We want to emphasize that, if possible, construction material, with putrescible landfills, and therefore, able to produce landfill gas should be avoided.
Some old landfills are exempt from landfill gas, but do not try a lot of attention to expert advice before thinking that a particular landfill is truly free from landfill gas and
so there is no danger. We found that the landfill has continued significantQuantity of landfill gas for many years and many sites continue to produce gas for more than thirty years before closing.
However, land is so scarce in many countries, and there are strong arguments to show that even in regions where land is still plentiful, we should use it again if the country is not possible. building has disposed of place on some sites to provide landfill gas, and no doubt you want to look ahead.
The experience gained with regard to adequate protectionMeasures, and it is obvious that the two main issues, namely reducing and methane, odor, to overcome.
The solutions are easier when the landfill is not a deep 3-4 m thick, where the excavation of the waste on site, for example, structures can be followed by an exchange of inert filler is the most secure
explosion of landfill gas entering the property and is financially sustainable. An interceptor trench is often necessary to prevent the migration of gases and waste residuestoo lazy to fill.
If it is not practical to remove the waste, then the buildings are generally based on slabs, which in turn built on piles driven into the ground support equipment firm under the base of the landfill. The use of this type makes the difficulties of reducing .
It remains to prevent the problem of landfill gas is now below the floor of the building. The simplest method is to construct an air gap below the ceiling, the vacuum is then naturally or artificially ventilated.
This technique has been the construction of many warehouses, supermarkets and sports facilities. The common practice was to provide an air space of 300mm to 500mm in depth, but some have even 1-1.5 m high, in order to facilitate the dissipation of gas for natural convection in large area, is established. Obviously, the use of natural air currents, the gas in ambient air is inherently safer to rely on electrically> Fan Driven, which can fail for various reasons.
For the soil under the pot with waterproof membrane or plastic can help to minimize odors, emissions of gas. Another approach is to use the stack again, but put the dish on a layer of porous rock on the surface of the landfill. Horizontal perforated pipes are placed in porous material and is continuously pumped through an intake pressure, so that it will take 1-2 air changes per hour under the covers, in someDrawings. However, the flow of air is necessary to be very different and must be determined by experts in the knowledge that the fall in rates of penetration of the site under the periods of maximum gas production (usually in the higher atmospheric pressure). This system was used successfully in many properties, but require a forced ventilation system shall be maintained for many years, and the owners and future buyers, the cost of committingthis.
These systems are often supported by the installation of a plastic membrane under the plate. Attempts concrete impermeable to gas diffusion through the sealant do with little success.
Surprisingly large amounts of gas to penetrate small cracks in the cement. It was also suggested that the gas may be problems simply by spreading a thick (at least 1 mm, and surpass, as a rule HDPE) plastic membrane on the surface and continuously building on them,suitable protection above and below the diaphragm to prevent the intrusion. This technique has been successfully carried out at least a motorway service in London.
But if the structure is related to waste, we will establish over time, and requires the stacking order to overcome the subsidence, then one must remain intact, with a good seal between the membrane and the stack after the settlement was faces. The tests are often necessary in order to avoid trapping of gas pockets betweenTraverse under the plate, slide, especially when the ground water may increase the gas pressure at the top is always possible.
It 'also important that, if services such as electricity, gas, water, sewerage, telecommunications, etc. related to penetrate the plate (or series), which are sealed in a satisfactory and truly sustainable.
As a final precaution is suggested that the rooms are equipped endangered buildings on the landfill with acoustic detection of gas, or that the controlMethane is done regularly
both during construction and after the building is occupied.
The gas can be transported easily ventilated through the air, but if significant flows of gas are involved, should be flared to overcome both problems, the smell, and to comply with the requirements of environmental authorities. In most developed countries, regulatory authorities will require combustion to reduce emissions of greenhouse gases.
All these precautions may be strict, but amust never forget that in a gas explosion when they occur, an event is extremely dangerous and the risk of serious injury is very high. For
For this reason, both active and passive landfill gas migration prevention of risks are usually used in tandem in these buildings.
All designs must be of good quality scientific data and detailed risk assessments based only prepared by recognized experts in this work.
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