Can sulfuric acid wastewater be purified and reused?
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The sulfuric acid wastewater, after neutralization treatment, meets the **discharge standards; can it be reused as make-up water in the purification system? (The discharged water is neutral.)
It can be recycled in the purification system, but the water must be clarified before reuse. Our factory is already using it; it would be best to have a filtering device to prevent scaling in equipment such as heat exchangers. However, we don’t have such a filter, but it’s not a big problem
On the 2nd floor, could you tell me if the system is in use and whether there are calcium sulfate crystals blocking the pipes? This is what I fear the most.
The process of reusing this wastewater directly after neutralization will definitely lead to scaling, as there is a high amount of calcium sulfate and magnesium sulfate. In Shandong Guoda Gold, pipes with a diameter of DN500 turned into DN50 pipes within just three months; currently, they are considering using RO membrane technology to reduce the hardness of the water before reusing it.
That expert solved this problem, thereby reducing the energy required for water use; groundwater levels are decreasing every year! ! ! ! ! ! ! !
I think we also need to pay attention to the chloride ion level. I’m not sure what kind of acid production you’re referring to; what is the chloride ion level in the system? If there is chloride present in the system, then we need to consider the issue of chloride accumulation, as chloride can cause corrosion of stainless steel. I tested it some time ago; if it’s reused, the Cl concentration will increase
We are also considering recycling! What we’re thinking now is whether there might be structural issues that have prevented implementation; as for CI, we haven’t conducted any tests on that either! We use a bottom-concentration unsteady-state acid production method, and we’re not sure if that could have any impact
It should be possible to utilize recycled water; some factories pump river water up, settle it, and then use it as recycled cooling water. However, it is best to add chemicals to the system when using recycled water, as scaling is inevitable otherwise. The system also needs to be cleaned regularly, which is somewhat troublesome.
I think it’s not appropriate. By measuring the hardness of the treated wastewater, you can determine how much scale inhibitor needs to be added to maintain stable water quality in the circulating water system – and the cost is not low at all. It’s unnecessary to go into detail about how neutralized wastewater tends to cause scaling on the water side of heat exchangers. Just the sludge that is regularly removed from the circulating water filters – which contains impurities such as F and As at that time – isn’t that a form of pollution? So, to put it simply, either discharge pollutants illegally or send them properly to the wastewater treatment plant.
Hehe, bro, with the current situation regarding sulfuric acid, who can afford to send wastewater to sewage treatment plants? Besides, in another year or two when environmental regulations will become even stricter and zero emissions will be required, won’t you still need to use a membrane system for treatment? The situation with solid slag is relatively mild.
It should be usable; in areas where strict requirements are not imposed on the quality of sulfuric acid, it can be added to the desiccant, though the amount used is relatively small