Electroplating Wastewater Treatment
General comprehensive surface treatment companies, the company has chemical oxidation, anodizing, galvanized, galvanized nickel alloy, chrome plating, copper plating, gold plating, nickel plating, silver plating and other plating species, the resulting wastewater is very messy. The company's wastewater is divided into six categories during the construction of environmental protection facilities. They are: integrated wastewater, copper-containing wastewater, oily wastewater, cyanide-containing wastewater, chromium-containing wastewater, and deplate wastewater. There are many difficulties encountered in the actual wastewater treatment, resulting in the waste water treatment has not been met. The environmental protection design process for various wastewater treatment is as follows:
Integrated wastewater conditioning tank, reaction tank, sedimentation tank, bag-type biological filter tank, PH feedback tank, discharge port
Chromium-containing waste water
Chrome-containing wastewater conditioning tank, reduction reaction tank, integrated wastewater conditioning tank,
Cyanide-containing waste water
Cyanide-containing wastewater conditioning tank, secondary oxidation reaction tank, integrated wastewater conditioning tank,
Copper-containing waste water
Copper-containing wastewater conditioning tank, reaction tank, sedimentation tank, integrated wastewater conditioning tank,
Oil-containing waste water conditioning tanks, air flotation machines, integrated wastewater conditioning tanks,
Ask a professional and qualified environmental company to handle it. The wastewater treatment process is also used by most electroplating companies. It is quite representative. In practice, there are many difficulties that have caused most of the electroplating factories' wastewater treatment to fail to meet the standards. When the environmental monitoring work is getting stricter, Many electroplating factories cannot keep up with the pace of environmental protection. And the relocation of the factory or the suspension of the emission permit.
The difficulties in the integration are as follows:
1. Waste water mixing serious
Electroplating factory wastewater discharged serious confusion (The quality of employees is poor and they are arranged in a row to save time.) Wastewater is not categorized into categories. The chemicals used in each sort of wastewater are highly targeted in order to reduce costs.As a result, the wastewater of each category is poorly treated, and the integrated water is still not up to standard.
2. Use plenty of lime to make the water clear and reduce costs. However, a large amount of sludge is produced, and 30% to 40% of the cost of waste water treatment is generated by the treatment of sludge.
3. The PH value of tap water changes greatly, and the pH of the reaction tank is unstable. PH instability caused sedimentation tank turbidity. With the water quality is also unstable, good times and bad.
4. The treatment of different metal ions with different pH conditions conflicts and is not considered during design. The precipitation effect of zinc and aluminum in 7 to 8 is good, and the precipitation produced by zinc and aluminum will be dissolved when the pH is increased. Nickel, copper and phosphorous require a higher pH.
5. The water treatment staff is not very responsible and does not exercise sufficient care and attention to detail. For example: There is a problem with incoming water, and the emergency treatment is not stopped in time. Various instruments and probes are not regularly calibrated and cleaned. The concentration of formulated drugs is not prepared according to the process requirements. In order to save time, the concentration is changed without permission.
6. Surface treatment industry products must undergo a lot of pre-treatment before surface treatment. The oil-removing powder used here contains emulsifiers, and a large amount of emulsifiers not only affect the content of COD, And affect the flocculation of sedimentation tanks, Into the mud is not ideal, resulting in precipitation is bad, A large amount of suspended matter follows the upper layer of purified water and flows out of the sedimentation tank. Re-dissolved in the water when the PH callback, resulting in excessive discharge of heavy metal ions.
7. Copper and nickel ions are the most commonly occurring pollution factors among all overweight heavy metals. In particular, copper ions often exceed the standard after using expensive heavy metal trapping agents. Is the presence of some strong complexing agents, for example: ammonia, pyrophosphate, low-cost phosphate, organic acids.
8. The COD of general surface treatment plants is only about 200 to 300, and they can meet the standard with a little treatment. However, some plants with electroless plating and small iron parts, such as plating screws, are protected by a large amount of oily substances. A large amount of oil pollution caused by the degreasing process before production enters the sewage station, and the COD content reaches 500 or more, the COD content of the electroless plating mother liquor can reach 20,000.
9. For some plants that use more cyanide, the cyanide treatment is incomplete, which is a very bad factor for subsequent heavy metal ion standards.
1. A number of combined treatment of the wastewater treatment process was performed using Kangding's water treatment agent. For example, the copper-bearing water is mixed into the chromium-containing waste water (because phosphorus copper is very unstable under acidic conditions), the oil-containing waste water is mixed into the cyanide-containing waste water, and the COD can be properly removed during the secondary oxidation of the cyanide water.
The top leader of Kangding Company took the lead to set up a sewage discharge monitoring team to conduct irregular inspections on the drainage of workshops.To urge the staff of the workshop and the management staff to pay attention to the discharge of sewage, The top leaders focus on monitoring goals in their safety and environmental protection. Let all employees and employees of the company realize that the company can reduce part of the company's normal operation. If the environmental protection is not up to standard, it will be a fatal blow to the company!
2. Use a new type of water treatment agent instead of lime and caustic soda. There are XX water treatment neutralizers available on the market. The effect is comparable to Caustic soda, and the price is between lime and caustic soda. The corresponding pharmaceutical dosage is reduced, and the output of sludge is also greatly reduced. The overall calculation reduces the cost.
3. Add a set of PH probes in the integrated water conditioning tank to test the pH of incoming water. And the adjustment pool pumping water to the reaction pool lift pump linkage, set the PH is greater than 5 automatic shutdown. The reaction pool is equipped with special person for PH detection. Now everyone is using the PH automatic adding system. But there are a lot of factors that affect the PH, For example: the probe is not accurate, uneven mixing, water fluctuations, dosing pump flow can not keep up and so on. It is also recommended to use PH test paper for frequent detection to ensure PH stability.
4. Treatment of sewage with a higher pH is now mixed together for pretreatment. In this way, the low pH can be controlled in the integrated reaction pool, which can save part of the alkali, and the acid that is later PH reversed, and it can ensure that the pH of the outlet is stable.
5. The work is planned and tabulated, and the responsibility for manipulating staff is personal. To make it work can consciously follow the operating process. In order to regulate the situation of the sudden law, it is necessary to stop the test in time. Solve the problem before starting processing.
6. Adding 80 mesh activated carbon to the integrated conditioning pond for adsorption increases the amount of coagulant aid.
7. The collection of heavy metals such as copper and nickel in the workshop can collect heavy metals and have certain economic value.
8. Chemical nickel waste liquid can be collected as much as possible by a professional environmental protection company. For pre-treated water containing a large amount of oil, a detonation tube can be set up in the comprehensive adjustment tank for detonation and a certain amount of activated carbon can be added.
9. The treatment of cyanide must be completely treated. Excessive bleaching water can be detected with starch-potassium iodide test paper.