Heavy metal wastewater treatment system and method

Abstract

The invention relates to the technical field of wastewater treatment systems, in particular to a heavy metal wastewater treatment system and method. The system comprises a pH adjustment pond, a coagulation pond, a flocculation pond, a sedimentation pond, a biochemical treatment pond, an ultrafiltration system, a reverse osmosis system and an evaporation-concentration-crystallization device which are communicated in sequence according to the flow direction of wastewater. The reverse osmosis system comprises a first-level RO device and a multi-level RO system which are arranged according to theflow direction of the wastewater, the first-level RO device is provided with a first purification water outlet and a first concentration water outlet, the first purification water outlet is communicated with a recycle pond, and the first concentration water outlet is communicated with the multi-level RO system. According to the heavy metal wastewater treatment system and method, reliable running and economical and reasonable cost are taken as a principle, a double-film-method water treatment technology with ultrafiltration and multi-level reverse osmosis as a core is adopted, the method is reasonable in design and stable in running, the quality of produced water meets the requirement, and all the devices have the advantages of being convenient to install, use, operate and maintain.

Description

technical field [0001] The invention relates to the technical field of sewage treatment systems, in particular to a heavy metal wastewater treatment system and method. Background technique [0002] Copper-containing wastewater is a type of wastewater produced by metallurgy, electronics and other industries, mainly including printed circuit board etching wastewater, electroplating wastewater, etc. The copper content in copper-containing wastewater is as high as 0.1-35g / L, which greatly exceeds the sewage discharge standard (GB8978-1996). If it is discharged directly, it will seriously pollute the environment. Therefore, necessary measures must be taken to treat copper-containing wastewater. [0003] Among the existing copper-containing wastewater treatment technologies, ion exchange method, precipitation method, adsorption method and electrolysis method are more widely used and more mature and reliable technologies. However, there are also many deficiencies, such as electro...

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Problems solved by technology

However, there are also many deficiencies, such as electrolysis, although the effect of removing heavy metal copper ions is not bad, but in the process of treatment, especially in the treatment of a large amount of wastewater, a large amount of electric energy will be consumed, and its energy consumption is relatively large, which is difficult to meet the current requirements. The requirements for energy saving and emission reduction advocated; precipitation method, precipitation method can usually be divided into chemical precipitation and physical precipitation. Chemical precipitation is to add a large amount of alkali to the wastewater to make the wastewater alkaline, and then generate insoluble precipitates. After filtration, the physical method is to add flocculant to the wastewater containing heavy metals. Most of the flocculants are colloids, which use a large number of similar charges on their surface to absorb heavy metal ions, and then settle by gravity and then remove them by filtration; ion exchange method and adsorption method, Although the operation is simple and the energy consumption is small, there is also the problem that the effect of a single method is not good.

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