Electroplating wastewater treatment process and the principles of heavy metal removal

 Principle heavy metal removal
Heavy metal ion removal agent generally over a wide pH range (pH3-12) within the application range of this PH can actually use the heavy metal ion removal agent treatment, and can achieve better results. But does not adjust PH value reacquisition agent tungsten carbide inserts directly in the cost is not economical, the pH should generally be adjusted to a certain range, a portion of the heavy metal ions in the form of a hydroxide precipitate, thereby reducing the heavy metal ion removal agent usage, reducing processing costs. Table 1 shows some of the precipitated metal hydroxide optimum pH range.
Metal ions Fe3 + Al3 + Cr3 + Cu2 + Zn2 + Sn2 + Ni2 + Pb2 + Cd2 + Mn2 +
The optimum pH precipitation 6-125.5-88-9> 89-105-8> 9.59-9.5> 10.510-14
Alkali will re-dissolve the pH> 8.5> 9> 10.5> 9.5
Cr (VI), should be restored by means of a reducing agent, so as to be reduced to trivalent chromium, and then be removed by the above method.
Finally, we pass a certain amount of coagulant, so heavy precipitate formed settle down in the settling tank to reduce the water of the SS, resorted to water becomes clear and transparent.
(Three) Process Features and Benefits
A deal with water quality is good.
2, high degree of automation, water quality and stability.
3, the use of energy-specific technology, low operating costs, can effectively achieve the plating wastewater comprehensive national emission standards (GB8978-1996), able to effectively respond to seventeen major energy conservation policy.
4, low operating costs, the Canadian pharmacy cheap.
5, we have equipment layout with upper and lower overlapping, sewage treatment equipment characteristics of small footprint, the system covers an area of ​​water treatment process is usually 1/5.