In the electronics industry, different types of circuit boards, their production processes are different, the circuit board industry production of large amounts of water, the discharge of wastewater will have a certain difference in composition, wastewater pollutants are many types, complex composition, a variety of heavy metal wastewater and organic wastewater discharged, treatment is more difficult to deal with the more serious harm to the environment, according to the main pollutants will be divided into the following: low concentration of acid and alkali cleaning wastewater, high concentrations of According to different main pollutants, it is divided into: low concentration acid and alkali cleaning wastewater, high concentration organic wastewater, complexing wastewater, concentrated acid (alkali) wastewater and other wastewater generated by the cylinder, etc. Certain manufacturers may also be divided into abrasive wastewater, electroplating wastewater, potassium permanganate wastewater, fluorine-containing wastewater, cyanide-containing wastewater, nickel-containing wastewater and so on. At present, most of the domestic treatment of this type of wastewater is still to meet the discharge standards for the purpose. However, the scarcity of water resources, the continuous development of the economy, the increase in population will certainly lead to the continuous increase in the price of water resources. Increase the production costs of enterprises, the implementation of cleaner production, recycling of water resources is not only to promote the economy, the environment, the need for coordinated development of society, but also the need for sustainable development of the circuit board industry.

The circuit board industry to implement the strategic goal of sustainable development, in the wastewater discharge on the basis of the depth of treatment and reuse, water recycling, water conservation, protection of the environment at the same time, reduce production costs, to achieve a win-win situation of economic and environmental benefits. At present, the process of water reuse mainly relies on membrane treatment, membrane separation technology is known as the ‘twenty-first century wastewater reuse treatment technology’, since the 1970s applied to the field of water treatment, has been extensive research and unprecedented development, by the world's water treatment practitioners of the general concern, to carry out different levels, Different levels of theoretical research and technology development and application. With the development of membrane separation technology, membrane performance technology to improve and reduce the cost of membrane separation products, the use of membrane technology to achieve wastewater resources and reuse, will become one of the effective means of wastewater treatment.

Our company with more than ten years of experience in the water treatment industry can be based on customer specific requirements, analysis of raw water quality characteristics, and design of water reuse system. The raw water of this project is the waste water discharged from the circuit board, and the total water intake of the system is 500 tonnes per day, and the water production is 300 tonnes per day. The project adopts the mature and reliable ‘double membrane method’: a new reuse process combining pre-treatment, ultrafiltration (UF) and reverse osmosis (RO), which not only solves the problem of environmental pollution of wastewater, but also saves water resources and achieves the purpose of clean production.

The wastewater of this project is the concentrated water of pure water system, sand carbon backwashing wastewater pre-treated in reverse osmosis system, and workshop wire cutting wastewater.

After the reverse osmosis to produce pure water, the remaining concentrated water is difficult to recycle, the main reason is that the salt, calcium, magnesium and other easy to scale the content of the concentration of substances are greatly increased, scale substances in the reverse osmosis membrane is easy to block the membrane; if you want to use it again, we must try to effectively reduce the concentration of scaling substances in the water. Quartz sand backwash water contains a certain amount of suspended solids and solid particles, but the relative content of pollutants is low, the reverse osmosis concentrated water can play a certain role in dilution, the main problem solved in this project is the removal of suspended impurities in the water, as well as calcium, magnesium and other substances prone to fouling, through the above analysis of the water is more suitable for the use of the addition of dosage of micro-flocculation and precipitation + multimedium filtration + carbon + ultrafiltration + reverse osmosis methods Treatment. According to the characteristics of the wastewater, firstly, the wastewater will be introduced into the water collection tank to mix fully, and then firstly, it will pass through the micro-flocculation and precipitation tank to remove the suspended matters in the water, and then after the multi-media filtration and carbon filter for further pretreatment, it will pass through the ultra-filtration and reverse osmosis to remove the calcium, magnesium and other easy-to-fouling substances with high content in the water, and then finally reuse it for pre-treatment in the workshop.