Reasons for low pH in electrodialysis drainage and countermeasures

Cause analysis: Excessive system concentration ratio: When the system’s concentration ratio is too high, the dissolved substances in water (including acidic substances) become concentrated to a greater extent, resulting in a lower pH value of the wastewater. A decrease in the system’s pH causes some of the precipitates (scale) to dissolve: If the system’s pH level drops for some reason, the precipitates or scale layers that have formed earlier may dissolve again, releasing acidic substances that lower the pH of the wastewater. Changes in make-up water: If the pH of the make-up water is low or it contains acidic substances, then the pH of the electrodialysis wastewater after mixing may also decrease. System contamination due to leakage: The leakage or contamination of external acidic substances can cause changes in the water quality within the system, including a decrease in pH value. Improper addition of water treatment chemicals: During the water treatment process, if chemicals are added improperly (such as in excessive amounts or with the wrong type selected), it can have a negative impact on water quality, including a decrease in pH levels. Recommendation: Adjust the system concentration ratio – increase the amount of wastewater discharged in order to reduce the system’s concentration ratio, thereby preventing an excessive accumulation of acidic substances. Adjusting the system pH: Monitor and adjust the system’s pH to prevent precipitation from dissolving due to excessively low values. If necessary, alkaline substances can be added to raise the pH value. Check and adjust the quality of make-up water: Ensure that the pH value and quality of the make-up water meet the system’s requirements. If there are issues with the supplementary water, corresponding measures need to be taken to improve the situation. Identify and address sources of leakage and contamination: Conduct a thorough inspection of the system to locate potential sources of leakage and contamination, and take appropriate measures to repair and address them. Standardize the addition of water treatment chemicals: Add water treatment chemicals strictly in accordance with the operating procedures to ensure that the dosage, type, and timing are all correct. Strengthen water quality monitoring and record management: Regularly monitor and record water quality to identify problems in a timely manner and take appropriate actions to address them. At the same time, strict management is applied to shift handover records to ensure the accuracy and completeness of the information. Improve the skills and awareness of operators: Strengthen training and education for operators to enhance their professional skills and environmental awareness. Ensure that they are proficient in the operating procedures and emergency response methods, in order to avoid water quality issues caused by improper operations.