Science and technology is a double-edged sword. Since the 20th century, the rapid development of science and technology has promoted economic development and the improvement of people's living standards. However, at the same time, mankind has also paid a heavy price, all kinds of environmental pollution. Heavy metal wastewater refers to wastewater containing heavy metals discharged in industrial production processes such as mining and metallurgy, machinery manufacturing, chemical industry, electronics, instruments and meters. Wastewater containing heavy metals (such as cadmium, nickel, mercury and zinc). ) is one of the most serious industrial wastewater that pollutes the environment and harms human beings, and its water quality and quantity are related to production technology. In general, heavy metals in wastewater can not be decomposed and destroyed, but can only transfer their existing positions and change their physical and chemical forms. The treatment method is to reform the production process first, without using or using less toxic heavy metals. Chemical precipitation method and ion exchange method are often used for local treatment in the production site (if not discharged from the production workshop), and the treated heavy metals in the water can be discharged or reused if they are lower than the discharge standard. Heavy metals form new concentrated products, which can be recycled or treated harmlessly as much as possible.
How to treat heavy metal wastewater to achieve pollution-free discharge or even resource utilization depends on integrated sewage treatment equipment. Changzhou Cursor Technology Co., Ltd. has specially developed special environmental protection equipment for this environmental problem. Next, I will introduce the principle of integrated sewage treatment equipment for heavy metal wastewater treatment.
Heavy metals in wastewater can't be decomposed and destroyed by various common methods, but can only transfer their existing positions and change their physical and chemical forms. After treatment, heavy metal wastewater forms two products, one is the treated water from which heavy metals are basically removed, and the other is the concentrated product of heavy metals.
Treatment methods of heavy metal wastewater can be divided into two categories:
Firstly, the dissolved heavy metals in wastewater are transformed into insoluble heavy metal compounds or elements, which are removed from wastewater by precipitation and flotation. Neutralization precipitation, sulfide precipitation, flotation separation, ion flotation, electrolytic precipitation or electrolytic flotation, diaphragm electrolysis and the like can be applied.
Second, heavy metals in wastewater can be concentrated and separated without changing their chemical forms, and methods such as reverse osmosis, electrodialysis, evaporation and ion exchange can be applied. The processing principle is as follows:
1) electrolytic method:
It is widely used to treat cyanide-containing heavy metal wastewater. Cyanide and heavy metals in wastewater are removed by electrolytic oxidation to decompose cyanide and precipitate heavy metals into hydroxide. Pure mercury or mercury compounds can be effectively recovered by electrolytic treatment of mercury sulfide waste residue.
2) Floating method:
Heavy metal hydroxides and sulfides in wastewater can also be removed by blowing flotation, and the pressurized dissolved air flotation method is the most effective. Electrolytic flotation can effectively treat all kinds of heavy metal wastewater, especially wastewater containing heavy metal complexes.
3) ion flotation method:
Anionic surfactants, such as sodium xanthate, sodium dodecyl benzene sulfonate, gelatin, etc. It is added to heavy metal wastewater to form a surface active complex or chelate with heavy metal ions. Different surfactants have selective complexing effect on different metal ions or the same surfactant has selective complexing effect on different heavy metal ions at different pH values, so that heavy metals in wastewater can be separated by flotation.
4) Thin film method
There are mainly electrodialysis and reverse osmosis. The characteristic of electrodialysis is that the concentration multiple is limited, and it must be treated by multistage electrodialysis to concentrate the useful substances in wastewater to the extent of recycling. Reverse osmosis is used to treat electroplating rinse wastewater such as nickel plating, copper plating, zinc plating and cadmium plating.
When the treated heavy metal wastewater still can't meet the discharge requirements, the heavy metal collector can be directly added for treatment. The reagent has fast reaction speed and good treatment effect, and is suitable for post-treatment of heavy metal wastewater. It is a good adjuvant therapy reagent.
Changzhou Cursor Environmental Protection Technology Co., Ltd. has absorbed and introduced many talents and continuously expanded its R&D team. Over the years, we have made continuous efforts to put our products into the market, and won the praise of users in the industry. Companies adhering to the "altruistic" culture, everywhere for the sake of others, mutual accommodation, selling products is selling services. Provide customers with one-stop products and lifelong after-sales service, and provide tailor-made solutions according to customer needs. We sincerely invite you to come and buy.