*The wastewater resulting from acid pickling does not contain nitrogen emissions
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After the manufacture of stainless steel equipment, it is generally subjected to acid washing and passivation treatment. Here’s the question: Acid is necessary during pickling, but some areas state that the discharge of nitrogen-containing wastewater is not allowed Dear sea friends, may I ask? Are there any technical methods to handle this? Note: It is not compliance-based emission, but zero nitrogen emissions. After doing some research, it seems that when *ao acid reacts with chromium in stainless steel to form a dense film of high-valent chromium oxides, the nitrogen in *ao acid should be converted into lower-valent forms of nitrogen, such as nitric oxide and nitrogen dioxide. However, no reaction equations could be found Does anyone know? Thanks!
Environmental regulations are indeed stricter now. . . Over all these years, the domestic companies I’ve seen have been discharging pollutants in a careless manner. Foreign-funded enterprises outsource pickling and passivation to third-party companies and do not carry it out in-house. I have no clue about chemical reactions. . .
Haha, thanks for the tip. The key is to prevent emissions, but there’s no way out – what should companies do? For outsourced transportation, processing, etc., there are ten thousand procedures required; haha, it’s impossible to move forward even before a stick of incense burns out.
This post was last edited by Menghan100 on 2016-1-17 at 16:46. We represent the Italian RICERCA CHIMICA group in terms of stainless steel pickling and passivation technologies. These processes are non-toxic, non-corrosive, and do not cause pollution; the main component of the solution is citric acid monohydrate. There are no highly corrosive substances such as sulfuric acid or hydrofluoric acid involved, so it can come into direct contact with skin without being harmful to the human body； The resulting waste liquid can be discharged directly without polluting the environment ； After pickling, the stainless steel returns to its original metal color, with no color difference ； The devices used in conjunction are small in size, light in weight, easy to carry, simple to operate, and efficient. The Italian R.C Group focuses on research in metal surface treatment, with products covering stainless steel, titanium alloys, copper alloys, aluminum alloys, magnesium alloys, and zirconium
Thank you! I’ll be sure to pay attention from now on! :)