A wastewater treatment method containing about 10% sodium sulfate
Thread Content
This post was last edited by zfy_80522 on 2010-6-10 at 15:59. There is wastewater in production that contains about 10% sodium sulfate and needs to be treated urgently; the continuous production volume is quite high, around 100 tons per day. After being left to stand for 2-3 hours, it solidifies like ice. I am looking for a cost-effective method for treating this wastewater or for purifying anhydrous sodium sulfate. Thank you all. Urgent! The wastewater contains only caustic soda and sodium sulfate, with caustic soda playing a role in neutralization.
It depends on the temperature of this waste liquid; if the temperature is high, vacuum flash evaporation can be used to remove a large amount of water, followed by crystallization for recovery. If the temperature is low, this method is not applicable.
Thank you to the person above; the temperature can be adjusted and heating is available, but I don’t want to use the vacuum flash distillation method as it’s too costly – too much energy is required to evaporate 90% of the water.
Does the solidification mentioned on the first floor refer to crystallization, or is it the formation of a colloid? If it crystallizes, isn’t that great for producing sodium sulfate? Oh, I’m talking nonsense a bit; I’ve never worked with inorganic substances
For distillation, it’s necessary to choose a multi-effect system, as this can significantly reduce costs
Use lime to neutralize it, producing calcium sulfate precipitate; the precipitate can then be dealt with in some way.
It is better to use it with barium chloride to produce barium sulfate, and then electrolyze the remaining sodium chloride solution to produce chlor-alkali.
Lower the temperature of the wastewater to see if sodium sulfate can crystallize out, and then filter it using a centrifuge.
I don’t think it has any value for recycling, as the cost of raw materials is too high, and after sodium sulfate is dissolved, it crystallizes into sodium sulfate decahydrate, which is not easy to dehydrate
Thank you to all the poster owners. I also want to remove it, but it forms crystals like large ice blocks, so I don’t dare to do it.
I agree with the view from floor 9. I have worked with sodium sulfate before; when it is concentrated, any drop in temperature can easily cause blockages in the pipes. Once blocked, those deposits become as hard as stones. The concentrated sodium sulfate also requires prompt handling – otherwise, it will remain in solid form inside the bags. The cost of using steam for concentration is also high. If the wastewater contains organic substances, things get even more complicated. I’m not sure what the COD level of your wastewater is; I suggest considering the option of freezing it, so that sodium sulfate with 10 molecules of water per molecule remains in a solid state at room temperature. Sodium sulfate with 10 molecules of water per molecule can then be reused