Generally leachate has a high biochemical oxygen demand (BOD) and high concentrations of organic carbon, nitrogen, chloride, iron, manganese, and phenols. Many other chemicals may be present, including pesticides, solvents, and heavy metals. The direction of groundwater flow.
What landfill contains?
Landfill sites contain both household and commercial rubbish. Household waste that gets sent to landfill consists of mostly organic waste, for example food, paper, cardboard or wood. Other household rubbish contains plastic or tin packaging. A lot of our individual rubbish is known as Municipal Solid Waste (MSW).
What are the major components of landfills?
WHAT IS THE COMPOSITION OF A LANDFILL? There are four critical elements in a secure landfill: a bottom liner, a leachate collection system, a cover, and the natural hydrogeologic setting. The natural setting can be selected to minimize the possibility of wastes escaping to groundwater beneath a landfill.
What is meant by leachate?
Leachate is defined as any contaminated liquid that is generated from water percolating through a solid waste disposal site, accumulating contaminants, and moving into subsurface areas. … The composition and concentrations of leachate may also shift with the age of deposited materials.
How is a landfill made?
Each day, trash is compacted a cell in order to make the most of the space available in the landfill. … Here, trash is organized in layers or lifts then compacted accordingly. Heavy machinery like bulldozers and compaction equipment are used to compress the trash and place it in the landfill.
How is leachate collected from landfills?
To collect leachate, perforated pipes run throughout the landfill (Figure 3). These pipes then drain into a leachate pipe, which carries leachate to a leachate collection pond. Leachate can be pumped to the collection pond or flow to it by gravity, as it does in the North Wake County Landfill.
What material should a landfill be built on?
What are the required elements of an EPA-regulated landfill liner? (Answer: A geotextile layer that only allows water through, a permeable sand layer, a leachate collection system, a plastic liner and a layer of impermeable clay material.)
What is leachate collection?
A leachate collection system basically consists of a drainage layer of inert material with high permeability, of drainage pipes which have to collect the leachate and to discharge it out of the dumping area, of collection and inspection shafts, and of collection pipes.
Where does leachate go in a landfill?
Leachate Disposal from Landfills
Leachate pipes collect the waste liquid that has seeped through to the base of the landfill. These pipes then transport the contaminated liquid into special containers, which are then collected by a hazardous waste transportation company for proper disposal.
What type of pollutants might be in a leachate created at a landfill?
of concentrated specific chemical waste, landfill leachate may be characterized as a water-based solution of four groups of pollutants (dissolved organic matter, inorganic macro components, heavy metals, and xenobiotic organic compounds [Christensen et al., 1994]).
How is landfill leachate treated?
Leachate can be treated by biological processes, such as activated sludge. Physicochemical processes are used to remove metals, ammonia, and dissolved solids, among other parameters. Membrane separation is an effective method for clarifying mixed liquor produced during biological treatment.