- Landfill leachate treatment is a challenge due to the high and variable concentrations of dissolved solids, organics, heavy metals and xenobiotic organics.
- To permit evaluators and landfill designers with a tool to rapidly evaluate and compare the performance of alternatives landfills designs.
- The primary criterion for design of the Leachate Treatment Plant Manufacturer is that all leachate be collected and removed from the landfill at a rate sufficient to prevent an unacceptable hydraulic head occurring at any point over the lining system.
A range of technologies are available for the treatment of landfill leachate, proven in many diverse cases. The following section introduces selected technologies that have predominantly been employed for landfill leachate treatment. The highlighted technologies are deployed both as stand-alone solutions and as part of a process combination. The composition of the landfill leachate plays a decisive role in selecting the appropriate technology.
Technology
Biological treatment has proven itself in many cases as a first step in treatment, and is also useful for nitrogen removal. MBBR, TFR, activated sludge processes, anammox and loop reactors are deployed. A downstream ultra filtration step is used in a great deal of cases to deal with sludge arising from biological processes. If persistent biological compounds remain in the wastewater, activated carbon filters or ozonisation are employed to remove the biorefractory contaminants.
The discharge values obtainable using reverse osmosis is beyond what may be achieved with any other procedure. The applicability of reverse osmosis is limited by osmotic pressure, and thus ultimately by the salt content of the landfill leachate. A high salt content results in very high trans membrane pressures, and thus requires very large amounts of electrical energy. The presence of inorganic impurities with encrusting tendencies also limits the applicability of reverse osmosis. Despite use of anti-scaling reagents, this often still leads to films accumulating on the membranes, which then require chemical removal or may even destroy the membranes.
The concentrate resulting from reverse osmosis must be conveyed for separate treatment or disposal, which may include the procedures described below. A growing problem is that although the problematic compounds have been removed from the water, they are eventually disposed of as waste anyway.
Wet oxidation processes, such as ozonisation, are used if it is possible to oxidize organic contaminants either completely or to convert biorefractory contaminants into biodegradable contaminants. Activated carbon adsorption is used for cases in which organic pollutants in the leachate cannot be degraded either biologically or using wet oxidation processes. The contaminants are first bound to the carbon through adsorption and then destroyed by incineration. Precipitation/flocculation and ion exchange processes are less widespread in the field of landfill leachate treatment. Both technologies are used to reduce inorganic ionogenic contaminants.
Current Leachate Treatment Plant for the treatment of leachate mainly consists of several treatment methods to meet the limiting concentrations for the effluent.
- Biological treatment.
- Flocculation/Precipitation and Neutralization.
- Adsorption (Active carbon).
- Oxidation (Ozone + UV).
- Reverse osmosis if necessary.
- Drying.
- Evaporation.
Methodology
- Optimum waste utilization
- Economical to use.
- Easy to install and low cost.
- High speed processing.
- Easy to install and maintain.
Leachate recirculation or bioreactor landfill are increased decomposition rate, lower Leachate Treatment/disposal costs, and shortened post-closure maintenance period
- Energy consumption
- Product recovery
- Cost effective.
- Compact Design
- Easy operation
The Leachate Treatment Plant Manufacturer requirements for leachate from landfills can vary, depending on the discharge requirements, and the contaminants present. By high TDS, high ammonia, high BOD and/or COD, heavy metals, and color Leachate from sanitary landfills is generally characterized. Discharge options include discharge to where no access to sewer is available, or publicly owned treatment works or discharge to ground or surface water. In the case of the latter, the requirements of Leachate Treatment Plant are much greater than when discharge to a POTW is available.
Due to the high and variable concentrations of dissolved solids, heavy metals, dissolved and colloidal organics and xenobiotic organics, Landfill Leachate Treatment is a major engineering challenge. Many different methods were in use to treat the landfill leachate. Most of these methods are adapted for wastewater treatment processing and have not yielded satisfactory results for Leachate Treatment Plant . Due to its varying characteristics and with high conductivity, leachate is hard to treat by Leachate Treatment Plant with biological treatment or chemical treatment.
Good Leachate Treatment Plant is essential for any leachate management system which features on site Leachate Treatment is to be successful, and the Leachate Treatment Plant itself cannot work successfully unless the Leachate Treatment Plant is capable of delivering the leachate to it reliably in the flows needed to prevent the build-up of leachate within the landfill cells.
The ability of the Leachate Treatment Plant to deal with variations in the flow and strength of the leachate is the first requirement to be considered when embarking on a Leachate Treatment Plant design. This means that a high level of integration is needed between the Leachate Treatment Plant design and the Leachate Treatment Plant Manufacturer.