Landfill leachate

One problem created by the depositing the solid waste is the formation of landfill leachate leaving the deposit and causing potential water pollution.


Generally, the landfill leachate is the precipitation water which percolates through landfill deposited waste and drains or ‘leaches’ from a landfill. It varies widely in composition regarding the age of the landfill and the type of waste that it contains. Usually landfill leachate contains both dissolved and suspended material.


The problem has been identified in all industrialised countries. Most commonly the landfill leachate problem linked to landfills containing organic wastes. The EU has implemented a prohibition to deposit organic matter. However, a sanitary landfill will produce leachate long time after its closure, and the leachate will contain considerable concentrations of polluting agents. So, even if a landfill is abandoned the responsibility to handle the leachate will remain for a very long time. One more aspect is that the landfill technology will be dominant for many countries around the world, independent of any EU directives.


Old landfills and landfills still operated in a rather unsophisticated way – the management and operation of such landfills rare includes adequate protection measures. In Europe most of such old-fashion operated landfills still exists and operates in the eastern part (post-soviet countries). As a result, large open deposit areas where the waste was disposed. This in turn means that many “old-fashion-operated” landfills are exposed to comparatively large amounts of rainwater, which percolates through landfill body and leach contanimnants. Depending on the shape of the landfill body part of falling rainwater can also shed from the surface forming surface runoff.

Thus, all the rainwater falling to the landfill footprint can be divided to the two flows: percolating and surface run off. Surface run off water is much lower contaminated neither percolating. There is the first key to the landfill leachate reduction: to move the water distribution balance in a way that reduces percolation and, on other hand, increases surface run-off. That can be achieved using impermeable and semi impermeable waste covers and landfill workface area reduction the active tipping area should be minimised to ensure that only the smallest possible area of waste is open and not sealed (either permanently or temporarily).


Since some rainwater flows through landfill body and leach contaminants in the end of leachate formation process it can be considered as a super contaminated water. The environmental risk from waste leachate is caused by its high organic contaminant concentrations and high concentration of ammonia. Toxic substances may, however, be present in variable concentrations, and their presence is related to the nature of the waste deposited. The level of landfill leachate contamination often is much higher than permitted to drain to municipal sewage, and landfill leachate discharge to the WWTP can cause a number of problems. Toxic metals from leachate passing through the sewage treatment plant concentrate in the sewage sludge, making it difficult or dangerous to dispose of the sludge. The WWTP operators reports that landfill leachate is difficult waste stream to treat. Reason is that leachate contains very high ammoniacal nitrogen concentrations, are usually too acidic, are often anoxic and, if received in significant volumes comparing to the incoming sewage water flow, results the phosphorus deficit in balance. Phosphorus is needed to prevent nutrient starvation for the biological communities performing the biological wastewater treatment processes. The result is that leachates are a difficult-to-treat waste stream. Most WWTP undertakers ammoniacal nitrogen concentration threshold in their sewers to 250 mg/l to protect maintenance personnel, and limits pH at 9 to 10, which is often the highest pH allowed in sewer discharges.


However only smaller part of the landfills is technically feasible to discharge leachate to the public sewage and to the municipal WWTP.  Most of the landfills have to find their own landfill leachate management solution.Most common leachate handling solutions are:

  • leachate storage in the ponds and surface evaporation;

  • leachate reinjection to the landfill body – leachate recirculation;

  • leachate on-site treatment;

  • leachate hauling to WWTP or discharge to the sewer (and then to WWTP). 


All of this leachate handling solutions have well-known disadvantages. Rather often landfill leachate biological treatment can’t be even proceeded due to the circumstances mentioned above. Due to this the landfill leachate treatment often processed by reverse osmosis or other membrane type treatment plants.Besides of treatment cost at the level of 5-10 EUR per m3 of treated leachate RO and other relative technologies have liquid reject average 30% of input wastewater. This reject or concentrate often considered as dangerous liquid waste with high disposal cost.

Leachate evaporation

Typical landfill leachate consists of H2O by 96-98%. In other words, removing water from the leachate can drastically reduce leachate volume. The apparent way of water removal from the leachate is leachate evaporation. The evaporation is a physical phenomenon of the phase transition from liquid to gas at the temperatures below boiling at certain pressure. Phenomenon of evaporation plays essential role in “water cycle” of the Earth. To reduce stored leachate volumes only we need is to enforce evaporation phase of natural water cycle action. We are not able to do it globally but it’s feasible for some certain volume of liquid. From science known that phase transition from liquid to gas (steam) requires energy – so-called latent heat of vaporization. 


During last decades different type leachate and wastewater evaporators were developed all around the world. Most of them utilizes the principle of water boiling – either at atmospheric pressure either in underpressurized vessels. All such type systems have relatively high energy consumption level due to heating up of the entire liquid volume to the boiling point. All such type systems have relatively high energy consumption level due to heating up of the entire liquid volume to the boiling point.These systems require external energy source like electricity or some fuel to burn. Heating up and vaporization of the liquid needs a big amounts of heat in it cause relatively high operation cost of boiler-type evaporators.


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Автоматически созданное описание

Typical landfill leachate consists of H2O. In the same time nature provides everlasting and absolutely free of charge energy source – Sun. 

Sun heats the atmosphere and atmospheric heat can be used for the leachate evaporation. How to capture this heat from the atmosphere and ensure sufficient heat flow from the air to liquid? The way is to increase heat exchange surface. Surface can be increased if liquid is atomized to the fine droplets having much bigger summary surface neither liquid surface in some vessel or pond. Below you can find heat exchange surface of 1 liter of atomized liquid depending on droplet size:

Droplet diameter, μm

Droplets quantity i

n 1 liter of liquid

Droplets summary 

surface, m2 per 1 liter


238 732 411 111



70 735 529 218



29 841 551 389



15 278 874 311



8 841 941 152



5 568 102 883



3 730 193 924



2 619 834 415



1 909 859 289



1 105 242 644



565 884 234



327 479 302



238 732 411



156 970 436


1 liter of liquid on flat horisontal surface 1mm thick layer:


So, atomizing of liquid increases heat exchange surface up to 300 times. Respectively increases summary heat flow per certain liquid volume and enhances evaporation. Thereby fine and uniform leachate or wastewater atomization in the air forces the evaporation comparing to natural evaporation from the pond surface.


Rotary atomizers ensure uniform droplet size and controllable droplet size atomization. Droplet size can be easily changed by to atomizer rotation speed adjustment.


Rotary atomizers used in leachate and wastewater evaporation systems developed by the New Waste Concepts Inc. (USA) and used in the wide spectrum of wastewater applications.

Systems are scalable, fully automated and requires low maintenance

Evaporation systems can be installed on the ground and on the floating platforms in the ponds.

Thanks to free of charge energy used for the evaporation system have very low operational costs per 1 m3 of disposed leachate.

Typhoon-and-rotary sketch

Of course, evaporation system capacity depends on weather conditions – temperature, relative humidity and wind as air exchange factor. Higher air temperature, lower air humidity, stronger wind – more can be evaporated. Surprisingly, but system is also quite effective in relatively cold and humid climate. Annual system productivity per 1 head:

  • Baltic region (Latvia, Riga) – 1400 m3/season per 1 head;

  • East Europe (Russia, Moscow region) – 1600 m3/season per 1 head;

  • East Europe (Ukraine, Kiev) – 2700 m3/season per 1 head;

  • Caucasus region (Georgia, Tbilisi) – 3600 m3/season per 1 head


For each destination annual evaporation can be estimated using our modelling based on historical climate.

Also we can configure system to your leachate or wastewater volumes, terrain, estimate capital and operation cost for your site.


Some evaporation systems installations are displayed below:

To get more information regarding leachate evaporation systems please contact us: