When waste is sent to landfill, various decomposition processes take place. One of the by-products of these processes is landfill leachate with a high pollutant load.
Landfill leachate is generated by precipitated water that passes through the various layers of waste in the landfill site, becoming contaminated with a wide variety of pollutants as it does so. The leachate collects at the bottom of the landfill site, from where it is removed via a drainage system for treatment at a special wastewater plant.
A particular feature of the leachate is that it is very slow to biodegrade, so special electrochemical treatment processes have to be used. It also contains high concentrations of organic contaminants mixed with nitrates, cyanides, sulphates, phosphates, chlorides and various heavy metals.
This contaminated wastewater presents a serious environmental risk, which means that it must not be treated at a municipal sewage treatment plant or discharged into groundwater.
Landfill sites are subject to special statutory requirements regarding treatment of the leachate. Accurate analytical monitoring of the treatment stages requires precise and reliable analysis, for which Hach Lange can supply special photometric cuvette tests and electrochemical measurement systems.
Key parameters for leachate monitoring include the following:
- COD (chemical oxygen demand)
- Ammonium, nitrate and nitrite
- Filterable substances
- Toxicology test (e.g. luminous bacteria)
With its years of experience in laboratory and online analysis, HACH LANGE can offer expert advice on almost any application within the field of leachate analysis.