[Possibilities for purification of refuse seepage water by sand containing humic substances]

Sands containing humic substances are proposed for protection of ground water from refuse tip seepage waters which containing heavy metals and organic polluting agents. Such sands are produced and spoiled southern of Leipzig during uncovering of brown coal. Humic acids have qualities such as ion-exchange materials, form hydrogen bondes and are able to form salts and complexes. Besides they can adsorb and include other substances. This properties qualify the humic acids in contact with the grained structure of the sand to interactions with heavy metal ions and organic pollution agents in water such as oils, phenols, surface-active agents and organic phosphorus compounds. The installation of sands containing humic substances on the base of the refuse tip gives chances to prevent the migration of heavy metal ions and organic pollution agents in seepage waters on principle. On the other hand it is possible to use sands containing humic substances for cleaning of seepage waters and recovering of anorganic and organic useful materials. First practical tests with an refuse tip seepage water from the district Erfurt confirm the cleaning effect and the recovering of heavy metals.