Electroplating wastewater treatment training table

1. Understand the process of processing the processing of chromium -cont--ning electroplating wastewater.

2. Deepen the understanding of the basic concepts of the experiment and improve theoretical and practical knowledge.

principle:

In acidic chromium -cont--ning wastewater, chromium is m--nly in the form of CY2O7 = in form, but there are also a small amount of Cyo4 =.

Use iron plates as yin and anode, and add a cert--n amount of salt to the wastewater to increase the conductivity and activate the anode. Stir with compressed --r and electrolytic processing at low voltage DC power. Under acidic conditions, iron anode is used to dissolve, generate di -valence iron ions into the wastewater, and restores hexavalent chromium into tri -chromium. When triad chromium pH> 5, generate chromium hydroxide precipitation, separate Exile the water after precipitation.

Anode reaction: Iron lost electrons into binary iron, ions enter the wastewater.

Fe-2E → Fe ++

The two -valent iron ion is a strong reducing agent that restores the hexavalent chromium in the wastewater into a three -valent chromium.

CY2O7 =+6Fe +++ 14H+→ 2cy3 ++ 6FE3 ++ 7H2O

CYO4 =+3Fe +++ 8H+→ Cy3 ++ 3FE3 ++ 4H2O

Cathode reaction: Hydrogen ions discharge on the cathode and become hydrogen. At the same time, a small amount of hexavalent chromium is discharged on the cathode to become hydrogen. It promotes the pH value in the wastewater to gradually increase, resulting in separation of chromium hydroxide and chromium hydroxide and separation. Chromium hydroxide is easy to precipitate at 5, and at the same time, the FE3+in the wastewater generates the precipitation of iron hydroxide.

1. Product characteristics

1. Project practicalization: Taking common actual connection and cooperative components as tr--ning objects;

2. Function systemic: Finding components, component disassembly, component measurement, and component drawing four -in -one tr--ning mode; tr--ning process from simple components to complex components.

3. The popularization of students: small, combined, portable tr--ning devices, a group of two or three people, so that as much as possible students get

Full tr--ning opportunities

4. Standardization of teaching: supporting and guidance books, teaching and learning are very convenient, and the teaching effect is significant;

5. Management convenience: parts, measurement tools and guidance books are placed in a refined box, which is very convenient to manage.