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Plating nickel rinse process will produce a large number of nickel-containing wastewater. Nickel has a strong organism toxicity, but also a precious metal, the research efficient nickel plating rinse water technology, good economic not only desirable, but also for environmental protection is important. This paper introduces a Nanofiltration nickel electroplating rinse water a small pilot study, the initial purification of industrial practice and nickel sulfate. Investigated three models Nanofiltration plating experiment by changing the operating conditions, the effects of temperature, the membrane surface flow, transmembrane pressure and other factors on the flux, Ni2, organic additives (COD characterization), boric acid rejection of impact; nickel rinsing water characteristics, the results show that the operating temperature, transmembrane pressure, membrane surface increases in flow can be increased through the liquid membrane flux; operating temperature range, the temperature has little effect for Ni2 rejection; increases transmembrane pressure and flow velocity also can improve the rate of Ni2 interception. The test also showed that the S-type film is suitable for the study of the subject. Concentration of 2% citric acid at a temperature of 35 ℃, operating pressure 0.1Mpa circulation flow 2400L / h cleaning conditions under 30min cleaning cycle can play a good cleaning effect of membrane flux recovery rate of over 85%. Based on a small pilot study, nickel plating rinse water in electroplating factory Nanofiltration and nickel and water recycling industrial practice research. The results show that the operating pressure 2.2Mpa, a feed flow 1800L / h under the conditions, nanofiltration process may be sealing nickel a rinsing water was concentrated to 20,000 mg / L or more, the average membrane flux is greater than 40L / (m2 · h ); NI2, the average rejection rate of organic additives, and boric acid, respectively, greater than 99%, 90% and 35%, the microporous agent is completely trapped. The results show that 60 days of industrial operation, concentrate and permeate were reused in the plating bath and rinse tank, electroplating production requirements; single batch operation cycle with water after 5min, and run five days later with a 2% solution of citric acid cycle 30min can effectively solve the problem of pollution of the membrane surface, to achieve the requirements of industrial production. In order to expand the scope of concentrate reuse, purified by chemical precipitation of nickel sulfate, and reached preliminary purification of nickel sulfate concentrate after precipitated, washed, acid hydrolysis step. The results showed that of NaOH as precipitating agent nickel-containing wastewater, control the precipitation reaction conditions for pH = 10, stirring 120r/min, temperature 60 ℃, reaction time 1h. Ni (OH) 2 filter cake washing conditions for the liquid to solid ratio of 2:1, deionized water three times, concentrated sulfuric acid dissolved nickel sulfate, nickel content of 21.2% gt; 20.5%, in line with national standards. Nickel recoveries greater than 96%.
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