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Municipal Solid Waste (municipal + solid_waste)
Selected AbstractsTrace metal distribution in soluble organic matter from municipal solid waste compost determined by size-exclusion chromatographyENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2002Arno Kaschl Abstract Municipal solid waste (MSW) composts carry high amounts of trace metals and organic complexing agents that may influence metal bioavailability and mobility after application to soils. In order to assess the degree of organic complexation of trace metals in the solution phase of MSW compost and the relevance of organic ligand type, size exclusion chromatography (SEC) was applied to compost-extracted organic ligands. Adjustment of the elution conditions minimized the interaction with the gel matrix for compost humic substances and dissolved organic matter (DOM) fractions. The SEC was then used to separate the aqueous compost extract into samples with distinct differences in chemical constituents. The highest quantities of Cu, Zn, Ni, Mn, and Cd were found to coelute with the main peak of the SEC elution curve, which, as observed by Fourier-transformed infrared (FTIR) spectroscopy, also had the highest density of carboxyl groups. The ratio of aromatic to aliphatic structures was higher for eluates with low retention times, and cations such as Al, Cr, and Fe were preferably associated with these larger organic molecules. All trace metals in the compost solution phase were bound mostly to DOM rather than forming inorganic complexes. [source] Prediction of municipal solid waste generation with combination of support vector machine and principal component analysis: A case study of MashhadENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 2 2009R. Noori Abstract Quantity prediction of municipal solid waste (MSW) is crucial for design and programming municipal solid waste management system (MSWMS). Because effect of various parameters on MSW quantity and its high fluctuation, prediction of generated MSW is a difficult task that can lead to enormous error. The works presented here involve developing an improved support vector machine (SVM) model, which combines the principal component analysis (PCA) technique with the SVM to forecast the weekly generated waste of Mashhad city. In this study, the PCA technique was first used to reduce and orthogonalize the original input variables (data). Then these treated data were used as new input variables in SVM model. This improved model was evaluated by using weekly time series of waste generation (WG) and the number of trucks that carry waste in week of t. These data have been collected from 2005 to 2008. By comparing the predicted WG with the observed data, the effectiveness of the proposed model was verified. Therefore, in authors' opinion, the model presented in this article is a potential tool for predicting WG and has advantages over the traditional SVM model. © 2008 American Institute of Chemical Engineers Environ Prog, 2009 [source] Pyrolysis of tetra pack in municipal solid wasteJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 8 2001Chao-Hsiung Wu Abstract The pyrolysis of tetra pack in nitrogen was investigated with a thermogravimetric analysis (TGA) reaction system. The pyrolysis kinetics experiments for the tetra pack and its main components (kraft paper and low-density poly(ethene) (LDPE)) were carried out at heating rates (,) of 5.2, 12.8, 21.8,K,min,1. The results indicated that the one-reaction model and two-reaction model could be used to describe the pyrolysis of LDPE and kraft paper respectively. The total reaction rate of tetra pack can be expressed by the summation of the individual class of LDPE and kraft paper by multiplying the weighting factors. The pyrolysis products experiments were carried out at a constant heating rate of 5.2,K,min,1. The gaseous products were collected at room temperature (298,K) and analyzed by gas chromatography (GC). The residues were collected at some significant pyrolysis reaction temperatures and analyzed by an elemental analyzer (EA) and X-ray powdered diffraction (XRPD). The accumulated masses and the instantaneous concentrations of gaseous products were obtained under the experimental conditions. The major gaseous products included non-hydrocarbons (CO2, CO, and H2O) and hydrocarbons (C1,5). In the XRPD analysis, the results indicated that pure aluminum foil could be obtained from the final residues. The proposed model may be supported by the pyrolysis mechanisms with product distribution. © 2001 Society of Chemical Industry [source] Speciation of zinc in secondary fly ashes of municipal solid waste at high temperaturesJOURNAL OF SYNCHROTRON RADIATION, Issue 4 2009Meijuan Yu The evaporation aerosols produced during the vitrification process of municipal solid waste incinerators (MSWI) fly ash represent a potential environmental risk owing to their high content of heavy metals. In this research, high-temperature heating processes were carried out on fly ashes collected from bag houses in a Chinese MSWI plant and the secondary fly ashes (SFA) were separately collected at three high temperatures (1273,K, 1423,K and 1523,K) below the melting range. Elemental analysis showed that high contents of both zinc and chlorine were present in these SFA samples and, according to the standard of the heavy metals industrial grade of ore, SFAs can be re-used as metallurgical raw materials or rich ore. Moreover, as shown by XAS analysis and for different high temperatures, zinc environments in the three SFA samples were characterized by the same local structure of the zinc chloride. As a consequence, a zinc recycling procedure can be easily designed based on the configuration information. [source] A composite model for municipal solid wastePROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2005Volker Krase The mechanical behaviour of municipal solid waste is very complex due to the internal structure and differs considerably from ordinary materials. The fundamental idea of the presented mechanical constitutive model is the split of the material into two solid phases, justified by experimental observations, where fibrous particles signi.cantly influence the composite behaviour. Constitutive laws are independently introduced for each phase. A .nite deformation theory is applied, whereas the concept of elastoplasticity allows reproducing the highly non-linear stress-strain relations. A creep law describes time-depending deformation under compression loads. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Operation of a municipal solid waste co-combustion pilot plantASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 6 2007V. K. C. Lee Abstract The co-combustion of municipal solid waste (MSW) is a novel and highly integrated design combining cement manufacturing, thermal processing of MSW and energy/electricity production (termed the Co-Co process). This novel design of the Co-Co process was developed in 2003,2004 and a pilot plant with a capacity of 40 tonnes per day was constructed and commissioned in 2005. The pilot plant was operated for a period of 10 weeks during 2005. Various feed protocols, namely, MSW as received and after removal of recyclables, were tested. Stack emissions were monitored either continuously (gas emission) or periodically (dioxins and heavy metal emissions). Solid residues including bottom ash and fly ash were also sampled and analysed for heavy metals and dioxins periodically. It was found that the levels of dioxins in the stack emissions and fly ash were below normal MSW thermal treatment processes, and government environmental and international limits (more than 1000 times less). Other gases, such CO, NOx, SOx and HCl, were also well below government environmental licence limits as defined by a best practical means (BPM). In addition, the materials recovery and recycling facility (MRRF) was tested. It demonstrated that different fractions, including metals, plastics and glass, of the MSW could be separated and recovered. The Co-Co process was successfully demonstrated and its emission levels were well below normal MSW thermal treatment processes. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Which Controls the Depolymerization of Cellulose in Ionic Liquids: The Solid Acid Catalyst or Cellulose?CHEMSUSCHEM CHEMISTRY AND SUSTAINABILITY, ENERGY & MATERIALS, Issue 2 2010Roberto Rinaldi Dr. Abstract Cellulose is a renewable and widely available feedstock. It is a biopolymer that is typically found in wood, straw, grass, municipal solid waste, and crop residues. Its use as raw material for biofuel production opens up the possibility of sustainable biorefinery schemes that do not compete with food supply. Tapping into this feedstock for the production of biofuels and chemicals requires,as the first-step,its depolymerization or its hydrolysis into intermediates that are more susceptible to chemical and/or biological transformations. We have shown earlier that solid acids selectively catalyze the depolymerization of cellulose solubilized in 1-butyl-3-methylimidazolium chloride (BMIMCl) at 100,°C. Here, we address the factors responsible for the control of this reaction. Both cellulose and solid acid catalysts have distinct and important roles in the process. Describing the depolymerization of cellulose by the equivalent number of scissions occurring in the cellulosic chains allows a direct correlation between the product yields and the extent of the polymer breakdown. The effect of the acid strength on the depolymerization of cellulose is discussed in detail. Practical aspects of the reaction, concerning the homogeneous nature of the catalysis in spite of the use of a solid acid catalyst, are thoroughly addressed. The effect of impurities present in the imidazolium-based ionic liquids on the reaction performance, the suitability of different ionic liquids as solvents, and the recyclability of Amberlyst 15DRY and BMIMCl are also presented. [source] Effect of inoculation dosing on the composting of source-selected organic fraction of municipal solid wastesJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2006Raquel Barrena Abstract The effects of a commercial inoculum (MicroGest 10X, Brookside Agra L.C.) on the field-scale composting of the source-selected organic fraction of municipal solid wastes (OFMSW) have been studied by following routine parameters of the composting process (temperature, oxygen content and moisture) and biologically-related tests such as the respirometric index and the maturity grade. The inoculum was added to composting piles of OFMSW at different levels: control (no added inoculum), treatment A (105 CFU g,1 of OFMSW), treatment B (106 CFU g,1 of OFMSW) and treatment C (107 CFU g,1 of OFMSW). The inoculum selected produced a significant acceleration of the composting process with high levels of biological activity in the thermophilic phase. In terms of the acceleration of composting and economy the optimal treatment was B, which produced a reduction of approximately half of the total composting time. Treatment C did not improve significantly the results obtained with treatment B, whereas treatment A has little effect on the composting of OFMSW when compared with the control experiment. Respirometric index (determined at 55 °C) and maturity grade appeared to be the most reliable tests to follow the biological activity of the composting of OFMSW. On the other hand, routine parameters such as temperature, oxygen content and moisture showed no significant differences among the different inoculation levels tested in the composting process. Copyright © 2005 Society of Chemical Industry [source] The potential reuse of biodegradable municipal solid wastes (MSW) as feedstocks in vermicompostingJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2010Edwin Yih Shyang Sim Abstract There is an urgent need globally to find alternative sustainable steps to treat municipal solid wastes (MSW) originated from mismanagement of urban wastes with increasing disposal cost. Furthermore, a conglomeration of ever-increasing population and consumerist lifestyle is contributing towards the generation of more MSW. In this context, vermicomposting offers excellent potential to promote safe, hygienic and sustainable management of biodegradable MSW. It has been demonstrated that, through vermicomposting, MSW such as city garbage, household and kitchen wastes, vegetable wastes, paper wastes, human faeces and others could be sustainably transformed into organic fertiliser or vermicompost that provides great benefits to agricultural soil and plants. Generally, earthworms are sensitive to their environment and require temperature, moisture content, pH and sometimes ventilation at proper levels for the optimum vermicomposting process. Apart from setting the optimum operational conditions for the vermicomposting process, other approaches such as pre-composting, inoculating micro-organisms into MSW and redesigning the conventional vermireactor could be introduced to further enhance the vermicomposting of MSW. Thus the present mini-review discusses the potential of introducing vermicomposting in MSW management, the benefits of vermicomposted MSW to plants, suggestions on how to enhance the vermicomposting of MSW as well as risk management in the vermicomposting of MSW. Copyright © 2010 Society of Chemical Industry [source] Biomethane production from starch and lignocellulosic crops: a comparative reviewBIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 4 2010Jean-Claude Frigon Abstract The methane produced from the anaerobic digestion of organic wastes and energy crops represents an elegant and economical means of generating renewable biofuel. Anaerobic digestion is a mature technology and is already used for the conversion of the organic fraction of municipal solid wastes and excess primary and secondary sludge from waste-water treatment plants. High methane yield up to 0.45 m3 STP CH4/kg volatile solids (VS) or 12 390 m3 STP CH4/ ha can be achieved with sugar and starch crops, although these cultures are competing with food and feed crops for high-quality land. The cultivation of lignocellulosic crops on marginal and set-aside lands is a more environmentally sound and sustainable option for renewable energy production. The methane yield obtained from these crops is lower, 0.17,0.39 m3 STP CH4/kg VS or 5400 m3 STP CH4/ha, as its conversion into methane is facing the same initial barrier as for the production of ethanol, for example, hydrolysis of the crops. Intensive research and development on efficient pre-treatments is ongoing to optimize the net energy production, which is potentially greater than for liquid biofuels, since the whole substrate excepted lignin is convertible into methane. Copyright © 2010 Crown in the right of Canada [source] | |||||||||||||||||||||||||