Chromium (III) Removal and Recovery from Tannery Wastewater by Precipitation Process | Science Publications

American Journal of Applied Sciences

Abass Esmaeili¹  Reza Vazirinejad¹  Alireza Mesdaghi nia¹ 

关键词: Chromium;    removal;    recovery;    precipitation;    tannery wastewater;   

DOI  :  10.3844/ajassp.2005.1471.1473

学科分类：自然科学（综合）

来源: Science Publications

【 摘 要 】

Chromium (III) salts are the most widely used chemicals for tanning processes, but 60-70% of total chromium salts reacts with the hides. In the other word, about 30-40% of the chromium amount remains in the solids and liquid wastes (especially spent tanning solutions). Therefore, the removal and recovery of the chromium content of these wastewaters are necessary for environmental protection and economic reasons. Removal and recovery of chromium were carried out by using precipitation process. For this purpose, three precipitating agents calcium hydroxide, sodium hydroxide and magnesium oxide were used. The effects of pH, stirring time, settling rate and sludge volume were studied in batch experiments. Results show that the optimum pH is 8-9 and the good sludge with high settling rate and lower volume obtain by the MgO precipitating agent. Hence the MgO is a good precipitating agent for removal and recovery of chromium from tanning wastewater.

【 授权许可】

Unknown