The sulfide acidification blow off system is a core process used for efficient removal of soluble inorganic sulfides in industrial wastewater treatment, and its commissioning quality directly affects the treatment efficiency and operational stability. The following are the key steps and technical points of systematic debugging:
1、 Preparation before debugging
1. Equipment integrity verification
Count all equipment (acid metering pump, pH online instrument, Roots blower, blow off tower packing, tail gas absorption device, etc.) against the design drawings, with a focus on checking the sealing of pipeline connections, especially the pressure test required at the outlet flange and valve of the acid storage tank.
Ensure reliable grounding of the electrical control system, and use explosion-proof motors with static discharge devices in explosion-proof areas.
2. Preparation of chemical reagents
Prepare a dilute sulfuric acid solution with a concentration of 5% -10% as an acidifier and store it in a corrosion-resistant storage tank; Sodium hydroxide solution is used for emergency neutralization.
Calibrate the pH meter and ORP probe using the two-point calibration method with standard buffer solution, and the error should be controlled within ± 0.1.
2、 Sub item functional testing
1. Debugging of acid dosing system
Start the metering pump in manual mode, observe the flow status of the burette, and eliminate the air in the pipeline; Set low/high liquid level alarm thresholds and simulate acid deficiency conditions to verify the interlock shutdown function.
The theoretical dosing ratio is determined through a stepwise acid addition experiment, and the typical control objective is to reduce the pH of the influent to the range of 3.0-4.5.
2. Blow off unit no-load test
Turn on the Roots blower, gradually adjust it to 70% of the design air volume, and run continuously for 2 hours to detect the vibration amplitude of the tower body (≤ 0.1mm/s); Check the pressure drop change of the packing layer, which should be less than 2kPa normally.
Spray system water pressure test to ensure that the atomizing nozzle is unobstructed and covers over 90% of the area.
3、 Whole process linkage debugging
1. Progressive inflow treatment
In the initial stage, low concentration simulated wastewater (such as Na ₂ S solution) is introduced, and the acid addition and air blowing system are synchronously activated to monitor the pH and dissolved oxygen content of the effluent in real time.
Establish a three-dimensional relationship curve of "inflow flow rate acid consumption stripping efficiency", optimize PID control parameters to stabilize pH within the target range.
2. Key node regulation
Control the hydraulic retention time (HRT) of the acidification section to be ≥ 15 minutes, ensuring that S ² ⁻ is fully converted into H ₂ S;
The gas-liquid ratio in the stripping section is maintained at 15:1-25:1, and precise control of the ratio can be achieved by adjusting the fan frequency conversion;
The circulation flow of alkali solution in the tail gas absorption tower needs to be matched with the exhaust gas emission to prevent secondary pollution.
4、 Performance validation and optimization
1. Load impact test
Suddenly increasing the concentration of sulfide in the incoming water to the design upper limit, the observation system should return to steady state time, and excellent systems should reach the standard again within 60 minutes.
Collect and send water samples to the laboratory for analysis, and calculate whether the removal rate is ≥ 95% (first level standard).
2. Energy balance adjustment
Dynamically adjust the fan frequency according to the actual processing capacity to avoid excessive aeration;
Pre store prepared acid solution during low electricity price periods at night to reduce overall operating costs.
5、 Safety protection and emergency response
Compulsory ventilation in the work area, equipped with a portable H ₂ S detector (alarm threshold set to 5ppm);
On site storage of emergency flushing equipment, with operators wearing gas masks and acid and alkali resistant protective clothing;
Develop emergency plans for sudden acid spills and clarify standardized processes for containment, neutralization, and cleanup.
Through the above structured debugging, the system can achieve safe and stable operation while ensuring processing efficiency. After debugging is completed, a continuous 72 hour full load assessment is required, and all indicators must be met before entering the formal operation phase.