Denitration: High sulfate concentration in the permeate fluid! ! !
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This post was last edited by sunjl1981 on 2013-1-6 at 22:25. Have those of you using out-of-stock devices encountered a situation where the sulfate concentration in the permeate fluid is high? Has the membrane’s performance declined? Can washing the membrane solve the problem? ? Urgent! ! Urgent! ! ! ! Thank you first! ! ， ， -
Did it appear from the beginning or later? It is necessary to find out the cause. If high levels of sodium sulfate in the permeate fluid occur right from the start of operation, by how much? This can be checked with the manufacturer. If it appears at a later stage, it is necessary to analyze the reasons – could it be an issue with the quality of the saltwater, or is the free chlorine level too high? This can have a severe impact on the membrane, even leading to its destruction； I don’t think washing the film will solve the major problems ； By the way, pre-treatment of the membrane is very important; how long did you rinse it for?
Reply 1# bozhenhai: How high is it? ? Are there any issues with the specific operating parameters? ?
This post was last edited and replied to by Zhong Hengming on 2010-10-9 at 10:58. Reply 3# Zhong Hengming: It is necessary to know the operating parameters and the status of the device in order to analyze the reasons! Membrane filtration pressure: Temperature: Pressure difference across the membrane: ORP: pH: Sulfate content in concentrated water and clean water:
The sulfate content in the permeate reaches around 8 g/l.
The control has always been very stable; the pH is generally between 3 and 7, with no free chlorine present.
What is the sulfate level of the brine feed going in? The permeate from each group of membranes can be analyzed. Is it possible that the central tube is broken?
Reply to 1# bozhenhai: The question isn’t specific enough, so it’s difficult to determine the cause. However, the high sulfate content in the permeate can be attributed to the following reasons: 1. Physical reasons: a. The membrane itself is oxidized by free chlorine, or high temperatures cause the membrane pores to enlarge. b. The pressure of the water entering the membrane is abnormally high; the membrane structure may be damaged, allowing concentrated water to leak into the permeate fluid. 2. Inadequate control of operating parameters: a. The pH level is too high; membranes generally need to operate in a slightly acidic environment. b. Is the flow rate of the produced water too low? c. Is the concentration of sodium sulfate in the feed water that is rich in nitrate too high?
It’s possible that the sulfate concentration in the dechlorinated salt water is relatively high; one can choose to reduce the amount of dechlorinated salt water used, and gradually increase it again once the sulfate concentration becomes lower. The membrane should not have any problems
It’s possible that the sulfate concentration in the dechlorinated salt water is relatively high; one can choose to reduce the amount of dechlorinated salt water used, and gradually increase it again once the sulfate concentration becomes lower. The membrane should not have any problems
Reply to 1# bozhenhai: There are two reasons: 1. Membrane failure, resulting in a decrease in desalination efficiency; the possible cause is damage caused by free chlorine. 2. The central tube is broken, the O-ring is damaged, or there is a problem with the adapter.