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1.
J Environ Sci (China) ; 149: 394-405, 2025 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-39181652

RESUMO

Heterogeneous crystallization is a common occurrence during the formation of solid wastes. It leads to the encapsulation of valuable/hazardous metals within the primary phase, presenting significant challenges for waste treatment and metal recovery. Herein, we proposed a novel method involving the in-situ formation of a competitive substrate during the precipitation of jarosite waste, which is an essential process for removing iron in zinc hydrometallurgy. We observed that the in-situ-formed competitive substrate effectively inhibits the heterogeneous crystallization of jarosite on the surface of anglesite, a lead-rich phase present in the jarosite waste. As a result, the iron content on the anglesite surface decreases from 34.8% to 1.65%. The competitive substrate was identified as schwertmannite, characterized by its loose structure and large surface area. Furthermore, we have elucidated a novel mechanism underlying this inhibition of heterogeneous crystallization, which involves the local supersaturation of jarosite caused by the release of ferric and sulfate ions from the competitive substrate. The local supersaturation promotes the preferential heterogeneous crystallization of jarosite on the competitive substrate. Interestingly, during the formation of jarosite, the competitive substrate gradually vanished through a dissolution-recrystallization process following the Ostwald rule, where a metastable phase slowly transitions to a stable phase. This effectively precluded the introduction of impurities and reduced waste volume. The goal of this study is to provide fresh insights into the mechanism of heterogeneous crystallization control, and to offer practical crystallization strategies conducive to metal separation and recovery from solid waste in industries.


Assuntos
Cristalização , Compostos Férricos , Compostos Férricos/química , Sulfatos/química , Compostos de Ferro/química , Ferro/química , Eliminação de Resíduos/métodos
2.
WHO South East Asia J Public Health ; 13(1): 29-34, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-39167133

RESUMO

Unsafe child feces disposal (CFD) is another form of open defecation and can pose a risk of disease in children. More than 30% of Indonesian households practice unsafe CFD, yet, its determinants are unknown. This study aims to identify the contextual and behavioral determinants of CFD through the lens of the Risk, Attitude, Norm, Ability, and Self-regulation (RANAS) framework. The cross-sectional study was conducted in 349 households in the suburbs of Kendari City, Southeast Sulawesi Province, Indonesia, in mid-2023. About 64% of the respondents practiced unsafe CFD. Most respondents used diapers that were immediately thrown into the trash without cleaning (i.e., 60.2%). Logistic regression analysis found two significant contextual factors associated with safe CFD: having received sanitation-related information and toddler age, i.e., children below 5 years old. Perceived severity was the most influential psychological factor behind the CFD practice, followed by knowledge. This study suggests that informing caregivers about the negative health effects of practicing unsafe CFD, especially on their children, can be a positive trigger for them to practice safe CFD. In addition, the promotion of early toilet initiation and recycling programs for used diaper waste should also be conducted to ensure comprehensive CFD management.


Assuntos
Fezes , Mães , Humanos , Indonésia , Estudos Transversais , Feminino , Mães/psicologia , Mães/estatística & dados numéricos , Pré-Escolar , Adulto , Lactente , Masculino , Conhecimentos, Atitudes e Prática em Saúde , Eliminação de Resíduos , População Suburbana , Adulto Jovem
3.
Water Sci Technol ; 89(12): 3163-3177, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39150418

RESUMO

Anaerobic co-digestion was conducted on the solid residues after three-phase separation of kitchen waste (KWS) and waste-activated sludge (WAS), the synergistic effects and process performance were studied during co-digestion at different ratios of KWS to WAS. KWS and WAS mix ratios of 0:1, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1 and 1:0 (based on TS). The results showed that a ratio of KWS to WAS of 1:1 got a very high methane recovery with a methane yield of 310.45 ± 30.05 mL/g VSadded. The highest concentration of free ammonia among all reaction systems was only 70.23 ± 5.53 mg/L, which was not enough to produce ammonia inhibition in the anaerobic co-digestion system. However, when the KWS content exceeded 50%, methane inhibition and prolongation of the lag phase were observed due to the accumulation of volatile fatty acids (VFAs), and during the lag phase. Microbial community analysis showed that various bacterial groups involved in acid production and hydrolysis were mainly dominated by phylum Firmicutes, Chloroflexi, Proteobacteria and Bacteroidetes. Hydrogenotrophic methanogen was found to dominate all archaeal communities in the digesters. Co-digestion of KWS with WAS significantly increased the relative abundance of Methanobacterium compared with anaerobic digestion of WAS alone.


Assuntos
Reatores Biológicos , Metano , Esgotos , Esgotos/microbiologia , Anaerobiose , Metano/metabolismo , Bactérias/metabolismo , Bactérias/classificação , Amônia/metabolismo , Eliminação de Resíduos/métodos , Resíduos Sólidos , Eliminação de Resíduos Líquidos/métodos , Resíduos de Alimentos
4.
Bioresour Technol ; 408: 131199, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39097235

RESUMO

Solids concentration, temperature, and digester configuration were subjected to biomethanation study to identify effective retrofitting schemes for old swine waste digesters. Batch assays were commenced to determine an appropriate scenario at 30-55 °C and total solids 1-3 %TS. Sub-thermophilic temperature (45 °C) was found desirable with an additional 11.1 % methane yield, while digestion at higher TS induced ammonium inhibition. Subsequent batch experiments lasted 72 hrs for hydrolytic-acidogenic assessment under various temperatures. Heating control at 45 °C and 55 °C for 24 hrs increased hydrolysis efficiency 4.6-5.7 folds above control but showed no significant difference (α = 0.05) between them. Limited heat supply from biogas engine dictated the continuous digestion study to operate pre-hydrolysis reactor at maximum temperature of 45 °C. The two-stage strategy demonstrated best overall performances at the sub-thermphilic combination, raising methane yield by 35.4 %. Next-Generation Sequencing indicated remarkable shifts in abundance and diversity, especially for hydrolytic organisms, which expanded from 54 to 70.2 % by sub-thermophilic temperature.


Assuntos
Biocombustíveis , Reatores Biológicos , Esterco , Metano , Temperatura , Animais , Metano/metabolismo , Suínos , Hidrólise , Eliminação de Resíduos/métodos
5.
Bioresour Technol ; 408: 131212, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39102964

RESUMO

This study evaluated the fate of food delivery boxes when subjected to biological treatments, reproducing at the lab-scale the conditions of full-scale plants. Four paper-based boxes were composted: two made of paper only, one coupled with polylactic acid (PLA), and one with a barrier coating. One paper only box and the box with PLA were also investigated for their anaerobic degradability with biochemical methane potential (BMP) and semi-continuous tests. During composting, the boxes were not recognisable inside the compost after four (paper only boxes), eight (box with PLA), and twelve (box with barrier coating) weeks. In BMP tests, the paper only box showed a degradability similar to that of food waste (92 %), while the box with PLA degraded only at 76 %. Furthermore, undigested pieces of PLA were found in semi-continuous tests. Accordingly, paper resulted suitable for biological treatments, while the presence of PLA or other barrier coatings can be critical.


Assuntos
Compostagem , Metano , Papel , Anaerobiose , Compostagem/métodos , Metano/metabolismo , Biodegradação Ambiental , Poliésteres/química , Alimentos , Ácido Láctico/metabolismo , Polímeros/química , Eliminação de Resíduos/métodos
6.
Environ Monit Assess ; 196(9): 788, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39105873

RESUMO

The ecology of the Qinghai‒Tibet Plateau is fragile, and the ecosystems in the region are difficult to remediate once damaged. Currently, landfilling is the mainstay of domestic waste disposal in China, and numerous, widely distributed county landfills exist. trace elements (TEs) in waste are gradually released with waste degradation and cannot be degraded in nature, affecting environmental quality and human health. To reduce the chance bias that exists in studies of individual landfills, we selected 11 representative county landfills in Tibet, total of 76 soil samples were collected, eight TEs (arsenic (As), mercury (Hg), chromium (Cr), copper (Cu), lead (Pb), cadmium (Cd), nickel (Ni), and zinc (Zn)) were determined, and analysed for the current status of pollution, risk to human health, and sources of TEs to explore the impact of the landfills. The results showed that only a few landfills had individual TEs exceeding the risk screening value of the Soil Environmental Quality Risk Control Standard for Soil Contamination (GB 15618-2018) (pH > 7.5). Most of the soils around the landfills had moderate levels of pollution, but some individual landfills had higher levels, mainly due to Cd and Hg concentrations. Source analysis showed that Hg originated mainly from atmospheric transport; the other TEs came mainly from the weathering of soil parent material and bedrock. The potential risk from TEs to human health was low, and the risk to children was greater than the risk to adults. Among the three exposure routes, oral ingestion resulted in the highest carcinogenic risk and noncarcinogenic risk, with a contribution rate of more than 95%. Among the TEs, Ni had the highest carcinogenic risk, followed by Cr and As, and As had the highest noncarcinogenic risk.


Assuntos
Monitoramento Ambiental , Poluentes do Solo , Solo , Oligoelementos , Instalações de Eliminação de Resíduos , Poluentes do Solo/análise , Tibet , Medição de Risco , Oligoelementos/análise , Solo/química , Humanos , Mercúrio/análise , Metais Pesados/análise , Arsênio/análise , Eliminação de Resíduos , Cádmio/análise
7.
BMC Public Health ; 24(1): 2150, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39112956

RESUMO

Waste management in Lira City, Uganda faces significant challenges, particularly in the area of waste collection. Pollution and health risks from uncollected waste are rampant, posing serious threats to human health and the environment. This persistent problem demands urgent attention and effective solutions to improve waste collection and safeguard the well-being of the community and the natural surroundings. This study aimed to assess households' willingness to pay for improved waste collection services, examine their waste management practices, and identify influencing factors. We employed a multistage sampling technique to randomly select 585 household heads and conducted key informant interviews with city officials and private waste collectors. Data analysis was conducted with STATA 17 and results showed that 48.12% of households were willing to pay an average of UGX 3012 ($0.84) per month for better services. Factors including education level, occupation, distance to waste collection sites, and environmental awareness significantly influenced this willingness. The study highlights a significant gap in public awareness and understanding of efficient solid waste management practices and concludes that enhancing public awareness is crucial for improving environmental health and safety in Lira City.


Assuntos
Cidades , Resíduos Sólidos , Gerenciamento de Resíduos , Humanos , Uganda , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Gerenciamento de Resíduos/métodos , Características da Família , Eliminação de Resíduos , Financiamento Pessoal/estatística & dados numéricos , Adulto Jovem , População Urbana
8.
Artigo em Inglês | MEDLINE | ID: mdl-39194141

RESUMO

Waste pickers constitute a marginalized demographic engaged in the collection of refuse, facing considerable occupational hazards that heighten their susceptibility to contract infectious diseases. Moreover, waste pickers contend with societal stigmatization and encounter barriers to accessing healthcare services. To explore the viral profile of waste pickers potentially linked to their occupational environment, we conducted a metagenomic analysis on 120 plasma specimens sampled from individuals employed at the Cidade Estrutural dumpsite in Brasilia city, Brazil. In total, 60 blood donors served as a comparative control group. Specimens were pooled and subjected to Illumina NextSeq 2000 sequencing. Viral abundance among waste pickers revealed the presence of significant pathogens, including HIV, HCV, and Chikungunya, which were not detected in the control group. Additionally, elevated levels of anelloviruses and Human pegivirus-1 were noted, with a comparable incidence in the control group. These findings underscore the utility of metagenomics in identifying clinically relevant viral agents within underserved populations. The implications of this study extend to informing public health policies aimed at surveilling infectious diseases among individuals facing socioeconomic disparities and limited access to healthcare resources.


Assuntos
Metagenômica , Humanos , Brasil , Masculino , Adulto , Feminino , Vírus/genética , Vírus/classificação , Vírus/isolamento & purificação , Exposição Ocupacional , Estudos de Casos e Controles , Pessoa de Meia-Idade , Eliminação de Resíduos
9.
J Environ Manage ; 367: 122040, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39094408

RESUMO

The Fossetto landfill has operated in the municipality of Monsummano Terme (Tuscany, Italy) since 1988, being considered a state-of-the-art landfill for 35 years. Initially, Fossetto acted as a conventional sanitary landfill for mixed municipal solid waste. With changes in regulations and technology, the Fossetto landfill was gradually equipped with a biogas recovery and valorisation system, a mechanical-biological treatment (MBT) plant in 2003 and a reverse osmosis leachate treatment plant, so the concentrated leachate has been recirculated back into the landfill body since 2006. Long-term biogas monitoring, enables the calculation of the efficiency of biogas recovery using a rather simplified methodology, which was assessed as being approximately 40% over the prior ten-years period. This value was lower than expected, confirming the results of previous studies and indicating the need of attributes. Applying the USEPA LandGEM model showed that the adoption of MBT substantially reduced biogas generation yields and rates by up to approximately 90% which was facilitated by the adoption of landfill leachate recirculation transforming the conventional landfill into a bioreactor. Detailed fugitive emission monitoring has allowed the evaluation of the impact of the cover type (final or temporary) and the emissions hotspots. From these results, possible remedial actions have been suggested including the more frequent monitoring of the fugitive emissions using simple and cost-effective methods (e.g., UAVs). Approximately 50% of fugitive emissions can be attributed to emissions hotspots, which reduce biogas recovery and the efficiency of temporary covers.


Assuntos
Biocombustíveis , Instalações de Eliminação de Resíduos , Biocombustíveis/análise , Itália , Eliminação de Resíduos/métodos , Reatores Biológicos , Resíduos Sólidos/análise
10.
J Environ Manage ; 367: 122033, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39096724

RESUMO

Landfill is an important means of municipal solid waste treatment. Previous studies have shown that the combination of "cut-off wall and pumping well" technology is an effective measure to deal with the leachate emission reduction and pollution control of landfill, and has been widely used in plain areas. However, for landfills in hilly areas with complex terrain and geological conditions, there is still a lack of clear and referable ideas and operational strategies for leachate emission reduction and pollution control. In this study, we proposed strategies for determining the position and depth of cut-off walls and pumping wells and reasonable combinations of the cut-off wall depth and pumping quantity for leachate reduction and pollution prevention of landfills in hilly areas. The determination of leachate reduction and pollution control strategy need to be achieved in two stages, qualitative and quantitative: (1) In the qualitative stage, the natural conditions (Weathering degree, groundwater flow characteristics, topography condition, hydrometeor condition, and aquifer thickness) and engineering conditions (Operation status, landfill location, and excavation status) of the study area are analysed in detail, and then the depth range and location of the cut-off wall and pumping well are determined. (2) In the quantitative stage, we need to quantify the combination of the cut-off wall depth and pumping quantity by using profile particle tracing and pollutant transport modelling. A reasonable cut-off wall depth needs to control the leakage of pollutants inside the wall, and a reasonable pumping quantity needs to ensure that the depth of the pollutant distribution is equivalent to the depth of the separation line, which separates the water flow towards the pumping well and the water flow downstream. (3) The effectiveness of the leachate reduction and prevention strategies proposed in this study was verified through an example of a landfill in Northeast China. This study provides a reference and operation method for leachate emission reduction and pollution control of landfills in hilly areas.


Assuntos
Água Subterrânea , Eliminação de Resíduos , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Eliminação de Resíduos/métodos , Monitoramento Ambiental
11.
J Environ Manage ; 367: 122014, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39098066

RESUMO

Researchers are actively investigating methodologies for the detoxification and utilization of Municipal Solid Waste Incineration Bottom Ash (MSWIBA) and Fly Ash (MSWIFA), given their potential as alkali-activated materials (AAMs) with low energy consumption. Recent studies highlight that AAMs from MSWIFA and MSWIBA demonstrate significant durability in both acidic and alkaline environments. This article provides a comprehensive overview of the processes for producing MSWIFA and MSWIBA, evaluating innovative engineering stabilization techniques such as graphene nano-platelets and lightweight artificial cold-bonded aggregates, along with their respective advantages and limitations. Additionally, this review meticulously incorporates relevant reactions. Recommendations are also presented to guide future research endeavors aimed at refining these methodologies.


Assuntos
Álcalis , Cinza de Carvão , Incineração , Resíduos Sólidos , Cinza de Carvão/química , Álcalis/química , Grafite/química , Eliminação de Resíduos/métodos
12.
J Environ Manage ; 367: 122013, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39098069

RESUMO

Leachate emanating from landfills contains ammonia which may cause serious health effects on living things. An effectively designed clay barrier should not allow the contaminant to infiltrate the soil and groundwater systems. The utilization of certain industrial by-products in engineered landfill barriers, not only reduces the need for conventional liner materials but also helps in sustainable waste management. This study investigated the hydraulic conductivity, unconfined compressive strength, compaction, and adsorption characteristics of lithomargic clay blended with an optimum percentage of bentonite (10%) and granulated blast furnace slag (15%) permeated with ammonia. The results revealed that increasing the content of granulated blast furnace slag decreased the maximum dry density while increasing the optimum moisture content. In comparison to lithomargic clay, the hydraulic conductivity of the amended soil liner permeated with ammonia decreased from a value of 3 × 10-8 m/s to 5 × 10-10 m/s. The unconfined compressive strength of the amended soil specimens showed an increasing trend with curing times (i.e., 0, 14, 28, and 56 days). The batch adsorption results revealed that Freundlich and Langmuir's isotherm fits the equilibrium adsorption data and the adsorption of ammonia on clay liner follows non-linear behaviour. Overall, the experimental results implied that lithomargic clay blended with 10% bentonite and 15% granulated blast furnace slag can be used as an impermeable soil reactive barrier in engineered landfills.


Assuntos
Amônia , Bentonita , Resíduos Sólidos , Instalações de Eliminação de Resíduos , Bentonita/química , Amônia/química , Adsorção , Eliminação de Resíduos/métodos , Solo/química , Gerenciamento de Resíduos/métodos , Poluentes Químicos da Água/química , Argila/química
13.
Bioresour Technol ; 408: 131221, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39111396

RESUMO

Food waste (FW) and its biogas residue were considered as sources of terrestrial microplastics (MPs) and phthalic acid esters (PAEs) contamination. However, there was a lack of research and understanding of the MPs and PAEs pollution problem in FW dry anaerobic digestion process (DADP). The MPs and PAEs in three stages of the DADP with the largest monomer disposal scale in China were identified. At the biogas residue extrusion stage, MPs abundance and PAEs concentration reached the highest values, which were 3.63 ± 0.45 × 103 N·kg-1 and 3.62 ± 0.72 mg·kg-1, respectively. Furthermore, there was a significant positive correlation between MPs and PAEs throughout the process (p < 0.05). Although bacteria and fungi with plastic degradation potential were present in all stages, the contamination problem of MPs and PAEs cannot be completely solved through DADP. This study provides a scientific basis for preventing and controlling the pollution of MPs and PAEs.


Assuntos
Biodegradação Ambiental , Ésteres , Perda e Desperdício de Alimentos , Microplásticos , Ácidos Ftálicos , Anaerobiose , Bactérias/metabolismo , Ésteres/metabolismo , Fungos/metabolismo , Ácidos Ftálicos/metabolismo , Eliminação de Resíduos/métodos
14.
Bioresour Technol ; 409: 131252, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39127359

RESUMO

Anaerobic digestion (AD) has the potential to catalyse the shift from a linear to a circular economy. However, effective treatment and management of both solid (DSF) and liquid (DLF) digestate fraction treatment and management require adopting sustainable technologies to recover valuable by-products like energy, biofuels, biochar, and nutrients. This study reviews state-of-the-art advanced technologies for DSF and DLF treatment and valorisation, using life cycle assessment (LCA) and techno-economic analysis (TEA) in integrated digestate management (IDM). Key findings highlight these technologies' potential in mitigating environmental impacts from digestate management, but there's a need to improve process efficiency, especially at larger scales. Future research should prioritize cost-effective and eco-friendly IDM technologies. This review emphasizes how LCA and TEA can guide decision-making and promote sustainable agricultural practices. Ultimately, sustainable IDM technologies can boost resource recovery and advance circular economy principles, enhancing the environmental and economic sustainability of AD processes.


Assuntos
Agricultura , Agricultura/métodos , Agricultura/economia , Anaerobiose , Biocombustíveis/economia , Eliminação de Resíduos/métodos , Eliminação de Resíduos/economia
15.
Waste Manag ; 187: 306-316, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39089146

RESUMO

Plastic waste poses a critical environmental challenge for the world. The proliferation of waste plastic coffee pods exacerbates this issue. Traditional disposal methods such as incineration and landfills are environmentally unfriendly, necessitating the exploration of alternative management strategies. One promising avenue is the pyrolysis in-line reforming process, which converts plastic waste into hydrogen. However, traditional pyrolysis methods are costly due to inefficiencies and heat losses. To address this, for the first time, our study investigates the use of microwave to enhance the pyrolysis process. We explored microwave pyrolysis for polypropylene (PP), high-density polypropylene (HDPE), and waste coffee pods, with the latter primarily comprising polypropylene. Additionally, catalytic ex-situ pyrolysis of coffee pod pyrolysis over a nickel-based catalyst was investigated to convert the evolved gas into hydrogen. The single-stage microwave pyrolysis results revealed the highest gas yield at 500 °C for HDPE, and 41 % and 58 % (by mass) for waste coffee pods and polypropylene at 700 °C, respectively. Polypropylene exhibited the highest gaseous yield, suggesting its readiness for pyrolytic degradation. Waste coffee pods uniquely produced carbon dioxide and carbon monoxide gases because of the oxygen present in their structure. Catalytic reforming of evolved gas from waste coffee pods using a 5 % nickel loaded activated carbon catalyst, yielded 76 % (by volume) hydrogen at 900 °C. These observed results were supported by elemental balance analysis. These findings highlight that two-stage microwave and catalysis assisted pyrolysis could be a promising method for the efficient management of waste coffee pods, particularly for producing clean energy.


Assuntos
Café , Hidrogênio , Micro-Ondas , Polietileno , Polipropilenos , Pirólise , Polipropilenos/química , Hidrogênio/química , Café/química , Catálise , Polietileno/química , Eliminação de Resíduos/métodos
16.
Huan Jing Ke Xue ; 45(7): 4352-4360, 2024 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-39022979

RESUMO

Food waste is one of the important reservoirs of antibiotic resistance genes (ARGs), and its resource utilization has potential environmental risks. Anaerobic digestion (AD) technology can concurrently achieve resource recovery and ARGs removal, which is one of the popular resource technologies for food waste management. However, the removal efficiency of ARGs during the AD process is limited, and thus the safety of digestate for agricultural use is still questioned. Therefore, how to improve the performance of ARGs removal during the AD process is critical for efficient and environmentally friendly bioconversion of food waste. This study summarized the transmission pathways and mechanisms of ARGs in food waste; discussed the effects of different operation parameters on the transmission of ARGs in food waste during the AD process; described the research progress of exogenous addition of conductive materials, feedstock pretreatment, etc., strategies to enhance the removal of ARGs; and analyzed the migration regularity and removal mechanism of ARGs in food waste during the AD process, which mainly included microbial community structure evolution, mobile genetic element changes, and environmental factor changes. Finally, this study prospected the future improvement of methane yield and ARGs removal in the AD process of food waste based on the existing research.


Assuntos
Resistência Microbiana a Medicamentos , Anaerobiose , Resistência Microbiana a Medicamentos/genética , Eliminação de Resíduos/métodos , Reatores Biológicos/microbiologia , Alimentos , Biodegradação Ambiental , Perda e Desperdício de Alimentos
17.
Environ Sci Pollut Res Int ; 31(31): 44401-44414, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38954329

RESUMO

Borehole samples were collected from a municipal solid waste (MSW) landfill in Xi'an, China, and subjected to a series of basic geotechnical and compression tests. This study aims to investigate the influence of composition, dry unit weight, moisture content, organic content, and landfill age on the compressibility of MSW. The results show that with increasing landfill age, the compressible components and organic content exhibit a decreasing trend while the dry unit weight increases. The moisture content does not vary significantly. There is also a linear trend between the logarithm of the primary compression strain and vertical stress. In addition, with an increase in compressible components content, moisture content, and organic content, the modified primary compression index (Cc') shows an increasing trend, whereas with an increase in dry unit weight and landfill age, Cc' shows a decreasing trend. Furthermore, regarding the 34 sets of data, authors only selected five data points for a detailed comparative analysis, this decision was made on the basis that these data points are representative. A modified primary compression index prediction model that considers the dry unit weight, moisture content, and landfill age of the MSW as influencing factors results in a fitting coefficient of 0.797. The Cc' values in this study are within the range of 0.12 to 0.36. These findings provide a reference for the vertical expansion design of existing landfills.


Assuntos
Eliminação de Resíduos , Resíduos Sólidos , Instalações de Eliminação de Resíduos , China
18.
Sci Total Environ ; 946: 174436, 2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-38964403

RESUMO

Semi-aerobic aged refuse biofilters (SAARB) are commonly-used biotechnologies for treating landfill leachate. In actual operation, SAARB often faces harsh conditions characterized by high concentrations of chemical oxygen demand (COD) and Cl-, as well as a low carbon-to-nitrogen ratio (C/N), which can disrupt the microbial community within SAARB, leading to operational instability. Maintaining the stable operation of SAARB is crucial for the efficient treatment of landfill leachate. However, the destabilization mechanism of SAARB under harsh conditions remains unclear. To address this, the study simulated the operation of SAARB under three harsh conditions, namely, high COD loading (H-COD), high chloride ion (Cl-) concentration environment (H-Cl-), and low C/N ratio environment (L-C/N). The aim is to reveal the destabilization mechanism of SAARB under harsh conditions by analyzing the fluorescence characteristics of effluent DOM and the microbial community in aged refuse. The results indicate that three harsh conditions have different effects on SAARB. H-COD leads to the accumulation of proteins; H-Cl- impedes the reduction of nitrite nitrogen; L-C/N inhibits the degradation of humic substances. These outcomes are attributed to the specific effects of different factors on the microbial communities in different zones of SAARB. H-COD and L-C/N mainly affect the degradation of organic matter in aerobic zone, while H-Cl- primarily impedes the denitrification process in the anaerobic zone. The abnormal enrichment of Corynebacterium, Castellaniella, and Sporosarcina can indicate the instability of SAARB under three harsh conditions, respectively. To maintain the steady operation of SAARB, targeted acclimation of the microbial community in SAARB should be carried out to cope with potentially harsh operating conditions. Besides, timely mitigation of loads should be implemented when instability characteristics emerge, and carbon sources and electron donors should be provided to restore treatment performance effectively.


Assuntos
Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Filtração , Eliminação de Resíduos Líquidos/métodos , Análise da Demanda Biológica de Oxigênio , Nitrogênio , Aerobiose , Eliminação de Resíduos/métodos , Reatores Biológicos , Fluorescência , Microbiota
19.
Environ Monit Assess ; 196(8): 763, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39052122

RESUMO

The soil, comprising minerals, organic matter, and living organisms, serves as a critical component of our environment. However, anthropogenic activities, such as uncontrolled sewage disposal and industrial waste, have led to pervasive soil pollution, impacting ecosystems and human health. This comprehensive study scrutinizes the intricate dynamics of soil pollution resulting from open waste dumping, specifically examining its impact on the health of local communities and the environment in Haridwar municipality. In this study, four solid waste dumping sites were meticulously surveyed, with soil samples analyzed for 19 parameters through statistical tools like one-way ANOVA, Kruskal-Wallis tests, soil pollution indices, and potential health risk assessment. The Geo-accumulation Index (Igeo) and contamination factor (CF) followed the heavy metals in the order of Zn > Mn > Fe > Cu in all selected sites. Additionally, a potential health risk assessment considered ingestion, inhalation, and dermal exposure pathways, revealing a high non-carcinogenic risk of metals (Mn > Fe > Zn > Cu) for both children and adults. In the ingestion pathway, the hazard quotient indicated a high risk of metals for both children and adults in the range of 1192.73 to 2066.94 for child and 191.98 to 312.16 for adults. Crucially, the HQ revealed potential health risks, emphasizing the urgency of addressing metal contamination. However, the findings indicate that dumping sites directly or indirectly affects the local people of Haridwar municipality. Therefore, this study provides a baseline framework for minimizing the impact of dumping sites on local population and the environment.


Assuntos
Monitoramento Ambiental , Metais Pesados , Poluentes do Solo , Solo , Instalações de Eliminação de Resíduos , Poluentes do Solo/análise , Humanos , Medição de Risco , Metais Pesados/análise , Solo/química , Resíduos Sólidos/análise , Eliminação de Resíduos
20.
Waste Manag ; 187: 22-30, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38971024

RESUMO

The widespread use of plastic mulch film (PMF) has led to significant environmental pollution, with PMF residues dispersed and mixed with straw and soil, posing challenges for recycling. Here, we proposed the mobile pyrolysis facility for the cotton straw and mulch film mixture (CMM) to mitigate the collection, storage, and transportation costs, while the application of co-pyrolysis technology for CMM conversion could improve the added value of products. Additionally, centralized combustion power generation and centralized pyrolysis systems were also established to evaluate and compare their sustainability from economic and environmental perspectives. Results showed that mobile pyrolysis has better economic performance than the centralized scenarios, due to its high internal rate of return (31 %) and significant net present value (29.21 M USD). Meanwhile, the mobile pyrolysis facility achieved a GWP of -1.298 kgCO2-eq/kg, reducing emissions by 70.79 % and 38.82 % compared to the two centralized scenarios. In conclusion, mobile pyrolysis technology provides a promising solution for PMF residue recycling because of its economically competitive approach with a lower carbon footprint.


Assuntos
Plásticos , Pirólise , Reciclagem , Resíduos Sólidos , China , Reciclagem/métodos , Resíduos Sólidos/análise , Gossypium , Gerenciamento de Resíduos/métodos , Eliminação de Resíduos/métodos
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