FR2645516A1 - Sanitary discharge and operating method - Google Patents

Abstract

Discharge characterised by the fact that its floor is composed of at least two and preferably more pools for collecting infiltration water. Operating method characterised in that the water recovered specifically for each waste product in each pool can be directed towards a special treatment or discharged.

Description

 Waste storage - takes place mainly in controlled landfills in which the waste is discharged, compacted or not by trench operations in which the compactor or the pusher works by descending the storage embankment, or by excavation, the the compactor or the waste pusher then works by mounting the waste slope, or on the surface, the compactor or the waste pusher then works horizontally in front of it.

 These landfills must guarantee the non-pollution of air and water.

 Air pollution is ensured by wells and drains ensuring the evacuation of the gases produced by the waste and their fermentation, these gases being recovered or burned at the exit of the wells by flares ensuring the combustion of these- below-standards guaranteeing the destruction of harmful gases.

 Landfills must be developed in a way that does not harm the environment, that is to say that they must not release harmful emissions.

 The water from landfills is produced by leaching, that is to say the dissolution of soluble materials by solvents and by percolation, that is to say by the penetration of meteoric water, rain and snow.

 This seepage water from landfills can cause problems for the environment, by polluting groundwater. To avoid this pollution, it is required that the landfills be sealed by the placement of clay, concrete, plastic sheets, etc.

However, these measures by their nature require perfect detection, disposal and appropriate treatment. The cost of these measures can represent for certain waste 95 Z operating costs of the landfill, the most important cost being the quantity of infiltration water to be treated.

 To reduce these costs, efforts are made to reduce the amount of this water as much as possible. This is achieved by as much compaction as possible and by covering the landfill after backfilling. But during operation, the landfill remains in the open air and rainwater falls on it and the seepage water must be treated and evacuated entirely.

 To further reduce the high costs generated by the treatment of infiltration water, landfills known as lockers or cells are installed which allow the landfill to be broken down into units reduced to the maximum.

The waste is then sealed around its perimeter, but water can pass through it.

 The present invention aims to improve cell landfills in order to reduce the costs necessary for the construction thereof and to increase the volume used of the entire landfill.

 The invention presented here is based on the idea that it is no longer necessary to carry out the entire discharge in the form of a cell discharge, that is to say to isolate the different discharge units from each other over all their height.

 The landfill of the present invention is characterized by the fact that its soil is composed of at least two and preferably several catchment basins for infiltration water, drainable independently of one another, separated by dykes, partition walls, intermediate sheets or other equivalent installations, the height of these installations preferably corresponding to a quarter of the depth or total height of the landfill maximum and in particular to a height of 25 cm.

According to the invention, the sealed floor of the landfill therefore consists of several collecting basins for infiltration water arranged in the form of a grid.

 Each of the collecting basins has its own installation for discharging infiltration water either using the natural slope or using pumps. In this way, contaminated and polluted water can be discharged separately from clean rainwater. Any leaks in the insulation of the landfill only affect a limited perimeter corresponding to the surface of the collecting basin concerned. The landfill can be sealed on the surface as it is filled, only a small part of the total surface has contaminated seepage water.

 The landfill of the present invention which can be used for household waste, hazardous or other, therefore has all the advantages of a cell landfill while offering compared to the latter other advantages, the partition walls are not not elevating over the total depth or height of the landfill; lower costs both in terms of the equipment required and the time required to construct the landfill; better use of the volume of the entire landfill, since waste can occupy practically the entire volume of the latter.

 The invention also relates to the method of operating the landfill presented here. The method consists in placing different wastes in the different collecting basins of the infiltration waters of the landfill according to their composition and in directing the infiltration waters having contents of various harmful products such as salts, acids, detergents, products harmful to the health, toxic, dangerous for water or radioactive to a special treatment or to dispose of them.

 In this way it is possible to considerably reduce the costs caused by the treatment of seepage water.

 The invention is clarified by the figures in the drawing plate 1/1.

Figs. 1 and 2 show schematically and in longitudinal section two versions of the discharge of the invention, and FIG. 3 show a plan view of the discharge of FIG. 2.

 As can be seen in the drawing, the ground (5) of the landfill (1) is made up of numerous basins or cavities (2) for collecting seepage water. In the exemplary embodiments presented, the walls (3), - (4) and the ground (5) of the landfill (1) are covered with impermeable sheets. The sheets covering each collecting cavity (2) are welded by covering; the overlapping edges are raised to form the walls 6 between the different cavities (2). A layer of gravel (7) is placed on the sheets covering the base (5) of the discharge (1).

This layer of gravel has several destinations. It protects the sheet from tears caused by the waste (8) placed in the landfill (1).

It also maintains in their position the raised edges of the cover sheet, which can thus act as partition walls.

In the model of fig. 1, the collecting cavities (2), during filling with waste (8), are provided with wells (9) composed of casing rings, closed at their base by the layer of gravel (7). The infiltration water can be evacuated by these wells using submersible pumps and directed by the pipes (10) to the treatment station.

The part of the dump (1) already filled with waste (8) is covered by a cover sheet (11), so that no rainwater can penetrate into this area of the landfill, in order to prevent the formation of seepage water. On the model presented in fig. 1, the ground t5) of the landfill (1) is sloping, so that the rainwater which collects in the collecting cavities (2) containing no waste must not be discharged from each cavity, but flows towards the end of the discharge and can be evacuated by a common intake pipe (12). This form of landfill should start to pile up the waste at the end of the landfill opposite the intake line (12). In fig. 2, the evacuation of the infiltration water is carried out by conduits (13) starting from the ground (5) of each collecting basin.

 Three zones (14), (15) and (16) can be distinguished for each discharge in service. In zone 14, the discharge (1) is already filled and covered with a sheet (11). There is no more seepage water in this area.

In zone 15, the landfill is partially filled with waste (8).

 There is an appearance in this zone of polluted infiltration water which is evacuated by pipes 10 or 13. In zone 16, there is clean rainwater, which can be evacuated either by intake pipe 12 or by the pipes 13.

Claims (2)

Claims 1. Landfill, characterized in that its soil (5) consists of  at least two, and preferably several water catchment basins  infiltration (2), drainable independently of each other,  separated by dikes, dividing walls, sheets  corresponding intermediaries or other equivalent installations (6)  preferably a quarter of the total depth or height of the  discharge (1) at most, and in particular at a height of 25 cm. 2. Method for operating a landfill according to  claim 1, characterized in that the waste is  deposited in the various water catchment basins  infiltration (2) of the landfill (1) according to their composition and  that infiltration waters with different contents  harmful substances such as salts, acids, detergents, products  harmful to health, toxic, dangerous for water or  radioactive are directed to special treatment or disposed of.