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.

Social competition drives collective action to reduce informal waste burning in Uganda.

Improving urban air quality is a pressing challenge in the Global South. A key source of air pollution is the informal burning of household waste. Reducing informal burning requires governments to develop formal systems for waste disposal and for residents to adopt new disposal behaviors. Using a randomized experiment, we show that social competitions between pairs of neighborhoods in Nansana municipality, Uganda, galvanized leadership and inspired collective action to reduce informal burning. All 44 neighborhoods in the study received a public health campaign, while 22 treated neighborhoods were paired and competed to reduce waste burning over an 8-mo period. Treated neighborhoods showed a 24 percent reduction (95% CI: 11 to 35 percent) in waste burning relative to control neighborhoods at the end of the competition period. There is no evidence that treated neighborhoods experienced a rebound in waste burning several months after the competitions. Community leaders reported greater effort in coordinating residents and more pride in their neighborhood when assigned to the competition treatment. These results suggest that creating focal points for leadership and collective action can be an effective and low-cost strategy to address policy problems that require broad participation and costly behavior change.

Evaluating factors promoting waste scavenging and its implications in a growing urban environ in Nigeria.

Despite the inherent risks associated with waste scavenging, it is surprising to note the age group involved in this activity. This study aimed to assess the motivating factors driving teenagers and youths to participate in waste scavenging, using a sample of 247 scavengers. The data underwent analysis using frequency counts, percentages, and factor analysis techniques. The findings revealed that all respondents were male and aged between 12 and 45 years. The primary sources of waste were dumpsites (61%), roadsides, and gutters (26%). Participants predominantly cited lack of formal education requirements and financial gain (93%) as key motivators for their involvement in waste scavenging. Additionally, 96% of scavengers were from northern Nigeria, with the remaining 4% from southern Nigeria. The factor analysis yielded significant results with a Kaiser-Meyer-Olkin (KMO) measure and Bartlett's test value of 67.770%, significant at p < 0.05. Four distinct factors emerged as significant motivators: (i) Lack of formal education (31.784%), (ii) Financial incentives (22.912%), (iii) Availability of wastes (14.297%), and (iv) Industrial demand for wastes (13.495%), in descending order of influence. Together, these factors accounted for 82.487% of the motivating factors behind youth engagement in waste scavenging in the study area. This outcome highlights potential challenges for the prospects of young individuals involved in scavenging unless substantial interventions are implemented. It is recommended that policies be developed to discourage scavenging activities while simultaneously promoting access to education and social welfare for this demographic. Such initiatives are crucial for redirecting young people away from scavenging and toward more sustainable livelihood options, ensuring a brighter future for them and contributing to overall societal development.

Unused, expired pharmaceuticals and their disposal practices among the general public in Burdur-Türkiye: a cross-sectional study.

BACKGROUND: Unused pharmaceuticals are currently a public health problem. This study aimed to identify unused pharmaceuticals, research practices about the disposal methods, classify the medicines according to Anatomical Therapeutic Chemical codes (ATC) and, to determine the number of unused medicines. METHODS: The study was designed as a cross-sectional study. Data were collected between April and August 2023 in Burdur-Türkiye by non-probability sampling technique (convenience method). Pharmaceuticals were classified according to ATC. Statistical Package for Social Science SPSS (V.24) package program was used for data analysis. RESULTS: A total of 1120 people, 1005 in the first sample group and 115 in the second sample group, participated in the study. Findings of first sample group: A total of 4097 boxes of unused pharmaceuticals (4.7 ± 4.3 boxes/per capita) were detected. It was found that pharmaceuticals were stored in areas such as kitchens (59.1%) and refrigerators (38.6%), the reason for keeping them was reuse (41%), and the disposal practice was household garbage (81%). Paracetamol (648 boxes), Other cold preparation (303 boxes), Dexketoprofen (239 boxes), Diclofenac (218 boxes), Amoxicillin and beta-lactamase inhibitor (190 boxes) were found to be the most frequently unused pharmaceuticals. Using the unused medicines at home without consulting a physician was 94.1% (self-medication). Findings of second sample group: Of the 6189 dosage forms in 265 boxes pharmaceutical, 3132(50.6%) dosage forms were used and 3057(49.4%) were found to be unused. CONCLUSION: There is a significant amount and number of unused medicines in households, and self-medication is common. Medicines are not properly disposed of and some of them expire. Public information is needed. A "drug take-back system" for unused medicines can be useful in solving this problem.

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.

Does owning improved latrine facilities enhance the safe disposal of child feces in Africa? a systematic review and meta-analysis.

INTRODUCTION: Improved sanitation refers to those that effectively avoid human contact with excreta in a hygienic manner. Having improved latrines is a key factor in adopting safe ways of disposing of child feces. However, previous studies in Africa that examined how owning improved latrine facilities associated with household child feces disposal practices has shown inconsistent results, and no systematic review of these findings has been done. Therefore, this study aims to synthesize the evidence on the significance of households having improved latrine facilities for safe child feces disposal practices among households with under five-year-old children in Africa. METHODS: The searched databases include: PubMed/Medline, Ovid/Embase, ScienceDirect, AJOL and the Cochrane Library. In the search process, Google Scholar and references of other studies were considered. This review included studies that were published in English without any time restrictions. The outcome of this study was an estimate of the association between the ownership of an improved latrine and the disposal practices of children's feces. Two reviewers used the Excel data extraction tool to extract the relevant data from the studies that were included in the review. Using Stata version 16, a meta-analysis was performed with a random effects statistical model. The inverse index of variance (I2) was used to assess heterogeneity. Forest plots were used to show the pooled estimate with a 95% confidence interval. Publication bias was assessed using Egger's test and a funnel plot. RESULTS: Out of the 616 studies that were retrieved, 15 were included in the systematic review analysis and 10 were included in the meta-analysis. All studies that were included are cross-sectional studies done in Ethiopia, Nigeria, Gambia, Malawi, Eswatini, Ghana, Zambia, and a study used data from sub-Saharan Africa. Improved latrine facilities significantly enhanced the practice of safe child feces disposal, as shown by the overall effect size (OR = 2.74; 95% CI = 1.24-1.35, I2 = 99.95%). In the subgroup analysis by sample size, the presence of improved latrines significantly enhanced safe child feces disposal in studies with sample sizes less than 1000 (OR = 3.24; 95% CI = 2.86-3.62, I2 = 61.38%), while there was no significant difference in studies with sample sizes greater than 1000 (OR = 2.67; 95% CI = 0.69-4.64, I2 = 99.97%). However, studies that involved children under 5 years old indicated that improved latrine facilities significantly enhanced the practice of safe child feces disposal (OR = 4.02; 95% CI = 2.03-6.09; I2 = 99.96%). CONCLUSIONS: In this research study, we examined the ownership of improved latrine facilities among households with five-year-old children to enhance the disposal of child feces in a safer manner in Africa. The high heterogeneity among the studies and the cross-sectional design of the included studies limit the causal inference and generalizability of the findings. Therefore, meta-analyses of longitudinal and experimental studies are needed to confirm the causal relationship between improved latrine facilities and safe child feces disposal practices in Africa.

Nanobubble technology to enhance energy recovery from anaerobic digestion of organic solid wastes: Potential mechanisms and recent advancements.

Nanobubble (NB) technology has gained popularity in the environmental field owing to its distinctive characteristics and ecological safety. More recently, the application of NB technology in anaerobic digestion (AD) systems has been proven to promote substrate degradation and boost the production of biogas (H2 and/or CH4). This review presents the recent advancements in the application of NB technology in AD systems. Meanwhile, it also sheds light on the underlying mechanisms of NB technology that contribute to the enhanced biogas production from AD of organic solid wastes. Specifically, the working principles of the NB generator are first summarized, and then the structure of the NB generator is optimized to accommodate the demand for NB characteristics in the AD system. Subsequently, it delves into a detailed discussion of how the addition of nanobubble water (NBW) affects AD performance and the different factors that NB can potentially contribute. As a simple and environmentally friendly additive, NBW was commonly used in the AD process to enhance the fluidity and mass transfer characteristics of digestate. Additionally, NB has the potential to enhance the functionality of different types of microbial enzymes that play crucial roles in the AD process. This includes boosting extracellular hydrolase activities, optimizing coenzyme F420, and improving cellulase function. Finally, it is proposed that NBW has development potential for the pretreatment of substrate and inoculum, with future development being directed towards this aim.

Assessing microbial stability and predicting biogas production in full-scale thermophilic dry methane fermentation of municipal solid waste.

Compared to typical anaerobic digestion processes, little is known about both sludge microbial compositions and biogas production models for full-scale dry methane fermentation treating municipal solid waste (MSW). The anaerobic sludge composed of one major hydrogenotrophic methanogen (Methanoculleus) and syntrophic acetate oxidizing bacteria (e.g., Caldicoprobacter), besides enrichment of MSW degraders such as Clostridia. The core population remained phylogenetically unchanged during the fermentation process, regardless of amounts of MSW supplied (∼35 ton/d) or biogas produced (∼12000 Nm3/d). Based on the correlations observed between feed amounts of MSW from 6 days in advance to the current day and biogas output (the strongest correlation: r = 0.77), the best multiple linear regression (MLR) model incorporating the temperature factor was developed with a good prediction for validation data (R2 = 0.975). The proposed simple MLR method with only data on the feedstock amounts will help decision-making processes to prevent low-efficient biogas production.

Waste-green infrastructure nexus: Green roof promotion by digestate and digestate biochar from food waste.

Waste-Green Infrastructure Nexus is crucial to mitigate carbon emissions in waste disposal and promote eco-functions of green infrastructure in a circular bio-economy. Our purpose is to verify the feasibility of the nexus via "food waste anaerobic digestion - digestate/digestate biochar - green roof promotion". The results found that food waste digestate and digestate biochar significantly promoted green roof plant growth, evapotranspiration, rainwater retention, runoff reduction, and prevention of nutrient leaching. Digestate treatments were better than digestate biochar for the green roof promotion. The promotion ranked consistently with 20 % digestate > 10 % digestate > 20 % digestate biochar > 10 % digestate biochar > control in stolon growth, leaf emergence, branching of Paspalum vaginatum, green roof establishment, rainwater retention, runoff reduction, and the leaching of nitrogen, phosphorus, potassium. This study demonstrated that food waste could be regenerated to promote urban green infrastructure to form a circular bio-economy by the Waste-Green Infrastructure Nexus.

Upgrade from aerated static pile to agitated bed systems promotes lignocellulose degradation in large-scale composting through enhanced microbial functional diversity.

Composting presents a viable management solution for lignocellulose-rich municipal solid waste. However, our understanding about the microbial metabolic mechanisms involved in the biodegradation of lignocellulose, particularly in industrial-scale composting plants, remains limited. This study employed metaproteomics to compare the impact of upgrading from aerated static pile (ASP) to agitated bed (AB) systems on physicochemical parameters, lignocellulose biodegradation, and microbial metabolic pathways during large-scale biowaste composting process, marking the first investigation of its kind. The degradation rates of lignocellulose including cellulose, hemicellulose, and lignin were significantly higher in AB (8.21%-32.54%, 10.21%-39.41%, and 6.21%-26.78%) than those (5.72%-23.15%, 7.01%-33.26%, and 4.79%-19.76%) in ASP at three thermal stages, respectively. The AB system in comparison to ASP increased the carbohydrate-active enzymes (CAZymes) abundance and production of the three essential enzymes required for lignocellulose decomposition involving a mixture of bacteria and fungi (i.e., Actinobacteria, Bacilli, Sordariomycetes and Eurotiomycetes). Conversely, ASP primarily produced exoglucanase and ß-glucosidase via fungi (i.e., Ascomycota). Moreover, AB effectively mitigated microbial stress caused by acetic acid accumulation by regulating the key enzymes involved in acetate conversion, including acetyl-coenzyme A synthetase and acetate kinase. Overall, the AB upgraded from ASP facilitated the lignocellulose degradation and fostered more diverse functional microbial communities in large-scale composting. Our findings offer a valuable scientific basis to guide the engineering feasibility and environmental sustainability for large-scale industrial composting plants for treating lignocellulose-rich waste. These findings have important implications for establishing green sustainable development models (e.g., a circular economy based on material recovery) and for achieving sustainable development goals.

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.

Revitalizing plastic wastes employing bio-circular-green economy principles for carbon neutrality.

The use of plastics has become deeply ingrained in our society, and there are no indications that its prevalence will decrease in the foreseeable future. This article provides a comprehensive overview of the global plastic waste disposal landscape, examining it through regional perspectives, various management technologies (dumping or landfilling, incineration, and reuse and recycling), and across different sectors including agriculture and food, textile, tourism, and healthcare. Notably, this study compiles the findings on life-cycle carbon footprints associated with various plastic waste management practices as documented in the literature. Employing the bio-circular-green economy model, we advocate for the adoption of streamlined and sustainable approaches to plastic management. Unique management measures are also discussed including the utilization of bioplastics combined with smart and efficient collection processes that facilitate recycling, industrial composting, or anaerobic digestion. Moreover, the integration of advanced recycling methods for conventional plastics with renewable energy, the establishment of plastic tax and credits, and the establishment of extended producer responsibility are reviewed. The success of these initiatives relies on collaboration and support from peers, industries, and consumers, ultimately contributing to informed decision-making and fostering sustainable practices in plastic waste management.

The potential impact of the new 'Right to Repair' rules on electrical and electronic equipment waste: A case study of the UK.

Every year an estimated two million tonnes of waste electrical and electronic equipment (WEEE) are discarded by householders and companies in the United Kingdom (UK). While the UK has left the European Union (EU), its waste-related policies still mirror those of the EU, including the WEEE-related policies. Motivated by the recent introduction the so-called 'Right to Repair' policy for electrical and electronic equipment (EEE) across the EU and UK, this paper aims to demonstrate that, depending on the commitment and behavioural changes by the consumers and the government, the future of the WEEE management of the UK will vary. To this end, focusing on landfilled WEEE reduction we develop a generic system dynamics model and apply it to eleven WEEE categories. They depict the flow of EEE and WEEE representing the interaction among the stakeholders (e.g., consumers and producers of EEE) and relevant government regulations of the UK. Our four scenario analyses find that longer use of EEE and better WEEE collection seem to be effective in reducing landfilled WEEE, while more reuse and more recycling and recovery have negligible impacts, despite excluding the additional generation of landfilled WEEE as a result of recycling and recovery. Comparing with the business-as-usual scenario, one year longer EEE use and 10% more of WEEE collection could at maximum reduce landfilled WEEE by 14.05% of monitoring and control instruments and 93.93% of display equipment respectively. Backcasting scenario analyses reveal that significant efforts are required to reduce the targeted amounts.

Early detection of deep-seated smouldering fires in wood waste storage using ERT.

Incidents of waste and biofuel fires are common at all stages of the waste recycling chain and have grave implications for business, employees, firefighters, society, and environment. An early detection of waste and biofuel fires in the smouldering stage could save precious lives, resources, and our environment. Existing fire detection methodologies e.g. handheld temperature sensors, IR cameras, gas sensors, and video and satellite-based monitoring techniques have inherent limitations to efficiently detect smouldering fires. An attempt was made to explore the potential of electrical resistivity tomography (ERT) as an alternate tool to address the problem. In the experiments an externally powered resistive wire was employed to initiate the smouldering fire inside the test material (wood pellets, wood shavings, wood fines). Time series of ERT that followed the initiation and development of smouldering were recorded using an automated monitoring instrument setup. The actual geometry of the experimental sample container and electrode setup was integrated in the 3D finite element method (FEM) model grid to perform inverse numerical modelling (inversion) and to develop resistivity tomographic images. The study shows a sharp increase in ratio of resistivity (R/Ro ≥ 50 %) in the test material in the region of smouldering hotspot and demonstrates the potential use of ERT technique for the detection of smouldering hotspots in silos and pile storage of organic material such as wood-based fuels, wood waste, coal, municipal solid waste (MSW), recyclables etc. More research is however required for enabling the use of this technique at the practical scale for different storage conditions.

From grass to gas and beyond: Anaerobic digestion as a key enabling technology for a residual grass biorefinery.

Roadside grass clippings hold potential as a sustainable source of bioenergy as they do not compete with crops for land use, and are only partially utilized for low-value applications. In this study, we proposed using roadside grass as a sole feedstock for anaerobic digestion (AD) in three different settings, and assessed the potential of producing biomaterials and fertilizers from grass-based digestate. Wet continuous digestion at pilot scale and dry batch digestion at pilot and large scales resulted in biogas yields up to 700 Nm3.t-1 DOM with a methane content of 49-55 %. Despite promising results, wet AD had operational problems such as clogging and poor mixing; once upscaled, the dry digestion initially also presented an operational problem with acidification, which was overcome by the second trial. Digested grass fibers from the pilot dry AD were processed into biomaterials and performed similarly or better than the undigested fibers, while around 20 % performance reduction was observed when compared to reference wood fibers. A mass balance indicated reduced fiber recovery when higher biogas production was obtained. The liquid fraction from the pilot dry AD was characterized for its nutrient content and used as a biofertilizer in another study. In contrast, the leachate collected from the large-scale dry AD had a low nitrogen content and high chloride content that could hinder its further use. Finally, a regional market analysis was conducted showing that the biocomposites produced with the available grass fibers could substitute at least half of the current European market based on our results.

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.

Leaching behavior of inert waste landfills.

Inert waste landfills are strictly limited to inert or non-reactive waste materials, nevertheless, due to human negligence or unavoidable circumstances, sometimes, small amounts of biodegradable or chemically reactive waste are mixed and disposed together with the inert waste. Over time, leachate generated from these biodegradable wastes may come into contact with rainfall water and percolate into groundwater and surrounding ground, degrading water quality. Additionally, the large sized industrial plastics present inside the inert waste landfill may trap and store the leachate thus enhancing the risk of contamination due to increased contact time and reducing the mechanical stability of the landfill. In this research, inert waste materials were collected from a Japanese inert waste landfill, and laboratory batch and column leaching tests were performed to determine the leaching behavior of the waste materials with variation in fibrous contents (FC) as 2% and 10% of total inert waste materials. From the batch leaching test, the inert waste was characterized as highly alkaline with a pH value of 10.3 and moderately reduced with a redox potential (Eh) value of 300 mV. The results from the column leaching test indicated that landfilling with 10% FC, comprising sizes below 10 cm, along with an installation of soil layer reduced the concentrations of heavy metals, metalloids, and total organic carbon in the leachate, thus confirming the environmental safety of the inert waste landfill.

Lead exposure by E-waste disposal and recycling in Agbogbloshie, Ghana.

BACKGROUND: Agbogbloshie in Ghana is the world's biggest dumpsite for the informal recycling of electronic waste (e-waste). E-waste is dismantled by rudimentary methods without personal or environmental protection. Workers and occupants are exposed to lead. There are no data so far about the extent and the consequences. We therefore analyzed blood lead levels (BLL) and creatinine levels (CL). METHODS: Full blood samples and basic data (i.e. age, job, length of stay) were collected from dumpsite volunteers. BLL were measured by atomic absorption spectrometry; CL were assessed using the standard clinical laboratory procedures of Aachen Technical University. European BLL reference values were used as Ghana lacks its own. Statistical analysis was by non-parametric tests (Mann-Whitney U test), with p < 0.05. RESULTS: Participants of both sexes (n = 327; 12-68 years; median age 23 years) were assessed. Most workers were aged <30 years. The collective's BLL was in pathological range for 77.7%; 14% had a BLL >10.0 µg/dl with symptoms consistent with high lead exposure including severe (6.5%) and intermediate (39%) renal disorder. BLL above 15.0 µg/dl were found in 5.9% of all workers which is the German threshold for those working with lead. Elevated CL in a pathological range were found in 254 participants. This is problematic as 75% of the lead entering the body is excreted via urine. CONCLUSION: Most of our volunteers had pathological BLL and CL. Preventive strategies are necessary to reduce health risks, particularly for vulnerable populations (i.e. children, pregnant women).

Occurrence and abundance of microplastics and plasticizers in landfill leachate from open dumpsites in Sri Lanka.

This is the first attempt that investigate the abundance of plasticizers in leachate sediment in the scientific literature, alongside the debut effort to explore the abundance of microplastics and plasticizers in landfill leachate and sediment in Sri Lanka. Microplastics in sizes ranging from ≥2.0-5.0, ≥1.0-2.0, and ≥ 0.5-1.0 mm were extracted from the leachate draining from ten municipal solid waste open dump sites and sediment samples covering seven districts. Microplastics were extracted by density separation (Saturated ZnCl2) followed by wet peroxide digestion and the chemical identification was conducted by Fourier Transform Infrared spectroscopy. Plasticizers were extracted to hexane and analyzed by high-performance liquid chromatography. The total mean microplastic abundance in leachate was 2.06 ± 0.62 mg/L whereas it was 363 ± 111 mg/kg for leachate sediments. The most frequently found polymer type was polyethylene (>50%), and white color was dominant. The average concentration of bisphenol A (BPA), benzophenone (BP) and diethyl-hydrogen phthalate (DHEP) in leachate was 158 ± 84.4, 0.75 ± 0.16 and 170 ± 85.8 µg/L respectively. Furthermore, BP and DHEP in leachate sediment was 100 ± 68.3 and 1034 ± 455 µg/kg respectively. As landfill leachate is directly discharged into nearby surface and groundwater bodies that serve as sources of drinking water, the study highlights the potential concerns of microplastic and plasticizer exposure to the surrounding Sri Lankan community through consumption of contaminated drinking water. Therefore, there is a timely need of develop the effective waste management and pollution control measures to minimize the possible threats to both the environment and human health.

Retention time and organic loading rate as anaerobic co-digestion key-factors for better digestate valorization practices: C and N dynamics in soils.

The growing use of anaerobic co-digestion (AcoD) in processing organic waste has led to a significant digestate production. To effectively recycle digestate back into soils, it is crucial to understand how operational variables in the AcoD process influence the conversion of organic matter (OM). To address this, a combination of biochemical fractionation and various soil incubation tests were employed to assess the stability of OM in digestates generated from anaerobic continuous reactors fed with a food waste-hay mixture and operating at different hydraulic retention times (HRT) and organic loading rates (OLR). This study revealed that digester performance and operating parameters impacted carbon dynamics in soils. A decrease in the carbon mineralization in soils when increasing the HRT was reported (48 ± 4 % for 70 days compared to 59 ± 1 % for 42 days). Specific HRT and OLR values were found to be linked to carbon accessibility and complexity, confirming that longer HRT lead to higher OM removal and increased complexity in soluble OM, despite minor discrepancies in relative carbon distribution. Furthermore, comparable rates of nitrogen mineralization in soils were observed for all digestates, consistent with the accessibility of nitrogen from the particulate OM. Nevertheless, AcoD converted substrates with the potential to immobilize nitrogen in soils into fast-acting fertilizers. In summary, this study underscores the importance of controlling the AcoD performances to evaluate the suitability of digestates for sustainable agricultural practices.