The following is a detailed operation guide for the cleaning and maintenance of sulfide acidification blow off system, covering key steps, precautions, and maintenance points:
1、 System Overview
The sulfide acidification blow off system is mainly used for the pretreatment of sulfides in water samples, releasing H ₂ S gas through acidification and enriching it through nitrogen blowing. Its core components include reaction bottles, gas conduits, absorption devices, temperature control modules, and air pumps. Regular deep cleaning and maintenance are crucial for ensuring accuracy and extending lifespan due to long-term exposure to corrosive/toxic substances such as strong acids and hydrogen sulfide.
2、 Daily cleaning standards
1. Instant rinse (after each use)
Reaction unit: Immediately rinse the reaction bottle, bottle cap, and sealing ring with deionized water to remove residual acid. Do not use a hard brush to scratch the inner wall to prevent scratches from breeding and hanging on the wall.
Gas system: Disconnect all interfaces and blow the pipeline in reverse with compressed air for more than 30 seconds to discharge residual gas; Wipe and disinfect the outer wall with 75% ethanol.
Absorption bottle: After emptying the waste liquid, inject 10% NaOH solution and soak for 10 minutes to neutralize the acidic residue, then rinse with pure water until neutral.
3、 Periodic maintenance strategy
1. Quarterly comprehensive maintenance
Sealing test: After assembling the system, introduce low-pressure nitrogen gas and apply soapy water to check all interface bubbles. If there is a leak, replace the silicone gasket or adjust the clamp torque.
Sensor calibration: For pH electrodes (if equipped), use standard buffer solutions (pH=4.01, 6.86) for two-point calibration. If the deviation is greater than ± 0.1, it needs to be returned to the factory for maintenance.
Bearing lubrication: Remove the protective cover of the air pump drive shaft and add high-temperature resistant silicone grease (such as Dow Corning # 4), with a dosage not exceeding the size of rice grains.
2. Annual hardware upgrade
Pipeline replacement: When the PTFE conduit turns yellow and hardens, replace it as a whole to prevent the risk of bursting.
Valve maintenance: Disassemble the check valve spring assembly, soak it in solvent to remove polymer deposits, dry it, and reassemble it to test its opening and closing flexibility.
Circuit dust removal: Open the control box cover, use a leather tiger with a soft bristled brush to remove dust from the PCB board, and focus on cleaning the oxide on the relay contacts.
4、 Special pollutant disposal plan
1. Removal of sulfide crystals
Phenomenon recognition: Yellow flocculent sediment adheres to the inner wall of the pipeline, accompanied by a decrease in flow rate.
Treatment method: Prepare a mixed solution of 5% sodium citrate and 0.5% EDTA and rinse for 2 hours, using chelation to dissolve the ferrous sulfide scale layer.
2. Response to heavy metal pollution
Emergency measures: If mercury containing waste liquid is accidentally spilled, immediately sprinkle sulfur powder to cover it and form HgS solid. Collect it and hand it over to the hazardous waste organization for disposal.
Subsequent verification: Mercury residues in the affected area should be detected using an atomic fluorescence spectrometer until they are below the detection limit before resuming use.
5、 Maintenance record management
Establish an electronic ledger to record the following information:
Time node: specific date and duration of each cleaning/maintenance
Execution personnel: Two person review and signature system
Consumable batch: Product number of replaced gaskets, filter membranes, etc
Abnormal remarks: Text description and photo archive of situations such as cracks, odors, etc. found