I. Pretreatment stage: Optimize influent conditions (reduce load at the source)
Control of suspended solids in influent
When the suspended solids in the raw water are greater than 10 mg/L, a quartz sand filter or sedimentation tank should be added to intercept silt and algae; an 80-100 mesh filter screen should be installed on the inlet pipe and cleaned once a month to prevent clogging of the aeration heads and filter media.
Stable aeration conditions
Clean the blower inlet filter weekly to avoid insufficient airflow; check the aeration head pores monthly and soak them in 5% hydrochloric acid (shorten to every 2 weeks for high-hardness water) to unclog pores blocked by iron and manganese oxides and calcium and magnesium scale.
Install an online DO monitor to ensure that the dissolved oxygen in the influent is ≥5mg/L; if the organic matter in the raw water is high (COD>30mg/L), a small amount of sodium hypochlorite can be added to assist oxidation and avoid excessive oxygen consumption.
＜5mg/L 时 6-8m/h,5-10mg/L 时 5-6m/h;
The filtration rate should be adjusted according to the iron and manganese content: 6-8 m/h for <5 mg/L, and 5-6 m/h for 5-10 mg/L;
Backwash once a day. If the pressure difference is >0.04MPa, backwash in advance. Use air and water to backwash for 10-15 minutes to ensure the filter bed expansion rate is 40%-50%. After the drainage is clear, backwash for 5-8 minutes.
Avoid parameter mutations
When starting or stopping the equipment, open or close the valves slowly (time > 30 seconds), and do not repeatedly start or stop in a short period of time;
When the pH of the raw water is <6.5, sodium hydroxide is added to adjust it to 7.0-8.0 to promote the oxidation of iron and manganese.
Take samples of manganese sand every 3-6 months: if the surface turns white, is non-sticky, or the particle size is <0.4mm, replace 30% of the filter media (retain the old filter media to accelerate biofilm formation);
Replace the entire filter after 5 years of use; after backwashing, check the drain valve and filter screen, and replace any damaged ones promptly to prevent filter media loss.
管路与阀门保养 Pipeline and valve maintenance
Daily inspections of pipelines, valves, and pressure gauges; monthly lubrication of valve screws; quarterly calibration of pressure gauges. Replace the flange seal every six months to prevent water and air leaks.
Aeration device maintenance
Check the aerator heads for blockages monthly and soak and clean them with dilute hydrochloric acid (5% concentration);
For high-temperature water (40-60℃), replace the aging-resistant aeration membrane every 2 years to prevent a decrease in oxygen transfer efficiency.
IV. Monitoring and Data Analysis (Early Warning of Faults)
Key parameter monitoring
.
Record daily DO, differential pressure, backwash frequency, and effluent iron and manganese content; analyze data trends weekly. If effluent iron and manganese levels rise by more than 0.1 mg/L for three consecutive days, immediately check for aeration head blockage or filter media aging.
Establish and maintain archives
Develop annual, quarterly, and monthly maintenance lists (such as quarterly water distributor inspections and annual lubricant replacements) to avoid maintenance omissions.
High-temperature water quality (40-60℃) : Shorten the cleaning cycle of aeration heads to once every 2 weeks, and increase the backwashing frequency to once a day to avoid rapid clogging of the biofilm caused by high temperature; select high-temperature resistant and anti-aging EPDM rubber aeration membranes.
For high-hardness water (calcium and magnesium ions > 200 mg/L) : Soak pipes in 0.5% citric acid every quarter to prevent calcium and magnesium scaling; control backwash intensity at 12-15 L/(m²・s) to avoid filter media loss.
By implementing the above measures, the failure rate of aeration systems can be significantly reduced, equipment lifespan extended (8-12 years with proper maintenance), and operating costs reduced by more than 30%. It is recommended to establish a management system that prioritizes prevention and supplements it with emergency repairs, based on the equipment manual and actual water quality adjustments.
