The research on practical application of the resource recovery type processing technology of waste water from electro-less deposition process for the information related parts

PurposeThe wastewater, from electro-less deposition processwidely utilized for the manufacturing of electronics and information相关parts such ashard disks and integrated electronic circuits in computers, includes phosphorus compoundsorganic substances and ammonia at the very high concentrationbesides the heavy metal recovery . After the final treatment for heavy metal recoverythe wastewater had been dumped into ocean. As the sea-disposal had been forbidden自1995年以来the residues been disposed in ground after evaporation to dryness. However，the processing technology of the resource recovery type not been established.The purpose of thisstudy is the establishment of the processing technology to recover nickel and phosphorus，organic substance and ammonia for the wastewater，and the guideline of design and operation of the processing plant necessary for the(2)ResultsNickel （II）电子技术的commercialization。process with lead dioxide coat titanium plate as an anode an d titanium plate as acathode.Hypo-phosphoric acid and phosphorous acid in waste water perfectly oxidized toortho-phosphoric acid. The consumed electric power for The process was 580kWh/m <3-> wastewater.100% phosphorus and 90% ammonia were recovered by the MAP(nh_4 mgpo_4 / 6h_2o) process. theeffective utilization as a fertilizer is possible for the crystalline precipitation of MAP. Optimumaddition of Mg(OH)_2 was 160kg for 1m^3 wastewater，and 650kg of MAP was recovered.BOD and ammonia respectively reduced down to 99.8% and 99% bymicroorganisms in the activated sludge process.The guideline of basic design and operation was madefor the actual processing plant.(3)ProspectIn the future research，the demonstration experiment是必要的在电子金属平台工厂cooperating with the private enterprises to商用技术。

(1)PurposeThe wastewater, from electro-less deposition process, which is widely utilized for the manufacturing of electronics and information related parts such as hard disks and integrated electronic circuits in computers, includes phosphorus compounds, organic substances and ammonia at the very high concentration, besides the heavy metals. After the final treatment for heavy metal recovery, the wastewater had been dumped into ocean. As the sea-disposal had been forbidden since 1995, the residues have been disposed in ground after evaporation to dryness. However, the processing technology of the resource recovery type has not been established.The purpose of this study is the establishment of the processing technology to recover nickel and phosphorus, organic substance and ammonia for the wastewater, and the guideline of design and operation of the processing plant necessary for the commercialization of this technology.(2)ResultsNickel (II) was perfectly recovered by electrolysis process with lead dioxide coat titanium plate as an anode an d titanium plate as a cathode.Hypo-phosphoric acid and phosphorous acid in waste water were perfectly oxidized to ortho-phosphoric acid. The consumed electric power for the process was 580kWh/m^<3-> waste water.100% phosphorus and 90% ammonia were recovered by the MAP(NH_4MgPO_4・ 6H_2O) process. The effective utilization as a fertilizer is possible for the crystalline precipitation of MAP. Optimum addition of Mg(OH)_2 was 160kg for 1m^3 wastewater, and 650kg of MAP was recovered.BOD and ammonia respectively reduced down to 99.8% and 99% by microorganisms in the activated sludge process.The guideline of basic design and operation was made for the actual processing plant.(3)ProspectIn the future research, the demonstration experiment is necessary to be carried out in electrolysis metal-plating factory by cooperating with the private enterprises to commercialize this technology.