Germany - Sludge disposal

Description

Thermal treatment of approx. 100 000 t of sewage sludge from old sludge sites of the former Kleine Emscher sewage treatment plant in Duisburg, Nordstraße 48 including pre-treatment of the old sludge and disposal of the residual materials/ashes.
The subject of this invitation to tender is the thermal treatment of these approx. 100,000 t of old sewage sludge including treatment/pre-treatment/pre-screening as well as the recycling/disposal of the residual materials.The Emschergenossenschaft operated a sewage treatment plant at Nordstraße in Duisburg until 1999. The sewage treatment plant included sludge yards which were used for storage and drying of the sewage sludge. According to an order with a deadline, the sewage sludge from four sludge sites (SP 2 to SP 5) is to be excavated and fed into a thermal treatment process. In a limited period of max. 8 months, about 63 000 m3 (approx. 100 000 t) of sewage sludge will accumulate in 2022 (February to September), which demonstrably has to be thermally treated in this period. This is sewage sludge from a municipal wastewater treatment plant, which is to be treated under waste code number 190805. Investigations showed that pollutant contents may occur which exhibit hazardous characteristics. These characteristics have to be considered with regard to storage, (intermediate) transports and acceptance conditions. Therefore, thermal treatment plants are to be provided, which are allowed to thermally treat not only municipal but also industrial sewage sludges classified as "hazardous".The consistency of these sludges ranges from compact to pasty/porous to wet.Due to impurities, a preliminary treatment of the sludges is necessary.63,000 m3 (approx. 100,000 t) of sewage sludge are produced for thermal treatment.The sewage sludges have been stored in the sludge pits for more than 40 years in a thickness of between 1.0 m and max. 3.5 m. The sludge is stored in one of the sludge pits with a thickness of between 1.0 m and max. 3.5 m. The sludge pits are filled with water. In a sludge yard filled with about 10 000 m3 , the sewage sludges bind into the groundwater throughout the year.Accordingly, the sewage sludges have a wide dry matter/water content range, from ≥ 50 % dry matter to ≤ 25 % dry matter. The consistency, which is of decisive importance not only for transport but also for leaching / stackability in the course of supply to the thermal treatment plant, ranges from crumbly to pasty and mushy to wet and flowing. Experience has shown that the sewage sludges in old sludge sites contain stones (concrete, building rubble, etc.) and other impurities which can impair the thermal treatment and therefore require pre-treatment, which is usually carried out via several stages of pre-screening and homogenisation or cf. as well as partly intensive drying.The results of chemical investigations show that the sewage sludges are also contaminated with non-ferrous metals (zinc, cadmium, mercury) in addition to the high organic content. These are the hazardous characteristics mentioned above, which must be taken into account with regard to (intermediate) transports, storage areas, etc.The entire clearing measure of the old sewage sludge basins is to be carried out and completed in the period from February 2022 to the end of September 2022, i.e. within 8 months. No extension beyond 30.9.2022 is possible. The Contractor shall thus ensure the acceptance of these sludges until the end of September, and the disposal, i.e. the final thermal treatment of the approx. 100,000 t of sewage sludges, shall be demonstrably completed by the end of 2022 and proven to the Client as proper disposal.Should the processing and interim storage not be located on the thermal treatment plant site, all relevant permits, (interim) transports and acceptance capacities of the individual sites shall be presented in the tender with regard to the above-mentioned acceptance quantities and possible downtimes and incidents. The costs for this are to be included in the calculation.

Opportunity closing date

01 July 2021

Value of contract

to be confirmed