The treatment of chromate waste water with Fe-Cu internal electrolysis coupling with bentonite

In this paper, a new coupling process called Fe-Cu internal electrolysis coupling with bentonite in treating chromate waste water was introduced. Iron slag, copper wire and bentonite with suitable proportion were put in an airtight jar with chromate waste water. The influence of contact time, pH, the ratio of weight of iron and copper, the dosage of bentonite and initial concentration of Cr(VI) on the removal of Cr(VI) was investigated here. The perfect reaction conditions were found out to this process. When the initial concentration of Cr(VI) was 30 mg/1, pH value was 3.0, contact time was 30min, the ratio of weight of iron and copper was 8:1 and the dosage of bentonite was 1.0g/1, the removal rate of chromium in the wastewater treated by the coupling process reached to 99.05%. Finally, this process was applied to remove chromium in the tannery wastewater; the removal rate of Cr was 99.89% as well. Therefore, this coupling process has the features of low cost, easy to make and use, high removal rate of Cr as well as the importance of controlling wastes by wastes.