Electroplating wastewater reverse osmosis membrane treatment method adopting energy recovery device

Abstract

The invention discloses an electroplating wastewater reverse osmosis membrane treatment method adopting an energy recovery device. Key points of the technical scheme are that: the method comprises the following steps that: electroplating wastewater sequentially passes through an ultrafiltration membrane filtering raw water tank, an ultrafiltration membrane filtering delivery pump, an ultrafiltration membrane filtering unit, a reverse osmosis raw water tank, a booster pump and a security filter, and is divided; one branch enters a reverse osmosis device after being boosted by a high pressure pump, wherein the energy recovery device for recovering the energy of high-pressure reverse osmosis concentrated water flowing out of the reverse osmosis device is connected to the reverse osmosis device; and the other branch enters the reverse osmosis device through a circulating pump after the energy is recovered by the energy recovery device, filtered water filtered by the reverse osmosis device flows into a reverse osmosis product water tank, and after filtration, the concentrated water is treated and discharged.

Description

【Technical field】 [0001] The invention relates to a method for treating electroplating wastewater. 【Background technique】 [0002] At present, the country is vigorously advocating energy conservation and emission reduction. Many industries are trying to treat wastewater up to standard and then carry out advanced treatment to recycle precious water resources. Most of the wastewater reuse processes used in the electroplating industry are: [0003] One is the sand filtration + activated carbon filtration process. Due to the particularity of electroplating wastewater, after the wastewater has been treated by physical and chemical precipitation, although most of the pollutants have been removed, the wastewater still contains a relatively high concentration of inorganic salts (generally 3000mg / L~6000mg / L), some organic matter, suspended matter, etc., because the filtration accuracy of sand filter is generally tens to hundreds of microns, a large number of fine suspended matter i...

AI Technical Summary

Problems solved by technology

[0003] One is the sand filtration + activated carbon filtration process. Due to the particularity of electroplating wastewater, after the wastewater has been treated by physical and chemical precipitation, although most of the pollutants have been removed, the wastewater still contains a relatively high concentration of inorganic salts (generally 3000mg / L~6000mg / L), some organic matter, suspended matter, etc., because the filtration accuracy of sand filter is generally tens to hundreds of microns, a large number of fine suspended matter in the wastewater cannot be intercepted, so the water quality of the filtered water is poor. It can be used as low-level reuse water such as miscellaneous production water, and cannot be widely used

[0004] The other is sand filter + activated carbon filter + reverse osmosis process. Although reverse osmosis technology is applied in the process, the filtration accuracy of sand filter is low, and activated carbon is easily caused by the adsorption of organic matter in wastewater during use. Saturation failure, loss of protection for subsequent reverse osmosis membrane elements, affecting the service life of reverse osmosis membrane elements, making the cost of membrane technology in wastewater reuse remains high

[0005] Moreover, in the practical application of this process, due to the need to overcome the osmotic pressure generated by the inorganic salts and organic matter in the wastewater, it is necessary to provide a higher operating pressure for the reverse osmosis membrane, generally 1.2-1.6MPa, and the wastewater enters the reverse osmosis membrane. After the element, inorganic salts and organic matter are intercepted by the reverse osmosis separation membrane, and water molecules are collected through the central water production pipe of the reverse osmosis membrane element to achieve separation, while inorganic salts, organic matter and other substances are concentrated on the concentrated water side, and the pressure is still 1.0 ~1.5MPa. Currently, in the commonly used process of wastewater reuse, reverse osmosis concentrated water is directly discharged, so that energy is directly wasted along with the discharge of concentrated water. Under the environment where the country vigorously advocates the development of circular economy and energy saving and emission reduction, The large amount of energy wasted during the application of this process cannot be ignored

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