Search Results (34)

As global plastic production increases, the problem of marine plastic pollution is becoming increasingly critical, and the development of effective identification technologies is particularly urgent as plastic debris not only poses a threat to aquatic ecosystems but also has a significant impact on human health. This paper presents the criteria for evaluating fluorescence technology and its mechanism for plastic identification, with an emphasis on its potential for the rapid detection of marine plastic pollution. By analyzing variations in the fluorescence lifetimes and intensities of plastics, different types of plastics can be effectively distinguished. In addition, this paper reviews the detection of microplastics using different fluorescent dyes and explores the fluorescence lifetime identification method. This paper also demonstrates the effectiveness of fluorescence techniques for macroplastic identification, highlighting how fluorescence lifetimes and decay rates change in various weathering environments. Monitoring these changes offers a foundation for establishing weathering models, aiding in understanding the transformation of macrolitter into microplastics. Future research should investigate the autofluorescence properties of different plastics further and focus on developing detection methods and instruments for various environments. This will improve the identification of plastic waste in complex environments. In conclusion, fluorescence technology shows great promise in plastic identification and is expected to provide substantial support for recycling plastic waste products and mitigating plastic pollution. Full article

Municipal Solid Waste (MSW) management presents a significant challenge for traditional separation practices, due to a considerable increase in quantity, diversity, complexity of types of solid waste, and a high demand for accuracy in classification. Image recognition and classification of waste using computer vision techniques allow for optimizing administration and collection processes with high precision, achieving intelligent management in separation and final disposal, mitigating environmental impact, and contributing to sustainable development objectives. This research consisted of evaluating and comparing the effectiveness of four Convolutional Neural Network models for MSW detection, using a Raspberry Pi 4 Model B. To this end, the models YOLOv4-tiny, YOLOv7-tiny, YOLOv8-nano, and YOLOv9-tiny were trained, and their performance was compared in terms of precision, inference speed, and resource usage in an embedded system with a custom dataset of 1883 organic and inorganic waste images, labeled with Roboflow by delimiting the area of interest for each object. Image preprocessing was applied, with resizing to 640 × 640 pixels and contrast auto-adjustments. Training considered 85% of images and testing considered 15%. Each training stage was conducted over 100 epochs, adjusting configuration parameters such as learning rate, weight decay, image rotation, and mosaics. The precision results obtained were as follows: YOLOv4-tiny, 91.71%; YOLOv7-tiny, 91.34%; YOLOv8-nano, 93%; and YOLOv9-tiny, 92%. Each model was applied in an embedded system with an HQ camera, achieving an average of 86% CPU usage and an inference time of 1900 ms. This suggests that the models are feasible for application in an intelligent container for classifying organic and inorganic waste, ensuring effective management and promoting a culture of environmental care in society. Full article

Converting food waste into biofuel resources is considered a promising approach to address the rapid increase in energy demand, reduce dependence on fossil fuels, and decrease environmental hazards. In Egypt, large quantities of fried tilapia fish waste are produced in restaurants and households, posing challenges for proper waste management due to its decaying nature. The current study investigates the kinetic triplet and thermodynamic parameters of fried tilapia fish waste (FTFW) pyrolysis. Kinetic analysis was carried out using four iso-conversional models, Friedman, Kissinger–Akahira–Sunose (KAS), Flynn–Wall–Ozawa (FWO), and Starink, at heating rates of 10, 15, and 20 °C/min. The study findings indicate that FTFW decomposes within the temperature range of 382–407 °C. The estimated activation energy using the Friedman, FWO, KAS, and Starink methods ranged from 43.2 to 208.2, 31.3 to 148.3, 22.3 to 179.3, and 24.1 to 181.3 kJ/mol, respectively, with average values of 118.4, 96.7, 109.7, and 100.5 kJ/mol, respectively. The average enthalpy change determined using the Friedman, FWO, KAS, and Starink methods was 113.45, 91.78, 95.58, and 104.73 kJ/mol, respectively. The average values of Gibbs free energy change for the Friedman, KAS, FWO, and Starink, methods were 192.71, 171.04, 174.83, and 183.99 kJ/mol, respectively. Full article

Active packaging using an edible coating could be an essential and sustainable alternative solution to preserve the properties of fruits and to prevent food loss and food waste. Fruits generate significant food wastes and losses. Reducing food waste is a global priority. For this research, nature-based solutions (NBSs) were applied, using micro-sized chitosan (CsMPs) and selenium microparticles (SeMPs), which are green-synthesized from black tea leaf extracts, and thyme essential oil. In this study, the effects of the new generation active food preservative coating agents formed from combinations of micro-sized chitosan (CsMPs) and selenium (SeMPs), and thyme essential oil (Oil) on the quality of “0900 Ziraat” sweet cherry fruits after harvest were investigated. After the fruits were coated with edible colloid solution, they were stored at 4 °C and 21 °C for 20 days, and quality parameter analyses were performed on days 0, 5, 10, 15, and 20. As a result of this study, it was determined that the application of CsMPs + SeMPs and the subsequent application of CsMPs + SeMPs + Oil from colloid solution coatings reduced weight loss, respiration, and decay rates. Also, it was determined that these applications were the most effective in preserving color values (L*, chroma, and hue), fruit firmness, total soluble solid (TSS) amount, acidity content and total phenolics, anthocyanin, and antioxidant capacity. These results show that CsMPs + SeMPs and CsMPs + SeMPs + Oil applications can be used as edible coatings to preserve the quality of sweet cherry fruits and extend their shelf life after harvest. This study’s results will contribute to obtaining micro-sized composite coating agents/agents produced with new technology to extend the shelf life. Full article

In this paper, the natural waste pinecone as a carbon precursor for the generation of satisfactory sulfur host materials in lithium–sulfur batteries was realized by introducing molybdenum carbide nanoparticles into the derived carbon structure. The conductive pinecone-derived carbon doped with N, O reveals an expansive specific surface area, facilitating the accommodation of a higher sulfur load. Moreover, the integration of Mo₂C nanoparticles also significantly enhances its chemical affinity and catalytic capacity for polysulfides (LiPSs) to alleviate the shuttle effect and accelerate sulfur redox conversion. As a result, the WPC-Mo₂C/S electrode displays excellent electrochemical performance, including a low capacity decay rate of 0.074% per cycle during 600 cycles at 1 C and an outstanding rate capacity (631.2 mAh g⁻¹ at 3 C). Moreover, with a high sulfur loading of 5.5 mg cm⁻², the WPC-Mo₂C/S electrode shows a high area capacity of 5.1 mAh cm⁻² after 60 cycles at 0.2 C. Full article

A two-dimensional longitudinal profile model was used to evaluate groundwater flow along a 48 km flowline in the Southeastern Hueco Aquifer, extending from the Diablo Plateau in Texas to the Sierra de San Ignacio in Chihuahua, Mexico. The model, incorporating geologically distributed permeability values, closely matched the predevelopment potentiometric surface. Predicted recharge rates and travel times aligned with published estimates and environmental isotopes, suggesting potential transboundary groundwater movement. The model estimated recharge rates needed to reach flow capacity, or the maximum volume a system can transmit, typically saturating the water table. Current moisture levels are insufficient, but flow capacity may have been reached during late Pleistocene pluvial periods. Required recharge rates were 297% higher than initial calibration in the U.S. and 1080% higher in Mexico, with only U.S. estimates appearing plausible for the Pleistocene–Holocene transition. These findings are relevant to regional waste disposal considerations because water tables near land surface present a risk to groundwater resources. A transient simulation modeled hydraulic head decay due to recharge abatement linked to climate change over 14,000 years. It simulated a decrease from a “flow capacity” recharge rate of 10.4 mm/year to 3.5 mm/year today. The modeling simulations ended with the hydraulic head remaining only 20 m above current levels, suggesting a minimal-to-negligible fossil hydraulic gradient in the low-permeability flow system. Full article

The relationship between the cellulose/lignin (C/L) ratio and degradation rate of municipal solid waste (MSW) in landfills remains unclear. In this study, the USA National Renewable Energy Laboratory (NREL) method was employed to determine the cellulose and lignin contents of MSW at different stages of aging. A normalized degradation-stabilization index (β) that represents the ratio of C/L change to the initial C/L value was introduced to characterize the degradation and stabilization degree of solid waste, aiming to provide a scientific basis for the sustainable management of landfills. We made the following observations: (1) Over time, the degradation rate of organic matter in MSW slows down and stabilizes. This process is crucial for predicting the long-term environmental impact of landfills and formulating resource recovery strategies, contributing to the sustainable management of landfills. (2) The degradation rates of lignin and cellulose change from fast to slow over time, and the relationship between the C/L ratio and landfill age can be described effectively by the exp-decay formula. Understanding this relationship helps to optimize the waste decomposition process, reduce the negative environmental impact of landfills, and promote the sustainable development of landfills. (3) During the aging process of the landfill, the degree of waste degradation and stabilization initially increases rapidly and then shows a gradually decreasing trend. The relationship between the landfill stabilization degree, landfill age, and degradation rate can be represented adequately by a logistic formula. We also obtained expressions showing the correlations among landfill degradation–stabilization degree, age, and organic matter content. The findings provide valuable insights into landfill capacity, operational lifespan, and the redevelopment of landfills for MSW disposal, all of which are essential aspects for the sustainable management of landfills. Full article

This study aimed to develop an active biodegradable bio-based (polylactic acid/PLA) equilibrium modified atmosphere packaging (EMAP) containing a carvacrol-emitting sachet (created by poly-hydroxybutyrate) (PLA-PHB-CARV) to extend the shelf-life of cherry tomatoes at 15 °C and 25 °C. Cherry tomatoes in macro-perforated polypropylene (PP) films (mimicking the commercial packaging) or in PLA-based micro-perforated film without the carvacrol sachet (PLA) were also tested. Weight loss, decay, headspace gases, pH, titratable acidity (TA), total suspended solids (TSS), ripening index, color, texture, total viable counts (TVC), and sensory analysis were performed. Decay was 40% in PLA-PHB-CARV, and 97% in PP after 20 days at 25 °C. PLA-PHB-CARV showed lower weight loss (p < 0.05) and stable firmness compared to PP and PLA at both temperatures. TSS and TA were not affected by the packaging at 15 °C, while at 25 °C, the TSS accumulation was inhibited in PLA-PHB-CARV compared to in PLA and PP (p < 0.05), indicating a notable delay in the ripening process. PLA-PHB-CARV retained their red color during storage compared to PP and PLA. Carvacrol addition inhibited TVC compared to PP and PLA by ca. 2.0 log CFU/g during storage at 25 °C, while at 15 °C, the packaging did not reveal a significant effect. Overall, the results indicated that the developed active EMAP may be adequately used as an advanced and alternative packaging for tomatoes or potentially other fruits with a similar respiration rate versus their conventional packaging, showing several advantages, e.g., a reduction in petrochemical-based plastics use, shelf-life extension of the packaged food, and consequently, the perspective of limiting food waste during distribution and retail or domestic storage. Full article

Mycelium-based green composites (MBCs) represent an eco-friendly material innovation with vast potential across diverse applications. This paper provides a thorough review of the factors influencing the production and properties of MBCs, with a particular focus on interdisciplinary collaboration and long-term sustainability goals. It delves into critical aspects such as fungal species selection, substrate type selection, substrate preparation, optimal conditions, dehydrating methods, post-processing techniques, mold design, sterilization processes, cost comparison, key recommendations, and other necessary factors. Regarding fungal species selection, the paper highlights the significance of considering factors like mycelium species, decay type, hyphal network systems, growth rate, and bonding properties in ensuring the safety and suitability of MBCs fabrication. Substrate type selection is discussed, emphasizing the importance of chemical characteristics such as cellulose, hemicellulose, lignin content, pH, organic carbon, total nitrogen, and the C: N ratio in determining mycelium growth and MBC properties. Substrate preparation methods, optimal growth conditions, and post-processing techniques are thoroughly examined, along with their impacts on MBCs quality and performance. Moreover, the paper discusses the importance of designing molds and implementing effective sterilization processes to ensure clean environments for mycelium growth. It also evaluates the costs associated with MBCs production compared to traditional materials, highlighting potential cost savings and economic advantages. Additionally, the paper provides key recommendations and precautions for improving MBC properties, including addressing fungal strain degeneration, encouraging research collaboration, establishing biosecurity protocols, ensuring regulatory compliance, optimizing storage conditions, implementing waste management practices, conducting life cycle assessments, and suggesting parameters for desirable MBC properties. Overall, this review offers valuable insights into the complex interplay of factors influencing MBCs production and provides guidance for optimizing processes to achieve sustainable, high-quality composites for diverse applications. Full article

Aerobic composting is an effective method of resource treatment for agricultural and forestry solid waste; however, while wheat straw is usually used as a conditioner and is not the main body as in aerobic composting, wheat straw is abundant in annual production, and fertilization is one of the main ways of resource utilization of wheat straw, how to use wheat straw as the main body of aerobic composting for efficient treatment is, therefore, a meaningful research direction. In this paper, to achieve the efficient and economic resource utilization of wheat straw and livestock manure, aerobic composting was carried out with wheat straw as the main body, and pig manure and cow manure were mixed with wheat straw crops at ratios of 20%, 30%, and 40%, respectively, for barrel suspension composting. The changes in pH, EC, NH₄⁺-N, NO₃⁻-N, TN, TP, organic matter and seed germination index, and shoot length inhibition rate before and after composting were compared between treatment groups using different material ratios in the aerobic composting process. The changes in the physicochemical properties and nutrient elements of compost products were studied. The results show that the co-composting of livestock manure and wheat straw can promote the decomposition of the pile, and the addition of 40% cow manure and 30% pig manure has the best effect in promoting decay. In contrast, the addition of excessive pig manure inhibits the decomposition of the pile. Organic matter degradation in the treatment groups using cow manure was more effective than in those using pig manure, and the best results were obtained with 40% cow manure. The pile was alkaline at the end of each treatment, and the wheat straw compost treated with 40% cow manure had the best nitrogen and phosphorus retention. The wheat straw compost treated with 40% cow manure had the highest integrated degree of decomposition, which promoted the deterioration of the pile and provided a research basis for the use of wheat straw as an efficient resource. Full article

Landfills are the third largest source of the greenhouse gas methane, contributing to 25% of global warming. Therefore, the characterization of national municipal solid waste (MSW) and estimation of methane generation rate are very important for the solid waste management (SWM) toward sustainable development goal no. 13, climate action. This study presents (a) an assessment of daily MSW generation, (b) the characterization of MSW, and (c) an evaluation of the methane generation rate constant (k value) in Mogadishu, Somalia. The MSW samples were collected from three (3) sampling zones (Zones 1, 2, and 3; 204 households) and weighted (kg). Next, the waste generation per person per day was estimated. The MSW characterization includes sorting (based on plastic/polythene, food wastes, wood, metals, yard waste, paper/cardboard, textile, glass/ceramic and miscellaneous components, %), the determination of bulk density (kg/L), and measuring moisture content (%). The k values were evaluated from the percentages of different components in MSW based on first-order decay models. Mogadishu city generated 1671.03 kg MSW per week (maximum on Friday: 348.72 kg, and minimum on Monday: 152.04 kg). The total mean MSW generation rate observed in this study was 0.2 kg/person/day. The solid waste generation found was in the decreasing order of food waste > plastic/polythene > yard waste > miscellaneous > papers/carboard > wood > glass/ceramic > textiles > metals by weight. The average bulk density was found to be 0.269 kg/L. The average moisture content was ranged from 61.6 to 73%. The total k values were categorized as fast (Zone 1: 0.216053 yr⁻¹, Zone 2: 0.228739 yr⁻¹, and Zone 3: 0.244595 yr⁻¹) and moderate (Zone 3: 0.244595 yr⁻¹) degradation. This research serves as Somalian MSW baseline data and projected the methane generation rate from the MSW production in the country. The MSW sorting may reduce the impact of global warming and is highly recommended for better SWM in the future. Full article

This research evaluates process instability together with microbial population dynamics of the startup of an anaerobic digestion of a mild pretreated solid olive oil waste. The pretreatment consisted of a mild thermal treatment called thermo-malaxation and a subsequent dephenolized process of the olive mill solid waste. The anaerobic digestion process of the mild pretreated and partially dephenolized biomass was studied for three Hydraulic Retention Times (HRTs), with 21 days each HRT, with an organic load rate of 1 g VS/L d, carried out at mesophilic temperature (35 ± 1 °C). The average value of methane yield decreased from 204 ± 9 mL CH₄/g VS d on day 21, the last day of the first HRT, to 87 ± 24 mL CH₄/g VS d on day 60, the last day of the third HRT. The alkalinity decreased drastically, indicating instability of the anaerobic digestion process. Although phenolic compounds were partially extracted in the pretreatment, the observed increase in phenolic compounds during reactor operation might be contributed to the methane production decay. Interestingly, volatile fatty acids decreased with time, indicating that not only the methanogenic stage but also the hydrolysis stage was affected. Indeed, the microbial analysis showed that the abundance of hydrolytic bacteria decreased over time. It is also worth noticing that hydrogenotrophic methanogens, while present during the first two HRTs, were not observed at the end of the last HRT. This observation, together with the increase in the relative abundance of acetoclastic methanogens, showed a shift in the methane production pathway from hydrogenotrophic methanogenesis to acetotrophic methanogenesis. Full article

An innovative and integrated scheme that encompasses two well-established waste treatment technologies, the aerobic biological degradation of organic matter bioprocess via membranes and anaerobic digestion, was demonstrated as a zero-waste approach that may effectively treat wastewater and biowaste in an integrated and symbiotic manner. Aiming to create a tool for the design, monitoring, and control of the scheme, prediction models were developed, validated, and implemented for the process simulation of the integrated scheme. The minimization of selected objective functions led to the estimation of the models’ parameters. The activated sludge model no. 1 (ASM1) was adopted for the simulation of the aerobic membrane bioreactor. The kinetic parameters were calibrated using volatile suspended solids and total nitrogen as the objective functions permitting the model to simulate the bioprocess satisfactorily (Nash–Sutcliffe efficiency > 0.86) and to calculate the concentration of the active biomass. The predominance of heterotrophic bacteria (4300 to 9770 mg COD/L) over autotrophic biomass (508 to 1422 mg COD/L) was showcased. For the anaerobic process unit, a simplified anaerobic digestion model 1 ADM1-R4 was used, and the first-order hydrolysis constants (k_ch 0.41 d⁻¹, k_pr 0.25 d⁻¹, k_li 0.09 d⁻¹) and microbial decay rate (k_dec 0.02 d⁻¹) were evaluated, enabling an accurate prediction of biogas production rates. A full-scale implementation of the integrated scheme was conducted for a decentralized waste treatment plant in a small community. Preliminary design calculations were performed in order to estimate the values related to certain process and technical parameters. The performance of this full-scale plant was simulated by the developed model, presenting clear benefits for practical applications in waste treatment plants. Full article

Moisture damage is one of the undesired distresses occurring in flexible asphalt pavements, mostly through water intrusion that weakens and ultimately degrades the asphalt mortar-aggregate interfacial bond. One method to mitigate this distress is using anti-stripping or anti-spalling filler materials that, however, require a systematic quantification of their interfacial bonding potential and moisture tolerance properties prior to wide-scale field use. With this background, this study was conducted to comparatively evaluate and quantitatively characterize the moisture sensitivity and water damage resistance of the interfacial bonding between the asphalt mortar and aggregate fillers. Using an in-house custom developed water-temperature coupling setup, numerous laboratory pull-out tests were carried out on the asphalt mortar with four different filler materials, namely limestone mineral powder, cement, slaked (hydrated) lime, and waste brake pad powder, respectively. In the study, the effects of moisture wet-curing conditions, temperature, and filler types were comparatively evaluated to quantify the water damage resistance of the asphalt mortar-aggregate filler interface. For interfacial microscopic characterization, the Image-Pro Plus software, 3-D digital imaging, and scanning electron microscope (SEM) were jointly used to measure the spalling rate and the surface micromorphology of the asphalt mortar and aggregate filler before and after water saturation, respectively. In general, the pull-out tensile force exhibited a decreasing response trend with more water damage and interfacial bonding decay as the moisture wet-curing temperature and time were increased. Overall, the results indicated superiority for slaked (hydrated) lime over the other filler materials with respect to enhancing and optimizing the asphalt mortar-aggregate interfacial bonding strength, moisture tolerance, and water damage resistance, respectively—with limestone mineral powder being the poorest performer. Full article

The anaerobic digestion of the organic fraction of municipal solid waste and the biogas production obtained from its stabilization are becoming an increasingly attractive solution, due to their beneficial effects on the environment. In this way, the waste is considered a resource allowing a reduction in the quantity of it going to landfills and the derived greenhouse gas emissions. Simultaneously, the upgrading process of biogas into biomethane can address the issues dealing with decarbonization of the transport. In this work, the production of biogas obtained from the organic fraction of municipal solid wastes in a plug flow reactor is analyzed. In order to steer the chemical reactions, the temperature of the process must be kept under control. A new simulation model, implemented in the MatLab^® environment, is developed to predict the temperature field within the reactor, in order to assess how the temperature affects the growth and the decay of the main microbial species. A thermal model, based on two equilibrium equations, is implemented to describe the heat transfer between the digester and the environment and between the digester and the internal heat exchanger. A biological model, based on suitable differential equations, is also included for the calculation of the biological processes occurring in the reactor. The proposed anaerobic digestion model is derived by the combination of these two models, and it is able to simultaneously simulate both thermal and biological processes occurring within the reactor. In addition to the thermal energy demand, the plant requires huge amounts of electricity due to the presence of a biogas upgrading process, converting biogas into biomethane. Therefore, the in-house developed model is integrated into a TRNSYS environment, to perform a yearly dynamic simulation of the reactor in combination with other renewable technologies. In the developed system layout, the thermal energy required to control the temperature of the reactor is matched by a solar thermal source. The electrical demand is met by the means of a photovoltaic field. In this work, a detailed thermoeconomic analysis is also proposed to compare the environmental impact and economic feasibility of a biomethane production plant based on a plug flow reactor and fed by renewables. Several economic incentives are considered and compared to determine the optimal solution, both in terms of energy and economic savings. The plant is designed for the treatment of a waste flow rate equal to 626.4 kg/h, and the biomethane produced, approximately 850 tons/years, is injected into the national gas grid or supplied to gas stations. In the proposed plant, a solar field of an evacuated tube collector having a surface of approximately 200 m² is able to satisfy 35% of the thermal energy demand while over 50% of the electric demand is met with a photovoltaic field of 400 m². A promising payback time of approximately 5 years was estimated. Full article