Questions regarding denitration using membrane technology
Thread Content
This post was last edited by sunjl1981 on 2013-1-6 at 20:41. The membrane permeability of the denitration system in our company is too high; in other words, the permeability of sulfate ions is too high (the membranes were replaced in October 2011). However, the pH and ORP values are within the specified ranges. I would like to ask everyone: what details should be taken into consideration when using such nanofiltration membranes, and why are there problems with our membranes? hcbbs !! .
Is the membrane contaminated? Rinse regularly; use chemicals for cleaning if necessary
Pay attention to controlling the temperature, pressure, pH, and ORP of the brine fed into the membrane. The pH and ORP meters must be regularly calibrated, and replaced every six months if necessary. Nanofiltration membranes are quite delicate; once damaged, they are difficult to repair. It is essential to ensure the quality of the brine used to feed the membrane, and duty personnel must exercise greater responsibility.
Is it easy to control the residual chlorine level in your PH? What concentration of hydrochloric acid is used to adjust the pH value?
It’s not easy to control; the personnel on duty need to be more responsible. 30% hydrochloric acid is used, and after adjusting the pH value with hydrochloric acid, sodium sulfite must be added to keep the ORP value within the specified range.
It is recommended to prepare 30% hydrochloric acid as a low-concentration solution of around 5%, as this makes it easier to control!
This is likely due to a decrease in the retention rate of the nanofiltration membrane. Nanofiltration membranes are organic polymer materials with limited tolerance to acids, bases, etc., and are particularly sensitive to free chlorine; please refer to the documents provided by the manufacturer
In fact, nanofiltration membranes are not produced in China; they all come from abroad. The lifespan of these membranes is closely related to the process requirements, and the demands placed on the membranes themselves are quite high. Most membrane manufacturers are similar; some produce high-quality products, while others’ products fail to function after just a few months.
We use the one from Guangzhou Simply
Take into account the issue of free chlorine to ensure there is no free chlorine. At the same time, based on the pressure of the high-speed pump, the mold should be flushed regularly with pure water