Regarding the issue of chloride content
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Colleagues, I have a question regarding chloride ions: does a high level of chloride ions in wastewater affect biochemical processes?
It should be, but there is relatively little information on this topic
This post was last edited by li*ch1968 on 2015-9-17 at 10:41. Generally, levels above 5000 mg/L inhibit the activity of sludge; meanwhile, chloride ions can also interfere with COD testing. However, it is possible to cultivate activated sludge that is tolerant to chloride ions, and this requires specialized cultivation. If the chloride ion concentration in wastewater is too high, it is recommended to treat it through pretreatment or dilution before feeding it into the biological treatment unit
Generally, chloride ions at a concentration of 9000 mg/L do not have a significant impact on activated sludge. The toxicity of divalent salts is higher than that of monovalent salts, and a concentration of sulfate ions at 6000 mg/L has an inhibitory effect on activated sludge. Chloride ions interfere with the detection of COD; more silver nitrate needs to be added during testing to eliminate this interference.
High chloride levels do have an impact on biochemical processes; they cause chlorination in microorganisms, disrupting certain enzyme systems in bacteria and leading to their death
How much can you achieve? Our chloride content is 16,000 mg/L; the sludge can be cultivated, and there are no issues with biochemical treatment. The treatment results will definitely meet the standards :)
I’ve never encountered such high levels of chloride ions; what is the removal rate in that case? Can the COD removal rate reach 80%? It’s hard to estimate.
The last edit to this post was made by hthghjl on 2015-9-18 at 08:34. It’s possible; we have multiple types of water streams, such as desulfurization water, propylene oxide water, and chloropropylene oxide water. We use a treatment process that combines chemical methods, biological treatment, and electrocatalysis, and as a result the COD level can be reduced from 800 to 50. Even if only chemical and biological treatment are used to remove 80% of the COD, the desired result can still be achieved
Will the chloride ions in the resulting biochemical sludge dissolve again, or remain stable by being bound in a special way?
Chlorides are generally quite soluble in water; if their concentration is tens of thousands of milligrams per liter, why not concentrate and separate them?