Saturday, October 29, 2011

Chromium and Cadmium Plating Waste Treatment

Iron oxide coated sand was found unsuitable for removal of chromium from a mixed oxidation state chromium plating waste but it promising for one step removal of cadmium and cyanide from cadmium plating waste.

The problem on electroplating treatment is the difficulties on removal or recovery of heavy metal from metal plating waste. The conventional waste treatment method usually use neutralization, precipitation, adsorption or ion exchange to remove the heavy metal content on waste solution. The newer method of removing heavy metal from this waste is used a novel method of adsorptive filtration using iron oxide coated sand. In laboratory test, this filtration showing good result useful in removing some metals such as copper, chromium, cadmium, lead and nickel from simulated plating waste; cadmium plating and chromium plating waste from an ordnance factory in Kanpur, India.

The result of this experiment get the conclusion that iron oxide coated sand unsuitable in removing chromium from the mixed oxidation state chromium plating waste. Apperently, hexavalent chromium, which constitute 85% of the total chromium in waste, was poorly removed by the iron oxide coated sand. But still show good for removing cadmium and cyanide plating waste by iron oxide coated sand.

The next problem on the above waste treatment is how to remove iron oxide coated sand that contain of heavy metal, because this sand have contaminated by heavy metal. This need further treatment like using conventional method that will result other solid waste like sludge that contain of heavy metal. This solid waste usually will treat by third party who have legal permit to treat hazardous waste and certified by government concerned.