ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Membrane processes used for separation of effluents from wire productions
Krzysztof Karakulski, Marek Gryta, and Antoni W. Morawski
Department of Water Technology and Environment Engineering, Institute of Chemical and Environment Engineering, Szczecin University of Technology, ul. Pułaskiego 10, 70-322 Szczecin, Poland
Received: 21 July 2008 Revised: 27 November 2008 Accepted: 1 December 2008
Abstract: Metal wires are produced from different metals using drawing methods. The metal used influences both the technology applied
and the composition of effluents generated during wires production. Ultrafiltration and nanofiltration are used for the separation
of waste emulsions from cable factories. Membrane distillation was proposed for the treatment of acidic saline wastewater
generated during steel wire manufacturing (etching). The possibility of the previously mentioned processes application for
water reuse is presented. The application of poly(vinylidene fluoride) (PVDF) membranes (FP 100) with the molecular weight
cut-off (MWCO) of 100 kDa in the ultrafiltration process resulted in the reduction of 99 % of oil and lubricants in the treated
emulsions and allowed complete removal of suspended solids and colloidal substances. Such pre-treated emulsion was subsequently
purified by nanofiltration (NF-90-2540) and a 98 % rejection of copper ions was achieved, resulting in a decrease of the permeate
electrical conductivity from 3200 μS cm−1 to 260 μS cm−1. The obtained permeate was suitable for preparation of fresh oil emulsion utilized for lubrication in the wire drawing process.
The spent etching baths (from steel wire production), which mainly contained FeSO4 and about 1 mass % of sulfuric acid, were separated by membrane distillation. The obtained permeates were: clean water with
electrical conductivity at a level of 3–5 μS cm−1. Concentrates (190–200 g of Fe per L) from the MD process were cooled to 295 K, which enabled the FeSO4 crystallization. Application of the above-mentioned membrane processes allows producing high quality product water, over
90 % of water was recovered from the treated wastewaters.
Keywords: ultrafiltration - nanofiltration - membrane distillation - emulsion - wire drawing
Full paper is available at www.springerlink.com.
Chemical Papers 63 (2) 205–211 (2009)