Common heavy metal wastewater treatment methods in sewage treatment
In China, many sewage units have spent huge investment because they have not found a suitable wastewater treatment plan, but the heavy metal wastewater cannot meet the standard after treatment; or the operating cost of the wastewater treatment facility is too high after the completion of the wastewater treatment facility, resulting in expensive heavy metal wastewater treatment. Equipment has become a decoration, these are very common phenomena! Heavy metal wastewater is common in electroplating, electronics industry and metallurgical industry, especially electroplating, electronics industry wastewater, its composition is very complex, in addition to cyanide wastewater and acid-base wastewater, according to The heavy metal elements contained in heavy metal wastewater can be classified into chromium (Cr)-containing wastewater, nickel (Ni)-containing wastewater, cadmium (Cd)-containing wastewater, copper (Cu)-containing wastewater, zinc (Zn)-containing wastewater, and zinc (Zn)-containing wastewater. Gold (Au) wastewater, silver (Ag) wastewater, etc. The heavy metals in wastewater cannot be decomposed and destroyed by various common methods, but can only transfer their location and change their physical and chemical forms. The metal ions in the wastewater are transferred to the ion exchange resin, and then transferred from the ion exchange resin to the regeneration waste liquid after regeneration. After the heavy metal wastewater is treated, two products are formed, one is the treated water from which heavy metals are basically removed, and the other is the concentrated product of heavy metals. The treated water whose heavy metal concentration is lower than the discharge standard can be discharged; if it meets the production process water requirements, it is best to reuse it. Heavy metal wastewater treatment methods usually include precipitation method, physical chemical method, electrochemical treatment technology, and biochemical method. The above-mentioned methods have their own advantages and disadvantages. When using these methods, it is necessary to design the scheme according to the specific characteristics of heavy metal wastewater. . In many cases, a single method is often difficult to achieve better results, and the use of two or more methods at the same time can achieve the purpose of treating heavy metal wastewater better and faster.