-450 was 33.33% and 16.67%, respectively, in the 90-day soil samples. The highest soil quality index was observed in BBC-BT. It can be concluded that BBC-BT enhances the soil quality of sugarcane-growing soil, and the barrel technique could serve as a viable option for small-scale farmers and for domestic use in producing biochar.Graphical

Opportunities, Technological Challenges and Monitoring Approaches in Agrivoltaic Systems for Sustainable Management

In the context of climate change and the increasing demand for innovative solutions in agriculture and energy, agrivoltaic systems (AVSs) have emerged as promising technologies. These systems integrate photovoltaic panels with agricultural practices, optimizing both food and energy production. This study provides a comprehensive review focused on monitoring techniques applicable to AVS, including fixed sensors and remote monitoring tools. Bibliographic analysis revealed a significant increase in scientific interest in AVSs since 2019, with most publications focusing on technological, agronomic, and environmental aspects. Key findings highlight environmental benefits such as reduced greenhouse gas emissions, improved water efficiency, and enhanced soil quality. Otherwise, challenges including high initial costs and the persistence of technical complexities. Innovative configurations such as semi-transparent or vertically bifacial panels enable resource optimization and improved agricultural yields if combined with advanced monitoring systems. This study highlights the importance of incentive policies and further research to maximize the potential of AVSs in promoting sustainable land management.

Unlocking biochar impacts on abiotic stress dynamics: a systematic review of soil quality and crop improvement.

Global agricultural challenges, especially soil degradation caused by abiotic stresses, significantly reduce crop productivity and require innovative solutions. Biochar (BC), a biodegradable product derived from agricultural and forestry residues, has been proven to significantly enhance soil quality. Although its benefits for improving soil properties are well-documented, the potential of BC to mitigate various abiotic stresses-such as drought, salinity, and heavy metal toxicity-and its effect on plant traits need further exploration. This review aims to elucidate BC production by highlighting primary feedstock's and synthesis techniques, and examining its role in boosting soil decomposition efficiency and fertility, which are pivotal for sustainable crop growth. This review also discuss how BC can enhance the nutritional and chemical properties of soil under different abiotic stress conditions, emphasizing its capacity to foster crop growth and development in adverse environments. Furthermore, this article serves as a comprehensive resource for agricultural researchers in understanding the importance of BC in promoting sustainable agriculture, and addressing environmental challenges. Ultimately, this review highlights critical knowledge gaps and proposes future research avenues on the bio-protective properties of BC against various abiotic stresses, paving the way for the commercialization of BC applications on a large scale with cutting-edge technologies.

Effects of Fish Pond Sediment on Yield and Productivity of Two Varieties of Amaranths (<i>Amaranthus</i> <i>spp.</i>)

The rising costs of inorganic fertilizers have rendered them inaccessible to many farmers, resulting in reduced crop yields. An affordable alternative for enhancing soil fertility is the use of organic materials such as fish pond sediments. These sediments are nutrient-rich and have the potential to enhance soil quality, promote crop growth, and increase yields. This study examined the effect of fish pond sediments on the yield and productivity of two amaranth varieties. The research was conducted at the University of Ilorin Teaching and Research Farm. A 2x6 factorial experiment was employed using a Randomized Complete Block Design. The experiment included six sediment application rates: a control (no sediments) and sediment rates of 5, 10, 15, 20, and 25 Mg/ha, applied to two amaranth varieties (green leaf with Accession IDs NHAM 0116-1-2 and NHAM 0112-1-4). Yield and productivity parameters were assessed after 10 weeks. The findings revealed that fish pond sediment application significantly enhanced the yield of both amaranth varieties. The highest yield (51.36 Mg/ha), Chlorophyll A (1.64 mg/dm2), chlorophyll B (1.76 mg/dm2), and crude fibre content (12.18%) were recorded at the sediment application rate of 25 Mg/ha. The results demonstrate that fish pond sediments are a viable nutrient source for improving soil fertility and boosting the growth and yield of amaranths.

Density functional theory calculation for understanding the roles of biochar in immobilizing exchangeable Al3 + and enhancing soil quality in acidic soils.

Soil acidification poses a significant threat to agricultural productivity and ecological balance. While lime is a common remedy, it can have limitations, including nutrient deficiencies and potential soil compaction. Therefore, exploring alternative and sustainable amendments is crucial. This study investigated the efficacy of biochar as a substitute for lime in reducing soil acidification and improving soil quality. Through incubation experiments, we compared the effects of biochar and lime on soil properties. Additionally, we employed density functional theory (DFT) calculations to elucidate the mechanisms underlying biochar's ability to immobilize exchangeable Al3+. Furthermore, we conducted 15N double-labeled incubation experiments to examine the impact of biochar on soil nitrogen (N) transformation in acidic conditions. Our results indicated that biochar was as effective as lime in enhancing soil quality and mitigating acidification. Soils developed from the Jurassic Shaximiao Formation (J2s) purple mudstone with 3 % biochar addition exhibited a 31.15 % and 17.43 % increase in total N compared to soils treated with 0.1 % and 0.2 % lime, respectively. Similarly, soils developed from the Cretaceous Jiaguan Formation (K2j) purplish red sandstone with 1 % and 3 % biochar addition showed a 38.75 % and 64.30 % increase in soil organic carbon compared to soils treated with 0.2 % lime. DFT calculations revealed that biochar's functional groups exhibited a stronger affinity for immobilizing exchangeable Al3+ than other soil cations. This preferential adsorption was attributed to the stronger interaction and higher bond dissociation energy between biochar functional groups and Al3+. These findings collectively highlight the potential of biochar as a sustainable and effective amendment to reduce Al toxicity in acidic soils, thereby promoting soil quality and sustainable agricultural and ecological practices.

Proposed Relationships Between Climate, Biological Soil Crusts, Human Health, and in Arid Ecosystems.

Biological soil crusts (or biocrust) are diminutive soil communities with ecological functions disproportionate to their size. These communities are composed of lichens, bryophytes, cyanobacteria, fungi, liverworts, and other microorganisms. Creating stabilizing matrices, these microorganisms interact with soil surface minerals thereby enhancing soil quality by redistributing nutrients and reducing erosion by containment of soil particles. Climatic stressors and anthropogenic disturbances reduce the cover, abundance, and functions of these communities leading to an increase of aeolian dust, invasive plant establishment, reduction of water retention in the environment, and overall poor soil condition. Drylands are the most degraded terrestrial ecosystems on the globe and support a disproportionately large human population. Restoration of biocrust communities in semi-arid and arid ecosystems benefits ecosystem health while decreasing dust emissions. Dust abatement can improve human health directly but also indirectly by reducing pathogenic microbe load circulating in the ambient air. We hypothesize that biocrusts not only reduce pathogen load in the air column but also inhibit the proliferation of certain pathogenic microbes in the soil. We provide a review of mechanisms by which healthy biocrusts in dryland systems may reduce soil-borne pathogens that impact human health. Ecologically sustainable mitigation strategies of biocrust restoration will not only improve soil conditions but could also reduce human exposure to soil-borne pathogens.

Enhancing soil quality and maize growth while reducing Cd accumulation with biochar and humic acid in northwestern China

Enhancing soil quality and maize growth while reducing Cd accumulation with biochar and humic acid in northwestern China

Integrating plant growth microorganisms in potato farming reduce soil CO2 emissions and improve crop quality

AbstractCurrent horticultural practices typically require high demands of fertilizers, leading to significant environmental impacts and increased production costs. Alternatives based on microbial inoculants have garnered considerable interest owing to their potential to enhance soil quality whilst reducing external inputs and costs, all without compromising productivity. This study aimed to compare the impact of four fertilizer application strategies, including mineral fertilizers and microbial inoculants, on crop yield, soil fertility and functionality and soil greenhouse gas emissions in potato production in Southern Spain. Four treatments were tested: (i) mineral fertilizers added to meet the crop's nutritional needs (F100); (ii) a 50% reduction of the F100 rate (F50); (iii) a 50% reduction of the F100 rate combined with the application of a formulation containing nutrient‐solubilizing bacteria, nitrogen‐fixing bacteria and non‐mycorrhizal fungi (BAI+FU) and (iv) a 50% reduction of the F100 rate combined with a formulation of N, P and K solubilizing bacteria (BAII). Results showed that crop yield was unaffected by the different fertilizer application treatments. However, the mean tuber weight and firmness were significantly higher under the BAI+FU treatment, indicating improved product quality. CO2 release rates decreased by 25%, 34% and 42% with F50, BAI+FU and BAII treatments, respectively, compared with F100. The N2O and CH4 emissions or soil nutrient contents were not affected by treatments, except for ammonium content, which was highest under the BAI+FU treatment. Additionally, whilst overall soil bacterial and fungal abundance was not significantly affected, the BAI+FU treatment resulted in a higher number of nirK (denitrification) and cbbL (carbon fixation) gene copies. Therefore, combining biofertilizers with reduced chemical fertilizer rates could represent a sustainable strategy for mitigating climate change whilst enhancing crop quality in potato production.

Characteristics of latosol soil after application of rice husk biochar in Bogor Regency, Indonesia

Latosol soil is one of the predominant soil types in the Bogor region, but it is characterized by low nutrient content. One approach to improving soil conditions is the use of biochar as a soil amendment. Biochar, being rich in carbon, has the potential to enhance soil quality. This study aimed to examine the characteristics of soil after the application of rice husk biochar. The application of rice husk biochar was found to influence the characteristics of latosol soil. Higher biochar doses resulted in increased soil electrical conductivity and total carbon content, with the highest values recorded at a treatment level of 125 tons/ha, reaching 335.7 μS/cm and 4.71%, respectively. In this study, the addition of biochar had no effects on soil pH and total nitrogen content. Additionally, silicon content in the soil was enhanced by the application of rice husk biochar. Overall, the application of rice husk biochar can improve the quality of latosol soil in Bogor Regency.

The Impact of Biochar Derived from Corncobs in Ameliorating Soil Quality of Rice Farm in Dutse, Nigeria

In response to the challenges posed by organic soil contamination, a promising approach involves the application of biochar. This study investigates the effects of biochar derived from corncobs on soil organic matter, organic carbon, and soil microbial biomass carbon through one-factor factorial design experiments. Crushed corncobs were subjected to pyrolysis at 300 °C to produce corncobs-biochar, which was incrementally added to pots containing four different levels of paddy soils. Results indicated a significant enhancement (p<0.05) in the physicochemical composition of samples and improved acid degradation upon the addition of corncob-biochar with pH increasing from 1.3 in control to 9.10 in the highest treatment (TP4), along with notable improvements in electrical conductivity, cation exchange capacity, and organic carbon levels. The most effective biochar applications, TP3 and TP4, demonstrated improved nutrient retention and reduced soil acidity. This suggests that incorporating corncob-biochar into the soil can ameliorate acidic conditions and sequester carbon for future ecosystem use. In conclusion, amending soil with corncob-biochar demonstrates a notable enhancement in soil quality. The environmentally friendly application of corncob-biochar could be recommended by offering a sustainable and economically practical strategy for enhancing soil quality, addressing soil degradation, and promoting long-term agricultural productivity.

The Impact of Protective Policies on Farmers’ Black Soil Conservation Behaviors: Empirical Insights from Sanjiang Plain, China

Understanding the logic of farmers’ black soil conservation behaviors and promoting these actions are crucial measures for enhancing soil quality and ensuring national food security. This article uses survey data from 676 farmers in typical black soil areas of the Sanjiang Plain, China, employing binary logistic regression and mediation effect models to empirically examine the impact of protective policies on farmers’ black soil conservation behaviors and the mediating effect of their perceptions. The results indicate: (1) Protective policies have a significant positive effect on farmers’ black soil conservation behaviors. (2) Farmers’ perception of black soil conservation plays a crucial mediating role in the impact of policy guidance on conservation behaviors. Protective policy not only directly influences farmers’ behaviors but also indirectly promotes conservation actions by shaping farmers’ sense of responsibility and awareness of obligations. (3) There are variations in the mediating effects of farmers’ cognition based on different types of cultivated land and operational scales. Therefore, efforts should be made to strengthen the promotion and implementation of black soil protection policies and subsidies to enhance the sustainability and effectiveness of conservation practices. Greater emphasis should be placed on policy advocacy to raise farmers’ sense of responsibility and awareness of the importance of black soil conservation. Additionally, the diverse needs of different types of farming households should be considered, and a range of measures should be implemented to encourage active participation in black soil conservation.

Contaminants Removal and Monitoring: The Role of Hybrid MOFs in Agricultural Advancement and Soil Amendment

AbstractThe interest in improving soil quality through innovative methods continues to grow in sustainable agriculture. Despite the emergence of new techniques, there has been limited research on methods based on metal‐organic frameworks (MOFs). This review first addresses the current issues in the soil and agriculture industry and discusses recent approaches for improving soil quality. It then explores the latest advancements in MOF‐based methods, which hold the potential to enhance soil quality and increase crop yields significantly. The unique properties and physicochemical mechanisms behind MOFs' applications and analytical performance are presented, highlighting their potential for more efficient and cost‐effective soil enhancement solutions. The review reveals that these new MOF approaches show promise in enhancing soil quality through processes such as adsorption, extraction, analyte monitoring, fertilization, soil washing, and moisture sensing. This review can lead to a future with higher soil quality, ensuring better food production and a more sustainable agricultural industry.

Photochemistry of dissolved organic matter derived from compost.

The extensive application of compost to enhance soil quality highlights the crucial role of dissolved organic matter (DOM) derived from compost in both terrestrial and aquatic ecosystems, influencing carbon cycling and the fate of contaminants. However, the photochemical behavior of compost-derived DOM (DOMCOM) remains poorly understood. In this study, we investigated the photochemical transformation and photoactivity of DOM derived from typical composts produced from cow manure (CDOM) and pig manure (PDOM). The results indicated that the initial CDOM exhibited higher molecular weight, aromaticity, humification, and photoactivity compared to PDOM. Under UV irradiation, both DOMCOM underwent photobleaching and photo-humification, resulting in a decrease in the average molecular weight by 23.68% for CDOM and 3.82% for PDOM, with CDOM being particularly affected. Meanwhile, 2D-COS analysis revealed that the fulvic-like fluorescence fraction was first to respond to photoirradiation in both DOM, followed by the protein-like and microbial humic-like fluorescence fractions, which showed contrasting response trends in CDOM and PDOM. Furthermore, CDOM with a higher concentration of humic-like substances efficiently generated 3DOM*, 1O2 and •OH (4.09×10-8, 1.17×10-8 and 7.05×10-12, respectively) under UV radiation, which were apparently greater than those produced by PDOM (3.30×10-8, 8.38×10-9 and 4.99×10-12, respectively).

Life Cycle Assessment of Crude Oil-Contaminated Soil Treated by Low-Temperature Thermal Desorption and Its Beneficial Reuse for Soil Amendment

The effectiveness of thermal treatment technologies for the remediation of soils contaminated with heavy hydrocarbons has been extensively documented in the scientific literature. In general, high-concentration crude-oil-contaminated soil is treated with high-temperature thermal desorption (HTTD) in order to achieve high remediation efficiency. However, this process has the unintended consequence of destroying soil fertility. Low-temperature thermal desorption (LTTD) represents an alternative approach that has been developed with the objective of remediating heavily crude-oil-contaminated soil in a more rapid and cost-effective manner while simultaneously enhancing soil fertility. The thermal desorption unit (TDU) was employed using both LTTD and HTTD, operating at 300 °C and 500 °C, respectively, with a 30 min residence time in the kiln. The concentration of total petroleum hydrocarbons (TPH) in both the LTTD- and HTTD-treated soils was found to be less than 1% by weight, thereby below regulatory standards. The environmental impacts of both processes were assessed using the OpenLCA software version 2.0. The HTTD process exhibited a total abiotic depletion potential (ADP) impact of 1.63 × 10−4 MJ and a global warming potential (GWP) of 414 kg CO2-eq. In contrast, LTTD demonstrated lower impacts, with an ADP of 1.29 × 10−4 MJ and a GWP of 278 kg CO2-eq. The transition from HTTD to LTTD resulted in a notable reduction in ADP by 20.5% and in GWP by 32.9%. The application of LTTD-treated soil coated with coke or carbonized residues has been demonstrated to serve as an effective soil amendment, with the capacity to sequester approximately 50% of organic hydrocarbon contaminants. The results of this study illustrate the potential of LTTD for not only economical and rapid soil remediation but also the enhancement of soil quality through beneficial reuse.