What Aspects Should Be Paid Attention to in the Daily Maintenance of Purified Water Equipment?

1.Pretreatment Unit: The First Line of Defense to Protect Core Components

Pretreatment needs to remove impurities in raw water to avoid blockage or damage to subsequent equipment. Four types of components need to be maintained:

Quartz Sand Filter: Backwash once every 1-2 months (pressure 0.2-0.3MPa, duration 15-20 minutes) to rinse the intercepted sediment and colloids; replace the quartz sand every 1-2 years (shorten the cycle when the raw water turbidity >5NTU) to ensure the effluent turbidity <1NTU and prevent RO membrane blockage.

Activated Carbon Filter: Backwash once a month, replace the activated carbon every 6-12 months (replace in advance if the effluent residual chlorine >0.1mg/L); select food-grade carbon with an iodine value ≥1000mg/g, and regularly detect the effluent TOC to avoid releasing organic matter to pollute water quality after adsorption saturation.

Softening Resin Filter: Regenerate with 8%—10% industrial salt water every 3-6 months (soak for 4-6 hours), rinse after regeneration until the effluent hardness <0.03mmol/L; replace the resin every 2-3 years. If the effluent hardness exceeds the standard, check whether the resin is aging or the regeneration device is faulty.

Precision Filter: Replace the 5-10μm PP cotton filter element every 1-3 months, and replace it immediately when the pressure difference between the inlet and outlet >0.1MPa; empty the accumulated water and check the sealing rubber ring during replacement to prevent unfiltered water from seeping into the RO system.

2.Core Purification Unit: The Key Link to Ensure Water Production Purity

The core unit determines the water quality grade, and targeted prevention of blockage and performance attenuation is required:

RO Reverse Osmosis System: Clean once every 1-2 weeks (emergency cleaning when the pressure difference >0.07MPa), use acidic cleaning agent (citric acid) to remove calcium and magnesium scaling, and alkaline cleaning agent (sodium hydroxide) to remove organic matter; control the inlet water temperature at 15-35℃ and pH at 2-11, replace the RO membrane every 2-3 years (replace when the produced water TDS increases by 30%), and conduct membrane integrity test regularly.

Ion Exchange Resin: Regenerate every 1-2 months (regenerate when the produced water resistivity <1MΩ・cm). For mixed beds, backwash and stratify first, then regenerate the cation resin with 5% hydrochloric acid and the anion resin with 8% sodium hydroxide; replace the resin every 3-4 years. For organic pollution, clean with sodium hypochlorite, and for iron pollution, treat with citric acid.

EDI Module: Clean and descale with 1%—2% citric acid every 3-6 months, control the inlet water TDS <500ppm and hardness <0.1mmol/L; replace the module every 3-5 years, monitor the current and voltage during operation to avoid overload burnout.

3.Post-Treatment and Monitoring: Prevent Secondary Pollution + Dynamic Control

Post-Treatment Maintenance: Replace the ultraviolet germicidal lamp every 6-12 months, and wipe the quartz sleeve with alcohol every 3 months; replace the terminal 0.22μm filter element (pharmaceutical grade) every month, and disinfect the interface before replacement; perform online sterilization (SIP) on pharmaceutical-grade equipment every month to ensure no microbial growth on the parts in contact with water.

Monitoring and Recording: Record the produced water resistivity, TOC, flow rate and pressure daily, and conduct a full-scale water quality test every quarter; establish a maintenance account, mark the replacement time of components, and shut down and investigate immediately in case of abnormalities (such as a sharp drop in resistivity) to ensure long-term stable operation of the equipment and the produced water meets industry standards.