酸性蚀刻废液中氨氮的去除研究

Study on Removal of Ammonia Nitrogen from Acid Etching Waste Liquid

主要研究线路板蚀刻加工产生的酸性蚀刻废液经铁粉置换出铜后产生的含氨氮酸性蚀刻废液中氨氮的去除。先采用氯酸钠将溶液中的二价铁离子氧化成三价铁离子,同时降低溶液中的游离酸含量,再用次氯酸钠氧化,除去溶液中的氨氮。考察次氯酸钠用量、次氯酸钠加药速度、反应时间对溶液中氨氮去除效果的影响。得出在次氯酸钠用量为理论用量3倍时基本能将溶液中的氨氮完全去除。

The removal of ammonia nitrogen from acidic etching waste liquid containing ammonia nitrogen produced by circuit board etching process by replacing copper with iron powder were mainly studied.Sodium chlorate was used to oxidize iron divalent ion into iron trivalent ion in the solution,while reducing the content of free acid in the solution,and then sodium hypochlorite was used to oxidize and remove ammonia nitrogen in the solution.The effects of dosage of sodium hypochlorite,dosage rate of sodium hypochlorite and reaction time on ammonia removal were investigated.It was concluded that ammonia nitrogen in the solution can be completely removed when the dosage of sodium hypochlorite was 3 times the theoretical dosage.