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Novel development of VOx–CeOx–WOx/TiO2 catalyst for low-temperature catalytic oxidation of chloroaromatic organics
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Yunfeng MaJian, wen LaiXiao, dong Li
Waste Disposal & Sustainable Energy. 2022 (4): 259-269.
DOI: https://doi.org/10.1007/s42768-022-00108-0
A novel selective catalytic reduction (SCR) catalyst with high catalytic activity on chloroaromatic organics at lower temperatures (160–180 ℃) is critical for municipal solid waste incineration (MSWI) plants. This study prepares a series of honeycomb-type VOx/TiO2 catalysts and finally develops a new low-temperature catalyst with high catalytic activity in eliminating chloroaromatic organics. Based on the conversion efficiency (CE) of 1,2-dichlorobenzene (1,2-DCB) and CO2 selectivity, the optimal VOx content of 4.06% (in weight) in VOx/TiO2 catalyst is first confirmed. By modifying CeOx and WOx, a novel honeycomb-type catalyst of VOx–CeOx–WOx/TiO2 achieves the highest CE (93.1%–93.6%) and CO2 selectivity (40.9%–60.7%) at 150–200 ℃. It was found that the CeOx and WOx can improve the catalytic activity by enriching the surface content of V and O, increasing the proportion of V5+ and Osurf, enlarging the supply source of reactive oxygen species and their storage capacity, and accelerating the redox cycle of VOx, CeOx, WOx, and reactive oxygen species. This study can guide the development of monolithic low-temperature catalysts with high catalytic activity in eliminating chloroaromatic organics in MSWI flue gas.
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Coal fly ash reinforcement for the property enhancement of crude glycerol-based polyurethane foam composites
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Linda Zhang, Weihong ZhangWei, hua Zou
Waste Disposal & Sustainable Energy. 2022 (4): 271-.
DOI: https://doi.org/10.1007/s42768-022-00112-4
Coal fly ash (CFA) is the main combustion residue of fine ground coal in the process of coal-fired thermal power generation, and crude glycerol (CG) is the byproduct of biodiesel production. The novel polyurethane/CFA (PU/CFA) foam composites were prepared from CFA and CG. Two kinds of CFA, CFAI and CFAII were used as fillers for the property enhancement of PU/CFA composites, and the effects on foaming behavior and the reinforcement for the PU/CFA composites were investigated. It was found that the addition of CFA can prolong the rising time and tack-free time, and the maximum rising time and tack-free time increased to 40 s and 42 s. Meanwhile, the maximum compressive strength of PU/CFAI and PU/CFAII increased to 0.2186 MPa and 0.2284 MPa with the addition of CFA. The thermogravimetric analysis showed that the PU/CFA composites underwent three stages of thermal decomposition, and the amount of carbon residue increased from 23.11% to 67.91% with increasing CFA dosage. Moreover, the values of the limit oxygen index increased from 21.5% to 23.7% with the incorporation of CFA into the PU foam matrix, indicating that CFA improved the thermal stability and flame retardant performance of the composites. This study provided a new method for the recycling and high-value utilization of CG and CFA.
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Research on the treatment of sludge drying gas spray wastewater using discharge free radicals
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Jiamin Ding, Zike Qiu, Changming Du
Waste Disposal & Sustainable Energy. 2022 (4): 297-.
DOI: https://doi.org/10.1007/s42768-022-00121-3
Wastewater from the spray absorption treatment of sludge drying gas is a kind of refractory wastewater with poor biodegradability. In this study, the free radicals generated from the double dielectric barrier were innovatively used for the degradation of simulated spray wastewater. The effects of residence time, input power, initial pH, aeration rate, and discharge area on the degradation rate and COD (chemical oxygen demand) removal rate were investigated. The optimal conditions were as follows: residence time=120 min, input power=170.0 W, initial pH=5.54, aeration rate=0.9 mL/min, discharge area=10.8 cm2, and the initial concentrations of NH3, H2S, methanethiol, trimethylamine, benzene and toluene were 250, 250, 50, 50, 50 and 100 mg/L, respectively. Meanwhile, it was also found that hydroxyl radical (⋅OH)
played an important role in the degradation process.
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An approach for selection of solid waste treatment and disposal methods based on fuzzy analytical hierarchy process
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Amarjeet Kumar, Atul SharmaNekram Rawal
Waste Disposal & Sustainable Energy. 2022 (4): 311-.
DOI: https://doi.org/10.1007/s42768-022-00117-z
Solid waste management is a severe challenge in India due to massive and rapid growth in waste generation rates, environmental difficulties, and financial constraints for proper treatment. Poorly managed municipal solid waste (MSW) has substantial negative consequences for society, including financial and aesthetic harm, contamination of natural resources, environmental pollution, and severe health danger. Both qualitative and quantitative factors are required to select the appropriate solid waste treatment and disposal technologies. Multi-Criteria decision-making tools helped in analyzing solid waste in terms of qualitative and quantitative factors. In this paper, seven criteria and their sub-criteria are selected for ranking solid waste treatment and disposal technology using fuzzy-analytic hierarchy process. The results showed that composting is the most suitable option for solid waste treatment and disposal technology, followed by refuse-derived fuel. The incineration and sanitary landfills are the least preferred MSW management alternatives. The sensitivity analysis reveals a high consistency, robustness, and stability level.
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A comprehensive review of the effects of biochar on soil physicochemical properties and crop productivity
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Ammal Abukari, James Seutra Kaba, Akwasi Adutwum Abunyewa
Waste Disposal & Sustainable Energy. 2022 (4): 343-359.
DOI: https://doi.org/10.1007/s42768-022-00114-2
Intensive land use has several detrimental effects on land function and imposes an undue burden on the environment. Continuous farming and pollution by heavy metals have negatively influenced many soils. Biochar is now gaining attention as a major research subject in the areas of agriculture, environment, and energy as an eco-friendly soil conditioner. The use of biochar for agricultural and environmental purposes has been widely studied and reviewed. Unfortunately, there are few reviews on biochar structures and other biochar uses. This review presents an overview of current developments in the effects of numerous biochar physicochemical properties and biochar uses, such as utilization as a soil microbial activity, contaminant adsorbent, ion exchange, soil amendment, gas storage and water retention. The physical, chemical and biological properties have been discussed following amendments to the soil and conditions of preparation. However, scientific observation and research are required to identify the negative effects of biochar in preparations and applications. It is envisaged that further in-depth studies of biochar amendment will lead to a deeper understanding of biochar's relationships with soils and that reviews of the negative impacts of biochar could reveal ways in which they might be mitigated.
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