Someone in the unit added water with high COD to the circulating water
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The COD level of the wastewater from this unit is relatively high; there is a suggestion to add something to the circulating water in order to remove scale – let’s see if this is feasible
The issue of water cannot be resolved in just a day or two. Tests can be conducted by referring to the indicators of circulating water.
I really want to know the reason why the person in charge of circulating water descaling gave such a suggestion. Excessive COD levels in water can cause new forms of corrosion ； It will damage the protective film on the condenser tube bundle ； It can also lead to safety accidents ； If there is a leak in the tube bundle, it will also affect product quality ；
Reply to 1# ghoul888: In my opinion, it’s best to decide whether to add this water based on the monitoring data. One should not consider only the COD value; other parameters of the water added also need to be taken into account, such as alkalinity, the levels of Ca and Mg, and the bacterial count Indicators such as pH value should not be considered in isolation; if the volume of water is large, failing to recycle it would represent a waste. If all other indicators meet the requirements but only the COD level is high, it is possible to add a small amount of water first, and by continuously monitoring the parameters of the circulating water, an appropriate amount can be determined. In my opinion, this approach is feasible.
Here, when reclaimed water is added to the circulating water, the water quality turns dark and its turbidity increases. The COD for reclaimed water is around 70.
When the COD level is too high, excessive chemicals must be added to prevent corrosion; and in order to treat the wastewater, more wastewater is generated, which is undoubtedly a solution that only masks the problem temporarily. That \"expert\" in your company who handles circulating water descaling is probably a fraud.
I really don’t know where the person who came up with this suggestion graduated from, nor what the principle behind reducing COD is. COD fosters the growth of bacteria and produces organic acids; it also causes coking when exposed to high-temperature heat streams. I truly can’t think of any way to reduce scaling. ;P;P:victory::victory:
The reason for the decrease in COD is likely, as you said, bacterial metabolism, or coking that deposits in the equipment or jackets. Additionally, it is also possible that during cooling by the fan, some volatile substances are evaporated into the air by the fan. Compared to wastewater, I think waste gas is more difficult to deal with.
Cramming at the last minute does more harm than good! It’s better to handle things honestly; reducing COD isn’t a difficult technical task at all!