The Removal Of Organic Substance In Bright Nickel Plating Bath And The Disposal Research Of Rinsing Wastewater Of Nickel Plating

At the base of understanding the actuality of nickel plating, the organic substance removal in the process of bright nickel plating bath maintenance was investigated, and the disposal effects of different methods were analyzed in contrast; The monitoring method of nickel ion in rinsing wastewater of nickel plating was perfected, and the craft route using chemical precipitation to dispose rinsing wastewater of nickel plating was confirmed.The main contents and conclusions of this thesis were as follows:1. In the process of bath maintenance, hydrogen peroxide oxygenation, potassium permanganate oxygenation and active carbon adsorption were used to remove saccharin and PPS in bright nickel plating. It was emphasized that the effects of diverse time, temperature and the amount of active carbon added on saccharin and PPS removal were detected. Consequently, hydrogen peroxide and potassium permanganate can not remove the saccharin and PPS in bright nickel plating efficiently. However, active carbon adsorption has better efficiency. Also temperature and time have lower impact on saccharin and PPS removal by active carbon adsorption. As the concentration of saccharin in plating bath is 1g/L, there is 0.22g saccharin absorbed at most by adding 1g/L floury active carbon. And as the concentration of PPS in plating bath is 0.3g/L, 0.047g PPS at most is absorbed by adding 1g/L floury active carbon.2. The monitoring method of nickel ion in rinsing wastewater of nickel plating called dimethylglyoxime spectrophotometry was perfected. The 《 Water quality-Determination of nickel-Dimethylglyoxime spectrophotometric method》(GB11910-89) was used to determine the iron content in rinsing wastewater of nickel plating. Iodine was used as oxidizer and dimethylglyoxime as developer. There are two absorption peaks of nickel at the place with wavelength of 550nm and 430nm after complexation. Compared with the result of ICP, the method had high veracity and reliability in both of the two wavelengths, so both of them can be used as the best wavelengths in the determination of the nickel iron. Furthermore the experiment detailed the process, and could be used to determine nickel iron in rinsing wastewater of nickel plating fast in enterprises.3. Five reagents including NaCO₃, Na₂S, NH₃·H₂O, NaOH and Ca(OH)₂were used to react with rinsing wastewater of nickel plating. The conclusions of this experiment showed that NaOH had the best disposal effect and operation condition, and benefited the recycling of precipitation. So NaOH was selected as the best precipitator of chemical precipitation method.4. The craft route of using chemical precipitation method in the disposal of rinsing wastewater of nickel plating was established. And the dosage and adding mean of NaOH were researched. The craft was intermittent operation. The adding of NaOH was controlled by pH servomechanism. The conclusions of this experiment showed: nickel irons can be all deposited though controlling pH 9.2 upwards, and the water purified by this craft could be recycled back to product and the precipitation Ni(OH)₂ also could be recycled after disposal. So the zero discharge would come true. Overall this craft has better economical interests and environmental effect.In summary, this thesis aimed to settle practical issue, and it came from enterprise and responded for enterprise. It strived to make enterprise track sustainable development.