Planning, construction and operation of a pilot plant for leachate treatment at a former industrial landfill site

On behalf of a public client, MuP Umwelttechnik GmbH is operating a pilot plant for leachate treatment at a former industrial landfill site.

The landfill is a secured contaminated site in the aftercare phase. From 1969 to 1972, mainly production waste was deposited there - including waste from the chemical and pharmaceutical industries. DGUV Rule 101-004 (formerly BGR 128) applies to the construction work to be carried out in the contaminated area.

The pilot plant is part of a variant study on the future process engineering design of a landfill leachate treatment plant (DSRA). The aim of this pilot test is to maintain an optimal, functionally reliable and economically viable operating condition and refurbishment operation, also for the coming years.

Taking economic efficiency into account, the feasibility of cleaning the contaminated landfill leachate via an activated carbon filtration stage without an upstream biological treatment stage should be examined. For this purpose, a partial flow of the water that is fed into the existing leachate treatment plant is bypassed via an activated carbon purification stage without additional chemical and/or biological pre-treatment. Due to the high suspended solids load of the water to be purified, the activated carbon stage is preceded by two cartridge filters connected in parallel as a mechanical purification stage. Due to some of the substances contained in the contaminated water, a neutralisation stage is installed downstream of the purification process. Before being discharged into the receiving watercourse, the water routed via the existing main plant, as well as the water routed via the bypass in the bypass via the pilot plant, is recombined before the neutralisation stage and fed together to the final treatment stage.

The test operation is subject to a number of boundary conditions and specifications that had to be taken into account when planning the pilot plant. Challenges which were focussed on during planning and which also have to be monitored during operation are the strong fluctuations in the availability of the water to be purified, as well as the composition of the pollutant load of the water to be purified.

The pilot system is designed for a flow rate of up to 100 l/h, which can be adjusted depending on the amount of water available. The volume flow is regulated via the feed pump at the start of the pilot process.

The technical and economic suitability is assessed on the basis of the results of the accompanying test programme.