Application status and prospects of activated carbon in industrial manufacturing industry

Activated carbon is sweeping the industrial manufacturing industry, providing a revolutionary solution that minimizes environmental impact while simplifying production processes. This innovative tool is changing the industry and providing a unique approach to sustainability, productivity and efficiency.

 

Activated carbon is sweeping the industrial manufacturing industry, providing a revolutionary solution that minimizes environmental impact while simplifying production processes. This innovative tool is changing the industry and providing a unique approach to sustainability, productivity and efficiency.

The current supply of activated carbon is relatively tight, there are few regeneration equipment, and the regeneration cost is high, which limits the widespread use of activated carbon. Different applications require activated carbon with different functions. The original activated carbon products cannot meet the new requirements, so it is very important to continuously develop new activated carbon products. Therefore, it requires the active participation of professional workers and the strong support of the government, and adopts a multidisciplinary cross-disciplinary and integrated research method to make the activated carbon wastewater treatment technology develop in a more scientific and beautiful direction.  

Industrial wastewater contains not only highly toxic components such as cyanide, but also metal ions such as chromium, zinc, and nickel. There are many methods for treating wastewater, mainly chemical precipitation, electrolysis, and membrane treatment. This article introduces the activated carbon adsorption method. Activated carbon has a huge surface area and has high physical adsorption and chemical adsorption functions. Therefore, the activated carbon adsorption method is widely used in wastewater treatment. And it has the characteristics of high efficiency and good effect.  

1 Overview of activated carbon

Activated carbon is a specially treated carbon with countless tiny pores and a huge surface area. The surface area of ​​each gram of activated carbon is 500-1500m2. Activated carbon has strong physical adsorption and chemical adsorption functions, and also has a detoxification effect. The detoxification effect is to use its huge area to adsorb poisons.

In the micropores of activated carbon, the absorption of poisons is prevented. At the same time, activated carbon can combine with a variety of chemical substances to prevent the absorption of these substances.

Classification of activated carbon

There are many types of activated carbon used in production. Generally, it is made into powder, column or granular form. Powdered activated carbon has strong adsorption capacity, easy preparation, low price, but difficult to regenerate and generally cannot be reused. Granular activated carbon is more expensive, but it can be regenerated and reused, and the working conditions during use are better and the operation and management are convenient. Therefore, granular activated carbon is more commonly used in water treatment.

Factors affecting activated carbon adsorption

Adsorption capacity and adsorption rate are the main indicators for measuring the adsorption process. The size of the adsorption capacity is measured by the amount of adsorption. The adsorption rate refers to the amount of substance adsorbed by a unit weight of adsorbent per unit time. In water treatment, the adsorption rate determines the contact time between sewage and the adsorbent. The adsorption capacity of activated carbon is related to the pore size and structure of the activated carbon. Generally speaking, the smaller the particles, the faster the pore diffusion rate, and the stronger the adsorption capacity of the activated carbon. The pH value and temperature of the sewage also affect the adsorption of activated carbon. Activated carbon generally has a higher adsorption capacity under acidic conditions than under alkaline conditions. The adsorption reaction is usually an exothermic reaction, so low temperature is beneficial to the adsorption reaction. Of course, the adsorption capacity of activated carbon is related to the concentration of sewage. At a certain temperature, the adsorption capacity of activated carbon increases with the increase of the equilibrium concentration of the adsorbed substance.  

2 Adsorption mechanism of activated carbon

During the manufacturing process of activated carbon, its volatile organic matter is removed, and gaps are generated between the crystal lattices, forming many pores of different shapes. Its pores account for 70%~80% of the total volume of activated carbon. The surface area of each gram of activated carbon can be as high as 500~1700 square meters, but % is inside the porous structure. The great adsorption capacity of activated carbon lies in its large adsorption area. The pore size distribution of activated carbon is very wide, ranging from 10-1nm to more than 104nm. It is generally divided into micropores, transitional pores and macropores according to the pore size. In the adsorption process, it is the microporous structure that really determines the adsorption capacity of activated carbon. Almost all the specific surface of activated carbon is composed of micropores, and the coarse pores and transitional pores only serve as adsorption channels, but their existence and distribution affect the adsorption and desorption rates to a considerable extent.  

Studies have shown that: during the adsorption process, mass transfer of solutes from the solvent to the surface of the activated carbon adsorbent occurs. The driving force can be the hydrophobic properties of the solute or the affinity of the solute to the adsorbent surface, or both. In water treatment, the substances removed by activated carbon adsorption are generally organic compounds with both hydrophobic groups and hydrophilic groups. The affinity of solutes to the adsorbent surface can be divided into two categories: one is the solubility of the solute in the solvent; the other is the van der Waals force, chemical bond force and electrostatic attraction between the solute and the adsorbent. Strictly speaking, activated carbon adsorption is a very complex process. It is a water treatment method that uses the physical adsorption, chemical adsorption, exchange adsorption, oxidation, catalytic oxidation and reduction properties of activated carbon to remove pollutants in water.  

3 Application of activated carbon adsorption in industrial wastewater treatment  

Treatment of oily wastewater by activated carbon adsorption

The rapid development of petroleum and its industry has made oil pollution a common pollution, which has seriously affected the balance of the environment and ecology. Since oil extraction, oil storage and transportation, oil refining, petrochemicals, vehicle washing and other processes will produce wastewater, the output of oily wastewater has gradually increased, and it covers a wide range. There are many methods for treating oily wastewater today, including gravity separation, coarse granulation, filtration, ultrasonic method, adsorption method, etc., and new treatment methods are still under continuous research and development.  

Adsorption is a method of using some lipophilic materials to adsorb dissolved oil and other soluble organic matter in water. Since there are many methods for treating oily wastewater, and activated carbon is relatively expensive, and the adsorption capacity of activated carbon on oil is limited, in the treatment of oily wastewater, activated carbon adsorption is generally used as the last stage of multi-stage treatment to remove trace pollutants in wastewater and conduct deep purification of water. The oil content of treated water can be reduced to a very low level.

Treatment of dye wastewater by activated carbon adsorption

The textile printing and dyeing industry is one of country's traditional pillar industries and has also achieved rapid development in the new era. However, the discharge of printing and dyeing wastewater is also gradually increasing. According to incomplete statistics, assuming that the daily discharge of printing and dyeing wastewater is 3000~4000kt, the printing and dyeing factory will produce 3~5t of wastewater for every 100m of fabric processed. Printing and dyeing wastewater has the characteristics of sufficient complexity, deep chroma, high concentration, high COD and BOD values, and large changes in water quality, which makes it difficult to treat. Activated carbon adsorption is to use the porosity of activated carbon to adsorb pollutants in wastewater to achieve the purpose of purifying printing and dyeing wastewater. It can effectively remove the color and COD and BOD of wastewater. There are many methods for treating printing and dyeing wastewater, mainly oxidation, biodegradation, flocculation, membrane separation, adsorption, etc. These methods have their own advantages and disadvantages. Activated carbon treatment of printing and dyeing wastewater has been studied both at home and abroad, but due to the difficulty of treating printing and dyeing wastewater, the use and research of activated carbon alone for printing and dyeing wastewater treatment are rare. Most of them are coupled with other processes, using activated carbon as a carrier and catalyst or using it for deep treatment to better purify and decolorize printing and dyeing wastewater.

The textile industry is notorious for its impact on the environment. Traditional dyeing and printing methods often rely on toxic chemicals that can harm the environment and workers. But with activated carbon, the situation is about to change. This unique solution provides a powerful tool to clean water, air and soil, allowing manufacturers to reduce their carbon footprint while improving the quality of the final product.  

Activated carbon works by absorbing impurities, pollutants and chemicals in water and air, leaving a clean, pure medium. This is particularly useful in the textile industry, where dyeing and printing processes rely heavily on water and chemicals. Activated carbon can be used to remove impurities from wastewater, ensuring that the water can be reused or recycled, reducing the amount of waste generated in the process.  

In addition, activated carbon can also be used to remove volatile organic compounds (VOCs) from the air, improving air quality in textile factories. This is particularly important because VOCs can cause respiratory problems and other health issues for industry workers.  

But the benefits of activated carbon don’t stop there. This innovative solution can also improve efficiency and productivity in the textile industry. For example, by removing impurities from water, activated carbon can help manufacturers achieve more consistent dyeing and printing processes, reducing the likelihood of errors and improving the quality of the end product. In addition, activated carbon can also help reduce the time and resources required to clean up wastewater, thereby reducing the overall cost of production.  

As a result, activated carbon is quickly becoming a popular choice in the textile industry, where manufacturers are looking to improve their sustainability credentials while maximizing output. According to a recent report by Marketsand, the global activated carbon market is expected to reach $6.9 billion by 2026, driven primarily by growing demand from industries such as textiles, water treatment, and food and beverage.  

Treatment of heavy metal wastewater by activated carbon adsorption

In addition to its large surface area, developed pores and large empty capacity, the adsorption of heavy metal ions by activated carbon is also due to the presence of stable, controllable and changeable oxygen-containing and functional groups on the surface of activated carbon. The chemical adsorption of heavy metal ions is the key factor that determines the amount of heavy metal ions adsorbed by activated carbon.  

4 Research progress and development prospects of activated carbon

The progress of science and technology and the demand for wastewater treatment have led to the development of research on activated carbon from the surface area and microporous structure of activated carbon itself to the influence of the functional groups on the surface of activated carbon on the chemical adsorption of activated carbon. It mainly includes the research on the combined use of activated carbon and membrane to treat wastewater, activated carbon as a catalyst carrier and the modification of activated carbon.

Since the production and application of activated carbon at home and abroad are relatively late, the research on activated carbon needs to be deepened to fully play its role in industrial wastewater treatment. At present, the supply of activated carbon in my country is relatively tight, and the use of activated carbon is limited by the few activated carbon regeneration equipment, low technology and high cost.

Solving the regeneration problem of activated carbon and developing new activated carbon products for application in different treatment processes are the current issues to be solved.

5 Conclusion

Activated carbon, as a low-cost adsorbent with large surface area and strong adsorption capacity, is widely used in the treatment of industrial wastewater. With the development and progress of society, it is of great significance to pay attention to the application of activated carbon adsorption method in real life.

 In short, activated carbon is changing various industrial production industries and providing a powerful tool for improving sustainability, quality and efficiency. With the growing demand for this innovative solution, the global activated carbon market is expected to continue its growth trajectory, and the Asia-Pacific region will lead this trend. As manufacturers continue to prioritize sustainability and efficiency, activated carbon may become an increasingly important tool in the industry, driving growth and innovation in the coming years.