Landfill evolution

Regarding leachate analysis, UV spectrophotometry can be useful for a fast characterisation or the study of landfill evolution. Depending on the nature of organic components, aqueous solutions can limit the interest of the approach. In this case, an extraction step of the solid matrix with an organic solution can be necessary in order to have more specific information. 

Hypalon raw polymer compounds or cured product may be disposed of in an approved landfill. Incineration is not recommended because of the evolution of toxic gases. Additional information is available from Du Pont concerning these and other potential health hazards when handling Hypalon compounds, finished products, thermal decomposition products, or waste disposal (43). 

The behaviour of poly(vinyl chloride) products in landfill sites longterm and their leachate products and gas evolution have been monitored. Over the period of the study no degradation of the poly(vinyl chloride) was observed. The leachate analysis determined that there was no significant contribution to the level of heavy metals in landfills, and that the presence of phthalates and organotin compounds presented no risk to the aquatic environment. 14 refs. 

The composition of pore waters from contaminated cores 1 and 2 were used to initialize the model (Table 2). Concentrations represent leachate collected from the initial half pore volume of each core. Eluent specified in the transport simulations had the composition of uncontaminated ground water in Table 2. Reactions proposed to describe concentration changes for selected constituents within the cores are based on comparisons between eluent and leachate chemistry and analysis of selected constituents in the core samples. Equilibrium constants and kinetic rates for the reactions were adjusted to give the best fit to leachate concentrations from core 1. The same reactions, equilibrium constants, and kinetic rates were then tested by modeling the concentrations of constituents in leachate from core 2. This geochemical model will be used in the future to simulate evolution of contaminated ground water associated with the Area 4 landfill at the aquifer scale. 

UV spectrophotometry also provides information about the evolution of leachates during classical treatments. Some treatment trials have been made on the previous landfill... 

Hunter et al. (1998) used a kinetic model to simulate reactive transport and ground-water evolution upon the intrusion of landfill leachate into an oxic aquifer. Most interestingly, they found that the patterns of redox fronts are similar to what have been seen in marine sediments. Hunter et al. (1998) first developed a one-dimensional multi-component reactive transport model biorxntrn and then conducted a numerical experiment using this code. The actual model is quite complex we describe here the essentials of it so that we can see what can be done. 

Fig. 9.4 Chemical evolution of municipal solid waste landfills ( reactor landfill)...

The impact of waste on the environment is not negligible, but it does not, by a long way, hold the first place. The share of plastics in waste is about 11%. The part of plastics in oil consumption is 4%. Waste treatments are not the same from a thermodynamic point of view. Waste prevention is a satisfactory concept but has limited application. Plastics are especially landfilled in mixture with other garbage or incinerated. They are not well recycled (7%) despite a rapid and positive evolution in the rate of recycling in the years 1997-2007. Recycling therefore remains an important activity to provide in the coming years. 

Monitor evolution of gases from the site after it has been covered. Provision of gas collection and treatment facility shall be made from final top cover of the landfill site. 

LLDPE+starch ( 6%) Molecular weight Elongation at break, and CO2 evolution Soil culture, landfill soil culture, and activated sludge [46]... 

Fig. 10.7. Long-term chemical evolution of municipal solid waste incineration slags on mono-landfills (Baccini et al. 1993)...

Between the above extremes are polymers which are required to biodegrade in a controlled aerobic compost. This is quite a different environment from sanitary landfill. Until quite recently, a major concern of environmentalists, particularly in the USA, was that plastics, unlike paper, did not biodegrade in landfill [9]. This has since been shown to be a misapprehension since neither paper nor biodegradable plastics will biodegrade in a properly prepared landfill. Furthermore, it is now considered important that waste products should not biodegrade in anaerobic landfill due to the subsidence that subsequently occurs with methane evolution and associated explosion hazard. 

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