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Zeitschrift für Hochschulrecht, Hochschulmanagement und Hochschulpolitik: zfhr     Hybrid Journal   (Followers: 3)
Zeitschrift fur Management     Hybrid Journal   (Followers: 1)
Zeitschrift für öffentliches Recht     Hybrid Journal   (Followers: 11)
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Zeitschrift für Psychodrama und Soziometrie     Hybrid Journal  
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Zeitschrift für Vergleichende Politikwissenschaft     Hybrid Journal   (Followers: 4)
Zoomorphology     Hybrid Journal   (Followers: 2, SJR: 0.417, h-index: 24)
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Journal Cover Journal of Material Cycles and Waste Management
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   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 1611-8227 - ISSN (Online) 1438-4957
     Published by Springer-Verlag Homepage  [2209 journals]   [SJR: 0.327]   [H-I: 13]
  • Gasification characteristics of sewage sludge combined with wood biomass
    • Abstract: Abstract The gas products from gasification processes have been considered to have some limitations in gas composition and heating value from the previous studies. Gasification characteristics of sewage sludge and wood mixture were investigated using different mixing ratios with the purpose of better quality of gas product suitable for energy/power generation. The gasification experiment was performed by an indirectly heated fluidized bed reactor. As reaction temperature increased from 600 to 900 °C, the yield of gas product increased with higher generation of CO, H2 and CH4 by more activated gas conversion reactions. As the equivalence ratio increased from 0.2 to 0.4, composition ratio of CO2 increased while CO, CH4, H2 decreased as expected. Several operating variables including mixing ratio of wood with dried sludge were also tested. From this initial stage of experiment, optimal operating conditions for the bubbling fluidized bed gasifier, could be considered 900 °C in temperature; 0.2 in equivalence ratio and 40 % in wood mixing ratio within test variables range. These results will be more thoroughly investigated for the application to the larger scale pilot system.
      PubDate: 2014-10-01
       
  • The potential of SO2
           for reducing corrosion in WtE plants
    • Abstract: Abstract Due to the high-temperature boiler corrosion induced by chloride-rich fly ash deposits, steam generation in today’s Waste-to-Energy (WtE) plants is typically designed only for 40 bar/400 °C as an economic compromise between acceptable corrosion rate and maximum power generation. The high-corrosive metal chlorides in the fly ash can react with SO2 forming low-corrosive sulfates. The sulfation efficiency is enhanced by high SO2 levels and sufficient residence time of the flue gas at high-temperatures (700–900 °C). The fly ash sulfation was tested in full scale in a Swedish WtE plant by applying the economic sulfur recirculation method. Probes of several alloys (16Mo3, Inconel 625, Sanicro 28) were exposed for 1000 h at controlled material temperatures in the superheater position, at normal and during sulfating operation respectively. Analyses of the fly ash showed that the molar Cl/S was decreased to values well below 1 and the corresponding corrosion rates of the individual material samples were less than half when sulfur recirculation was in operation. These positive findings demonstrate that the sulfur recirculation process has high potential for low-corrosive high-temperature steam generation (T ≈ 500 °C) and improved electricity production. Further steam superheating can be realized by staged superheating using small amounts of secondary fuel.
      PubDate: 2014-10-01
       
  • Dechlorination and decomposition of Aroclor 1242 in real waste transformer
           
    • Abstract: Abstract This research was done to assess the dechlorination and decomposition of polychlorinated biphenyls (PCBs) in real waste transformer oil through a modified domestic microwave oven (MDMW). The influence of microwave power (200–1000 W), reaction time (30–600 s), polyethylene glycol (PEG) (1.5–7.5 g), iron powder (0.3–1.5 g), NaOH (0.3–1.5 g), and H2O (0.4–2 ml) were investigated on the decomposition efficiency of PCBs existing in real waste transformer oil with MDMW. Obtained data indicate that PEG and NaOH have the greatest influence on decomposition of PCBs; while, iron did not influence, and H2O decreased, the decomposition efficiency of PCBs. Experimental data also indicated that with the optimum amount of variables through a central composites design method (PEG = 5.34 g, NaOH = 1.17 g, Fe = 0.6 g, H2O = 0.8 ml and microwave power 800 W), 78 % of PCBs was degraded at a reaction time of about 6 min. In addition, the PCBs decomposition without using water increased up to 100 % in the reactor with the MDMW at 6 min. Accordingly, results showed that MDMW was a very efficient factor for PCBs decomposition from waste transformer oil. Also, using microwave irradiation, availability and inexpensive materials (PEG, NaOH), and iron suggest this method as a fast, effective, and cheap method for PCB decomposition of waste oils.
      PubDate: 2014-10-01
       
  • Greenhouse gases emissions from solid waste: an analysis of Expo 2010
           Shanghai, China
    • Abstract: Abstract The management of greenhouse gases (GHGs) emissions is currently a very important environmental issue. Mega-event organizers and host cities have attached great importance to GHGs emissions associated with event-related activities. However, GHGs emissions from event solid waste have never been thoroughly discussed. This study investigated GHGs emissions of major event’s solid waste using life cycle assessment, based on Shanghai Expo case. The results showed that GHGs from collecting and sorting, transportation and landfill treatment amount to 9790 t CO2e. And the emission intensity is estimated to be 134 g CO2e per event service. GHGs reduction from recycling amounts to 48 kt CO2e, with 78 % of these the result of construction waste recycle. It illustrates that waste recycle plays a vital role in GHGs mitigation. Finally, the study suggests that the concept of waste avoidance, waste reuse and waste recycle is an effective waste management to mitigate climate change and should be implemented in major event to achieve the goal of green event.
      PubDate: 2014-10-01
       
  • The feasibility of converting solid waste into refuse-derived fuel 5 via
           mechanical biological treatment process
    • Abstract: Abstract The aim of our study was to investigate the feasibility of utilizing solid waste after mechanical biological treatment (MBT) processing at a landfill site in Phitsanulok, Thailand, as refuse-derived fuel 5 (RDF-5). The waste composition, and physical and chemical characteristics of each waste fraction were determined to evaluate the suitability of the waste for recycling and reuse as RDF-5. Results showed that after MBT processing, the solid waste >40 mm in size was observed to have 33.8 MJ/kg of calorific value. The average concentrations of heavy metals were also found to be within the acceptable limit for plastic waste combustion, thus proving that MBT-processed solid waste >40 mm in size has high potential for use as RDF-5. The optimal weight ratio of MBT-processed solid waste and crude oil sludge for transformation into RDF-5 was found to be 80:20. With this optimum ratio, the average calorific values of the RDF-5 were determined to be 47 MJ/kg, with sulfur and chlorine contents of 0.16 and 0.74 %, respectively. The characteristics of the produced RDF-5 could meet the specified ASTM standards in terms of calorific value (>15 MJ/kg), and sulfur and chlorine contents. In addition, the compressive strength of the produced RDF-5 was also found to be suitable for compact storage and transportation without any damage. Finally, the energy production cost from this RDF-5 process was estimated as USD $0.05/kWh.
      PubDate: 2014-10-01
       
  • Measurement and management of hospital waste in southern Iran: a case
           study
    • Abstract: Abstract One of the requirements for development of human societies is the establishment of new healthcare centers. A variety of wastes are generated in healthcare centers depending on the type of activities. This study was conducted to identify, measure and manage different types of hospital wastes as a case study in a hospital located in southern Iran. For this purpose, a questionnaire was initially designed and distributed among the relevant experts to survey the current trend of waste management in the hospital in terms of waste collection, storage and disposal. Afterwards, the hospital waste was sampled during two seasons of fall and winter. The samples were weighted for seven consecutive days in the middle of each season. Approximately, 10 % of the total waste bags per day collected round the clock were selected for further analysis. The obtained results indicated that infectious-hazardous and pseudo-household wastes were, respectively, about 3.79 kg/day/bed, 1.36 kg/day/bed and 2.43 kg/day/bed of the total generated waste in the hospital. As the research findings suggest, proper separation of infectious and pseudo-household wastes at the source would be an essential step towards mitigating environmental and health risks and minimizing the cost of the hospital waste management.
      PubDate: 2014-10-01
       
  • Analysis of reduction stage of chemical looping packed bed reactor based
           on the reaction front distribution
    • Abstract: Abstract Traditional combustion of syngas derived from biomass has incurred numerous environmental problems, and syngas chemical looping combustion is environmentally friendly for syngas energy conversion. As a key part of chemical looping combustion, reactor configuration is noticeable. The dynamically operated packed bed reactor is an emerging conception applied to chemical looping combustion. Our attention is paid to the conversion of the oxygen carrier in the packed bed as the limited maximum conversion of the oxygen carrier in a packed bed is unclear. In this paper, the reaction front distribution during iron oxide reduced by CO is firstly proposed on the basis of chemical equilibrium and then validated by the effluent gas profile. Based on the reaction front distribution, the detail of the reduction stage in iron-based chemical looping combustion is analyzed to obtain the characteristics of reaction fronts. The reaction rates of reduction from Fe2O3 to Fe3O4, Fe3O4 to Fe0.947O and Fe0.947O to Fe are 5.280, 3.329 and 4.379 mol m−3 s−1, respectively. And the velocities of reaction front I, II, III are 0.605, 0.326, 0.044 cm min−1, respectively, which demonstrate the reaction front distribution. The methodology established in this paper can be used to study multiple reaction front system in the packed bed reactor.
      PubDate: 2014-10-01
       
  • Environmental impact of fly ash utilization in roadway embankments
    • Abstract: Abstract The leaching potential of heavy metals from a roadway embankment constructed of fly ash and soil mixture was studied. Leaching of eight environmentally concerned metals Ag, As, Ba, Cd, Cr, Hg, Pb, and Se from the fly ash–soil mixtures was examined through batch leaching test and column leaching test. The batch leaching test results showed that the fly ash meets the local regulatory standards for beneficial use of nonhazardous wastes. The column leach test revealed that only Ba, Cr, and Se were detectable in the effluents. The peak concentration of Ba in the effluents was much lower than the US EPA Primary Drinking Water Regulations’ maximum contaminant level (MCL). The peak concentrations of Cr and Se exceeded the MCLs only in the initial flush stage and quickly decreased to below the MCLs. Results of this study suggest a great potential for fly ash to be used in roadway embankments to enhance their mechanical properties, reduce the use of soil, and avoid the disposal of fly ash as waste.
      PubDate: 2014-10-01
       
  • Dynamic studies on lead volatilization from CaO–SiO       class="a-plus-plus">2–Al       class="a-plus-plus">2O       class="a-plus-plus">3 molten slag under N       class="a-plus-plus">2–CO–CO       class="a-plus-plus">2, N       class="a-plus-plus">2–HCl and N       class="a-plus-plus">2–H       class="a-plus-plus">2S gas atmospheres
    • Abstract: Abstract Dynamic studies on the volatilization of lead from CaO–SiO2–Al2O3 molten slags were conducted in a lab-scale melting furnace from 1623 to 1773 K under different mixed gas atmospheres of CO 0.05–0.3 atm to CO2 0–0.3 atm to N2 (balance), HCl 1.7 × 10−3–6.7 × 10−3 atm to N2 (balance), and H2S 3.0 × 10−4 to 1.7 × 10−3 atm to N2 (balance). The slag samples consisted of the mixed powders of 20–50 wt% CaO, 30–60 wt% SiO2, and 10–40 wt% Al2O3, containing 2000 ppm PbO.Results showed that the rates of volatilization of lead from the CaO–SiO2–Al2O3 molten slags under the N2–CO–CO2, N2–HCl, and N2–H2S gas atmospheres were higher than those under the simulated air (N2–O2), which increased with CO, HCl, and H2S partial pressures. At \(p_{{HCl}}\)  =  \(p_{H_{2}S}\)  = 1.7 × 10−3 atm, the apparent rate constants for the volatilization of lead under the N2–H2S and N2–HCl gas atmospheres were nearly equal, which increased with a rise in temperature. Results also showed that the rate of volatilization of lead from the molten slag decreased drastically with the increasing viscosity of the molten slag, in the viscosity range lower than 3 Pa s. Consequently, the volatilization of lead from the CaO–SiO2–Al2O3 molten slag was significantly influenced by CO, HCl, and H2S partial pressures and by the viscosity of the molten slag.
      PubDate: 2014-10-01
       
  • Effect of leachate recirculation on the migration of copper and zinc in
           municipal solid waste and municipal solid waste incineration bottom ash
           co-disposed landfill
    • Abstract: Abstract Municipal solid waste incinerator (MSWI) bottom ash was allowed to be disposed of with municipal solid waste (MSW) in landfill sites in the recently enacted standard of China. In this study, three sets of simulated landfill reactors, namely, conventional MSW landfill (CL), conventional MSWI bottom ash and MSW co-disposed landfill (CCL), and leachate recirculated MSWI bottom ash and MSW co-disposed landfill (RCL), were operated to investigate the environmental impact of the co-disposal. The effect of leachate recirculation on the migration of Cu and Zn in the co-disposed landfill was also presented. The results showed that the co-disposal of MSWI bottom ash with MSW would not enhance the leaching of Cu and Zn from landfill. However, the co-disposal increased the Cu and Zn contents of the refuse in the bottom layer of the landfill from 56.7 to 65.3 mg/kg and from 210 to 236 mg/kg, respectively. The recirculation of the leachate could further increase the Cu and Zn contents of the refuse in the bottom layer of the landfill to 72.9 and 441 mg/kg, respectively. Besides these observations, the results also showed that the co-disposed landfill with leachate recirculation could facilitate the stabilization of the landfill.
      PubDate: 2014-10-01
       
  • Humification index of composts originating from three types of woody
           biomass
    • Abstract: Abstract Composting is a good method for recycling surplus manure and stabilizing organic matter from biowastes. Compost is used as a soil amendment and recently, for restoration of vegetation in barren areas. We investigated the relationship between the type of woody biomass (using Robinia pseudoacacia, Japanese larch and apple) and the humification index (HI) of the resulting compost. This study evaluated the difference in HI between the three compost types, and the structural features of composts and extracted humic acids (HAs). The HIs for R. pseudoacacia and apple were larger than that for Japanese larch after composting for 11 months. The structural features of the Japanese larch compost were also different from the apple and R. pseudoacacia, with a very high carbon/nitrogen ratio. The average molecular weights and ultraviolet–visible spectra (A600/C) of HAs extracted from composting samples at 0 and 11 months indicate that the humification rate of Japanese larch was slower than that of R. pseudoacacia and apple. During composting, the average molecular weights of apple and R. pseudoacacia decreased, while their A600/C values increased, but the reverse was observed for Japanese larch. The humification rate was found to depend on the type of woody biomass being composted.
      PubDate: 2014-10-01
       
  • Study of hydrodynamic characteristics in a circulating fluidized bed
           gasifier for plastic waste by computational fluid dynamics modeling and
           simulation
    • Abstract: Abstract For designing an efficient circulating fluidized bed reactor, understanding the complex hydrodynamic characteristics in the reactor is required. Hence, in the present study, the modeling and simulation of the circulating fluidized bed gasifier using plastic waste were carried out with Eulerian-Granular approach. Several cases were investigated as changing superficial gas velocities or sizes of plastic waste particle. Firstly, cases were examined with four different velocities when the particle diameter is 1 mm. At the gas velocity of 6 or 8 m/s, gas volume fraction is more than 95 % throughout the reactor and particle velocity has positive value overall. Therefore, a circulating fluidized bed seems to be formed in both cases. Comparing those two cases, better solid mixing can be expected considering the mass fraction and solid velocity at the superficial gas velocity of 6 m/s. Thus this case was further studied for the effect of particle size. As the diameters of plastic waste particle are 1 or 3 mm, it is considered that a circulating fluidized bed is formed. And plastic waste and sand particles are well mixed throughout the reactor. However, the particle diameter increases over 3 mm then, it is very hard to maintain circulating fluidization condition.
      PubDate: 2014-10-01
       
  • A comparison study on high-temperature water–gas shift reaction over
           Fe/Al/Cu and Fe/Al/Ni catalysts using simulated waste-derived synthesis
           gas
    • Abstract: Abstract A comparative study on Fe/Al, Fe/Al/Cu, and Fe/Al/Ni catalysts in high-temperature water–gas shift reaction (HT–WGS) using simulated waste-derived synthesis gas has been carried out. The metal oxide (Cu and Ni) and aluminum incorporated Fe catalysts were designed to get highly active HT–WGS catalysts. Despite the high CO concentration in the simulated waste-derived synthesis gas, Fe/Al/Cu catalyst exhibited the highest CO conversion (84 %) and 100 % selectivity to CO2 at a very high gas hourly space velocity (GHSV) of 40,057 h−1. The outstanding catalytic performance is mainly due to easier reducibility, the synergy effect of Cu and Al, and the stability of the magnetite.
      PubDate: 2014-10-01
       
  • Characterization of residue from leached cathode ray tube funnel glass:
           reutilization as white carbon black
    • Abstract: Abstract Cathode ray tube (CRT) funnel glass remains an urgent environmental problem and is composed mainly of lead oxide and silicon oxide. In this research, the residue could be obtained from 2 h to 500 rpm activated CRT funnel glass after extracting lead via acid leaching under the conditions of HNO3 concentration 1.0 mol/L, leaching temperature 95 °C and leaching time 1 h. In order to reutilize the residue, its physico-chemical properties were characterized by scanning electron microscopy, Brunauer–Emmett–Teller, thermogravimetric analysis, X-ray diffraction and Fourier transform infrared spectroscopy. The results indicated that the residue was an amorphous superfine powder with approximately 93 wt% silica oxide and specific surface area of more than 170 m2/g. It can be reutilized as white carbon black.
      PubDate: 2014-10-01
       
  • Cobalt separation from waste mobile phone batteries using selective
           precipitation and chelating resin
    • Abstract: Abstract Separation of cobalt from mixed-waste mobile phone batteries containing LiCoO2 cathodic active material was investigated using selective precipitation and chelating resin. Cobalt was recovered from the active powder materials containing 47 % Co oxide together with Mn, Cu, Li, Al, Fe, and Ni oxides. The metal ions were leached sufficiently using 4 M HCl. The metal ions detected spectrophotometrically were removed from the leaching solution by selective precipitation at pH 5.5, with cobalt loss of 27.5 %. Conditions for achieving a recovery of Co in the filtrate by chelating resin were determined experimentally by varying the pH and time of the reaction, as well as the initial resin-to-liquid ratio. The cobalt was efficiently determined by absorption spectrometry at λ max 510 nm. Chelating polyamidoxime resin was synthesized by polymerization of acrylonitrile and followed by amidoximation reaction. Physically cross-linked gel of polyacrylonitrile was made by a cooling technique.
      PubDate: 2014-10-01
       
  • Mechanical behavior of typical hazardous waste and its influence on
           landfill stability during operation
    • Abstract: Abstract The stability of hazardous waste (HW) landfill is a major security risk to the landfill environmental safety. The mechanical behavior of waste controls many aspects of landfill design and operation, including stability and settlement issues and the integrity of geosynthetic and liner components. This study presents the results of a laboratory experiment to learn the mechanical properties of HW collected from the Hangzhou HW landfill. Measured mechanical behavior was compared with results for municipal solid waste (MSW) to assess their discrepancies. The particle size of HW was analyzed by the sieving and hydrometer methods. Because HW comes primarily from industrial plants in the form of sludge or slag, their particle sizes are generally smaller than those of MSW. This study indicates that the shear strength parameters of HW are more sensitive to the methods of testing and calculation than those of MSW. Numerical simulations demonstrate that the safety factor of a landfill is affected by the mechanical properties of HW, especially cohesion and friction angle. Because of the lower particle size and wider compression ratio, compared to MSW, an HW landfill should be taken more care in its operational procedures so as to increase its stability.
      PubDate: 2014-10-01
       
  • Heavy metal speciation in various types of fly ash from municipal solid
           waste incinerator
    • Abstract: Abstract Fly ash (FA) from municipal solid waste incinerators has been known as hazardous waste, which is mostly because of the high content of heavy metal and dioxins. Besides the content, the form of the heavy metals in fly ash is also very important, because it is tightly related with the leaching behavior of fly ash in diverse circumstances. To evaluate the environment potential risk of fly ash, the Tessier chemical extraction method was adopted. In this study, four kinds of fly ash were examined, one sample from China (CFA) and the other three from Japan (RFA, CaFA and NaFA). Five metal elements were detected and they were Ni, Cr, Cd, Pb, and Cu. The result of total heavy metals’ concentration showed CFA has the lowest content. As to the Tessier chemical extraction experiments, the results show that Cd, Pb, and Cu have higher leaching risk in the environment than other heavy metals. The result of leaching test experiment showed that the more exchangeable speciation of Cd, Cr and Pb in FA, the more it could leach out in natural environment.
      PubDate: 2014-10-01
       
  • Recovery of rare earth elements from waste fluorescent phosphors:
           Na2O       class="a-plus-plus">2 molten salt decomposition
    • Abstract: Abstract In this paper, an efficient recovery of rare earth elements from waste fluorescent phosphors has been reported and the novel process of alkali fusion and acid leaching has been proposed. The experimental results have shown that the key for efficient recycling is the complete dissolution of waste fluorescent phosphors. The Na2O2-to-waste mass ratio, calcination temperature and reactive time play considerable roles in rare earth elements extraction during the alkali fusion process. The optimal conditions in terms of temperature, time and Na2O2-to-waste mass ratio are 650 °C, 15 min and 2:1, respectively, under which more than 99.5 % rare earth elements are extracted. The possible reaction mechanism of alkali fusion has been proposed.
      PubDate: 2014-08-05
       
  • Study on optimal energy efficiency of a sludge drying-incineration
           combined system
    • Abstract: Abstract Thermal drying is a frequently used technology to further remove the water in dewatered sludge. However, it is an expensive solution due to its highly energy consumption. The combination of sludge drying and incineration system, in which, the energy generated from sludge incineration is reused to sludge drying, can largely save the energy consumption of sludge treatment facilities. A bench-scale paddle sludge dryer was built to study the drying characteristics of sludge. Results show that, a significant fluctuation of sludge drying rate and stirring power emerges at the moisture content of 55–65 %. An energy model was established based on a sludge drying and incineration project. The most reasonable dryness of sludge outlet from sludge dryer and input to sludge incinerator was analyzed, in the purpose of achieving optimal energy efficiency. The mono-incineration of dry sludge can be achieved at 850 °C combustion temperature, when sludge lower heating value (LHV) is about 11213 kJ/kg and moisture content is about 60 % w/w. The effect of operation conditions, including sludge moisture content, LHV, and operation load were analyzed based on the energy model. This energy model could be applied for the improvement of energy efficiency of sludge drying and incineration combined system.
      PubDate: 2014-07-30
       
  • Detoxification effect of chlorination procedure on waste lead glass
    • Abstract: Abstract This work reports the detoxification effect of chlorinating volatilization procedure on waste lead glass. The effects of various reaction parameters on lead removal efficiencies were examined, and the optimal operation conditions were 1000 °C, 2 h, and 600 ± 50 Pa, respectively. Moreover, it was found that the residues could be safely applied in a wide range, e.g., for wollastonite synthesis by an environmental benign technique. Accordingly, the typical hazardous waste was successfully converted into a safe raw material for further industrial application.
      PubDate: 2014-07-20
       
 
 
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