Application of alkaline solid residue of electric arc furnace dust for neutralization/purification of electroplating wastewaters

Abstract

The purpose of this work was development of an appropriate procedure for the neutralization/purification of electroplating wastewater (EWW) with alkaline solid residue (ASR) by-product of the alkaline extraction of zinc and lead from electric arc furnace dust (EAFD). Removal efficiency of ASR at optimum purification conditions (pH 8 and mixing time; 20 minutes) for the elements Pb, Cr (VI), Cr (III), Fe, Ni, Cu and Zn were 94.92%, 97.58%, 99.59%, 99.48%, 97.25% and 99.97%, respectively. The concentrations of all elements in the purified wastewater were significantly lower in relation to the upper permissible limit for wastewaters suitable for discharge into the environment. The remaining waste mud was regenerated in the strong alkaline medium and successfully applied once again for the neutralization/purification of EWW. Removal efficiencies of heavy metals accomplished with regenerated waste mud were comparable to these achieved by original ASR. Elemental concentrations in the leachates of the waste mud were in accordance with regulated values.

Inertisation of galvanic sludge with calcium oxide, activated carbon, and phosphoric acid

“…confi rmed our previous research (22)(23)(24) showing high susceptibility of these three elements to organic lygands. The DIN38414-S4 leachate composition shows that this sludge was not suitable for landfi lling with inert waste since mean zinc and nickel were 10 and 1.5 times higher than the upper permissible limit, and the maximum zinc and nickel values were 27 and 2.5 times higher than the upper permissible limit, respectively (25).…”

“…DIN 38414-S4 leachates of original and inertised samples were prepared as described in our earlier studies (20,22). Instrumental settings as well as quality control have been described in detail in our earlier research (21,22).…”

Ecotoxicological assessment of industrial effluent using duckweed (Lemna minor L.) as a test organism

“…For the analysis of Fe, Cu, Zn, Ni, Pb, Cr 100 ml of the solution was adjusted to pH 3 and 11 by addition of HCl and NH 4 OH, respectively, and preconcentrated by 2 ml of 1% (w/v) ammoniumpyroloidinedithiocarbamate (APDC) (Elez et al 2008). After the complexation, which lasted 20 min, the suspension was filtered through a Millipore HAWP filter (pore size 0.45 lm).…”

“…After the complexation, which lasted 20 min, the suspension was filtered through a Millipore HAWP filter (pore size 0.45 lm). Prepared thin targets were air dried, protected by thin mylar foil (2 lm) and analyzed (Elez et al 2008;Orescanin et al 2008) with MiniPal 4 X-ray spectrometer (PANalytical, Almelo, Netherlands). Spectral data were analyzed by MiniPal/ MiniMate software version 3.0.-63(2.64) (PANalytical).…”

Citotoxicity status of electroplating wastewater prior/after neutralization/purification with alkaline solid residue of electric arc furnace dust

“…[3] At optimum purification 274 Orescanin et al facility prior/after its treatment with alkaline solid residue (ASR) of electric arc furnace dust (EAFD).…”