How to handle accident chlorine and chlorine-containing wastewater from liquid chlorine bottle cleaning?
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This post was last edited by sunjl1981 on 2013-1-6 at 22:29. How should accident chlorine and chlorine-containing wastewater generated from the washing of bottles with liquid chlorine be treated to meet environmental discharge requirements? Please help me. # hcbbs
Accident chlorine-containing wastewater is nothing but alkaline, saline wastewater containing some hypochlorite ions; wastewater from cleaning steel cylinders contains substances such as ferric chloride and iron oxide. The former is alkaline while the latter is acidic. These two types of water can be mixed together, allowed to settle, and then discharged. Of course, these two water volumes cannot be matched. Use a bit more water for bottle washing, and discharge it in a concentrated manner; it is recommended to carry out an alkaline reaction with the water used for washing bottles and then let it settle in a sedimentation tank. These waters are inorganic wastewater, and it’s quite easy to treat them; as long as they are colorless, it’s straightforward.
The treatment must be carried out in an open area, as neutralization generates a large amount of heat and chlorine gas； Neutralization inside the exhaust pipe can also cause explosion accidents; that’s what happened when our main sewage pipe exploded back then.
I don’t think so; the chlorine content in it shouldn’t be very high. It can be neutralized with alkali directly
Is the quantity large? How about producing hyposodium? Another by-product can be added.
Reply to poster on floor 2 "huawei": What are some good ways to address the color issue of wastewater generated from cleaning gas cylinders?
Don’t you have a wastewater treatment system? It’s fine to send it to the sewage treatment plant for centralized processing; the volume of this wastewater represents only a small fraction of the total wastewater handled by the entire sewage treatment system.
Reply to poster “huawei” on floor 2: When chlorine-containing wastewater from bottle washing is reacted with alkali, in addition to the formation of iron hydroxide, which precipitates easily, a low-concentration sodium hypochlorite solution is also produced； Moreover, the chlorine-containing wastewater resulting from accidents already contains a certain concentration of sodium hypochlorite solution. After both types of water are settled in sedimentation tanks to address the color issue before being discharged, it is likely that the free chlorine level will exceed the specified limits, and thus the requirements for environmentally safe discharge will still not be met. Is it possible to convert these two types of water into sub-acid products for use in the PVC acetylene purification process or for sale? Thank you!
7# Junyi: Since these two types of water contain sodium hypochlorite solutions at certain concentrations, adding acid at the wastewater treatment plant to adjust the pH of the wastewater releases chlorine, thereby contaminating the environment. Therefore, environmental protection authorities insist that the water should be treated at the source before being discharged or reused; it is best not to discharge it at all.
8# wang16851 The total amount of wastewater generated from bottle washing is still limited; after sedimentation, it can be returned to the circulating water system, or it can be mixed with the process wastewater from PVC production after sedimentation, and then both can be sent back to the circulating water system after passing through a sand filter. In this way, that small amount of hypochlorite can be eliminated.
In 10# Huawei, due to the high content of available chlorine (Cl-) in the chlorine-containing wastewater resulting from accidents (around 1–2%), as well as its high alkalinity and high pH value, the alkalinity remains high even after mixing it with the wastewater from bottle washing； Water with high levels of free chlorine and alkalinity, if it enters a circulating water system, can cause corrosion of the equipment in that system as well as scaling in the pipes. Therefore, I believe this method is not advisable; it’s better to find a way to produce the product in the form of a weak acid.