Use of HEDP-Kx Hydroxyethylidene Diphosphonic Acid in Recycled Water Treatment
- 674668073
- Mar 11
- 3 min read
In circulating water treatment, the use of Hydroxyethylidene Diphosphonic Acid Potassium (HEDP-Kx), as a highly efficient scale and corrosion inhibitor, is of utmost importance. The following are the specific steps and precautions on how to use HEDP-Kx correctly based on the available information:
1. System Pretreatment
Before adding HEDP-Kx to a circulating water system, it is often necessary to pretreat the system to improve the stability and water solubility of the agent. This may involve cleaning the system of old scale layers and other impurities to ensure system cleanliness.
6. In addition, the pH of the system needs to be adjusted, as HEDP-Kx has a high solubility under neutral conditions.
2. pH Adjustment
In order to ensure the best results of HEDP-Kx, it is recommended that the pH of the circulating water be controlled within a suitable range. In general, HEDP-Kx is suitable for environments with a pH between 6.0 and 8.0. If the pH value is too high or too low, it may affect the effectiveness of HEDP-Kx and the formation of protective film on the metal surface. Therefore, the pH should be properly adjusted to the desired range by adding acid or alkali before dosing.
3. Regular analysis and monitoring
It is very important to monitor the water quality parameters regularly during use. Key indicators such as total phosphorus content, calcium hardness, magnesium hardness and other key indicators in circulating water should be tested regularly and the dosage of HEDP-Kx should be adjusted according to the actual situation. For example, the free chlorine concentration in the water can be measured to assess the microbial control; the measurement of chemical oxygen demand (COD) trends can help to understand the degree of organic pollution; and the presence or absence of residual chlorine is also extremely critical to prevent microbial reproduction.
4. Dosing method
Manual dosing
For small or temporary circulating water system, can be used manually directly to the storage tank or collector well to add the appropriate amount of HEDP-Kx solution. However, this method is difficult to accurately control the dose and is likely to cause local concentration of too high a problem.
Automatic dosing system
A more recommended approach is to utilize an automatic dosing system for accurate dosing. This type of system automatically adjusts the rate of HEDP-Kx injection based on real-time monitoring data, ensuring that the drug concentration is evenly distributed throughout the system. There are two main types of automatic dosing systems: one is a monitoring device based on fluorescence technology, and the other controls the concentration of the drug in the water based on changes in conductivity.
5. Cautions
Avoid over-concentration: While increasing the concentration rate can help to save water and reduce costs, it can increase the risk of scaling and reduce the effectiveness of the HEDP-Kx if the circulating water is overloaded with hazardous substances. Therefore, it is important to find a balance that maintains a reasonable level of concentration without causing deterioration in water quality.
Preventing microbial contamination: Even with good physico-chemical conditions, the influence of biological factors cannot be ignored. Microbial slime not only affects heat transfer efficiency, but also accelerates equipment corrosion. Therefore, in addition to the use of HEDP-Kx, it should be combined with other means such as regular cleaning, disinfection and other measures to jointly maintain good water quality conditions.
Consider seasonal variations: Different seasons may bring different water quality challenges, such as high temperatures in the summer when microbial growth is rapid, and cold winters that may cause certain components to crystallize and precipitate. Therefore, it is important to take these factors into consideration when developing your annual maintenance program and adjust the dosage of HEDP-Kx and other auxiliary chemicals as appropriate.
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