Sludge Lagoon Bitterfeld-Süd
MDSE mbh, Bitterfeld-Wolfen
C&E Consulting und Engineering
Heilit Umwelttechnik GmbH, Chemnitz
March 2012 till September 2013
The clarification ponds Süd in Bitterfeld-Wolfen are located in the Bitterfeld industrial park. Two of the three existing basins were to be covered with geosynthetics and soil material as part of a renaturation measure. The basins have a depth of up to 6 m and the contents range from sewage sludge to chemical waste and scrap. The aim of the measure was to prevent contaminated water and air from entering the environment and to prevent direct contact between living organisms and the ponds.
A special aspect of covering sludge lagoons is that work can be carried out safely during every phase including installation. It is also important to ensure that the sludge pond is successfully covered, that there are no sludge leaks and that safe reuse can finally take place. Based on experiences with other projects, the idea of covering these ponds with a large panel instead of single liners was soon adopted. A special hemstitch was prefabricated at the factory on one single liner, which enabled the floating adjacent panel to be attached to the cable winches. The rectangular shape of the basins was suitable for this type of installation, as the panel could be sewn along the longer side and then pulled over the shorter side. The particular challenge of this project was the size of the area to be covered. The panels to be produced on site had lengths of 200 m and 220 m respectively with a width of 80 m each. The areas of approx. 16,000 m2 and 18,000 m2 to be covered were enclosed for the first time with a panel. Due to the large size of the single liners, it proved to be beneficial to carry out the seam work on site.
The advantage of this solution - using one large 18,000 m² panel - lies in the very short time required for the actual installation of the geotextile to the sludge lagoon; approximate time taken was 20 minutes. Avoiding the installation of a single liner in both the longitudinal and transverse directions eliminates the possibility of the sludge from being squeezed out and ensures necessary overlaps. The on-site sewing of panels of this size takes about 2 days. Only on the day of installation is there a requirement for larger machine operations and the need for operating personnel for the necessary winches.