Waste Management

Article	Citations
Trustworthy and Human Centric neural network approaches for prediction of landfill methane emission and sustainable waste management practices	232
Advanced data augmentation techniques to enhance instance segmentation dataset for construction and demolition waste management	222
Machine learning-aided unveiling the relationship between chemical pretreatment and methane production of lignocellulosic waste	213
BIM-driven transformation of waste management toward enhanced reduction and circularity in the built environment	209
Strategies for industrial residue valorization through metal recovery, use in construction, or CO2 mineralization	196
Editorial Board	187
How microplastics affect sludge pyrolysis behavior: Thermogravimetry-mass spectrum analysis and biochar characteristics	166
High hydrophobic silanized paper: Material characterization and its biodegradation through brown rot fungus	163
Structural study and metal speciation assessments of waste PCBs and environmental implications: Outlooks for choosing efficient recycling routes	162
What activities reduce plastic waste the most? – The path to a circular economy for Japan’s manufacturing industry	162
Incinerator ash characterization – Implications for elevated temperature landfills	159
Biochemical, hydrological and mechanical behaviors of high food waste content MSW landfill: Numerical simulation analysis of a large-scale experiment	149
Natural and recyclable alginate hydrogels as extracting media for recovering valuable metals of spent lithium-ion batteries from a deep eutectic solvent	138
Enhanced lactic acid production from household food waste under hyperthermophilic conditions: Mechanisms and regulation	135
Frequent export of pig slurry for outside storage reduced methane but not ammonia emissions in cold and warm seasons	119
Efficient conversion of waste-to-SNG via hybrid renewable energy systems for circular economy: Process design, energy, and environmental analysis	117
Quantification of indicator and pathogenic bacteria in manures and digestates from three agricultural biogas plants over a one-year period	117
Evaluating the impact of drying on leaching from a solidified/stabilized waste using a monolithic diffusion model	108
Energy effective utilization of circulating fluidized bed fly ash to prepare silicon-aluminum composite aerogel and gypsum	104
Coagulation studies on photodegraded and photocatalytically degraded polystyrene microplastics using polyaluminium chloride	104
Migration and transformation of sulfur during pyrolysis of waste tires for high-value utilization of poly-generation products	104
Charting the electric vehicle battery reuse and recycling network in North America	102
The development of China's Circular Economy: From the perspective of environmental regulation	92
Influence of long-term natural degradation processes on near-infrared spectra and sorting of post-consumer plastics	92
Circular waste management: Superworms as a sustainable solution for biodegradable plastic degradation and resource recovery	91

Earthworms and lactic acid bacteria (LAB) cooperate to promote the biodegradation of tetracycline residues in livestock manure	87
Green illusions in self-reporting? Reassessing the intention-behavior gap in waste recycling behaviors	85
Sulfuric acid leaching of ball-milling activated FePO4 residue after lithium extraction from spent lithium iron phosphate cathode powder	84
Thermal and mechanical characterization of composite materials from industrial plastic wastes and recycled nylon fibers for floor paving tiles application	84
Low-carbon and high-value utilization of hazardous industrial organic waste: From molecular mechanism to application	82
Physicochemical properties of carbon-based materials enhance in situ biomethanation performances under organic overload	80
Leaching behavior and release mechanism of pollutants from different depths in a phosphogypsum stockpile	80
Soil flushing for remediation of landfill leachate-contaminated soil: A comprehensive evaluation of optimal flushing agents and influencing factors	79
A novel subcritical water synergistic co-treatment of brominated epoxy resin and copper-based spent catalysts: debromination, phenol production, and copper recovery	78
Microwave absorbent enhancement of multi-thermal field effect: Pyrolysis of waste printed circuit boards	78
Recovery and recycling of silica fabric from waste printed circuit boards to develop epoxy composite for electrical and thermal insulation applications	78
Environmental sustainability of an integrate anaerobic digestion-composting treatment of food waste: Analysis of an Italian plant in the circular bioeconomy strategy	78
Preferential and efficient extraction of lithium under the combined action of reduction of herb-medicine residue and leaching of oxalic acid	76
High-rate in-vessel continuous composting of olive mill byproducts	76
Innovative hydrothermal technique in efficient disengagement of waste solar panels	74
Efficient recovery of valuable metals from cathode materials of spent LiCoO2 batteries via co-pyrolysis with cheap carbonaceous materials	74
Techno-economic and environmental assessments for sustainable bio-methanol production as landfill gas valorization	74
Composition and selected properties of bio-waste collected in towns from single- and multi-family housing and in rural areas	71
Plastics to fuel or plastics: Life cycle assessment-based evaluation of different options for pyrolysis at end-of-life	70
Techno-economic and scalability analysis of nitrogen plasma gasification of medical waste	70
Detection of degraded high-density polyethylene via near-infrared hyperspectral imaging	69
Deep eutectic solvent as a solution for polyester/cotton textile recycling	69
Insight into SO4(-II)- dependent anaerobic methane oxidation in landfill: Dual-substrates dynamics model, microbial community, function and metabolic pathway	68
Waste LCA and the future	68
Prediction of metal recovery potential of end-of-life NEV batteries in China based on GRA-BiLSTM	67
Social Hotspot analysis of the e-waste sector in Ghana and Nigeria	67
Quantitative water content estimation in landfills through joint inversion of seismic refraction and electrical resistivity data considering surface conduction	67
A comparative pyrolysis study of different waste wind turbine blade parts: Kinetics, product distribution and evolution, and economics	66
Microbial community assembly and chemical dynamics of raw brewers’ spent grain during inoculated and spontaneous solid-state fermentation	66
Identifying plastic materials in post-consumer food containers and packaging waste using terahertz spectroscopy and machine learning	66
On the use of plastic precursors for preparation of activated carbons and their evaluation in CO2 capture for biogas upgrading: a review	65
Real-time construction demolition waste detection using state-of-the-art deep learning methods; single–stage vs two-stage detectors	65
Contaminants of concern (CoCs) pivotal in assessing the fate of MSW incineration bottom ash (MIBA): First results from India and analogy between several countries	64
Insights on dissolved organic matter and bacterial community succession during secondary composting in residue after black soldier fly larvae (Hermetia illucens L.) bioconversion for food waste treatm	64
Conversion and migration of iron and nitrogen under co-hydrothermal carbonization of pomelo peel and dyeing sludge	63
Retraction notice to “Impact of different schemes for treating landfill leachate” [Waste Manage. 71 (2018) 255–266]	63
Editorial Board	62
Terahertz-based identification of waste paper for improved recycling in Japan	62
Geotechnical characterization of municipal solid waste via cone penetration testing – A case study from landfills in Delhi, India	62
Exploring incentives to move up the food waste Hierarchy: A case study of the Australian cheese manufacturing sector	62
Copper-catalyzed VOCs formation and combustion control during pyrolysis of waste polyester-imide enameled wires	61
New powder reuse schema in laser-based powder bed fusion of polymers	60
Editorial Board	60
Transforming waste into value: High-performance hollow fiber adsorbents from municipal solid waste incinerator bottom ash	59
Prototype of AI-powered assistance system for digitalisation of manual waste sorting	59
Develop intelligent waste bin prototype based on fusion feature recognition of sounds and RGB images	59
Recycling of hazardous jarosite residues based on hydrothermal crystal transformation	59
A review on end-of-life waste toner powder: recovery, utilization and upcycling	59
Characterization of methanotrophic community and activity in landfill cover soils under dimethyl sulfide stress	58
Efficient hydrogen production in single-chamber microbial electrolysis cell with a fermentable substrate under hyperalkaline conditions	58

Effects of different conditions tested “in vitro” on the phosphorus runoff potential of livestock manure	58
Gaseous elemental mercury emissions from informal E-Waste recycling facilities in Pakistan	58
Lean-circular maturity model (LCMM) for companies' self-assessment in terms of process, product and life cycle thinking	56
Carbon and hydrogen dynamic isotope equations are used to describe the dominant processes of waste biodegradation: Effect of aeration in methanogenic phase of the landfill	56
Multi-faceted analysis of thermophilic anaerobic biodegradation of poly(lactic acid)-based material	55
Ceramic shell waste valorization: A new approach to increase the sustainability of the precision casting industry from a circular economy perspective	55
Relationship between Leachate Pollution Index and growth response of two willow and poplar hybrids: Implications for phyto-treatment applications	55
Towards automatic waste containers management in cities via computer vision: containers localization and geo-positioning in city maps	55
Biochar amendment to cattle slurry reduces NH3 emissions during storage without risk of higher NH3 emissions after soil application of the solid fraction	54
Fermentation broth of food waste: A sustainable electron donor for perchlorate biodegradation	54
Editorial Board	54
Fast co-pyrolysis behaviors and synergistic effects of corn stover and polyethylene via rapid infrared heating	53
Editorial Board	53
Environmental assessment of phosphorus recovery from dairy sludge: A comparative LCA study	52
Secondary aluminum dross self-heating enhances hazardous waste vitrification	52
Current state of building demolition and potential for selective dismantling in Vietnam	52
Recovery of aluminum, magnetic ferrous metals and glass through enhanced industrial-scale treatment of different MSWI bottom ashes	52
Numerical simulation on the deposition characteristics of MSWI fly ash particles in a cyclone furnace	52
A picture of pharmaceutical pollution in landfill leachates: Occurrence, regional differences and influencing factors	52
The need to consider the service life of all components of a modern MSW landfill liner system	52
Reuse of straw in the form of hydrochar: Balancing the carbon budget and rice production under different irrigation management	51
Simultaneous Extraction and Separation of Phosphorus and Heavy Metals from Freshwater Sediments using Electrodialysis – Influence by Sediment Characteristics	51
Subcritical hydrothermal oxidation of semi-dry ash from iron ore sintering flue gas desulfurization: Experimental and kinetic studies	51
Emission of volatile sulphur compounds during swine manure composting: Source identification, odour mitigation and assessment	50
The relationship between retail price promotions and household-level food waste: Busting the myth with behavioural data?	50
Effects of pyrolysis and incineration on the phosphorus fertiliser potential of bio-waste- and plant-based materials	49
Machine learning modeling of thermally assisted biodrying process for municipal sludge	49
pXRF on printed circuit boards: Methodology, applications, and challenges	49
Evaluating the capability of municipal solid waste separation in China based on AHP-EWM and BP neural network	49
Meta-analysis of ecological and phylogenetic biomass maturity metrics	49
Towards the implementation of hydrothermal carbonization for nutrients, carbon, and energy recovery in centralized biogas plant treating sewage sludge	48
Discussion about suitable applications for biodegradable plastics regarding their sources, uses and end of life	48
Co-composting of kitchen waste with agriculture and forestry residues and characteristics of compost with different particle size: An industrial scale case study	47
Enabling the twin transition of the textile industry: A systematic literature review	47
Efficient extraction of refractory Cr from stainless steel dust by sodium persulfate oxidation roasting	46
The fate of bromine during microwave-assisted pyrolysis of waste printed circuit boards	46
Chicken manure-based bioponics: Effects of acetic acid supplementation on nitrogen and phosphorus recoveries and microbial communities	46
The influence of bio-plastics for food packaging on combined anaerobic digestion and composting treatment of organic municipal waste	46
Safe utilization of bioresources in gentamicin mycelial residues by thermal treatment: Antibiotic degradation, resistance gene inactivation and available nutrients promotion	46
Numerical simulation to optimize passive aeration strategy for semi-aerobic landfill	46
Simultaneous adsorption of ciprofloxacin and Cu2+ using Fe and N co-doped biochar: Competition and selective separation	46
Thermal conductivity of dry fly ashes with various carbon and biomass contents	46
Recovery, separation and production of fuel, plastic and aluminum from the Tetra PAK waste to hydrothermal and pyrolysis processes	45
A review of landfill odors assessment: Advancing from stationary measurement to spatiotemporal monitoring	45
Estimation of spontaneous waste ignition time for prevention and control of landfill fire	45
Editorial Board	45
Upcycling onion peels for enhanced gas barrier and antioxidant bioplastics based on starch from potato processing slurries	45
EPA model estimates and waste characterization studies: US paper disposal dynamics	45
Comprehensive assessment of environmental and economic impacts of the entire EU waste management system	44
National evaluations of pharmaceutical and personal care products in Chinese landfill leachate: non-negligible socio-economic and rainfall status	44
Prediction of landfill gases concentration based on Grey Wolf Optimization – Support Vector Regression during landfill excavation process	44
Development of silica-modified biochar for sustainable and efficient stabilization of heavy metals in municipal solid waste incineration fly ash	44
Reducing the climate impact of residual waste treatment: A German case study on carbon management strategies	44
RETRACTED: From waste to Innovation: Silver-Doped silicate ink coating from waste coal fly ash for hydrophobic antimicrobial fabric and Water-Oil separation	44
Integration of mesophilic biogas plant in the animal slaughter process under real limitations: Techno-economic evaluation of a colombian bovine slaughterhouse	43
Performance of fish sludge solubilization and phototrophic bioconversion by purple phototrophic bacteria for nutrient recovery in aquaponic system	43
Multivariate and multi-interface insights into carbon and energy recovery and conversion characteristics of hydrothermal carbonization of biomass waste from duck farm	43
Syngas biomethanation: In a transfer limited process, is CO inhibition an issue?	43
Utilization of polyethylene sleeves with forced aeration for composting of broiler carcasses on mass depopulation events: Laboratory-scale simulations and sensitivity analyses	43
Fungal community diversity and their contribution to nitrogen cycling in in-situ aerated landfills: Insights from field and laboratory studies	43
Co-hydrothermal carbonization of swine manure and lignocellulosic waste: A new strategy for the integral valorization of biomass wastes	43
Life cycle sustainability assessment of short chain carboxylic acid produced from municipal bio-wastes	43
Process modeling, environmental and economic sustainability of the valorization of whey and eucalyptus residues for resveratrol biosynthesis	43
Automated gradation design of natural waste gravel soil stabilized by composite soil stabilizer based on a novel DNNSS-APDM-PFC model	42
Effects of cornstalk and sawdust coverings on greenhouse gas emissions during sheep manure storage	42
Editorial Board	42
Integrated cost and environmental impact assessment of management options for dredged sediment	42
Process efficiency in relation to enzyme pre-treatment duration in black soldier fly larvae composting	42
Mechanisms and effects of novel ammonifying microorganisms on nitrogen ammonification in cow manure waste composting	42
Thermo-catalytic conversion of waste plastics into surrogate fuels over spherical activated carbon of long-life durability	42
A simple mass balance tool to predict carbon and nitrogen fluxes in anaerobic digestion systems	42
A comprehensive assessment on sludge conditioning by pyrite acid eluent-activated peroxymonosulfate based on dewaterability, heavy metals risk and ore recovery	42
Smart-sight: Video-based waste characterization for RDF-3 production	42
Environmentally sustainable and cost-effective recycling of Mn-rich Li-ion cells waste: Effect of carbon sources on the leaching efficiency of metals using fungal metabolites	42
Process and systematic study of gold recovery from flexible printed circuit boards (FPCBs) using a choline chloride–ethylene glycol system	41
Fluoride removal from NMC black mass leachates during Lithium-Ion battery recycling via aluminum sulfate precipitation	41
Co-firing characteristic prediction of solid waste and coal for supercritical CO2 power cycle based on CFD simulation and machine learning algorithm	41
Ni-FeOx synergy induced by metal-support interaction on Ni-impregnated incineration bottom ash for effective tar reforming	41
Efficient and high-selective lithium extraction from waste LiMn2O4 batteries by synergetic pyrolysis with polyvinyl chloride	41
Corrigendum to “Effect of alkali additives on desulfurization of syngas during supercritical water gasification of sewage sludge” [Waste Manag. 131 (2021) 394–402]	41

Material Recovery Facilities (MRFs) in the United States: Operations, revenue, and the impact of scale	41
Carbon filter layer for respirator derived from acrylic filter felt	41
Assessing and predicting the illegal dumping risks in relation to road characteristics	41
Investigating the influencing factors of incentive-based household waste recycling using structural equation modelling	41
Exploring the potential of chemical recycling using a distributed model in the UK – A life cycle assessment perspective	41
Efficient recovery of valuable metals from electroplating sludge smelting soot via a combined alkali roasting and acid-free aluminum salts leaching methods	41
Sustainable physical recycling of rigid PVC waste: A biobased solvent approach for the recovery of PVC, TiO2, and CaCO3	40
Pyrolysis of mixed contaminated plastic wastes: Assessing the influence of polymers composition, temperature and residence time	40
Laser flash pyrolysis of face mask waste to vinylidene-terminated PP wax and further functionalized as compatibilizer	40
Impacts of regional socioeconomic statuses and global events on solid waste research reflected in six waste-focused journals	40
First principles insights into the interaction mechanism of iron doped thermally activated kaolinite with Cd and Pb pollutants in organic solid waste incineration flue gas	40
Sustainable reprocessing of lithium iron phosphate batteries: A recovery approach using liquid-phase method at reduced temperature	40
Understanding the mechanisms of household and stakeholder engagement in a recycling ecosystem: The SDL perspective	40
Meta-analysis addressing the potential of antibiotic resistance gene elimination through aerobic composting	40
Improved energy recovery from food waste through hydrothermal carbonization and anaerobic digestion	40
Characterization of hatchery residues for on farm implementation of circular waste management practices	40
Calcium enhances phosphorus reclamation during biochar formation: Mechanisms and potential application as a phosphorus fertilizer in a paddy soil	39
Conversion of waste cork to N-doped porous carbons by urea-assisted hydrothermal method for enhanced VOC capture	39
The effect of reactor scale on biochars and pyrolysis liquids from slow pyrolysis of coffee silverskin, grape pomace and olive mill waste, in auger reactors	39
Anaerobic digestate management, environmental impacts, and techno-economic challenges	39
The effectiveness of inter-municipal cooperation for integrated sustainable waste management: A case study in Ecuador	39
Recycling of waste denim: A stepwise utilisation strategy for clean decolourisation, opening and degradation	39
Restoring the incentives for eco-design in extended producer responsibility: The challenges for eco-modulation	39
Life cycle assessment: Sustainability of biodiesel production from black soldier fly larvae feeding on thermally pre-treated sewage sludge under a tropical country setting	39
An attempt to study the photoreduction rate of divalent mercury in landfill cover soils using experimental control systems	39
Study of the variation law of the airflow resistance and related physical parameters of the pile throughout compost process with cattle manure	39
Chemical profiling of paper recycling grades using GC-MS and LC-MS: An exploration of contaminants and their possible sources	38
Habit-based interventions for maintaining reduction in disposable cutlery usage: A longitudinal experiment	38
Maximal fines and corruption: An experimental study on illegal waste disposal	38
Editorial Board	38
Beyond the runway – Quantifying the climate impact of international catering waste	38
Facilitating anaerobic digestion of kitchen waste through diatomite-mediated spatial ecological niches construction	38
Does exposure enhance interest? An analysis of composting exposure on interest in household waste management	38
Losses and emissions in polypropylene recycling from household packaging waste	38
Mechanisms on nitrogen amendment stimulating methane oxidation in landfill cover soils	38
Phage display screening for highly specific nickel- and cobalt-binding peptides for bio-recovery of metals	37
Lessons learned from a UAV survey and methane emissions calculation at a UK landfill	37
Isolation and characterization of cellulose from spent ground coffee (Coffea Arabica L.): A comparative study	37
Evaluating the potential of hydrochar as a soil amendment	37
Retention time and organic loading rate as anaerobic co-digestion key-factors for better digestate valorization practices: C and N dynamics in soils	37
Microbial mercury methylation potential in a large-scale municipal solid waste landfill, China	37
Plasma gasification as a potential solution for waste minimization and clean energy production: A critical review on techno-economic-environmental assessment and modelling approaches	37
Impact of bioplastic contamination on the mechanical recycling of conventional plastics	37
Parameter-sensitive life cycle assessment of sludge incineration technologies integrating energy balance model	36
Water-heat balance characteristics of the sewage sludge bio-drying process in a full-scale bio-drying plant with circulated air	36
Exploring consistency between stated and revealed preferences for the plastic bag ban policy in Chile	36
Higher heating value estimation of wastes and fuels from ultimate and proximate analysis by using artificial neural networks	36
Recycling PCBs for nanoparticles production with potential applications in cosmetics, cement manufacturing, and CO2 capture	36
Influence of social capital on rural household garbage sorting and recycling behavior: The moderating effect of class identity	36
Impacts of advanced metals recovery on municipal solid waste incineration bottom ash: aggregate characteristics and performance in portland limestone cement concrete	36
Machine learning-assisted assessment of municipal solid waste thermal treatment efficacy via rapid image recognition and visual analysis	35
Filling in the gaps in biowaste biorefineries: The use of the solid residue after enzymatic hydrolysis for the production of biopesticides through solid-state fermentation	35
Insights into leachate reduction in landfill with different ventilation Rates: Balance of Water, waste physicochemical Properties, and microbial community	35
Thermal plasma processing of high temperature insulation wools	35
Wheat straw biochar as an additive in swine manure Composting: An in-depth analysis of mixed material particle characteristics and interface interactions	35
Detailed estimation of generated woody biomass ash for use as fertilizer material	35
Viability and removal assessment of Escherichia coli and Salmonella spp. by real-time PCR with propidium monoazide in the hygienization of sewage sludge using three anaerobic processes	35
Using nanosecond laser pulses to debond the glass-EVA layer from silicon photovoltaic modules	35
Recognition on characteristics and applicability of typical modes for manure & sewage management in pig farming: A case study in Hebei, China	35
Performance of nano zero-valent iron activated peroxydisulfates prepared by carbothermal reduction using various bagasse components	35
Effects of calcium, sodium and potassium on ash fusion temperatures of solid recovered fuels (SRF)	35
Performance and methane potential of up-flow anaerobic sludge blanket treating thermal hydrolyzed sludge dewatering liquor	35
The physical encapsulation and chemical fixation of Zn during thermal treatment process of municipal solid waste incineration (MSWI) fly ash	34
Testing data envelopment analysis models on the performance of European Union regions in sustainable waste management	34
PCDD/Fs, PAHs and HCl emissions from co-combustion of lignite and chicken manure in a circulating fluidized bed boiler with compact refractory casting	34
Enhanced biohydrogen production from high loads of unpretreated cattle manure by cellulolytic bacterium Caldicellulosiruptor bescii at 75 °C	34
Investigating the sustainable development goals derived due to adoption of circular economy practices	34
Determination of risk of spontaneous waste ignition and leachate quality for open municipal solid waste dumpsite	34
Transformation of mixtures of olive mill stone waste and oat bran or Lathyrus clymenum pericarps into high added value products using solid state fermentation	34
Methacrylic acid in situ modified steel converter slag/natural rubber composites: Resourceful utilization of steelmaking solid wastes	34
An explainable machine learning system for efficient use of waste glasses in durable concrete to maximise carbon credits towards net zero emissions	34
BOF slag as a new alkalizing agent for the stabilization of sewage sludge	34
A weakly acidic and reductive deep eutectic solvent used for one-step efficient separation of Li and Co from spent lithium-ion batteries	34
Microbial safety of black soldier fly larvae (Hermetia illucens) reared on food waste streams	34
Mathematical optimization of waste management systems: Methodological review and perspectives for application	34
Editorial Board	34
Biomass gasification ash reutilization: Recirculation reusability and mechanism analysis	34
Glass waste derived silicon carbide synthesis via direct current atmospheric arc plasma	33
How can the recycling of power batteries for EVs be promoted in China? A multiparty cooperative game analysis	33
Fate and effects of polyethylene terephthalate (PET) microplastics during anaerobic digestion of alkaline-thermal pretreated sludge	33
Assessing the economic and ecological viability of generating electricity from oil derived from pyrolysis of plastic waste in China	33
Catalytic pyrolysis of oxygen-containing waste polycarbonate for the preparation of carbon nanotubes and H2-rich syngas	33
Leaching behavior of inert waste landfills	33
Closing global P cycles: The effect of dewatered fish sludge and manure solids as P fertiliser	33
Exploring the chemistry of waste eggshells and its diverse applications	33
Catalytic hydrothermal conversion of polypropylene at sub-critical conditions with Ni-supported zeolites	33
Review of inventory data for the thermal treatment of sewage sludge	33
A cleaner route of biodiesel production from waste frying oil using novel potassium tin oxide catalyst: A smart liquid-waste management	33
PbSO4 reaction mechanism in oxygen and reduction atmospheres during co-smelting process with primary lead material	33
Improving salt-tolerant artificial consortium of Bacillus amyloliquefaciens for bioconverting food waste to lipopeptides	32
Optimised design of concrete recycling networks: The case of North Rhine-Westphalia	32
Assessing the relation between waste management policies and circular economy goals	32
Recovery of iron from iron tailings by suspension magnetization roasting with biomass-derived pyrolytic gas	32
Recycled PMMA prepared directly from crude MMA obtained from thermal depolymerization of mixed PMMA waste	32
Influence of speciation distribution and particle size on heavy metal leaching from MSWI fly ash	32