DY-227 electrolytic treatment of chromium-containing electroplating wastewater training platform
Release time：2024-06-23 16:00viewed：times
1. Experimental principle and purpose:
1. Understand the process flow of electrolytic treatment of chromium-cont*ning electroplating wastewater.
2. Deepen the understanding of the basic concepts of the experiment and improve theoretical and practical knowledge.
Principle:
In acidic chromium-cont*ning wastewater, chromium m*nly exists stably in the form of CY2O7=, but there is also a small amount of CYO4=.
Use iron plates as cathodes and anodes, and add a cert*n amount of salt to the wastewater to increase the conductivity and activate the anode. Stir with compressed *r and use low-voltage direct current for electrolysis. Under acidic conditions, the iron anode is dissolved by the current, generating divalent iron ions that enter the wastewater, reducing hexavalent chromium to trivalent chromium. When the trivalent chromium pH>5, chromium hydroxide precipitation is generated, and the water is discharged after separation of the precipitation.
Anode reaction: Iron loses electrons to become divalent iron, and ions enter the wastewater.
Fe-2e→Fe++
Divalent iron ions are a strong reducing agent that reduces hexavalent chromium in wastewater to trivalent chromium.
CY2O7=+6Fe+++14H＋→2CY3++6Fe3++7H2O
CYO4=+3Fe+++8H+→CY3++3Fe3++4H2O
Cathode reaction: Hydrogen ions are discharged at the cathode and become hydrogen gas. At the same time, a small amount of hexavalent chromium is discharged at the cathode and becomes hydrogen gas, which causes the pH value in the wastewater to gradually increase, causing the trivalent chromium to form chromium hydroxide precipitation and separate. Chromium hydroxide is easy to precipitate when pH>5, and at the same time, Fe3+ in the wastewater forms iron hydroxide precipitation.
CY3++3OH－→CY（OH）3↓
Fe3++3OH－→Fe（OH）3↓
After precipitation, it can meet the emission standards.
2. M*n technical indicators and parameters:
1. Chromium concentration in raw water: 50-150 mg/L
2. Electrolysis duration: 30-60 min
3. Salt addition: 1-1.5 g/L
4. Voltage: 7 volts to 10 volts
5. Current concentration: 0.6-0.75 amperes/liter
6. Power consumption: 2.76-3.76 kWh/m3 of water
7. Sediment volume (estimated): slag volume: 1 g/L (wastewater) (regular slag discharge)
8. Stirring gas volume: 0.075 m3/min = 4.5 m3/h
9. Electrode reversing time: 4-6 hours
10. PH before treatment = 3-5.5 PH after treatment = 5-7
11. Device dimensions: 1300 mm × 500 mm × 1300 mm,
12. Working power supply: AC220V±10%, 50Hz, single-phase three-wire system, power 500W, safety protection: with grounding protection, leakage protection, overcurrent protection
III. M*n configuration:
1. 1 raw water tank: white PP board material, thickness 10mm, 400×400×500mm, a dr*n valve is installed on the bottom plate to facilitate the dr*nage of water;
2. 1 clean water tank: white PP board material, thickness 10mm, 400×400×400mm, a dr*n valve is installed on the bottom plate to facilitate the dr*nage of water;
3. Equipped with 1 raw water tank stirring motor and 1 set of 304 st*nless steel stirring paddles; (power 25W, speed 120rpm), (including 1 speed regulator)
4. 1 set of electrolytic cell, including: 10 pieces of 304 st*nless steel electrode plates and graphite plates, transparent organic glass material, wall thickness 10mm, 300×200×250mm, including 1 DC stabilized power supply,
5. Vertical flow sedimentation tank, transparent organic glass material, wall thickness 8mm, Ø 250×300mm;
6. 1 anti-corrosion lifting magnetic pump, flow rate: 16~19 (L/min), head: 2.7~3.4 (m), power 20W;
7. 1 *r pump, power: 20 W, maximum gas volume: 6L/min, with 1 set of microporous aeration tubes,
8. Flow measurement and regulation: 1 rotor flowmeter, (LZS-15, range 6~60L/h)
9. Flow measurement and regulation: 1 gas flowmeter, (LZB-10, range 100~1000L/h)
10. Experimental table (white 10mm thick PP board),
11. Power control system: 1 double-sided matte dense pattern spray-p*nted electric control box, leakage protector (Delixi brand), voltmeter, lockable button switch, wire pipe, etc.,
12. Equipped with UPVC connecting pipes and valves (Zhongc* brand).
13. St*nless steel frame test bench (30mm×30mm st*nless steel square tube, equipped with universal casters with locking feet).
14. Virtual simulation software for electrical installation of building and intelligent building Based on unity3d design, users can choose different sizes of interactive interface according to computer configuration, and can choose six levels of image quality. The model in the software can be rotated 360°, enlarged, reduced, and translated. There are assistant prompts during the use of the software, as follows: A. Wet alarm system 1. System overview: Overview of wet alarm system
2. Equipment recognition: It has the best viewing angle, equipment det*ls (displaying the introduction or parameters of the equipment), exercises (built-in 6 multiple-choice questions, with prompts for correct and incorrect choices), and schematic diagrams (you can enter the equipment from the schematic diagram). The equipment includes: sprinklers, water flow indicators, signal butterfly valves, exhaust valves, fire alarm controls, high-pressure gauges, high-level water tanks, Wia control cabinets, pressure-stabilizing tanks, flow switches, terminal water testing devices, dr*nage facilities, water pump connectors, hydraulic alarms, timers, wet alarms, butterfly valves, check valves, fire pumps, safety pressure-stabilizing valves, and fire water tanks.
3. Principle display: Displays the working principle of the wet alarm system, 3D animation demonstrations, and semi-transparent 3D models so that the internal water flow can be seen. Equipped with practice module (built-in 4 multiple-choice questions, with prompts for correct and wrong choices)
4. Design layout: There are multiple-choice questions and calculation questions, each of which is scored, and the correct answer and score will be displayed after submission
B. Gas fire extinguishing system
1. System overview: Overview of gas fire extinguishing system
2. Equipment cognition: It is equipped with the best viewing angle, equipment det*ls (displaying the introduction or parameters of the equipment), practice (built-in 8 multiple-choice questions, with prompts for correct and wrong choices), schematic diagram (you can enter the equipment from the schematic diagram). The equipment includes: nozzle, HFC-227 storage bottle, bottle head valve, heptafluoropropane check valve, high-pressure hose, gas check valve, safety valve, weighing alarm, electromagnetic starter, selection valve, smoke alarm, fire alarm controller.
3. Principle display: Display the working principle of the gas fire extinguishing system, 3D animation demonstration, 3D model is semi-transparent, and the internal gas can be seen. Equipped with practice module (built-in 3 multiple-choice questions, with prompts for correct and wrong choices)
4. Design and layout: There are 6 multiple-choice questions, each with scores, and the correct answer and score will be displayed after submission
. C. Escape drill: Teaching in the form of fun games, escape from the burning room within a limited time, and wrong choices will directly enter the score interface.
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