Method of non-noxious treatment of scrapped silicon dioxide etching solution

Abstract

The invention discloses a method of completely non-noxious treatment of a scrapped silicon dioxide etching solution. The method adopts a second stage method, and specifically, the primary treatment is to adjust the pH value of waste fluid, add calcium salt to remove fluorine and meanwhile perform air stripping to remove ammonia nitrogen; secondary treatment is to adjust the pH value of filtrate, add calcium hypochlorite, keep the pH value and perform stirring reaction for a certain time, enable ammoniacal nitrogen to be oxidized into harmless nitrogen gas for complete removing, add ferrous salt to remove active chlorine, ensure that all filtered residues enter a cement kiln, so as to be comprehensively utilized, and ensure that secondary filtrate can achieve the primary standard of integrated wastewater discharge standard. Completely non-noxious treatment of the scrapped silicon dioxide etching solution can be realized through the treatment method.

Description

technical field [0001] The invention belongs to the technical field of comprehensive sewage treatment, and in particular relates to a harmless treatment method for waste silicon dioxide etching solution. Background technique [0002] Wet etching is widely used in today's integrated circuit manufacturing field because of its process can accurately control the amount of film removal and the loss of raw materials during the process, and the waste etching solution contains high concentrations of fluorine and ammoniacal nitrogen, which is harmful to the environment. and ecosystem pollution is very serious. CN201010525143A, CN103030234A, CN104961304A, Liu Kai’s research and application of fluorine-containing wastewater treatment technology for integrated circuit industry, Cheng Xiumian’s technical improvement of fluorine-containing wastewater treatment process, Chen Liaoyuan lime-aluminum sulfate method for treating high-concentration fluorine-containing wastewater experimental re...

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Problems solved by technology

CN201010525143A, CN103030234A, CN104961304A, Liu Kai’s research and application of fluorine-containing wastewater treatment technology for integrated circuit industry, Cheng Xiumian’s technical improvement of fluorine-containing wastewater treatment process, Chen Liaoyuan lime-aluminum sulfate method for treating high-concentration fluorine-containing wastewater experimental research only for fluorine-containing wastewater Research on the treatment method of ammonia nitrogen, without mentioning the treatment of ammonia nitrogen; Huo Ying et al. Experimental research on high-concentration ammonia-nitrogen wastewater, Huang Jun et al. High-efficiency air stripping and breakpoint chlorination method to treat high-ammonia nitrogen wastewater only studied high-concentration ammonia nitrogen wastewater ; CN102126799A, CN103011441A, CN103011441A fluorine-containing, ammonia-nitrogen-containing waste water treatment whose fluorine, ammonia-nitrogen content does not exceed the gram level; CN104961304A, CN103936218A fluorine-containing nitrogen-containing waste water treatment, the treatment method used is more equipment, and the process is long; Zhang Xinlong's photovoltaic waste water treatment In the experimental research, the combination of physicochemical and reverse osmosis is used to treat photovoltaic fluorine-containing nitrogen-containing wastewater, and the reverse osmosis membrane needs to be cleaned continuously, and the treatment cost is very high; CN102659277A is an ammonium fluoride wastewater treatment process, which uses ultrafiltration, electrodialysis, and nanofiltration Combined treatment is only suitable for the application of low-concentration ammonium fluoride wastewater, and the investment and operating costs are high

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