Why isn’t the addition of NaClO included in the traditional saltwater preparation process?
Thread Content
This post was last edited by sunjl1981 on 2013-1-6 23:12. Why isn’t NaClO added in the traditional saltwater preparation process? Is the impact of bacteria and algae not taken into account? # hcbbs
This can be put in reverse terms: with the traditional Dowell barrel and carbon tube process, the TOC of the water coming out of the carbon tubes is less than 10 mg/l, which meets the requirements for primary brine. This indicates that organic matter was retained in the absence of zinc nitrate; primarily, after adding sodium polyacrylate flocculant to the tank, calcium carbonate, magnesium hydroxide, and organic microorganisms and algae were aggregated and flocculated, leading to their collective sedimentation. The α-cellulose pre-coating also has an excellent effect on retaining organic matter. However, in diaphragm electrolysis systems, there is no subsequent carbon tube filtration; when the amount of sodium polyacrylate added to the Dowler tank exceeds the limit, it results in a high level of organic substances in the purified brine. Fortunately, the requirements for diaphragms are not high.
This post was last edited by Li Yisi on 2009-9-24 at 12:34. In membrane processes, FeCl3 is actually used as a coagulant in the form of Fe(OH)3; can it be assumed that its ability to adsorb organic substances is relatively poor, and it does not achieve as good results as sodium polyacrylate coagulants? Is that why NaClO needs to be added? In membrane processes, could sodium polyacrylate also be used as a coagulant for pre-treatment? Has anyone thought about this?
3# Li Yishi: The flocculation effect of ferric chloride (converted to iron hydroxide) is certainly inferior to that of charged macromolecular polymers. However, the filtration membranes are very sensitive to sodium polyacrylate; molecular weights in the range of tens to millions can block the membrane pores, leading to an increase in filtration pressure and a significant decline in filtration efficiency. Therefore, despite the fact that ferric chloride can corrode pipeline equipment and introduce iron ions, it remains the best flocculant available at present. Furthermore, sodium hypochlorite can destroy the molecular structure of sodium polyacrylate, causing its flocculation effect to disappear. The addition of sodium hypochlorite can also remove ammonium.
After adding NaClO, the macromolecular organic substances are oxidized into smaller molecules. Are these smaller molecules still organic substances? Why are smaller molecules more easily adsorbed by Fe(OH)3? I thought that macromolecules would be more easily adsorbed
One of our doctoral students is working on this issue, specifically the mechanism by which NaClO affects organic substances in saturated saltwater. No results have been obtained yet; it seems like a simple problem, but the more research is done on it, the more complex it becomes.
The answer on the 4th floor is good; it’s detailed, and NaClO also has the effect of removing ammonium. Reduce the total ammonium content in the system