With the rapid development of industrialization, the problem of wastewater pollution is becoming more and more serious, among which excessive chromium trivalent is a common pollution phenomenon. Trivalent chromium is a toxic and harmful substance, and long-term emissions can cause serious effects on the environment and human health. Therefore, the research and application of the treatment process of excessive chromium trivalent in wastewater is particularly important.
1. The ** and hazards of trivalent chromium in wastewater.
The trivalent chromium in the wastewater is mainly used for wastewater discharge in electroplating, metallurgy, tanning, chemical and other industries. The trivalent chromium ions contained in these wastewaters have high toxicity and bioaccumulation, and long-term contact or ingestion will cause damage to the human body, such as causing allergies, respiratory diseases, liver and kidney damage, etc. At the same time, trivalent chromium will also cause damage to the ecological environment, affecting the self-purification ability and ecological balance of water bodies.
2. Wastewater trivalent chromium excess treatment process.
In view of the problem of excessive chromium trivalent in wastewater, the commonly used treatment processes mainly include chemical precipitation method, ion exchange method, adsorption method, membrane separation method, etc. The principles, characteristics and applications of these processes are described in detail below.
1.Chemical precipitation.
The chemical precipitation method is to add chemicals to the wastewater, so that the trivalent chromium ions and the agent react chemically to form a precipitate, so as to achieve the purpose of removing the trivalent chromium. Commonly used chemical agents are hydroxides, sulfides, etc. This method is simple to operate, the treatment effect is stable, and it is suitable for treating a large amount of wastewater. However, chemical precipitation tends to produce large amounts of sludge and requires subsequent treatment.
2.Ion exchange method.
The ion exchange method uses exchangeable ions on ion exchange resins to exchange trivalent chromium ions in wastewater to remove trivalent chromium. This method has the advantages of good treatment effect, small footprint, and useful metals. However, ion exchange methods are costly, and resins are susceptible to contamination and aging, requiring regular replacement.
3.Adsorption method.
The adsorption method uses the adsorption of the adsorbent to adsorb the trivalent chromium ions in the wastewater on the surface of the adsorbent, so as to achieve the purpose of removing the trivalent chromium. Commonly used adsorbents include activated carbon, bentonite, nanomaterials, etc. The adsorption method has the advantages of easy operation, good treatment effect, and reusable adsorbent. However, the adsorption capacity of the adsorption method is limited and the adsorbent needs to be replaced regularly.
4.Membrane separation.
The membrane separation method uses the special properties of membrane materials to separate and remove trivalent chromium ions in wastewater. Commonly used membrane separation technologies include ultrafiltration, nanofiltration, and reverse osmosis. The membrane separation method has the advantages of good treatment effect, easy operation, and useful substances. However, membrane separation is costly, and membrane materials are susceptible to contamination and clogging, requiring regular cleaning and replacement.
3. Selection and optimization of wastewater trivalent chromium treatment process.
The selection of the treatment process of excessive chromium trivalent in wastewater should be comprehensively considered according to the water quality, treatment requirements, treatment cost and other factors of wastewater. In practical application, the most suitable treatment process should be selected according to the actual situation, and optimized and improved to improve the treatment effect, reduce the treatment cost, and reduce secondary pollution.
At the same time, the research and application of the treatment process of excessive chromium trivalent in wastewater also need to pay attention to environmental protection and sustainable development. Through the development of new, efficient and environmentally friendly treatment processes, the energy consumption and emissions in the wastewater treatment process are reduced, the pollution and damage to the environment are reduced, and the coordinated development of wastewater treatment and environmental protection is realized.
In short, the research and application of the treatment process of excessive chromium trivalent in wastewater is of great significance for solving the problem of wastewater pollution and protecting the ecological environment and human health. In the future, with the continuous progress of science and technology and the continuous improvement of environmental protection requirements, the wastewater trivalent chromium treatment process will be continuously improved and optimized, and make greater contributions to wastewater treatment and environmental protection.