Effect of plastic fragments on hydraulic characteristics of pretreated municipal solid waste

2006 ◽  
Vol 43 (12) ◽  
pp. 1333-1343 ◽  
Author(s):  
Mingliang Xie ◽  
Dirk Aldenkortt ◽  
Jean-Frank Wagner ◽  
Gerhard Rettenberger

A systematic study was undertaken of the granular composition and hydraulic properties of municipal solid waste (MSW) produced by mechanical–biological pretreatment (MBP–MSW) from three different treatment plants with the aim of evaluating the potential application of MBP–MSW as an alternative barrier material for landfill final cover systems. Despite its coarse granular composition, MBP–MSW has low hydraulic conductivity. Long-term permeability tests show that the hydraulic conductivity decreases with time. The most likely explanation for the long-term changes in permeability is the swelling of organic material contained within the compost. In the case of saturated flow, the virtually impermeable plastic fragments embedded in the material impede fluid flow. In the unsaturated case, such fragments slow down the drying process by disrupting fluid flow and allowing pooling of water above horizontally oriented fragments. The larger the number and size of the plastic fragments, the greater the influence on hydraulic conductivity and shrinkage. These processes can be better understood with the newly developed conceptual model, the thin-sheet model. Based on this conceptual model, laboratory tests were undertaken to compare natural soil material with mixtures of soil material and plastic fragments. Corresponding numerical simulations of some experiments verified the influence of plastic fragments on the hydraulic properties of MBP–MSW.Key words: mechanical–biological pretreatment, municipal solid waste (MSW), thin-sheet model, plastic fragment, hydraulic conductivity, drying test.

2004 ◽  
Vol 39 (3) ◽  
pp. 223-229 ◽  
Author(s):  
Mostafa A. Warith ◽  
Graham J. Takata

Abstract Municipal solid waste (MSW) is slow to stabilize under conventional anaerobic landfill conditions, demanding long-term monitoring and pollution control. Provision of aerobic conditions offers several advantages including accelerated leachate stabilization, increased landfill airspace recovery and a reduction in greenhouse gas emissions. Air injection was applied over 130 days to bench-scale bioreactors containing fresh and aged MSW representative of newly constructed and pre-existing landfill conditions. In the fresh MSW simulation bioreactors, aeration reduced the average time to stabilization of leachate pH by 46 days, TSS by 42 days, TDS by 84 days, BOD5 by 46 days and COD by 32 days. In addition, final leachate concentrations were consistently lower in aerated test cells. There was no indication of a gradual decrease in the concentration of ammonia, and it is likely this high ammonia concentration would continue to be problematic in bioreactor landfill applications. This study focussed only on biodegradability of organics in the solid waste. The concentrations of the nonreactive or conservative substances such as chloride and/or heavy metals remain in the bioreactor landfills due to the continuous recirculation of leachate. The results of this study demonstrate the potential for air injection to accelerate stabilization of municipal solid waste, with greatest influence on fresh waste with a high biodegradable organic fraction.


2019 ◽  
pp. 1-8
Author(s):  
Yingfeng Wang ◽  
Zhenying Zhang ◽  
Hui Xu ◽  
Dazhi Wu ◽  
Xinyu He ◽  
...  

2014 ◽  
Vol 38 (4) ◽  
pp. 1281-1292 ◽  
Author(s):  
Luis Alberto Lozano ◽  
Carlos Germán Soracco ◽  
Vicente S. Buda ◽  
Guillermo O. Sarli ◽  
Roberto Raúl Filgueira

The area under the no-tillage system (NT) has been increasing over the last few years. Some authors indicate that stabilization of soil physical properties is reached after some years under NT while other authors debate this. The objective of this study was to determine the effect of the last crop in the rotation sequence (1st year: maize, 2nd year: soybean, 3rd year: wheat/soybean) on soil pore configuration and hydraulic properties in two different soils (site 1: loam, site 2: sandy loam) from the Argentinean Pampas region under long-term NT treatments in order to determine if stabilization of soil physical properties is reached apart from a specific time in the crop sequence. In addition, we compared two procedures for evaluating water-conducting macroporosities, and evaluated the efficiency of the pedotransfer function ROSETTA in estimating the parameters of the van Genuchten-Mualem (VGM) model in these soils. Soil pore configuration and hydraulic properties were not stable and changed according to the crop sequence and the last crop grown in both sites. For both sites, saturated hydraulic conductivity, K0, water-conducting macroporosity, εma, and flow-weighted mean pore radius, R0ma, increased from the 1st to the 2nd year of the crop sequence, and this was attributed to the creation of water-conducting macropores by the maize roots. The VGM model adequately described the water retention curve (WRC) for these soils, but not the hydraulic conductivity (K) vs tension (h) curve. The ROSETTA function failed in the estimation of these parameters. In summary, mean values of K0 ranged from 0.74 to 3.88 cm h-1. In studies on NT effects on soil physical properties, the crop effect must be considered.


2021 ◽  
Author(s):  
Graham Jon Takata

Under the anaerobic conditions of conventional sanitary landfill, entombed municipal solid waste (MSW) is slow to stabilize necessitating long-term monitoring and pollution control. Although anaerobic conditions can provide revenue through energy generation, aerobic stabilization may offer several advantages including reduced fugitive greenhouse gas emissions, accelerated landfill stabilization, and increased landfill airspace recovery. Air injection was applied to bench-scale bioreactor landfills in order to determine the potential for active aeration to accelerate municipal solid waste stabilization and settlement in both new and pre-existing landfills. Fresh and aged wastes were used to represent newly constructed and existing landfill matrices over 130 days. In the fresh MSW bioreactors, aeration reduced the time to stabilization of leachate pH by 44%, TSS by 25%, TDS by 54%, BOD5 by 38% and COD by 59%. Ammonia concentrations stabilized after 129 days of aeration, but remained problematic in the anaerobic bioreactors at the study conclusion. Final leachate concentrations were consistently lower in the aerobic bioreactors than in their anaerobic counterparts. Physical settlement also improved, resulting in a 21.5% recovery of landfill airspace in the aerobic fresh waste bioreactors. Aeration had a similar but reduced influence in the aged waste bioreactors since they were near stabilization at the study inception. The results of this study indicate that aeration significantly accelerates stabilization of MSW with greatest influence on fresh waste with a high biodegradable organic fraction.


2019 ◽  
Vol 116 ◽  
pp. 00070 ◽  
Author(s):  
Elena V. Savenkova ◽  
Marderos Ara Sayegh ◽  
Alexandr Y. Bystryakov ◽  
Tatiana K. Blokhina ◽  
Oksana A. Karpenko

Municipal solid waste (MSW) collection and disposal is one of the major problems of urban environment in most countries worldwide today. The problem of utilization of solid waste in the Northern Europe on the Kola Peninsula was raised in this article, where the ground arrangement in a subarctic zone is very special and the weather conditions are severe. The paper main goal is to verify long-term impact of the Mezhdurechie municipal landfill on the atmosphere in Kola Peninsula. The paper also aims to establish the holding actions for recycling and utilization of worn-out tires for mentioned municipal landfill. The ground concentrations of pollutants from the operational sources were presented. The proposed recycling development in this paper has a positive impact on the ecoindustry and ensures environmental safety and municipal economy.


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