Granular activated carbon for domestic sewage purification

With the acceleration of urbanization, the discharge of domestic sewage has increased year by year, bringing great pressure to the environment. How to effectively purify domestic sewage and protect water resources has become an urgent problem to be solved. Granular activated carbon, as a commonly used adsorption material, plays an important role in the purification of domestic sewage

 

With the acceleration of urbanization, the discharge of domestic sewage has increased year by year, bringing great pressure to the environment. How to effectively purify domestic sewage and protect water resources has become an urgent problem to be solved. Granular activated carbon, as a commonly used adsorption material, plays an important role in the purification of domestic sewage.

 

1. Basic characteristics of granular activated carbon  

Granular activated carbon is a porous carbon material with the characteristics of large specific surface area, strong adsorption capacity and good chemical stability. Its surface is covered with a large number of micropores and mesopores. These pore structures make the activated carbon have extremely high adsorption capacity and can effectively remove pollutants such as organic matter, heavy metal ions and pigments in water.  

2. Application of granular activated carbon in domestic sewage purification  

1. Removal of organic matter: Domestic sewage contains a large amount of organic matter, such as protein, fat, sugar, etc. These organic matter will consume dissolved oxygen in water, leading to eutrophication of water bodies and affecting water quality. Granular activated carbon can effectively remove these organic matter and improve the stability of water quality through adsorption.  

2. Removal of heavy metal ions:

Domestic sewage may also contain heavy metal ions such as lead, cadmium, and mercury, which are potentially harmful to human health and the environment. Granular activated carbon has a strong adsorption capacity for heavy metal ions, which can remove them from water to ensure the safety of water quality.  

3. Removal of pigments and odors:

Domestic sewage may also contain pigments and odor substances, such as dyes, detergents, pesticides, etc. These substances not only affect the appearance of the water body, but may also cause harm to human health. Granular activated carbon can effectively remove these pigments and odor substances through adsorption, and improve the sensory quality of the water body.

3. Advantages and disadvantages of granular activated carbon  

1. Strong adsorption capacity:

Granular activated carbon has an extremely high specific surface area and pore structure, which can effectively remove a variety of pollutants in water.  

2. Easy operation: The addition and replacement of granular activated carbon is relatively simple, and does not require complex equipment and technical support.  

3. Economical: The price of granular activated carbon is relatively low, suitable for large-scale application.

(II) Disadvantages  

1. Saturated adsorption: As the adsorption proceeds, the granular activated carbon will gradually become saturated and needs to be replaced regularly.  

2. Poor effect on some pollutants: Although granular activated carbon has a good removal effect on most pollutants, it may not be effective for some specific pollutants.  

IV. Future development direction of granular activated carbon

1. Improve adsorption performance: Improve the adsorption performance of granular activated carbon by improving the preparation process, optimizing the pore structure, etc., so that it can better adapt to the complex and changeable water quality environment.  

2. Develop composite materials:

Compound granular activated carbon with other materials (such as nanomaterials, biomaterials, etc.) to improve its removal effect on specific pollutants.  

3.Realize recycling:

Study the recycling technology of granular activated carbon, reduce its use cost, and improve its sustainability in practical applications.

 Domestic sewage treatment is a complex process that aims to remove pollutants from sewage and ensure that the treated water meets discharge standards or can be used for other purposes. The following are the main steps and methods of domestic sewage treatment:

‌Pretreatment‌:

Domestic sewage is first collected to the sewage treatment plant through municipal sewage pipes, and large suspended particles and sediments are removed through coarse screening, sand settling, sedimentation and other steps. ‌

‌Primary treatment‌: Suspended matter and suspended pollutants are removed by sedimentation, filtration and aeration. This step is mainly physical treatment, using gravity to separate suspended matter and sediment. ‌

‌Secondary treatment‌: Purify the colloids and organic matter in sewage, usually using biological treatment technology such as activated sludge method or biofilm method to further remove organic matter and some nutrients such as nitrogen and phosphorus. ‌ ‌

Tertiary treatment‌: On the basis of primary and secondary treatment, physical and chemical methods such as coagulation, filtration, ion exchange, reverse osmosis, etc. are used to remove insoluble organic matter, phosphorus, nitrogen and other nutrients to improve water quality. ‌ ‌

Disinfection‌: Finally, the treated water is disinfected to kill residual bacteria and viruses to ensure water quality safety.

Sewage treatment methods include:  

‌Physical treatment‌: Removing suspended matter, sediment, grease and other pollutants in sewage through physical action, such as screen filtration, sedimentation and flotation. ‌ ‌

Chemical treatment‌: Removing soluble pollutants and colloids in sewage through chemical reactions, such as coagulation, neutralization, oxidation-reduction and other methods.

‌Biological treatment‌: Decomposing organic matter by the metabolism of microorganisms, such as activated sludge method and biofilm method.

In addition, the sewage treatment process also involves emerging technologies, such as membrane separation technology and advanced oxidation technology, which can more efficiently remove tiny particles and organic pollutants in sewage.