Treatment Of Chromium-rich Tannery Solid Wastes With Hydrated Lime Powder The Case Of Awash Tannery Addis Ababa Ethiopia

Tanneries generate huge amount of different solid wastes. Among tannery solid wastesrnchromium containing tannery solid wastes are the most difficult to utilize and to disposernbecause of their high chromium content and acidic pH. The chromium (III) found inrntannery solid wastes can easily be converted to chromium (VI) which is one of highlyrncarcinogenic and mutagenic substances. Chromium containing tannery solid wastesrngenerated from ELICO-Awash Tannery per year were found to be wet blue shavingrn(991,411 kg), wet blue trimming(372,312kg), crust shaving (82,555 kg), crustrntrimming(110,448), buffing dust (12, 575kg), finished leather trimming(36,411kg) andrnwaste water treatment sludge(481,440 kg). Hence the total amount of chromiumrncontaining (chromium rich) solid wastes generated from Awash Tannery was found to bern2,087,152 kg per year. Based on the laboratory result of this study the average chromiumrncontent of the above mentioned solid wastes were between 12.94±0.92- 38.43±0.96rngm/Kg and the leachabilty of chromium from these solid wastes were between 26±1.6 -rn378±2.4 mg / l. One of the objectives of this study was to stabilize (fix) chromium (III) inrntannery solid waste with hydrated lime powder, and the result on wet blue shaving waste,rnwhich is one of the chromium containing tannery solid waste showed that by treatingrnwith 2% lime powder the leachability of chromium from the shaving waste was reducedrnby 98% and its pH was also changed from acidic media to neutral media.rnKey words; Chromium containing tannery solid wastes, Chromium stabilization,rnChromium (III), Chromium (VI), Toxicity of Chromium

Get Full Work

Report copyright infringement or plagiarism