The optimal conditions for the treatment effect of polyaluminum chloride on electroplating wastewater containing acidic substances are: the sewage needs to be controlled at about 8.5 in the use of polyaluminum chloride, and the stirring time of the coagulant in the use of polyaluminum chloride should be 4min. The mass concentration of copper ions in the wastewater treated with polyaluminum chloride is significantly lower than the national discharge standard.
Adding polymer organic flocculant polyaluminum chloride can significantly increase the settling speed and increase the flocculation particles significantly. Polyaluminum chloride can also be beneficial to the recovery of copper in sewage in the later stage. Compared with the flocculation effect of organic flocculants and inorganic flocculants selected for general treatment of electroplating wastewater, polyaluminum chloride is less used, and the precipitation effect is better than that of ferrous sulfate.
On the whole, polyaluminum chloride(PAC) is selected as the flocculant for the treatment of acidic copper-containing electroplating wastewater, and the effect is better. The technical characteristics of polyaluminum chloride can choose different contents of polyaluminum chloride according to different sewage and wastewater. Polyaluminum chloride can meet the use function of different levels of sewage; polyaluminum chloride can save the construction period of biological treatment system, Moreover, it is not affected by changes in weather and seasons. The dissolution speed of polyaluminum chloride is fast and reliable, and the service life is long. The tank body using polyaluminum chloride does not require maintenance costs, and the cost performance is very high.