The application of activated carbon in water treatment

The application of activated carbon in water treatment has a wide range of significance, and its unique adsorption characteristics make it an indispensable part of the water treatment process. Activated carbon is a carbon material treated by physical or chemical methods. It has a high specific surface area and rich pore structure, which can effectively adsorb harmful substances in water.

 

 The application of activated carbon in water treatment has a wide range of significance, and its unique adsorption characteristics make it an indispensable part of the water treatment process. Activated carbon is a carbon material treated by physical or chemical methods. It has a high specific surface area and rich pore structure, which can effectively adsorb harmful substances in water. The role of activated carbon in water treatment will be discussed in detail below.

 

1. Basic characteristics of activated carbon

Activated carbon is a porous material, usually made from raw materials such as coal, wood, coconut shells, etc. after high-temperature treatment. Its surface contains a large number of micropores and mesopores, which provide it with a huge specific surface area, generally up to 500-1500 m²/g.

The pore structure and surface chemical properties of activated carbon give it good adsorption capacity, which can effectively remove organic matter, inorganic matter, gas and microorganisms in water.  

2. The role of activated carbon in water treatment

1. Removal of organic pollutants

Organic pollutants are common pollutants in water, usually from industrial wastewater, agricultural wastewater and urban sewage. Activated carbon effectively removes organic matter in water through its strong adsorption capacity. Its adsorption mechanism is mainly achieved through physical adsorption (van der Waals force) and chemical adsorption (interaction between molecules). Activated carbon has good adsorption performance for various organic substances in water (such as soluble organic matter, oils, pesticides, solvents, etc.). Especially for low concentrations of organic pollutants, activated carbon can play a significant removal role.  

2. Removal of odor and harmful gases

Activated carbon can effectively remove odor and harmful gases in water. The odor in water usually comes from the decomposition of corrupted organic matter or algae. Although the concentration of these odorous substances in water is low, they can still affect the sensory effect of water quality. Activated carbon can improve the taste and smell of water by adsorbing these odorous substances. In addition, activated carbon can also remove chlorine, chlorides and volatile organic compounds (VOCs) in water, so it is often used in drinking water treatment.

3. Removal of heavy metal ions

Although the main function of activated carbon is to adsorb organic matter, it also has a certain adsorption capacity for some inorganic substances, especially heavy metal ions. Heavy metals such as lead, mercury, arsenic, and cadmium in water are extremely harmful to the human body and the ecological environment. Studies have found that activated carbon that has been surface-modified (such as acidic, alkaline or metal ion-modified activated carbon) can improve its adsorption capacity for these heavy metal ions. This feature enables activated carbon to not only remove organic pollutants in water treatment, but also effectively remove certain toxic inorganic pollutants.  

4. Removal of microorganisms and viruses

Activated carbon has a certain microbial removal effect. Although activated carbon is not a traditional disinfectant, its surface can intercept and remove bacteria, viruses and other microorganisms in water through physical adsorption or chemical action. In addition, activated carbon can also indirectly improve the water purification effect and reduce the spread of pathogenic microorganisms by increasing the contact time of water flow. However, activated carbon cannot completely replace disinfection methods and usually needs to be used in conjunction with other disinfection technologies (such as ultraviolet disinfection and ozone disinfection).  

5. Removal of suspended matter and colloids Suspended matter and colloids in water can also be effectively removed by the adsorption of activated carbon.

The surface of activated carbon can not only adsorb organic pollutants in water, but also remove solid particles and colloids in water through physical interception. This plays an important role in the initial purification of water bodies such as urban sewage and industrial wastewater.

3. Application areas of activated carbon water treatment

1. Drinking water purification

Activated carbon is often used in the purification process of drinking water, especially in the water treatment system of urban water plants. Through activated carbon adsorption, the odor, color and harmful substances in the water can be effectively removed to ensure that the water quality meets the drinking water standards. Activated carbon filter tanks, activated carbon columns and other devices are widely used in drinking water treatment. Through the adsorption of activated carbon, harmful substances such as residual chlorine and chloroform in the water are effectively removed, ensuring the safety and taste of the water.  

2. Industrial wastewater treatment

In the treatment of many industrial wastewaters, activated carbon plays an important role in purification. Especially in the chemical, pharmaceutical, food processing and other industries, water often contains a large amount of organic pollutants, and traditional treatment methods (such as chemical precipitation and flocculation) may not be effective or costly. At this time, activated carbon can efficiently remove these organic matter through adsorption. In addition, activated carbon can also be used for decolorization, such as removing dyes and pigments from water in papermaking, textile and other industries.  

3. Municipal sewage treatment

In the process of municipal sewage treatment, activated carbon can be used as an auxiliary means of secondary or tertiary treatment to further remove dissolved organic matter and micro-pollutants in water. Activated carbon is widely used in water treatment plants for deep water purification after biological treatment and chemical treatment, especially in areas with high water quality requirements (such as protected areas of urban drinking water sources).  

4. Fish ponds and aquaculture In fish ponds and aquaculture, activated carbon is also used to purify water. Aquaculture water bodies often have problems such as water quality deterioration, lack of oxygen, and excessive ammonia nitrogen.

Activated carbon can effectively adsorb ammonia nitrogen, nitrates, phosphates and other harmful substances in water, thereby maintaining the ecological balance of water bodies and promoting the healthy growth of aquatic organisms.  

The role of activated carbon in water treatment cannot be ignored. With its excellent adsorption performance, activated carbon is widely used in the purification of various water bodies. Whether in the treatment of drinking water, industrial wastewater or municipal sewage, activated carbon can effectively remove a variety of pollutants in water and improve water quality. With the continuous development of water treatment technology, the application methods and effects of activated carbon will be further improved.