How should waste liquids containing acids, bases, and salts be treated?

Thread Content

How should waste liquids containing acids, bases, and salts be treated? 1). In principle, acid, alkali, and salt waste liquids should be collected separately. But if there are no obstacles, they can be neutralized with each other, or used to treat other waste liquids. 2). Waste liquids containing heavy metals and fluorine must be collected and treated separately. 3). Waste liquids containing yellow phosphorus, phosphine, phosphorus oxyhalides, phosphorus halides, phosphine sulfide, etc. are oxidized using H2O2 under alkaline conditions and then treated as phosphate waste liquids. The waste liquid containing polyphosphates is acidified with sulfuric acid, and then boiled for 2–3 hours to undergo hydrolysis. 4). For its dilute solution, it can be discharged after diluting it with a large amount of water to a concentration of less than 1%. Treatment method [Procedure] 1) Once it has been confirmed that there is no risk even if the acid and alkali waste liquids are mixed with each other, one of the waste liquids can be added to the other in small amounts over several steps. 2) Test using a pH strip (or pH meter) to adjust the pH of the solution to approximately 7 by adding acid or base waste. 3) Dilute with water to reduce the solution concentration to below 5%, and then discharge it.