Research Article
Post-harvest technologies
F. Kiumarsi Darbandi; Y. Selahvarzi; B. Abedy; M. Kamali; H. Sadrnia
Abstract
IntroductionVarious methods have been used to dry grapes. The main purpose is to increase shelf life, produce high-quality dried grapes, and also produce raisins to reduce post-harvest losses. Different methods can be used to dry grapes. Sun drying is the method traditionally used to dry commercial raisins. ...
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IntroductionVarious methods have been used to dry grapes. The main purpose is to increase shelf life, produce high-quality dried grapes, and also produce raisins to reduce post-harvest losses. Different methods can be used to dry grapes. Sun drying is the method traditionally used to dry commercial raisins. However, this process is very slow and depends mainly on weather conditions, which can cause microbial and insect contamination in dried fruits and hence, reduce their quality. Recently, advanced vacuum drying techniques have been used in order to increase the amount of water removal and ensure better quality of raisins. Vacuum drying (VD) is a process in which wet materials are dried under subatmospheric pressure. Vacuum pressure reduction increases the mass of water between the fruit and its surroundings, thereby reducing the heat needed for rapid drying. Therefore, vacuum drying is a promising technology for drying grapes and has been used in current works. Preserving the quality of raisins and maintaining their essential nutritional indicators is a vital aspect of effective management strategies aimed at enhancing product quality. This improvement boosts demand for raisins in both domestic and international markets. Finding new methods of drying while maintaining the desired quality and preventing contamination are other factors that determine the quality of raisins. On the other hand, it is very important to determine the right time to harvest grapes according to the climatic conditions of each region and its effect on the quality of raisins. For this purpose, in this study, some quantitative, qualitative, and nutritional indicators related to raisins were compared between the sun-dried and vacuum drying methods for the white Quchan cultivar, evaluating the potential of each method in this field.Materials and MethodsThis research was conducted in 2021-2023 in one of the vineyards of the Quchan region in Iran. Quchan city is located within the geographical coordinates of 36 to 37 degrees north latitude and 58 degrees 10 minutes to 58 degrees 58 minutes east longitude. The relative humidity of this city is 40% in summer, 65% in spring, and 60% in autumn. Based on 10-year statistics, the average annual rainfall in this area is 274 mm. This research project was done in the form of a split plot, based on a randomized complete block design with four replications. Experimental factors include three harvesting times (August 27th, September 6th, and 16th) and four modes of drying (sun drying, and vacuum drying at 60, 70, and 80 °C). Fruits were harvested at three different stages, with time intervals of 10 days from August 27 to September 16, based on the sugar content in the pods and the ratio of total soluble solids (TSS) to titratable acidity (TA). At each harvest time, the grapes were dried in four different ways. In the first method, the grapes were dried traditionally in the open environment and in front of the sunlight. In the second method, the grapes were dried using a vacuum system at three different temperatures of 60, 70, and 80°C.Results and DiscussionIn general, the interaction of harvesting time and drying method had a significant effect on most of the studied traits. The grape drying methods employed in this research significantly influenced the levels of phenolic compounds, flavonoids, and the antioxidant capacity of the resulting white seedless raisins. The amount of these compounds in sun-dried raisins was lower than the raisins produced using the vacuum drying method. The interaction effect of harvesting time and drying method on the production raisin yield was significant at the 1% probability level. The highest yield was related to the third harvest under the vacuum dryer at 60°C (305.52 g kg-1), and the lowest yield was related to the first and second harvests with an average of 270.29 g kg-1 in the sun-dried method. In general, the highest amount of TSS was related to the treatments of the third harvest, which was observed in vacuum drying at 60°C. After that, no significant difference was observed in temperatures of 70 and 80°C. The amount of antioxidant, phenol, flavonoid, and total sugar content in the vacuum drying treatment was higher than the sun drying method. The total soluble sugars in sun-dried raisins were, on average, 22.68% lower compared to those dried using the vacuum method. In terms of total microbial count, the highest microbial load (126.51 Cfu g-1) was related to sun-dried raisins. The treatments under vacuum drying at all three temperatures of 60, 70, and 80°C showed the lowest amount of microbial load (almost zero). The low level of microbial contamination in raisins produced by the vacuum method in this research can be attributed to the short drying time and also the lack of contact with the surrounding environment.ConclusionVacuum drying is a new technology that has been developed in recent years, employing a lower pressure in the chamber to increase the moisture transfer during the drying process. In this method, due to the lack of oxygen in the environment, some undesirable biochemical reactions such as browning, oxidation, and degradation reactions are reduced. In addition, the periodic pressure change can create fissured and porous structures in the skin of the sample, thereby increasing the mass transfer through the pores. Overall, the results of this research showed that the raisins produced in the third harvest and using vacuum drying at 60°C had better quality than other treatments in terms of biochemical and sensory characteristics, including flavor, texture, and color. It can also be concluded that the vacuum drying method is a good alternative to traditional drying methods.
Research Article
Agricultural systems engineering (greenhouse, fish farming, mushroom production)
M. Bamdad; M. Zangeneh; S. H. Payman
Abstract
IntroductionThe cooperative system for agricultural mechanization services holds significant potential to boost agricultural production. Key benefits include providing services during crop cultivation to reduce labor demands, delivering centralized and specialized services to lower production costs, ...
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IntroductionThe cooperative system for agricultural mechanization services holds significant potential to boost agricultural production. Key benefits include providing services during crop cultivation to reduce labor demands, delivering centralized and specialized services to lower production costs, facilitating the adoption of new technologies, and improving productivity in agricultural processes and supply chains. However, in Gilan Province, Iran, over 198 of the 260 registered mechanization service cooperatives, approximately 76%, are currently inactive. This significant decline highlights an urgent need to assess the performance of the mechanization service system to ensure its sustainability. Therefore, this study aims to identify the main challenges underlying the inactivity of these cooperatives in Gilan Province.Materials and MethodsThis study aims to evaluate the performance of mechanization service cooperatives in Gilan Province. To achieve this objective, a combined methodology incorporating Delphi methods, hierarchical analysis process, and the SWOT (strengths, weaknesses, opportunities, and threats) analysis was employed. Initially, factors influencing the performance of agricultural service cooperatives were identified through a review of existing literature concerning the performance pathology of agricultural cooperatives, as well as the specific factors impacting mechanization cooperatives and the associated challenges they face. The Delphi method was utilized to align the identified factors with the operational conditions of agricultural mechanization service cooperatives in Gilan Province. The Delphi process was conducted over three rounds, culminating in the identification and prioritization of the primary factors. Subsequently, the SWOT matrix was applied to assess the strengths, weaknesses, opportunities, and threats related to the mechanization service cooperatives, with input from a panel of experts for ranking purposes. Ultimately, strategies to address the performance challenges were developed based on the SWOT results and prioritized using AHP.Results and DiscussionThe findings of this research indicate that the lack of capital in the cooperative company, coupled with financial and credit difficulties, insufficient tools and equipment needed for generating income for members, stringent bank policies regarding the provision of financial aid, and the presence of discrepancies in the selection of cooperative members constitute the primary obstacles faced by these companies. The most important recommended strategies are as follows: Leverage internal investment from cooperative members. Attract capital from entrepreneurs. Organize tours to visit successful cooperatives for information exchange and learning. Reduce service fees. Increase access to financial assistance. Lower guarantee requirements for newly established cooperatives and entrepreneurs seeking financial supportConclusionIn this study, a comprehensive review of existing literature was conducted to identify the challenges affecting cooperative performance. These challenges were categorized into six main groups: financial, operational, organizational, structural, social, and environmental. The Delphi method, involving a panel of nine field experts, was used to evaluate these issues. Additionally, a SWOT analysis, based on previous research, was carried out to assess the strengths, weaknesses, opportunities, and threats related to cooperatives. To determine the relative importance of each challenge, a hierarchical analysis was performed to rank them accordingly.The results revealed that the most pressing challenges are primarily financial or have a significant financial impact on cooperative operations. Key issues include strict bank loan requirements, internal financial and credit difficulties, limited capital resources, and a lack of necessary tools and equipment to generate income for members. Moreover, the member selection process was identified as a critical concern, as it can lead to reduced motivation and inadequate fulfillment of responsibilities among cooperative members.
Research Article
Design and Construction
H. Samimi Akhijahani; M. S. Barghi Jahromi
Abstract
IntroductionWalnut (Juglans regia L.) is a highly valued horticultural product, and significant efforts are underway to enhance its production in Iran. Despite the development of various tools aimed at increasing productivity and improving harvesting efficiency, over 90% of walnuts in Iran are still ...
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IntroductionWalnut (Juglans regia L.) is a highly valued horticultural product, and significant efforts are underway to enhance its production in Iran. Despite the development of various tools aimed at increasing productivity and improving harvesting efficiency, over 90% of walnuts in Iran are still harvested manually, often with the aid of specialized tools or by striking the trees with sticks. Although numerous mechanical devices have been introduced, the considerable height of walnut trees and the asynchronous ripening of the nuts continue to make traditional harvesting methods predominant. In this research, a novel walnut peeling system incorporating a horizontally rotating cutting plate was developed and evaluated. The cutting plate, designed with specific grooves and curvature, aims to enhance the mechanical efficiency of the peeling process. This analysis investigates the influence of rotational speed and groove depth on system performance. In addition, the life cycle assessment is conducted to evaluate the environmental and operational impacts of the proposed system, with comparative analysis against conventional peeling methods.Materials and MethodsThe designed and constructed system consists of three main parts: the container, the rotating disk, and the power system, which includes the electric motor. The rotating disk, as the heart of the system, is made from a 1.5 mm thick steel sheet with a diameter of 640 mm. It has been laser-cut with sufficient precision to cut and transfer walnuts. The third part of the system is the power unit, which includes a 3-hp, 1400 rpm electric motor. Power transmission is carried out using a V-shaped belt. In this system, the product is first collected from the designated garden and stored in equally weighted bags. The rotating plate is the most important component of the walnut peeler, essentially the heart of the system. On this plate, there are 12 oval grooves, each 5 mm in diameter and 150 mm in length. One side of each groove is raised, with a depth that can be varied. Increasing the groove depth increases the amount of peel removed and exposes a larger surface of the walnut. The plate is connected to the driven pulley and then to the electric motor via a shaft. In this research, a life cycle assessment was also used to evaluate the impact of various parameters of the walnut peeling system on the environment and its pollution level.Results and DiscussionThe findings from the variance analysis regarding the impact of groove depth and rotation speed on peeling percentage indicate that variations in plate groove depth and electric motor rotation speed during walnut peeling are significant at the 1% level. Furthermore, the impact of changes in the groove depth of the cutting plate on machine performance and the reduction of walnut losses is substantial, showing significance at the 1% probability level. The effect of this factor on the amount of damage to walnuts is significant at the 5% level. By increasing the groove depth from 1.5 to 3 mm and from 3 to 5 mm, changes of 6.99% and 5.12% in walnut skin removal were observed. By reducing the elevation of the groove, the amount of cutting removed from the walnut surface is also reduced, and the peeling process becomes more abrasive. In this case, for proper peeling, the cycle duration and retention time in the machine should be increased. By increasing the rotational speed from 218 to 275 rpm, the momentum and linear velocity increase, resulting in more green shell removal. Conversely, reducing the rotational speed decreases the impact, leaving more green skin on the product. The interaction between rotational speed and groove depth is also significant in the amount of peeled product at the 1% level. The results of the life cycle assessment showed that the human health index has the highest value due to the use of electric power, iron profile (in the system chassis and container), and copper wire in the electric motor armature. Optimizing the system and using clean energy can help improve system efficiency and reduce environmental impact.ConclusionUtilizing a walnut peeling machine achieves an impressive 94% efficiency in walnut peeling while ensuring less than 5% damage. The results of the life cycle assessment showed that the use of a walnut peeling machine has less environmental damage than the traditional method and is highly cost-effective.
Research Article
Precision Farming
N. Salehi Babamiri; H. Haji Agha Alizadeh; M. Dowlati
Abstract
IntroductionSoil surface roughness is an important factor in determining the intensity and quality of tillage operations, and obtaining accurate information essential for precision tillage. Using an inappropriate technique due to the lack of precise discrepancy detection can lead to increased time spent ...
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IntroductionSoil surface roughness is an important factor in determining the intensity and quality of tillage operations, and obtaining accurate information essential for precision tillage. Using an inappropriate technique due to the lack of precise discrepancy detection can lead to increased time spent on analysis and potential damage. Generally, there are two methods for measuring soil surface roughness: contact and non-contact. Contact methods are less accurate for measuring the roughness of soft soil because they involve physical contact, which can partially disturb the soil. Most non-contact measurement methods are also performed in stop-and-go conditions, which increases measurement time and related analysis. The aim of this study is to measure soil surface roughness in real-time using optical sensors in the field. The accuracy and precision of two non-contact measurement methods will be compared to determine the best approach for precision tillage operations.Materials and MethodsIn the current research, a real-time soil surface roughness measurement system consisting of mechanical and electrical modules, data collection, and processing was built. The system performance was evaluated at different forward speeds and roughness categories, with two types of infrared and laser sensors. To assess the sensors’ accuracy, the collected data was compared against the pin gauge method, which served as the reference standard. The method exhibiting the least variation from this reference is considered to provide the most reliable data. Also, to further examine the accuracy of the sensors, the roughness data obtained from the sensor at various frequencies was compared against the roughness data obtained from the pin measuring device at the same level, resulting in a suitable curve plot. The interpretation of the obtained mathematical relationship indicates the precision of the sensor data.Results and DiscussionThe results obtained from the optical sensors were compared to the pin meter, used as the reference method, in both stationary and moving conditions. It was demonstrated that the optical sensors detect distance in the static state similarly to the reference pin meter. The calibration curve interpretation factor was 0.99 for the infrared sensor and 1 for the laser sensor, indicating a strong correlation between the sensor signals and their distance from the soil surface. The random roughness index was significant for different roughness classes at the 1% probability level, showing that this index effectively distinguishes between the resulting roughness classes. Analysis of variance results revealed that the measurement method had a significant effect at the 1% level. The method with the smallest difference from the reference method is considered the most appropriate measurement technique. The effect of forward speed was also significant at the 1% level; the speed at which the sensor’s performance did not significantly differ from the reference method was identified as the optimal speed for the system. Additionally, the effect of roughness class was significant at the 1% level, confirming that the created roughness classes had meaningful differences. The results of the sensor accuracy evaluation showed that the data obtained from the laser sensor at speeds of 1 and 2.6 km h-1 had no significant difference with the reference method. Therefore, it is appropriate to use the laser sensor at speeds of 1 and 2.6 km h-1. At speeds higher than 3.5 km h-1, the laser sensor successfully detected smooth surfaces, but did not correctly distinguish uneven surfaces. In general, the laser sensor was able to detect all categories of roughness at a speed of 2.6 km h-1. One reason the laser sensor did not perform well at speeds above 2.6 km h-1 was its low data acquisition rate. By using laser sensors with a higher data collection rate, the soil height profile can be plotted similarly to a pin scale. The infrared sensor was successful only in detecting smooth surfaces but failed to detect other types of surfaces.ConclusionDue to limited accuracy and the risk of damaging or altering the surface roughness, the contact method is not recommended for use on soft soil surfaces. Among non-contact methods, the most suitable technique is the one that provides the highest accuracy and precision while minimizing cost and time for data collection and analysis. In this study, two types of sensors including laser and infrared ranging were selected based on their reasonable price, ease of operation, compatibility with a mobile system, and ability to deliver real-time roughness measurements in the shortest possible time. The results demonstrated that real-time measurement of soil surface roughness can effectively replace traditional, tedious, and time-consuming methods.
Research Article
Bioenergy
B. Dosti; A. Asakereh
Abstract
IntroductionProper lighting and safety equipment on roads are essential for the optimal use of roadside services and the timely, safe transportation of goods. Supplying electricity for road lighting, especially in remote and hard-to-reach areas via the power grid, involves high costs for building power ...
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IntroductionProper lighting and safety equipment on roads are essential for the optimal use of roadside services and the timely, safe transportation of goods. Supplying electricity for road lighting, especially in remote and hard-to-reach areas via the power grid, involves high costs for building power transmission infrastructure. Using renewable energy enables electricity generation directly at the point of use and on a local scale. This approach reduces transmission and distribution costs and significantly lowers the environmental impact associated with fossil fuel-based electricity generation. Kermanshah province plays a key role in road transportation, yet most of its roads lack lighting systems. The province has significant wind energy potential, but wind power has not been utilized to supply electricity for road lighting. This suggests that installing small-scale wind turbines along the roads could be a promising solution. This study aims to assess the wind energy potential for powering road lighting and to prioritize the counties of Kermanshah province for installing small-scale wind turbines to supply electricity to road lighting systems.Materials and MethodsThe main steps of the study include data collection, preparation of the wind atlas, identification of locations with high wind potential, determination of effective factors and indicators for siting wind turbines, weighting of these factors and indicators, scoring counties based on them, and finally ranking the counties for installing wind turbines to supply electricity for the road lighting system using multi-criteria decision-making models. Using the wind atlas, we evaluated wind energy potential within a 3 km buffer zone around roads and identified 46 points with high wind potential. Based on these points, the counties of Kermanshah province were assessed and ranked for installing small-scale turbines to power the road lighting system. The indicators considered to determine suitable turbine locations included wind energy potential, distance from roads, traffic volume, distance from high-voltage power lines, distance from protected areas, distance from rivers and flood-prone zones, distance from faults, distance from residential areas, and land slope. Counties were scored on these indicators based on previous studies and expert opinions. A decision-making matrix was created using these scores, and indicator weights were calculated using Shannon entropy combined with expert evaluation. The SAW, TOPSIS, ELECTRE, and VIKOR methods were then applied to rank and prioritize the counties.Results and DiscussionThe energy potential of wind, with a weight of 0.360, was the most important indicator for selecting locations for wind turbine installation and road lighting systems. Traffic and distance from the road were the next most significant factors, with weights of 0.228 and 0.151, respectively. Kermanshah County had the highest wind energy potential, featuring seven high-potential sites, while Sarpole Zahab and Qasr Shirin counties each had only one suitable site, indicating lower wind potential. The top three counties in terms of wind energy potential were Kermanshah, Ravansar, and Paveh. Kermanshah County also had the highest traffic volume, carrying the greatest weight in that category. For distance from the road, Sanghar and Sahneh ranked first and second, with unscaled weights of 0.094 and 0.070, respectively, and Kermanshah ranked third with 0.047. Kermanshah County scored highest on all indicators except distance from faults and protected areas. Across all decision-making methods, Kermanshah and Sanghar consistently ranked first and second. Overall, Kermanshah, Sanghar, and Ravansar were prioritized as the top three counties for installing wind turbines to supply electricity for road lighting systems.ConclusionAccording to the wind atlas, 46 points with suitable wind potential for the road lighting system were determined. Based on multi-criteria decision-making methods, Kermanshah, Sanghar, and Ravansar counties were prioritized for installing road lighting systems powered by wind turbines.Acknowledgement The authors would like to thank Shahid Chamran University of Ahvaz and its Vice Chancellor for Research and Technology for their financial support in the form of funding (SCU.AA1400.29747).
Research Article
Precision Farming
M. Safaeinejad; M. Ghasemi-Nejad Raeini; M. Taki
Abstract
IntroductionOne of the key structural factors in agricultural mechanization is the selection of appropriate technology. Today, examining the effects of technology application and development on agricultural production remains of highly importance. Innovative technologies, such as spraying drones, play ...
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IntroductionOne of the key structural factors in agricultural mechanization is the selection of appropriate technology. Today, examining the effects of technology application and development on agricultural production remains of highly importance. Innovative technologies, such as spraying drones, play a critical role in advancing agriculture and ensuring food security. Without these technologies and proper input management, environmental impacts are likely to intensify. Achieving sustainable production and ensuring food security is a major challenge for researchers and global policymakers. This study evaluates and compares the performance of spraying drones and boom sprayers in controlling weeds and yellow rust disease in wheat fields. The aim of this study is to optimize pesticide use and achieve sustainable agriculture.Materials and MethodsThis research was conducted to evaluate the field performance and economic feasibility of using spraying drones compared to boom sprayers for controlling weeds and yellow rust disease in wheat fields. Experiments were carried out in regional Khorramabad, Iran, using a DJI Agras MG-1P spraying drone and a 400-liter 400B8 TF boom sprayer. The aim was to investigate the impact of modern technology, specifically spraying drones, compared to traditional methods, such as boom sprayers, for managing weeds and yellow rust disease. Additionally, the study assessed the profitability of these technologies. The experiments followed a randomized complete block design with three treatments: boom sprayer, spraying drone, and control. They were conducted in two separate, independent fields to examine treatment effects on weeds and yellow rust in wheat. For weeds control, 2-4-D herbicide was applied at 1.5 L ha-1, and for yellow rust control, Tilt fungicide was used at 0.5 L ha-1.Results and DiscussionResults showed that the deposition rate of pesticides in boom sprayers (82.8%) was higher than with drone spraying (69.9%). Furthermore, the average dry weight of weeds in boom sprayer was 172 g m-2, and in drone spraying, it was 163 g m-2, which was not statistically significant. Additionally, the average weed density was 25 plants per square meter for boom sprayers and 29.3 plants per square meter for drone spraying, with no statistically significant difference. The average harvest index in weed control experiments was 44% for boom sprayer and 41% for drone spraying, which was statistically significant at the 1% level. The average severity of yellow rust infection in wheat fields was 30.7% for boom sprayer and 25.3% for drone spraying, which was not statistically significant at the 1% level, but both treatments were significantly different from the control (68.3%). The harvest index in yellow rust experiments was better in drone spraying (43.8%) compared to boom sprayer (41.9%). The total annual cost for drone owners in the studied region (2980.3 million rials) was higher than the total cost for boom sprayer owners (513.48 million rials). However, the benefit-cost ratio for drone owners (1.215) exceeded that of boom sprayer owners (1.030), demonstrating economic viability for both sprayers. Overall, drones are found to be more economical for spraying than boom sprayers due to their higher efficiency and profitability. The use of drones can significantly increase the efficiency and profitability of spraying operations.ConclusionThe results of this study showed that both drone and boom sprayer were effective in reducing the dry weight of weeds, but there was no statistically significant difference between them. Weed density was higher with drone spraying, and the harvest index was better with drone spraying compared to boom sprayer. The costs of using drones were higher than boom sprayers, but despite the higher costs, drones are superior option for spraying due to their increased efficiency and profitability.
Research Article
Bioenergy
Sh. Shokri; V. Rostampour; K. Mollazade; S. Amiri; A. Fathoolahi Qharachapogh
Abstract
IntroductionThe increasing global population has intensified the demand for sustainable energy solutions. Meeting this need requires leveraging renewable energy sources that also address pollution management and reduce greenhouse gas emissions. Plant microbial fuel cells (PMFCs) have gained attention ...
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IntroductionThe increasing global population has intensified the demand for sustainable energy solutions. Meeting this need requires leveraging renewable energy sources that also address pollution management and reduce greenhouse gas emissions. Plant microbial fuel cells (PMFCs) have gained attention as innovative systems that produce electricity by decomposing organic matter in their anodic chambers, providing a dual benefit of clean energy generation and environmental remediation. These systems align closely with global sustainable development goals and represent a novel approach to energy production from organic materials.Materials and MethodsThis research focused on a plant microbial fuel cell system designed to contribute to sustainable development objectives. The system employed Cyperus plant and Shewanella oneidensis microorganisms to decompose organic substrates, including carbohydrates secreted by plant roots or other external sources, within the anodic chamber. Voltage output was measured using a voltage sensor connected to an Arduino UNO board, with data collected at two-hour intervals. The experiment investigated the effects of two parameters: oxygenation rate in the cathodic chamber and sodium acetate concentration in the anodic chamber, on the system performance.Results and DiscussionThe results revealed significant effects of both oxygenation and sodium acetate concentrations on the voltage output of the PMFC system. Increasing the oxygenation rate from 0 to 1 liter per minute enhanced the voltage output from 103 mV to 185 mV. Similarly, increasing sodium acetate concentration from 0 to 10 g L-1 raised the voltage from 103 mV to 170 mV. Furthermore, pollution removal efficiency was evaluated using chemical and biological oxygen demand (COD and BOD) measurements. At the highest levels of sodium acetate concentration (20 g L-1) and oxygenation rate (3 L min-1), the pollution removal rate reached 90%. These findings underscore the capability of PMFCs to combine energy production with effective environmental cleanup.ConclusionThe microbial-plant fuel cell system demonstrates considerable potential as a dual-purpose solution for renewable energy generation and pollution removal. Its high efficiency in utilizing microorganisms and plants for these tasks suggests that it could play a critical role in sustainable development. Future research should focus on addressing the system’s limitations and enhancing its scalability and reliability to support broader applications in renewable energy and environmental remediation.
