SOLIDIFICATION OF THE ELECTROPLATING SLUDGE USING BLENDED CEMENTS
Abstract
This research work investigated the performance of solidified electroplating wastes using OPC blended with condensed silica fume (CSF) and furnace slag (FS) as solidification binder. CSF and FS were used to substitute for OPC at 0, 5, 10 and 0, 20, 30%(w/w), respectively. Electroplating sludge from a zinccyanide process was loaded to the blended cements at 0, 20, 35 and 50%(w/w). Strength development, leachability of heavy metals and durability to acid corrosion of the solidified waste forms were studied. Experimental results showed that compressive strength of cement blended with 5 and 10%(w/w) of CSF gave higher strength than that of cement paste after curing for 7 days, whereas cement with 5% (w/w) CSF and 20%(w/w) FS gave similar strength to that of the control after 28 days. A dramatic decrease in compressive strength of all solidified plating waste samples was observed, but the concentration of heavy metals in the TCLP leachates did not exceed the limit specified by the US.EPA. In addition, durability of the cement-based solidified waste matrices against sulfuric acid corrosion was greater compared to acetic and nitric acid solutions.
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