Hasil untuk "Standardization. Simplification. Waste"

E. van Sebille, C. Wilcox, L. Lebreton et al.

Microplastic debris floating at the ocean surface can harm marine life. Understanding the severity of this harm requires knowledge of plastic abundance and distributions. Dozens of expeditions measuring microplastics have been carried out since the 1970s, but they have primarily focused on the North Atlantic and North Pacific accumulation zones, with much sparser coverage elsewhere. Here, we use the largest dataset of microplastic measurements assembled to date to assess the confidence we can have in global estimates of microplastic abundance and mass. We use a rigorous statistical framework to standardize a global dataset of plastic marine debris measured using surface-trawling plankton nets and coupled this with three different ocean circulation models to spatially interpolate the observations. Our estimates show that the accumulated number of microplastic particles in 2014 ranges from 15 to 51 trillion particles, weighing between 93 and 236 thousand metric tons, which is only approximately 1% of global plastic waste estimated to enter the ocean in the year 2010. These estimates are larger than previous global estimates, but vary widely because the scarcity of data in most of the world ocean, differences in model formulations, and fundamental knowledge gaps in the sources, transformations and fates of microplastics in the ocean.

Barbara Lamolinara, A. Pérez-Martínez, E. Guardado-Yordi et al.

Digestate is a nutrient-rich by-product from organic waste anaerobic digestion but can contribute to nutrient pollution without comprehensive management strategies. Some nutrient pollution impacts include harmful algal blooms, hypoxia, and eutrophication. This contribution explores current productive uses of digestate by analyzing its feedstocks, processing technologies, economics, product quality, impurities, incentive policies, and regulations. The analyzed studies found that feedstock, processing technology, and process operating conditions highly influence the digestate product characteristics. Also, incentive policies and regulations for managing organic waste by anaerobic digestion and producing digestate as a valuable product promote economic benefits. However, there are not many governmental and industry-led quality assurance certification systems for supporting commercializing digestate products. The sustainable and safe use of digestate in different applications needs further development of technologies and processes. Also, incentives for digestate use, quality regulation, and social awareness are essential to promote digestate product commercialization as part of the organic waste circular economy paradigm. Therefore, future studies about circular business models and standardized international regulations for digestate products are needed.

Julius Sechang Mboli, Omolara Aderonke Ogungbemi

Efficient waste sorting is crucial for enabling circular-economy practices and resource recovery in smart cities. This paper evaluates both traditional machine-learning (Random Forest, SVM, AdaBoost) and deep-learning techniques including custom CNNs, VGG16, ResNet50, and three transfer-learning models (DenseNet121, EfficientNetB0, InceptionV3) for binary classification of 25 077 waste images (80/20 train/test split, augmented and resized to 150x150 px). The paper assesses the impact of Principal Component Analysis for dimensionality reduction on traditional models. DenseNet121 achieved the highest accuracy (91 %) and ROC-AUC (0.98), outperforming the best traditional classifier by 20 pp. Principal Component Analysis (PCA) showed negligible benefit for classical methods, whereas transfer learning substantially improved performance under limited-data conditions. Finally, we outline how these models integrate into a real-time Data-Driven Decision Support System for automated waste sorting, highlighting potential reductions in landfill use and lifecycle environmental impacts.)

P. Felizardo, M. Joana Neiva Correia, Idalina Raposo et al.

Andrei Stsiapanau

Amidst a period marked by growing volumes of nuclear waste and ongoing discussions regarding its management, technologies that utilise natural materials for containment are gaining prominence. This article takes a historical view of Russian nuclear waste management practices with a focus on the role of clay as a natural material for containing nuclear waste. In particular, it explores the use of clay in multi-barrier technology, highlighting its dual role as a protective layer and a resource for managing nuclear safety risks. The siting of the liquid nuclear waste disposal at the Ignalina NPP site in Lithuania (1976–1980) and of solid nuclear waste disposal at Leningrad NPP in Sosnovy Bor, Russia (2013–2018) are the main foci of this article. These cases contribute to understanding nuclear waste disposal siting in the USSR and modern Russia and enable analysis of nuclear waste discourses describing the sites’ geology as a static or dynamic environment within active or passive safety systems.

S. Varshini, M. Kesavalakshmi, R. Varun Prasath et al.

Plastic, a synthetic material made from a wide range of polymers, has become an integral part of our everyday life. Due to their non-biodegradability and limited recyclability, they pose major environmental threats and waste management issues. Thus, an alternative to plastics is the need of the hour. While there are many alternate solutions in the form of bioplastics, many of them lack crucial properties like tensility, flexibility and stretchability to be able to completely replace plastics. Various additives and plasticizers are added to enhance their properties. Latex, a milky white colloidal substance, is one of the potential bio additives which not only elevates the strength of the blend but also enhances various properties including elasticity, hydrophobicity, and reduces water absorptivity. This study summarises the effect of latex on most common bio plastic bases including starch, cellulose, poly lactic acid and highlights the exploitation of the inherent elasticity of latex which has the potential to provide a plausible solution to the solid waste accumulation threat. This study also explores the future prospects of latex blended bioplastics and provides an insightful road map for further research.

David Sinkhonde, Destine Mashava, Tajebe Bezabih et al.

The investigations on the performance of concrete incorporating waste materials hold promise in achieving sustainable construction. Although various studies have addressed the mechanical behaviour of concrete containing waste tyre rubber (WTR) and clay brick powder (CBP), an advanced understanding of predicting the compressive strength of such concrete remains underdeveloped. In this study, predicting the compressive strength of rubberized concrete incorporating CBP using the artificial neural network (ANN)-based models is proposed for the first time. The prediction is based on multilayer perceptron (MLP) and radial basis function (RBF) neural networks. It is shown that MLP is superior in predicting the compressive strength of rubberized concrete incorporating CBP compared with RBF. However, regardless of the algorithm used, the R2 and adjusted R2 values are higher than 0.75. Results on Pearson’s r values greater than 0.85 illustrate higher predictive abilities of the neural networks. Moreover, the study demonstrates that it is not possible to obtain significant relationships between the individual independent variables of rubberized concrete incorporating CBP and concrete compressive strength. The ANN-based models in this research contribute towards an understanding of predicting the compressive strength of rubberized concrete incorporating CBP, which can inspire further modeling studies involving such materials.

Emmanuel Mache, Magdalena Rajczakowska, Andrzej Cwirzen

Portland cement (PC) production accounts for about 8 % of global CO2 emissions. As the demand for cement grows, sustainable alternative raw materials for cement production are essential for reducing the impacts of its production. Process residues from industrial processes like mine tailings, metallurgical slags, incinerated municipal solid wastes (MSWI), glass industry wastes, and Kraft pulp mill wastes are being studied as suitable raw materials for clinker production. These materials contain CaO, SiO2, Al2O3, and Fe2O3, which are required for the formation of tricalcium silicate (C3S, alite), dicalcium silicate (C2S, belite), tricalcium aluminate (C3A), and tetracalcium aluminoferrite (C4AF) clinker phases. However, these raw materials may contain impurities such as alkali oxides and heavy metals, which can significantly influence the clinkering process. While alkali oxides tend to lower the eutectic temperature, heavy metals can modify phase stability and hinder the formation of essential clinker phases. This review examines whether these residues are chemically and mineralogically suitable for alternative raw materials. It examines their impact on phase transformations, reactions, environmental sustainability, hydration and performance of the resultant cement. Process residues in clinker production present challenges and opportunities, affecting hydration, workability, and setting times. However, research remains limited to the combined effects of multiple residues on clinker reaction kinetics, durability, heavy metal stabilization, and life cycle impacts.

Maria do Céu de Sena Moura, Geórgia Patrícia da Silva Ferko, Marcos Felipe Falcão Sobral et al.

Higher education institutions (HEIs) offer promising opportunities to develop strategies and actions for managing Solid Waste (SW). This study aimed to analyze the perceptions of employees working at HEIs in Boa Vista, Roraima, Brazil, on how their institutions manage SW. HEIs 1 and 2 (public) and HEI 3 (private) were evaluated. The study method was qualitative and quantitative. Face-to-face interviews were conducted using a questionnaire addressing five domains of Waste Management: I − Recycling program; II − Treatment of organic waste; III − Campaign to reduce the use of paper and plastic; IV − Treatment of inorganic waste; and V − Treatment of toxic waste. A multidimensional similarity analysis was carried out between the HEIs. HEI2 showed better overall performance when compared to the other HEIs (p = 0.012). In domain I, only HEI 2 has a selective waste collection program and disposes of waste properly (score = 150, p < 0.001). None of the HEIs treat organic waste (domain II). In Domain III, only public HEIs dematerialize administrative procedures and processes. Only HEI2 and HEI3 maintained similar behavior on domain IV (score = 300). In domain V, all HEIs have outsourced companies specialized in waste collection. The multidimensional analysis showed a high similarity among the HEIs. In conclusion, the HEI 2 showed slightly better waste management practices according to the worker’s perception. However, all HEIs in Roraima still need to make progress in managing their SWs.

David Sinkhonde, Derrick Mirindi, Ismael Dabakuyo et al.

To refine the process of anticipating the structural integrity of laterite block components, the use of machine learning (ML) algorithms is required. This study initiates an exploration into forecasting the compressive strength of laterite blocks infused with metakaolin-based geopolymer (MKG) and sugarcane molasses (SM), utilizing machine learning techniques such as artificial neural networks (ANN), random forests (RF), decision trees (DT), and support vector machines (SVM). The models were developed using four input values, including the MKG, SM, laterite soil, and water, with compressive strength as the output. Results show that for all the models, the majority of the data points lie within the error lines range of −20 % and +20 %. Using the Taylor diagram model, the results demonstrate that the SVM (train) model achieves the highest performance in predicting the compressive strength of laterite blocks, with a correlation coefficient of 0.99 and the lowest root mean square error (RMSE) of 0.139. The correlation coefficient values (R) for training and testing algorithm models ranged between 0.65 and 0.99, implying that all models fairly predict the compressive strength of laterite blocks containing MKG and SM. The RF model emerges as an important model for generalization across training and testing phases, with R values of 0.9828 and 0.789, respectively. SHapley Additive exPlanations (SHAP) analysis assesses the model’s explainability behavior. According to a SHAP-based feature importance study, age (85.33 %) and water content (17.87 %) are critical components that may improve compressive strength compared to MKG (8.60 %) and SM (6.74 %), respectively. This study not only assists in comprehending the essential parameters necessary for making well-informed decisions but also opens exciting possibilities for the application of ML in fostering sustainable construction practices.

Heng Xia, Jian Tang, Loai Aljerf et al.

Municipal solid waste incineration (MSWI) with grate technology is a widely applied waste-to-energy process in various cities in China. Meanwhile, dioxins (DXN) are emitted at the stack and are the critical environmental indicator for operation optimization control in the MSWI process. However, constructing a high-precision and fast emission model for DXN emission operation optimization control becomes an immediate difficulty. To address the above problem, this research utilizes a novel DXN emission measurement method using simplified deep forest regression (DFR) with residual error fitting (SDFR-ref). First, the high-dimensional process variables are optimally reduced following the mutual information and significance test. Then, a simplified DFR algorithm is established to infer or predict the nonlinearity between the selected process variables and the DXN emission concentration. Moreover, a gradient enhancement strategy in terms of residual error fitting with a step factor is designed to improve the measurement performance in the layer-by-layer learning process. Finally, an actual DXN dataset from 2009 to 2020 of the MSWI plant in Beijing is utilized to verify the SDFR-ref method. Comparison experiments demonstrate the superiority of the proposed method over other methods in terms of measurement accuracy and time consumption.

Yutao Chen, Hekai Zhang, Yalan Liu et al.

Per- and polyfluoroalkyl substances (PFAS) have been found at high levels within landfill environments. To assess PFAS distributions, this study aimed to evaluate PFAS mass flux leached from disposed solid waste and within landfill reservoirs by mass balance analyses for two full-scale operational Florida landfills. PFAS mass flux in different aqueous components within landfills were estimated based on PFAS concentrations and water flow rates. For PFAS concentration, 26 PFAS, including 18 perfluoroalkyl acids (PFAAs) and 8 PFAA-precursors, were measured in samples collected from the landfills or estimated based on previous studies. Flow rates of aqueous components (rainfall, evapotranspiration, runoff, stormwater, groundwater, leakage, gas condensate, and leachate) were evaluated through the Hydrologic Evaluation of Landfill Performance model, water balance, and Darcy's Law. Results showed that the average PFAS mass flux leached from the solid waste standardized by area was estimated as 36.8 g/ha-yr, which was approximately 1 % to 3 % of the total amount of PFAS within the solid waste. The majority of PFAS leached from the solid waste (95 % to 97 %) is captured by the leachate collection system, with other aqueous components representing much smaller fractions (stormwater system at 3 % to 5 %, and gas condensate and groundwater at < 1 %). Also, based on the results, we estimate that PFAS releases will likely occur at least over 40 years. Overall, these results can help prioritize components for waste management and PFAS treatment during the anticipated landfill release periods.

Wei Wei, Qian Liu, Zhibo Zhang et al.

Leaching of potentially hazardous substances, especially the heavy metals from Incineration Bottom Ash (IBA) is a major problem in its recyclable usage. To address this concern, treatment of IBA is indispensable before it can be reused. IBA subjected to laboratory-scale treatment typically yields clearer conclusions in terms of leaching behaviors, benefiting from the controlled laboratory environment. However, the leaching behaviors of commercially treated IBA appear to be more ambiguous due to the complex and comprehensive nature of industrial-scale treatments, where multiple treatment techniques are involved concurrently. Furthermore, treatment efficiencies vary among different plants. In this study, three types of commercially treated IBA were sampled from leading waste treatment companies in Singapore. Characterization and leaching tests were performed on the treated IBAs in both standardized and modified manners to simulate various scenarios. Besides deionized water, artificial seawater was used as a leachant in leaching tests for simulating seawater intrusion. The results reveal the promoting effect of seawater on the leaching levels of several elements from three types of treated IBA, which may require special attention for IBA application and landfill near the coast. Furthermore, the elements examined in these three types of commercially treated IBA generally comply with the non-hazardous waste acceptance criteria outlined in Council Decision, 2003/33/EC (2003), except Sb. By combining two leaching tests, the elements were categorized into different types of leaching behavior, making it possible to prepare and respond to the concerning leaching scenarios in future engineering applications.

Sandesh Behera, Priyanka Barik, Bikash Chandra Behera et al.

In the present study, nano-ligninwas synthesized from rice straw using Lactobacillus rhamnosus for the cost-effective removal of harmful dye from wastewater. The UV absorption maxima of the synthesized nano-lignin were around 280–290 nm. Several FTIR bands between 1075 cm−1 to 3500 cm−1 confirmed the successful confirmation of nano-lignin synthesis from rice straw. STEM and DLS studies confirmed the spherical morphology of nano-lignin with an average particle size of 286.3 nm. The nano-lignin showed a negative zeta potential value of −16.9 ± 5.94 mv. Afterward, nano-lignin was used to remove basic methylene blue (MB), phenol red (PR),and brilliant green (BG) dye from aqueous solutions. The adsorption of these dyes increased with increased incubation time. The adsorption concentration of the MB, PR, and BG dyes ranged from 3.5 mg/g to a final of 24 mg/g, 2.5 mg/g to 42.5 mg/g, and 1.5 gm/g to 5.5 mg/g, respectively.

Otmane Sarti, Emilia Otal, Fouad El Mansouri et al.

Carbonating metallurgical slags plays a pivotal role in achieving efficient mineral CO2 sequestration and waste valorization. This research introduces a novel integrated approach that combines the carbonation of Ladle Furnace Slag (LFS) with the simultaneous degradation of Methyl Orange (MO) in synthetic water. The comprehensive characterization of LFS was conducted using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), Brunauer-Emmett-Teller (BET) analysis, and Scanning Electron Microscopy (SEM). The adsorption experiments reveal the high LSF capacity for MO degradation (149.25 mg/g) following pseudo-second-order kinetics (R2 = 0.99) and Langmuir isotherm (R2 = 0.98). The adsorption process was primarily governed by chemical and electrostatic interactions. Analysis of LFS-loaded MO indicated a reduction in Ca(OH)2 phases, responsible for CO2 mineralization and the formation of calcite (CaCO3). Furthermore, the study explored the reusability of LFS-MO composites through chemical and thermal modifications. Pyrolysis of carbonated LFS with KOH impregnation exhibited potential for regenerating Ca(OH)2 phases, while thermal modification induced significant mineral and microstructural changes, creating new active sites at various temperatures. Additionally, the Fenton-like reaction followed by thermal modification resulted in a highly organized and microporous LFS structure with enhanced surface area and porosity. Moreover, modification with ZnSO4 followed by thermal activation promoted the formation of ZnO nanoxides on the LFS surface. This research proposes an innovative carbonating approach for metallurgical slags and wastewater treatment, extending their utility and enhancing industrial sustainability. Carbonated LFS-MO composites hold promise for applications in construction, CO2 capture, and wastewater treatment, thereby fostering sustainable industrial practices with ongoing research and development efforts.

Uplabdhi Tyagi, Neeru Anand

Globally, human activity and fast modernization have an impact on the ecological and economic aspects. These factors have led to the generation of complex wastewater consisting of recalcitrant toxic and carcinogenic contaminants. The inaccuracy of the traditional treatment techniques using traditional adsorbents to lower the concentration of pollutants below desired standards has paved the way for technological advancements in the synthesis method and operating conditions. Hence, this has become highly imperative to utilize effective and advanced remediation strategies for the removal of pollutants. Several remediation strategies were put forth and were effective because of their unique characteristics such as their affordability, adaptability, and simplicity of use. The present review article organizes the scattered available information on potential and abundant biomass-derived low-cost adsorbents for the effective removal of toxic contaminants. It has been discovered that biomass-derived adsorbents are extremely effective, alternative, and carbon–neutral offering a new perspective on the modular adsorption process.

Felicia Ling Wen Xia, Sarifah Supri, Heder Djamaludin et al.

Seafood by-products from various organisms like fish, shellfish, squids, and bivalves are often thrown away as waste, even though they could be utilized in creating new types of valuable foods. Up to 75% of the entire organism consists of industrial processing wastes, which can lead to a loss of profit and ecological sustainability if natural resources are not recycled efficiently. Various types of fish parts and byproducts, such as heads, viscera, skin, bones, scales, exoskeletons, pens, ink, and clam shells, can be categorized as valuable waste based on their weight percentages, which vary depending on the species and taxonomy. This review paper delves into the extraction and valorization strategies of seafood by-products, with a focus on transforming waste into valuable resources. Marine by-products can provide bioactive substances such as collagen, peptides, polyunsaturated fatty acids, antioxidants, chitin, and catalysts for biodiesel production. This review highlights the utilization of innovative techniques like microwave- and ultrasound-assisted extraction as well as supercritical fluid extraction and subcritical water extraction to extract bioactive compounds from seafood waste efficiently. This section also discusses the optimization of extraction processes to enhance efficiency and yield. Furthermore, the paper explores the potential applications of seafood by-products across various industries, emphasizing sustainable resource utilization and the creation of high-value products to be applied in our current circular economy.

Arti Yadav, Pushpa Rani, Deepak Kumar Yadav et al.

This study aimed at a comparative analysis of enzymatic hydrolysis of sugarcane bagasse biomass by using a free holocellulase cocktail of an enzyme (Cellic CTec2) and immobilized enzyme system on IOMNP@SiO2-NH2 support to make the process cost-effective. The immobilization was substantiated by examining the nano biocatalysts using FTIR, TEM, and DLS analysis. IOMNP@SiO2 –NH2 and immobilized enzyme system have average particle sizes of 81.1, and 455.9 nm confirmed by DLS. Response surface methodology (RSM) based on the Box Behnken design was employed to optimize the saccharification process conditions. The free cellulase cocktail showed a maximum hydrolysis yield of 70.71 % at 12.5FPU/gm enzyme dose, while the immobilized enzyme at a dose of 20 FPU/gm achieved a conversion rate of 74.19 % under optimized parameters likes hydrolysis time, surfactant and substrate concentration. Pretreated sugarcane bagasse substrate was used to evaluate the reusability potential of magnetically immobilized cellulase enzyme compared to recovered free enzyme up to 5 cycles. In the second and third cycles, the conversion rates of cellulose to glucose were determined to be 68.21 %, and 52.6 %, respectively. The findings of this study demonstrate that the immobilized Cellic CTec2 enzyme cocktail on functionalized IOMNP is effective for hydrolyzing sugarcane bagasse which also provides the advantages of easy recovery and reusability of enzyme for multiple hydrolysis cycles.

Subhrajit Mandal, Anamika Yadav, Sanjeev Kumar et al.

Tea (Camellia Sinensis) is a popular and extensively consumable drink after water due to its excellent health benefits and medicinal properties. Global tea production is rapidly increasing to keep up with demand, but this also creates massive waste piles of tea that negatively influence the environment. By 2025, tea consumption is expected to have increased from approximately 6.3 million tons in 2020 to 7.4 million tons. Increasing the intake rate of tea has also been accompanied by a spike in the production of tea waste after usage. The present review study investigates the emerging application of tea waste management. Also, it addresses the sustainable recycling of waste from the tea industry, the beneficial application of biomass in agriculture composting, and other applications. Additionally, a thorough assessment of the manufacture of various value-added products from the generated tea waste. A detailed explanation of the challenges and new prospects of using tea waste in multiple industries, such as energy production and environmental remediation. The outcomes of this review research are essential for the world’s sustainable and environmentally friendly growth. This review will address resource management within the framework of zero-waste principles and a regenerative economy. Also, this study will help academics acquire extensive knowledge about the many sustainable uses of waste from tea production as an economical and environmentally favourable alternative to biomass.

Amruta Koli, Akshata Pattanshetti, Shubhangi Mane-Gavade et al.

In the previous years, activated carbons (ACs) derived from agro-waste have demonstrated excellent adsorption capability. Production of ACs using easy available and low cost agro-waste marks them as unique materials for several environmental applications including but not limited to CO2 capture, dyes and heavy metal ion removal by adsorption etc. This review highlights the present scenario of available agricultural land, global agricultural production and generation of enormous agro-waste worldwide with their alternative management by producing value-added and applicable ACs as an adsorbent for environmental remediation instead of burning. This review specifically aims to support researchers by providing an all-inclusive overview of different aspects of agro-waste management with a perspective in AC preparation, characterization and its environmental applications such as CO2 capture, dye and metal ion adsorption for enhancing the pathways to clean air and water.