Entwicklung eines Verfahrens zur Reinigung Komplexbildner enthaltender Abwaesser Abschlussbericht

The degradability of EDTA by cells of an EDTA-degrading bacterial mixed culture or the primary utilizer, strain BNC1, is determined by the stabilities of the metal-EDTA chelates. Chelates with conditional thermodynamic stability constants <1012 are readily degraded, whereas the degradation of stronger complexes requires a physico-chemical pretreatment stage. In contrast to uncomplexed EDTA, high concentrations of Ca- or Mg-EDTA (up to 5 g/L) are not resulting in an inhibition of growth. Growth of the cells and degradation of EDTA can be mathematically described by a modified Monod model. By immobilization of the cells on solid particles and the use of special arilift-loop reactors the mean hydraulic retention time could be decreased to less than one hour without a reduction in the degradation degree (97%). EDTA in waste waters from pulp and paper factories and from the cleansing of milk-pipes can be readily degraded by the mixed culture. Photographic waste waters containing EDTA in form of the stable and therefore non-biodegradable Fe(III)-EDTA chelate, can be purified in a two-stage treatment process. In a first stage, the Fe(III)-ions are displaced from the complex by the addition of Ca"2"+ or Mg"2"+ and precipitated as Fe(OH)_3. In the second stage, Ca- and Mg-EDTA can be efficiently degraded by cells of the bacterial mixed culture. (orig.)SIGLEAvailable from TIB Hannover: F97B2032+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Entwicklung eines Reaktionssystems zur biologischen Reinigung EDTA-haltiger Abwaesser Schlussbericht

Available from TIB Hannover: F99B947 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEArbeitsgemeinschaft Industrieller Forschungsvereinigungen e.V., Koeln (Germany)DEGerman

Entwicklung eines Reaktionssystems zur biologischen Reinigung EDTA-haltiger Abwaesser Schlussbericht

SIGLEAvailable from TIB Hannover: F00B1426 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekArbeitsgemeinschaft Industrieller Forschungsvereinigungen 'Otto von Guericke' e.V. (AIF), Koeln (Germany)DEGerman