Leachate Trickling Filters

Process Type:

Trickling filters with and without forced aeration

Description:

Process designs using packed towers as trickling filters with forced aeration (contra-airflow) or low profile filter bed type filters with nature airflow and no active ventilation

This process type may be used as an air/ ammonia stripping system, for the removal of dissolved methane from solution, where dissolved methane removed will be a function of air volume flow.

This process has in the past been used for organic contaminant removal as well. Systems did not work reliably or consistently for all normal strength leachates from modern lined and water ingress controlled landfills.

Advantages:

The simplicity and efficiency (meaning also low cost) of allowing the leachate to trickle under the influence of gravity over the media.

Disadvantages:

Possible high rate of build-up of organic matter.

Possibility of ammoniacal nitrogen overload causing loss of organic biomass (slime) loss from media. Control and monitoring difficult within body of media.

Iron and calcium build-up and H&S concerns for operatives during cleaning works.

Where best used:

Not recommended.

Costs comments:

Low cost.

Sustainability comments:

N/A.

Energy usage comments:

Low, to operate - but benefit over lifetime of process is unlikely when energy use during regular cleaning is considered. (See also Ammoniacal-N Removal by air stripping in a "Methane Stripping Plant" here.

Chemical usage/by-product production:

None/unlikely to be any - except concern about potential for air stripped ammonia present in emissions to atmosphere.