Common knowledge of coating: source and type of waste water from coating operation

Core tip: in order to carry out the wastewater treatment of coating operation, it is necessary to analyze and test the harmful substances contained in the wastewater first, so as to determine the method to be used and the degree to be removed See Table 1 for the source and type of waste water discharged from the coating process, and see Table 2 for the concentration of waste water and harmful substances in the coating production line Table 1 source and type of waste water from painting operation waste water type of sheet metal stamping process drawing oil, rust proof oil and other metal pretreatment processes degrease, acid pickling, phosphating and other waste water and wash water painting (DIP) primer process spraying primer, electrophoresis and dip primer and other polluted water painting middle drawing process spraying middle layer Paint knowledge | precautions for wall paint color selection Recommended introduction: when painting the wall, the owner sometimes has difficulty in choosing what color of the wall paint to paint In fact, there is no ugly color in the wall paint, only the disharmonious color matching The use of wall color contains the knowledge of health Too strong color will stimulate people's perception, make people have a sense of fidgety, affect people's mental health Grasp the basic principles of wall color and paint a colorful space 1、 Wall paint color selection notice 1 Light color is generally used for the top surface Light colors make people feel light, dark colors make people feel heavy Usually, the treatment of rooms is from top to bottom, from shallow to deep For example, the ceiling and walls of rooms are white and Paint Home News: in order to carry out the wastewater treatment of coating operation, first of all, it is necessary to analyze and test the harmful substances contained in the wastewater, so as to determine the method to be used and the degree to be removed See Table 1 for the source and type of waste water discharged from the coating process, and see Table 2 for the concentration of waste water and harmful substances in the coating production line Table 1 source and type of waste water from painting operation waste water type of sheet metal stamping process drawing oil, rust proof oil and other metal pretreatment processes degrease, acid pickling, phosphating and other waste water and wash water painting (DIP) primer process spraying primer, electrophoresis, dip primer and other polluted water painting intermediate drawing process spraying intermediate layer, polishing putty and other polluted water painting finishing process Table 2: concentration of wastewater and harmful substances in the painting production line of sewage for top coating: zinc phosphating (automobile production line) chromate (aluminum alloy) electrophoretic washing water (automobile products) water system coating (5% wastewater) water based baking coating (5% spraying wastewater) pH 6.5 ~ 7.52.5 ~ 5.5 6.8 ~ 8.26 ~ 8.56 ~ 8.5 suspended matter / 10-6 30 ~ 130 100 ~ 1000 500 ~ 1200 ＞ 12000 > 10000 Chemical oxygen demand / 10-6 25 ~ 60 400 ~ 500 ~ 1800 ＞ 6000 ＞ 15000 biochemical oxygen demand / 10-6 25 ~ 60 30 ~ 50 Fe / 10-6 1 ~ 10 ≥ 300 Ze / 10-6 1 ~ 4 ＞ 1 hexane extract / 10-6 3 ~ 20 150 ~ 400 FCR / 10-6 40 ~ 70 ＞ 3 Cr6 + / 10-6 30 ~ 60 5 ~ 20 coating family is specialized in coating, diatom mud, paint coating, coating process, news information and coating of fireproof coating, diatom mud, paint coating, coating process, Decoration knowledge and effect drawing of fireproof coating,