Integrating fuzzy-AHP and GIS for solid waste disposal site selection in Kenitra province, NW Morocco.

Selecting an optimal solid waste disposal site is one of the decisive waste management issues because unsuitable sites cause serious environmental and public health problems. In Kenitra province, northwest Morocco, sustainable disposal sites have become a major challenge due to rapid urbanization and population growth. In addition, the existing disposal sites are traditional and inappropriate. The objective of this study is to suggest potential suitable disposal sites using fuzzy logic and analytical hierarchy process (fuzzy-AHP) method integrated with geographic information system (GIS) techniques. For this purpose, thirteen factors affecting the selection process were involved. The results showed that 5% of the studied area is considered extremely suitable and scattered in the central-eastern parts, while 9% is considered almost unsuitable and distributed in the northern and southern parts. Thereafter, these results were validated using the area under the curve (AUC) of the receiver operating characteristics (ROC). The AUC found was 57.1%, which is a moderate prediction's accuracy because the existing sites used in the validation's process were randomly selected. These results can assist relevant authorities and stakeholders for setting new solid waste disposal sites in Kenitra province.

Forecasting municipal solid plastic waste generation and management policy using system dynamics: a case study of Khulna City in Bangladesh.

A comprehensive analysis of municipal solid plastic waste (MSPW) management while emphasizing plastic pollution severity in coastal cities around the world is mandatory to alleviate the augmenting plastic waste footprint in nature. Thus, decision-makers' persuasion for numerous management solutions of MSPW flow-control can be met through meditative systematic strategies at the regional level. To forecast solutions focused on systematic policies, an agent-based system dynamics (ASD) model has been developed and simulated from 2023 to 2040 while considering significant knit parameters for MSPW management of Khulna City in Bangladesh. Baseline simulation results show that per-capita plastic waste generation will increase to 11.6 kg by 2040 from 8.92 kg in 2023. Eventually, the landfilled quantity of plastic waste has accumulated to 70,000 tons within 18 years. Moreover, the riverine discharge has increased to 834 tons in 2040 from a baseline quantity of 512 tons in 2023. So the plastic waste footprint index (PWFI) value rises to 24 by 2040. Furthermore, the absence of technological initiatives is responsible for the logarithmic rise of non-recyclable plastic waste to 1.35*1000=1350 tons. Finally, two consecutive policy scenarios with baseline factors such as controlled riverine discharge, increased collection and separation of plastic waste, expansion of recycle business, and locally achievable plastic conversion technologies have been simulated. Therefore, policy 2, with 69% conversion, 80% source separation, and 50% riverine discharge reduction of MSPW, has been found adequate from a sustainability perspective with the lowest PWFI ranges of 3.97 to 1.07 alongside a per-capita MSPW generation of 7.63 to 10 kg from 2023 till 2040.

Potentially toxic elements (PTEs) and ecological risk at waste disposal sites: An analysis of sanitary landfills.

This study presents an analysis of soil contamination caused by Ni, Zn, Cd, Cu, and Pb at municipal solid waste (MSW) landfills, with a focus on ecological risk assessment. The approach aims to assess how different landfill practices and environmental conditions affect soil contamination with potentially toxic elements (PTEs) and associated environmental risks. Soil samples were collected from MSW landfills in Poland and the Czech Republic. The research included a comprehensive assessment of PTEs in soils in the context of global environmental regulations. The degree of soil contamination by PTEs was assessed using indices: Geoaccumulation Index (Igeo), Single Pollution Index (Pi), Nemerow Pollution Index (PN), and Load Capacity of a Pollutant (PLI). The ecological risk was determined using the Risk of PTEs (ERi) and Sum of Individual Potential Risk Factors (ERI). The maximum values of the indicators observed for the Radiowo landfill were as follows: Igeo = 4.04 for Cd, Pi = 24.80 for Cd, PN = 18.22 for Cd, PLI = 2.66, ERi = 744 for Cd, ERI = 771.80. The maximum values of the indicators observed for the Zdounky landfill were as follows: Igeo = 1.04 for Cu, Pi = 3.10 for Cu, PN = 2.52 for Cu, PLI = 0.27, ERi = 25 for Cd, ERI = 41.86. The soils of the tested landfills were considered to be non-saline, with electrical conductivity (EC) values less than 2,000 µS/cm. Varying levels of PTEs were observed, and geostatistical analysis highlighted hotspots indicating pollution sources. Elevated concentrations of Cd in the soil indicated potential ecological risks. Concentrations of Cu and lead Pb were well below the thresholds set by the environmental legislation in several countries. In addition, Ni concentrations in the soils of both landfills indicated that the average levels were within acceptable limits. Principal Component Analysis (PCA) revealed common sources of PTEs. The identification of specific risk points at the Radiowo and Zdounky sites contributes to a better understanding of potential hazards in landfill environments. By establishing buffer zones and implementing regular maintenance programs, emerging environmental problems can be addressed in a timely manner.

Co-processing of end-of-life wind turbine blades in portland cement production.

The objective of this paper is to evaluate the feasibility of co-processing wind turbine blade (WTB) material in cement manufacturing to provide an end-of-life means to divert the solid waste of decommissioned WTBs from landfills. Many WTBs consist primarily of glass fiber reinforced thermoset polymers that are difficult to recover or recycle. Portland cement is produced world-wide in large quantities, requiring immense quantities of raw materials (mostly calcium oxide and silicon oxide) and kiln temperatures approaching 1,450 °C. This work contributes analyses of WTB material composition, and predicts the energy provided through the combustible components of the WTBs and raw material contributions provided by incorporating the incombustible components of the WTBs to produce cement. Approximately 40 to 50 % of the WTB material will contribute as fuel to cement production, and approximately 50 to 60 % of the WTB material is expected to be incombustible. One tonne of WTB material can displace approximately 0.4 to 0.5 tonne of coal, while also contributing approximately 0.1 tonne of calcium oxide and 0.3 tonne of silicon oxide as raw material to the cement production process. The glass fiber WTB tested had an average boron content of 4.5 % in the ash. The effects of this high boron content on the cement and its production process should be evaluated. Co-processing WTBs in cement plants will slightly reduce combustion-related CO2 emissions due to avoided calcination. It seems feasible to co-process glass-fiber reinforced WTBs in cement production as WTBs provide suitable raw materials and compatible fuel for this process.

Mechanism of soot and particulate matter formation during high temperature pyrolysis and gasification of waste derived from MSW.

This research investigates the formation mechanism of soot and particulate matter during the pyrolysis and gasification of waste derived from Municipal Solid Waste (MSW) in a laboratory scale drop tube furnace. Compared with CO2 gasification atmosphere, more ultrafine particles (PM0.2, aerodynamic diameter less than 0.2 µm) were generated in N2 atmosphere at 1200℃, which were mainly composed of polycyclic aromatic hydrocarbons (PAHs), graphitic carbonaceous soot and volatile alkali salts. High reaction temperatures promote the formation of hydrocarbon gaseous products and their conversion to PAHs, which ultimately leads to the formation of soot particles. The soot particles generated by waste derived from MSW pyrolysis and gasification both have high specific surface area and well-developed pore structure. Compared with pyrolysis, the soot generated by gasification of waste derived from MSW had smaller size and higher proportion of inorganic components. The higher pyrolysis temperature led to the collapse of the mesoporous structure of submicron particles, resulting in a decrease in total pore volume and an increase in specific surface area. Innovatively, this research provides an explanation for the effect of reaction temperature/ CO2 on the formation pathways and physicochemical properties of soot and fine particulate matter.

A systematic comparison of salt removal efficiency in washing treatment by using fly ashes from 13 MSWI plants in China.

Municipal solid waste incineration (MSWI) fly ash contains large amounts of Ca, Si, and other elements, giving it the potential to be used as a raw material for cement production. However, fly ash often contains a high content of salts, which greatly limits its blending ratio during cement production. These salts are commonly removed via water washing, but this process is affected by the nature and characteristics of fly ash. To clarify the influence of the ash characteristics on salt removal, a total of 60 fly ash samples from 13 incineration plants were collected, characterized, and washed. The ash characterization and cluster analysis showed that the incinerator type and flue gas purification technology/process significantly influenced the ash characteristics. Washing removed a high percentage of salts from fly ash, but the removal efficiencies varied significantly from each other, with the chlorine removal efficiency ranging from 73.76% to 96.48%, while the sulfate removal efficiency ranged from 6.92% to 51.47%. Significance analysis further revealed that the salt removal efficiency varied not only between the ash samples from different incinerators, but also between samples collected at different times from the same incinerator. The high variance of the 60 ash samples during salt removal was primarily ascribed to their different mineralogical and chemical characteristics. Mineralogical analysis of the raw and washed ash samples showed that the mineralogical forms and proportion of these salts in each ash sample greatly influenced their removal. The presence of less-soluble and insoluble chloride salts (e.g., CaClOH, Ca2Al(OH)6(H2O)2Cl etc.) in fly ash significantly affected the chlorine removal efficiency. This study also found that Fe, Mn, and Al in fly ash were negatively correlated with the dechlorination efficiency of fly ash. In summary, the different physical and chemical properties of fly ash caused great discrepancies in salt removal. Consequently, it is suggested to consider the potential impact of the ash source and ash generation time on salt removal to ensure a reliable treatment efficiency for engineering applications.

Life cycle assessment applications to reuse, recycling and circular practices for textiles: A review.

To understand which are the best strategies for textile waste management and to analyse the effects on the environment of applying circular economy practices to textile products, a review of 45 publications where life cycle assessment (LCA) is applied to these topics has been carried out. The separate collection of textiles, followed by reuse and recycling brings relevant environmental benefits, with impacts related to reuse resulting lower than those of recycling. At the opposite, when mixed municipal solid waste is addressed to energy recovery, the textile fraction is the second most impacting on climate change, right after plastics, while for landfill disposal impacts textiles directly follow the more biodegradable fractions. Textiles manufacturing using recycled fibres generally gives lower impacts than using virgin ones, with a few exceptions in some impact categories for cotton and polyester. The circular practices with the lowest impacts are those that ensure the extension of the textiles service life. Another aim of this review is to identify the main variables affecting the life cycle impact assessment (LCIA). These resulted to be the yield and material demand of recycling processes, the use phase variables, the assumptions on virgin production replaced by reuse or recycling, the substitution factor in reuse, and transportation data in business models based on sharing. Thus, in LCA modelling, great attention should be paid to these variables. Future research should address these aspects, to acquire more relevant data, based on industrial-scale processes and on people habits towards the circular economy strategies applied to textiles.

Effects of landfill void fraction and moisture content on the formation of aerobic areas in a semi-aerobic bioreactor.

The main disposal method for municipal solid waste (MSW), including the growing worldwide volumes of kitchen waste, involves transport to landfills. Because kitchen waste is mainly composed of organic matter and has a high moisture content, large amounts of leachate and landfill gas are generated when it is sent to landfills. Therefore, rapid waste stabilization is essential. In this study, four semi-aerobic bioreactors (named NS, SS, MS, and LS) were established with void fractions of 33.76%, 39.84%, 44.62%, and 41.31%, respectively. The results showed that the void fractions of landfill directly affected the gas flow path. When the landfill void fraction was small (e.g., NS), most airflow traveled directly through the pipeline and minimal airflow entered the waste layer. When the landfill void fraction was large (e.g., MS), air easily entered the waste layer and some air flowed into the gas vent with the landfill gas. As the reaction proceeded, the void fraction gradually decreased due to gravity-induced sedimentation. During the water addition experiment, the voids were occupied by water, leading to formation of an anaerobic area. Among the four bioreactors, only MS had negligible formation of an anaerobic zone in the center. Methane (CH4) generation was detected only at the connection between the gas vent and the leachate collection pipe. A larger void fraction led to formation of a smaller anaerobic zone. The ratio of air flowing in pipeline was lowest in MS. These results indicated that a large void fraction promotes the decomposition of organic matter.

Impact of volatile organic compounds in large municipal solid waste landfills on regional environment.

Landfill disposal is a major approach of disposing municipal solid waste (MSW) in China. In order to explore the impact of volatile organic compounds (VOCs) generated by landfill on the air quality of regional environment, Jiangcungou landfill in Xi'an and its surrounding area were taken as a research object to analyze the spatial distribution and seasonal variation patterns of non-methane hydrocarbon (NMHC) and VOCs components through seasonal sampling of regional NMHC concentration and VOCs concentration (116 species). CALPUFF model was adopted to analyze the regional dispersion characteristics of NMHC on landfill. In addition, propylene equivalent concentration (PEC) and maximum incremental reactivity (MIR) methods were used to estimate O3 formation potential of the landfill, while fraction aerosol coefficient (FAC) and SOA potential (SOAP) methods were used to estimate SOA formation potential of the landfill. It was indicated that, the component with the highest concentration of VOCs on the working surface and the surrounding area of landfill was p + m-xylene (41.0 µg/m3) and halohydrocarbon (111.2 µg/m3-156.3 µg/m3), respectively. The component with the greatest impact on the surrounding air was acetone, which accounts for 75 %-87 % of the corresponding substance concentration on the landfill. In summer, the surrounding area was affected most by NMHC from landfill, whose emissions contributed 9.5 mg/m3 to the surrounding area. The component making the largest contribution to O3 formation was p + m-xylene (8 %-24 %), while ethylbenzene was the component making the largest contribution to SOA formation (20 %-24 %).

Biomass acid pretreatment impacts on metabolic routes and bacterial composition of dark fermentation process.

Complex organic matter represents a suitable substrate to produce hydrogen through dark fermentation (DF) process. To increase H2 yields, pretreatment technology is often required. The main objective of the present work was to investigate thermo-acid pretreatment impact on sugar solubilization and biotic parameters of DF of sorghum or organic fraction of municipal solid waste (OFMSW). Biochemical hydrogen potential tests were carried out without inoculum using raw or thermo-acid pretreated substrates. Results showed an improvement in sugar solubilization after thermo-acid pretreatments. Pretreatments led to similar DF performances (H2 and total metabolite production) compared to raw biomasses. Nevertheless, they were responsible for bacterial shifts from Enterobacteriales towards Clostridiales and Bacillales as well as metabolic changes from acetate towards butyrate or ethanol. The metabolic changes were attributed to the biomass pretreatment impact on indigenous bacteria as no change in the metabolic profile was observed after performing thermo-acid pretreatments on irradiated OFMSW (inactivated indigenous bacteria and inoculum addition). Consequently, acid pretreatments were inefficient to improve DF performances but led to metabolic and bacterial community changes due to their impact on indigenous bacteria.

Effects of carbon-based conductive materials on semi-continuous anaerobic co-digestion of organic fraction of municipal solid waste and waste activated sludge.

Organic fraction of municipal solid waste (OFMSW) and waste activated sludge (WAS) are the most produced organic waste streams in urban centres. Their anaerobic co-digestion (AcoD) allows to generate methane (CH4) and digestate employable as renewable energy source and soil amendment, respectively, fully in accordance with circular bioeconomy principles. However, the widespread adoption of such technology is limited by relatively low CH4 yields that fail to bridge the gap between benefits and costs. Among strategies to boost AcoD of OFMSW and WAS, use of conductive materials (CMs) to promote interspecies electron transfer has gained increasing attention. This paper presents one of the few experimental attempts of investigating the effects of four different carbon(C)-based CMs (i.e., granular activated carbon - GAC, graphite - GR, graphene oxide - GO, and carbon nanotubes - CNTs) separately added in semi-continuous AcoD of OFMSW and thickened WAS. The presence of C-based CMs has been observed to improve CH4 yield of the control process. Specifically, after 63 days of operation (concentrations of GAC and GR of 10.0 g/L and of GO and CNTs of 0.2 g/L), 0.186 NL/gVS, 0.191 NL/gVS, 0.203 NL/gVS, and 0.195 NL/gVS of CH4 were produced in reactors supplemented with GAC, GR, GO, and CNTs, respectively, compared to 0.177 NL/gVS produced in the control process. Likewise, at the end of the test (i.e., after 105 days at concentrations of C-based CMs half of the initial ones), CH4 yields were 0.193 NL/gVS, 0.201 NL/gVS, 0.211 NL/gVS, and 0.206 NL/gVS in reactors supplemented with GAC, GR, GO, and CNTs, respectively, compared to 0.186 NL/gVS of the control process. Especially with regard to GR, GO, and CNTs, results obtained in the present study represent a significant advance of the knowledge on the effects of such C-based CMs to realistic and scalable AD process conditions respect to previous literature.

Meta-analysis addressing the potential of antibiotic resistance gene elimination through aerobic composting.

The significant increase in antibiotic resistance genes (ARGs) in organic solid wastes (OSWs) has emerged as a major threat to the food chain. Aerobic composting is a widely used technology for OSW management, with the potential to influence the fate of AGRs. However, the variability of the ARG elimination effects reported in different studies has highlighted the uncertainty regarding the effects of composting on ARGs. To identify the potential of composting in reducing ARG and the factors (e.g., composting technologies and physiochemical properties) influence ARG changes, a meta-analysis was conducted with a database including 4,232 observations. The abundances of ARGs and mobile genetic elements (MGEs) can be substantially reduced by 74.3% and 78.8%, respectively, via aerobic composting. During composting, the ARG levels in chicken and swine manure tended to be reduced more significantly (81.7% and 78.0%) compared to those in cattle manure (52.3%) and sewage sludge (32.6%). The reduction rate of sulfonamide resistant genes was only 35.3%, which was much lower than those of other types. MGEs and composting duration (CD) were identified as the most important factors driving ARG changes during composting. These findings provide a comprehensive insight into the effects of composting on ARG reduction, which may help prevent the transmission in food systems.

Impacts of regional socioeconomic statuses and global events on solid waste research reflected in six waste-focused journals.

The research pertaining to solid waste is undergoing extensive advancement, thereby necessitating a consolidation and analysis of its research trajectories. The existing biblio-studies on solid waste research (SWR) lack thorough analyses of the factors influencing its trends. This article presents an innovative categorization framework that categorizes publications from six SWR journals utilizing Source Latent Dirichlet Allocation. First analyse changes in publication numbers across main categories, subcategories, journals, and regions, providing a macro-level study of SWR. Temporal analysis of keywords supplements a micro-level study of SWR, which highlights that emerging technologies with low Technology Readiness Level receive significant attention, while studies on widespread technologies are diminishing. Additionally, this study demonstrates the substantial influence of socioeconomic factors and previous SWR publications on current and future SWR trends. Finally, the article confirms the impact of global events on SWR trends by examining the structural breakpoints of SWR and their correlation with global events.

Optimizing MSW incineration bottom ash reuse: A study on treated wastewater washing and leaching control.

The current study introduces an innovative methodology by utilizing treated wastewater (TWW) from an effluent treatment plant as a washing agent to enhance the characteristics of incineration bottom ash (IBA). This approach addresses sustainability concerns and promotes the circular economy by reusing wastewater generated in municipal solid waste incineration facilities. Previous research has underscored the challenges of open IBA reuse due to elevated leaching of chlorides, sulfates, and trace metal(loid)s. Thus, the experimental setup explores various combinations of washing, with or without screening, to optimize the properties of soil-like material (SLM < 4.75 mm) and overall material (OM < 31.5 mm) fractions of IBA for unrestricted applications. Batch leaching tests were conducted on treated samples, and leaching characteristics were evaluated in accordance with regulatory standards, primarily the Dutch standard for unrestricted IBA reuse. The findings reveal that washing in isolation proves insufficient to enhance IBA properties; however, washing followed by screening, specifically for removing fines (<0.15 mm), proves effective in reducing contamination. The study identifies that multiple steps of washing and screening (with recirculation) process render OM and SLM fractions suitable for unrestricted reuse with a cumulative liquid-to-solid ratio of 6 L/kg and a total washing time of 15 min. The multi-step treatment was found effective in reducing sulfate contamination by 65-74 % and chloride contamination by 83-89 % in IBA fractions. This approach offers a promising solution for overcoming the limitations associated with IBA leaching, thereby promoting sustainable waste reuse practices.

Characterization of per- and polyfluoroalkyl substances (PFAS) and other constituents in MSW landfill leachate from Puerto Rico.

Elevated per- and polyfluoroalkyl substance (PFAS) concentrations have been reported in municipal solid waste (MSW) landfill leachate with higher levels in wet and warmer subtropical climates. Information about landfill leachate characteristics is much more limited in tropical climates. In this study, 20 landfill leachate samples were collected from three MSW landfills on the tropical island of Puerto Rico and results were compared against landfills nationally and within Florida, USA. The samples collected in Puerto Rico underwent physical-chemical analysis, as well as a quantitative analysis of 92 PFAS. Samples described in this study include discrete leachate types, such as leachate, gas condensate, and leachate which has undergone on-site treatment (e.g., RO treatment, phytoremediation, lagoons). A total of 51 PFAS were detected above quantitation limits, including perfluorohexylphosphonic acid, a perfluoroalkyl acid (PFAA) which has not been reported previously in landfill leachate. ∑PFAS concentrations in this study (mean: 38,000 ng L-1), as well as concentrations of individual PFAS, are significantly higher than other reported MSW landfill leachate concentrations. The profiles of leachates collected from on-site treatment systems indicate possible transformation of precursor PFAS as a result of treatment processes - oxidizing conditions, for example, may facilitate aerobic transformation, increase the concentrations of PFAAs, and possibly increase the apparent ∑PFAS concentration. Extreme climate events, including rising temperatures and more frequent hurricanes, have placed additional strain on the solid waste management infrastructure on the island - adding complexity to an already challenging PFAS management issue. As concern grows over PFAS contamination in drinking water, these findings should inform solid waste and leachate management decisions in order to minimize PFAS emissions in island environments.

Solidification/stabilization and optimization of municipal solid waste incineration fly ash with aluminosilicate solid wastes.

Alkali-activation is an effective municipal solid waste incineration fly ash (MSWIFA) solidification/stabilization (S/S) technology. However, the characteristics of calcium-rich silica-poor aluminum phase in MSWIFA easily cause the structural instability and contamination of alkali activated MSWIFA S/S bodies. Therefore, the aluminosilicate solid wastes are used in this work to optimize the immobilization and structural properties. Results showed that incorporation of aluminosilicate solid wastes significantly improved the compressive strength and heavy metals pollution toxicity of MSWIFA S/S bodies. Compared to alkali activated MSWIFA, the compressive strength of S/S bodies with addition of coal fly ash, silica fume and granulated blast furnace slag improved by 31.0%, 47.6% and 50.8% when the curing time was 28 days, respectively. Leachability of Pb, Zn and Cd in these alkali activated MSWIFA S/S bodies was far below the threshold value specified in Standard GB16889. Aluminosilicate solid wastes provided abundant Si/Al structural units, and some new phases such as ettringite(AFt, 3CaO⋅Al2O3⋅3CaSO4⋅32H2O), calcium sulfoaluminate hydrate (3CaO⋅Al2O3⋅CaSO4⋅12H2O) and Friedel's salt (CaO⋅Al2O3⋅CaCl2⋅10H2O) can be detected in S/S matrix with aluminosilicate solid wastes, along comes increased the amount of the amorphous phases. Lower Ca/Si molar ratio tended to form the network structure gel similar to tobermorite with higher polymerization degree. Meanwhile, the silica tetrahedron of the gels changed from the oligomerization state like island to the hyperomerization state like chain, layer network or three-dimensional structure, and average molecular chain length increased. These findings provide theoretical basis for structural properties optimization and resource utilization of MSWIFA S/S matrices.

Analysis of composition characteristics and treatment techniques of municipal solid waste incineration fly ash in China.

The rapid development of the economy and society is causing an increase in the amount of municipal solid waste (MSW) produced by people's daily lives. With the strong support of the Chinese government, incineration power generation has steadily become the primary method of treating MSW, accounting for 79.86%. However, burning produces a significant amount of municipal solid waste incineration fly ash (MSWI-FA), which contains heavy metals, soluble chlorine salts, and dioxins. China's MSWI-FA yield increased by 8.23% annually to 7.80 million tons in 2022. Besides, the eastern region, especially the southeastern coastal region, has the highest yield of MSWI-FA. There are certain similarities in the chemical characteristics of MSWI-FA samples from Northeast, North, East, and South China. Zn and CaO have the largest amounts of metals and oxides, respectively. The Cl content is about 20 wt%. This study provides an overview of the techniques used in the thermal treatment method, solidification and stabilization, and separation and extraction of MSWI-FA and compares their benefits and drawbacks. In addition, the industrial applications and standard requirements of landfill treatment and resource utilization of MSWI-FA in China are analyzed. It is discovered that China's resource utilization of MSWI-FA is insufficient through the study on the fly ash disposal procedures at a few MSW incineration facilities located in the economically developed Guangdong Province and the traditional industrial city of Tianjin. Finally, the prospects for the disposal of MSWI-FA were discussed.

Categorization of leaching behaviors of elements from commercially treated incineration bottom ash in Singapore.

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.

The impact of chronic and acute problems on sea turtles: The consequences of the oil spill and ingestion of anthropogenic debris on the tropical semi-arid coast of Ceará, Brazil.

Sea turtle mortality is often related to materials that reach the coast from different anthropic activities worldwide. This study aimed to investigate whether sea turtle mortality was related to older marine problems, such as solid waste, or one of the largest oil spill accidents on the Brazilian coast, that occurred in 2019. We posed three questions: 1) Are there solid residues in the digestive tract samples, and which typology is the most abundant? 2) Can meso­ and macro-waste marine pollutants cause mortality? 3) Is the dark material found really oil? A total of 25 gastrointestinal content (GC) samples were obtained, of which 22 ingested waste of anthropogenic origin and 18 were necropsied. These 22 samples were obtained during or after the 2019 oil spill, of which 17 specimens were affected, making it possible to suggest oil ingestion with the cause of death in the animals that could be necropsied. Macroscopic data showed that the most abundant solid waste was plastic (76.05 %), followed by fabrics (12.18 %) and oil-like materials. However, chemical data confirmed only three specimens with oil levels ranging from remnants to high. It was possible to infer possible causes of death in 16 of the total 18 necropsied cases: Most deaths were due to respiratory arrest (62.5 %), followed by pulmonary edema (12.5 %), cachexia syndrome (12.5 %), circulatory shock (6.25 %), and head trauma (6.25 %), which may have been caused by contact with solid waste, oil, or both. The study showed that not all dark material found in the GCs of turtles killed in oiled areas is truly oil, and in this sense, a chemical analysis step to prove the evidence of oil must be added to international protocols.