ORIGINAL RESEARCH
The Recovery of Chromium from Galvanic
Wastewater Sludge
I. Bojanowska
More details
Hide details
Department of Environmental Engineering, Faculty of Chemistry, University of Gdańsk
ul. J. Sobieskiego 18, 80-952 Gda.sk, Poland
Pol. J. Environ. Stud. 2002;11(3):225-229
KEYWORDS
ABSTRACT
The recovery of chromium from prepared (mixed and co-precipitated) sludge, generated during the
neutralisation process of galvanic wastewater was investigated. Studied sludge contained hydroxide and
oxide mixtures of various metals including chromium(III) hydroxide. The recovery procedure included
precipitation of hydroxides and their dissolution, oxidation of chromium(III) to chromium(VI) and final
extraction and reextraction of chromium(VI). The recovery of chromium from the mixed and co-precipitated
sludge was limited by the sludge solubility in the sodium hydroxide solution. The yield of chromium
recovery did not exceed 36%, which suggests that sludge should not be mixed after neutralisation [1, 2]. The
recovery of chromium from the co-precipitated sludge was about 18% of its initial amount. This group of
sludges should be managed according to the method proposed in papers [3, 4].