High iron content in circulating water
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This post was last edited by cdpulin on 2009-9-22 at 10:20. At the beginning of operation of our company’s circulating water system, the iron content gradually increased while the turbidity decreased rapidly. Currently, our waste discharge pipes lead only to rainwater drains and not to wastewater treatment facilities. From an environmental perspective, it is not possible to discharge the water directly into rainwater drains. Does anyone have any experience in reducing iron levels when it is not possible to discharge the waste? ? ? Urgent
It is quite normal for new pipe drainage systems to have a high iron content; it is precisely because of this high iron content that the turbidity can be reduced, due to the effect of iron ions or flocculation. Check whether the pH of the circulating water meets the specified requirements; if the pH is low, the iron content will also be high, as acidic corrosion is intensified ； It is best not to discharge circulating water into the rainwater drainage system, as it contains chemicals that can cause pollution if it enters the rainwater. It is appropriate to reuse this circulating water or send it to a wastewater treatment plant.
The pH of the circulating water should be at the normal level of 7.7, right? What you mentioned about not discharging it into the rainwater drains cannot be done for now; so under such circumstances, how can we lower the iron content?
This post was last edited by cdpulin on 2009-9-22 at 10:19. If water is not drained, an increase in level is inevitable. Moreover, if the slope of this increase becomes steeper, it means that the chemicals you are using are not effective, or the pre-coating process has not been carried out properly; in such cases, more effective water treatment chemicals are needed. Or equipment can be added to process iron.
Since new systems generally require cleaning and pre-coating, the cleaning process is aimed at removing iron filings and rust from the system, so that these substances do not end up in the water as iron ions during operation, as this would accelerate the corrosion of the system. Without cleaning or pre-coating, an increase in iron ions is inevitable. Currently, reducing the level of iron ions can be achieved through coagulation treatment or ion exchange.
This post was last edited by li*ch1968 on 2009-9-22 at 18:47. Let Lagun take care of the pipelines temporarily; without proper drainage of the circulating water, stable operation is not possible. The iron ion level is high; change the water immediately, otherwise corrosion in the system will be severe.
Generally, a cleaning and pre-coating process is required before putting a new system into use; depending on the situation, you haven’t done this. After the system is started, the reason for the increase in total iron content is that the corrosion products on the pipe wall are washed away, resulting in an excessively high level of total iron ； 2 The system load is too low; the water has corrosive properties, resulting in system corrosion ； Based on what you’ve described, the iron level in the system is rising while the turbidity is decreasing; it is suspected that this is caused by an excessively low pH value. Please pay attention to the pH of the cooling water. To find out the reason for the low pH, investigate 1) the pH of the make-up water, and 2) any acid leaks