In recent years, many studies have been carried out at home and abroad. The principle is to use magnesium salt and alkali to generate magnesium hydroxide hydroxide to precipitate, and strongly adsorb the negatively charged anion dyes, which in turn makes dye wastewater off -color.Magnesium salt discoloration process is simple, the treatment agent has a wide range of sources, and the cost is low, which is easy to implement.
For a black wastewater with a pH value of 9-10, suspended solid concentration of 100-200mg/L, coloring is 150-250, and the chromosomal component is directly tolerant blue, direct gray, dyeing auxiliary, etc.The effects of liquid separation method, magnesium salt, and pH value have been analyzed on the effect of decolorizing effects.The results have proved that magnesium hydroxide has a good decolorization effect.
Secondly, it is proposed that magnesium hydroxide adsorption and ceramic membrane micro filter are proposed to handle printed and dyeing waste water. Find:
(1) The combination of magnesium hydroxide adsorption treatment and ceramic membrane microfiltration treatment is completely feasible for active dye wastewater. Under certain conditions, the decolorization rate of 0.1 μm and 1.0 μm membrane can reach more than 98%.
(2) The appropriate treatment conditions are: operating pressure of 600-800mg/L, 1.0 μm membrane, and pH value of 11-12, 0.15MPa, and error flow speed is 3-5m/s.
(3) Magnesium hydroxide adsorption combined with the micro -filtration of the titth of the titth to treat the printing and dyeing wastewater in the process has certain advantages. Magnesium salt adsorption can be performed directly in the micro filter storage groove, realizing the integrated and rapid separation, and the water is clear and transparent. The possibility of recycling water for printing and dyeing.
In addition, the magnesium salt is used as a treatment agent to the acid-free blue/red wastewater, the wastewater containing a variety of printing and dyeing agents, the active red K-2BP, the active orange K-GN, the active purple K-3R and other dyes True treatment has a good decolorization effect.
Under the same conditions, the decolorization effect of magnesium salt method is more ideal than the iron salt method. The main reason is that the iron salt method residue will consume oxygen, thereby reducing the dissolved oxygen and increasing the turbidity of the discharge fluid. Any impact on the environment. Analyze the adsorption law of magnesium hydroxide (direct, alkaline, acidic) of water -soluble dyes (direct, alkaline, acidic), and find that magnesium hydroxide can effectively absorb these dyes.