Influence of Different Electroplating Sludge Types on the Iron Ions Recovery Yield

Abstract

Electroplating sludge resulting from wastewater (washing wastewater and technological solutions) treatment is considered to be a hazardous waste, being a mixture of hydroxides of many heavy metals such us: iron, chromium, copper, nickel, cadmium or zinc. The metal compounds from electroplating sludge have a great economic value, thus, a number of techniques have been investigated in order to recover them. This paper presents the results of the research activity in the laboratory in order to recover Fe (II, III, VI) from two types of electroplating sludge: a fresh sludge from wastewaters treatment and an old sludge, stabilized by disposal for many years. Iron recovery was performed by the solubilization of the sludge in several stages, to yield hydroxides or metal salts of chromium, iron, or zinc. The iron recovery has been performed from the cake obtained after the chromium recovery. In this cake, the iron is present in the form of divalent, trivalent and hexavalent iron. The iron recovery yield was 98.50% from fresh sludge (recovery in one stage) and 96.80% from old sludge (recovery in two stages).

Thermal Stability of Inorganic Pigments Synthesized from Galvanic Sludge

“…Lead chromate was obtained by precipitation process with lead acetate [Pb(CH3COO)2 3H2O] and barium chromate was obtained by precipitation with barium chloride [BaCl2 2H2O]. The precipitates were vacuum-filtered, the cakes were washed stepwise in order to remove the soluble salts adsorbed on the cake, dried and prepared by grinding [20].…”

Danube River Basin Waters on Romanian Territory: Chemical Status Assessment Based on Priority Substances Data Analysis

“…Industrial activities, especially the mining, have become a global concern due to the local and regional degradation of life quality by polluting the water, degrading the fertile land and lowering the air quality. Issues as the polymetallic tailing dumps and mining wastewater from the mining processes, can lead to depletion of natural resources and therefore require special attention in the context of sustainable management [9][10][11][12]. It is known that the Romanian mining industry has a long tradition in this field and the environmental issues still exists [13].…”