1、 Zero discharge of electroplating wastewater The treatment method is as follows.
Collect the wastewater from electroplating pretreatment into the organic wastewater collection well. When the level of the collected electroplating wastewater reaches the design height, raise the pump to start, and the pump flows into the regulating tank.
Copper plating cleaning water, nickel plating cleaning water and chromium plating cleaning water are pumped into the chemical reaction tank respectively by their respective lift pumps. Copper plating cleaning water, nickel plating cleaning water and chromium plating cleaning water are respectively the waste water from the first cleaning tank during the tank cycle. The heavy gold ion particle size in the waste water is increased by chemical precipitation method to form the hydroxide and sulfide of the metal. The settled high concentration metal salt waste water pump flows into the low-temperature evaporation equipment to obtain solid metal salt, the distilled water flows into the regulating tank, and the supernatant pump of each chemical sedimentation tank flows into the regulating tank. The wastewater from the regulating tank flows into the hydrolysis acidification tank → anoxic tank → contact oxidation tank → circulating tank of the external membrane bioreactor in turn, and is pumped into the tubular microfiltration membrane system set outside the biological treatment tank from the large flow circulating pump. The tubular microfiltration membrane system filters the wastewater under the promotion of the circulating pump. The first is that the high-pressure pump absorbs water from the microfiltration tank, the pump flows into the reverse osmosis membrane separation system, the reverse osmosis permeate flows into the recovery tank to supplement the electroplating production line cleaning water, and the concentrated water flows into the concentration tank; the second is that the high-pressure pump absorbs water from the concentration tank, the pump flows into the reverse osmosis circulating concentration system, and the permeate of the reverse osmosis concentration system flows into the microfiltration tank. Evaporate the pure metal, recover the heavy metal salt, and the distilled water flows into the regulating pool.
2. According to the method of zero discharge treatment of electroplating wastewater, the electroplating wastewater collection system includes a cleaning tank, an organic wastewater collection well, a regulating tank and a chemical reaction tank. A drainage outlet is set at the bottom side of the cleaning tank, the drainage pipe flows into the organic wastewater collection well, and the ground cleaning water flows into the organic wastewater collection well along the ground ditch. When the liquid level in the well reaches the design high water level, The lift pump is started, the organic wastewater in the collection well is transported to the regulating tank for pre aeration, and the pH value is adjusted to neutral.
3. According to the characteristics of the required zero discharge treatment method for electroplating wastewater, in B, the particle size of heavy metal ions in the wastewater is specifically put into sodium hydroxide, sodium sulfide and other agents through chemical precipitation to increase the particle size of heavy metal ions in the wastewater.
4. The zero discharge treatment method for electroplating wastewater according to requirement 1 is characterized by setting a liquid level controller in the circulating pool in D. When the liquid level reaches the design high level, the circulating pump starts, and when the liquid level of the tubular microfiltration membrane system drops to the design low level, the circulating pump stops.
5. The zero discharge treatment method for electroplating wastewater as required in claim 1 is characterized in that in step D, the filtering system filters the wastewater under the drive of the circulating pump, and also includes that the concentrated water of the tubular membrane microfiltration system flows into the hydrolysis acidification pool in the biological treatment process.
6. The zero discharge treatment method for electroplating wastewater as required in requirement 1 is characterized by that in step e, the first is that the high-pressure pump is a vertical multistage centrifugal pump with a pressure of more than 1.5MPa.
7. The zero discharge treatment method for electroplating wastewater according to claim 1, which is characterized by that in step e, the second is that the high-pressure pump uses a vertical multistage centrifugal pump with a pressure of more than 2.0Mpa.
8. The electroplating wastewater zero discharge treatment system is characterized by electroplating wastewater collection system, dosing system, chemical precipitation system, external membrane bioreactor treatment system, tubular microfiltration membrane system, reverse osmosis membrane separation and concentration system, low temperature evaporation system, water recovery and solid metal salt collection system, and electroplating wastewater collection system for electroplating wastewater collection When the collected electroplating wastewater is collected in the organic wastewater collection well and the collected electroplating wastewater surface reaches the design height, the lack of pumps will be improved. The dosing system flowing into the regulating tank will be recycled by adding the concentration pump of hydrogen peroxide filtration pump and sodium sulfide and other drug over concentration pumps, and concentrating the water flow through the concentration pump equipment of the concentration pump.
9. According to the electroplating wastewater zero discharge treatment system described in 8, it is characterized by that the electroplating wastewater collection system includes an organic wastewater collection well, multiple tanks, lift pumps, regulating tanks and chemical reaction tanks. There is a drainage outlet at the side of the bottom of the tank, the drainage pipe flows into the organic wastewater collection well, and the ground cleaning water flows into the organic wastewater collection well along the surface ditch. When the liquid level in the well reaches the design high level, The lift pump is started to transport the organic wastewater from the collection well to the regulating tank.
10. According to 8, the characteristics of the electroplating wastewater zero discharge treatment system are: first, the vertical multistage centrifugal pump is used as the high-pressure pump, and the pressure is above 1.5MPa; Second, the high-pressure pump is a vertical multistage centrifugal pump with a pressure of more than 2.0MPa.
