Method and equipment for recovering heavy metal in electroplating wastewater

Abstract

The invention discloses a method and equipment for recovering heavy metal in electroplating wastewater, belonging to the technical field of electroplating wastewater disposal. The method comprises the following steps of: (1) performing ion exchange resin treatment on the electroplating wastewater, and enabling heavy metal ions in the electroplating wastewater to be adsorbed onto the ion exchange ions; (2) eluting the heavy metal ions adsorbed on the ion exchange ions through a regenerant to obtain a regenerated solution; and (3) electrolyzing the regeneration solution by adopting a rotational flow electrolysis technology, and separating out heavy metal on a negative electrode. The equipment comprises a resin exchange treatment unit and an electrolysis recovery treatment unit, wherein the electrolysis recovery treatment unit consists of a rotational flow electrolyzer and a reflux device for controlling the flow velocity of liquid. The concentration polarization can be avoided by introducing the rotational flow electrolysis technology, the simple substance ion finally electrolyzed is smoother and has more selectivity, the low-concentration regenerated solution can be electrolyzed, the electrolysis effect can be ensured, and the exchange resin regenerated solution treated by adopting an electrolysis method can be applied into practical engineering.

Description

technical field [0001] The invention relates to the technical field of electroplating wastewater treatment, in particular to a method and equipment for recovering heavy metals in electroplating wastewater. Background technique [0002] The wastewater in the electroplating industry has the characteristics of large water volume, complex composition, serious environmental pollution, and many precious metals and heavy metals. At present, the domestic treatment of this type of wastewater generally adopts general physical and chemical treatment methods, and at the same time, it uses non-standard reflux to the accident pool for further treatment. Discharge after meeting environmental protection requirements. However, this method has the following defects: First, a large amount of chemicals need to be added in the process of physical and chemical treatment, thereby generating a large amount of physical and chemical sludge, which causes secondary pollution to the environment; second,...

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Problems solved by technology

However, this method has the following defects: First, a large amount of chemicals need to be added in the process of physical and chemical treatment, thereby generating a large amount of physical and chemical sludge, which causes secondary pollution to the environment; second, a large amount of precious metals and heavy metals in the electroplating wastewater cannot be recycled. It not only causes environmental pollution, but also has the disadvantage of waste

In response to the above problems, people have carried out research and development, and obtained the technical means of combining ion exchange resin and electrolysis technology, which can better treat electroplating wastewater and recover heavy metals in it at the same time, but these technical means also have some defects to varying degrees , because the electrolysis method will eventually produce concentration polarization, which has the disadvantages of low selectivity, low purity of electrolyzed copper, and not easy to form flakes, many burrs and pinholes, ugly appearance, low current efficiency, and inability to electrolyze low-concentration solutions, etc. , which in turn affects the operation of the entire system. Due to the limitations of these technologies, the electrolytic treatment of the exchange resin regeneration solution is still in the laboratory stage or the small test and pilot test stages, and it is rarely used in actual engineering treatment.

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