Classification of industrial wastewater by wastewater activated carbon treatment method

Jiangsu Zhongming Environmental Protection Technology Co., Ltd. is an environmental engineering company engaged in industrial waste gas on-site research, technology research and development, process customization, equipment manufacturing, project site construction and installation, operation and maintenance. At present, the company has 8 branches in the country, including four standard production plants, which are located in Suzhou, Langfang, Hebei and Shenyang, with a total production area of more than 42,000 square meters. The company has more than 10 years of experience in environmental protection equipment manufacturing, and now has a scientific quality management system and passed the ISO9001-2008-14001-18040 quality management system and the EU CE certification.

The core products are catalytic combustion equipment, photo-oxygen catalytic equipment, RTO, RCO, activated carbon adsorption equipment, condensation and low-temperature plasma equipment, and the successful implementation of waste gas treatment projects of hundreds of factories has left a good reputation in the field of VOCs waste gas treatment

According to the chemical properties of the main pollutants contained in industrial wastewater, it is divided into: inorganic wastewater containing inorganic pollutants, organic wastewater containing organic pollutants, mixed wastewater containing both organic and inorganic substances, heavy metal wastewater, wastewater containing radioactive substances and cooling water polluted by heat only. For example, electroplating wastewater and mineral processing wastewater are inorganic wastewater, and food or petroleum processing wastewater is organic wastewater.

According to the products and processing objects of industrial enterprises, it can be divided into papermaking wastewater, textile wastewater, tanning wastewater, pesticide wastewater, metallurgical wastewater, oil refining wastewater, etc.

According to the main components of pollutants contained in wastewater, it can be divided into acidic wastewater, alkaline wastewater, phenol-containing wastewater, chromium-containing wastewater, organic phosphorus-containing wastewater and radioactive wastewater.

The main components are: carbon, oxygen and hydrogen.

Activated carbon is black powdery or lumpy, granular, honeycomb-shaped amorphous carbon, and there are also crystalline carbon arranged in a regular manner.

In addition to carbon elements, activated carbon also contains two types of admixtures: one is chemically bound elements, mainly oxygen and hydrogen, which are left in the carbon due to incomplete carbonization, or in the activation process, foreign non-carbon elements are chemically combined with the surface of activated carbon;

Another type of admixture is ash field, which is the inorganic part of activated carbon, and ash is easy to cause secondary pollution in activated carbon. Activated carbon is widely used in production and life due to its strong adsorption.

Chemical characteristics: In addition to physical adsorption, the adsorption of activated carbon also has chemical adsorption. The adsorption of activated carbon depends both on the pore structure and on the chemical composition.

Activated carbon not only contains carbon, but also contains a small amount of oxygen and hydrogen that are chemically bound and functionally activated, such as carbonyl, carboxyl, phenols, lactones, quinones, and ethers.

These surfaces contain oxides and complexes, some of which are derived from the derivatives of the raw material, and some of which are formed by the action of air or water vapor during and after activation.

Surface sulfides and chlorides are also sometimes formed. In the activation process, the minerals contained in the raw materials are concentrated in the activated carbon to become ash, and the main components of the ash are alkali metals and alkaline earth metal salts, such as carbonates and phosphates. <>

Hello, according to the information you provided, I found out for you, generally speaking, activated carbon itself does not belong to hazardous waste Activated carbon after adsorption of waste gas and waste water needs to see whether it is a hazardous solid waste in the "National Hazardous Waste List" (2016 Edition). If Yintanshi is said to belong to these waste lists, then it is naturally also classified as waste hazards, if it is not in the list: Xinlao needs to be identified in accordance with the relevant provisions of the "Hazardous Waste Identification Standards for Toxic Substance Content".

If the adsorbed waste gas and wastewater do not belong to toxic and harmful substances or dangerous substances, they are not necessarily hazardous solid waste. If waste activated carbon prepared from pure water, etc. The construction shall be consulted with the local environmental protection bureau or a unit with hazardous waste disposal qualifications.

Waste activated carbon refers to used or expired activated carbon, which has a wide range of applications in the fields of sewage treatment, air purification, decolorization drugs, odor removal, etc., but the large amount of biomass and fossil fuel waste generated in the production process, industrial pollutants and other reasons lead to a rapid increase in the amount of waste activated carbon. Therefore, the reuse of waste activated carbon has become one of the priorities of environmental protection.

At present, there are various treatment methods for waste activated carbon, such as physical separation, chemical remediation and microbial remediation. Among them, physical separation is a traditional method, but it requires large facilities and energy consumption, and cannot effectively degrade organic matter such as humus. Chemical remediation methods are more efficient, economical and practical than physical separation, especially in the case of some pollutant substances are very complex.

Microbial remediation, on the other hand, is a biotechnology that not only degrades organic matter, but also converts pollutants into safe and harmless substances with less impact on the environment, but it takes a longer time to do so.

With the popularization of environmental awareness, the reuse of waste activated carbon and the development of environmental awareness complement each other. Therefore, we need to continue to carry out the reuse of waste items on the basis of environmental protection technology, so as to achieve the purpose of maintaining the environment and achieving sustainable development.

Waste activated carbon is a kind of high-efficiency adsorption material made of various natural raw materials, and the main components are lignin, hard coal, coconut shells, etc. It has good pore structure, small pore size, high specific surface area and strong adsorption capacity. Therefore, waste activated carbon has been widely used in sewage treatment, air purification, decolorization and deodorization, food and food sales processing, pharmaceutical production and other fields.

There are generally two preparation methods for waste activated carbon: physical adsorption method and chemical adsorption method. The physical adsorption method is to carbonize the raw materials and treat them at high temperatures to make them present a complex pore structure. The chemical adsorption method is based on physical adsorption to produce more active sites through chemical reactions in the banquet solution.

Waste activated carbon has good adsorption properties and can adsorb various harmful substances in water, such as dissolved organic matter, heavy metal ions such as lead and mercury, as well as harmful gases such as ammonia and hydrogen sulfide. In addition, waste activated carbon can also be used to purify harmful gases and odors in the air, such as sulfur dioxide, hydrogen sulfide, etc.

In short, as a comprehensive and efficient adsorption material, waste activated carbon has a wide range of application prospects in industrial production and life.

The main component of waste activated carbon: carbon, containing a small amount of oxygen, nitrogen, hydrogen, sulfur and other elements.

It has strong adsorption and purification capabilities, can effectively adsorb all kinds of organic and inorganic pollutants in the gas phase and water phase environment, and is widely used in medicine, chemical industry, food, environmental protection and other fields, for decolorization and deodorization, purification of wastewater and adsorption of formaldehyde, VOCs, smoke and other toxic and harmful substances.

Although the strong adsorption capacity of activated carbon solves the problems of wastewater and waste gas treatment in the industrial production process for enterprises, the chemical changes and structural changes generated by activated carbon after multiple adsorption reactions will lead to the reduction of activated carbon activity and specific surface area, and the adsorption capacity cannot meet the production needs and become waste activated carbon.

According to the provisions of the National Hazardous Waste List, waste activated carbon contaminated with hazardous waste is hazardous waste. That is, activated carbon adsorbs toxic and harmful substances specified in the list of hazardous wastes such as VOCs, formaldehyde, land-buried benzene-containing waste gas, and heavy metals, which is a hazardous waste, and how to dispose of it has become a new problem faced by enterprises.

The principle of regeneration

Activated carbon regeneration refers to the process of removing the adsorbate adsorbed in the micropores of activated carbon and restoring its adsorption performance by physical or chemical methods without destroying its original structure. In the process of activated carbon adsorption, there is an adsorption effect on both the adsorbate and the solvent, and the adsorption equilibrium is reached after a certain period of adsorption due to the different affinity.

Activated carbon regeneration is to take measures to destroy this equilibrium, which is mainly based on the following aspects: changing the chemical properties of adsorbents; Extracted with a solvent with a strong affinity for adsorbates. Be careful.

The adsorbate is replaced with a substance with a greater affinity for activated carbon than the adsorbate, and then the replacement substance is desorbed, and the activated carbon is regenerated; Changing the equilibrium conditions by external heating and increasing the temperature; Regeneration by reducing the solute concentration (or pressure) in the solvent; The adsorbate (organic matter) is decomposed or oxidized and removed.

Activated carbon is a very fine carbon particle with a large surface area, and there are even smaller pores in the carbon particle - capillaries. This capillary has a strong adsorption capacity and is in full contact with gases (impurities) due to the large surface area of the carbon particles. When these gases (impurities) touch the capillaries, they are adsorbed and purified.

Welch exhaust gas treatment equipment.

Adsorption is a slow-acting process in which a substance attaches to the surface of another substance. Adsorption is an interfacial phenomenon that is related to changes in surface tension and surface energy. The specific surface area and pore structure of activated carbon directly affect its adsorption capacity, and when selecting activated carbon, it should be determined by test according to the nature of the exhaust gas.

In addition, ash content also has an effect, the smaller the ash content, the better the adsorption performance; The closer the size of the adsorbate molecule is to the diameter of the carbon pore, the easier it is to be adsorbed. The concentration of adsorbate also has an effect on the adsorption capacity of activated carbon. In a certain concentration range, the adsorption capacity increases with the increase of adsorbate concentration. In addition, temperature and pH also have an effect.

The adsorption capacity decreases with the increase of temperature and increases with the decrease of pH value. Therefore, low temperature and low pH value are conducive to the adsorption of activated carbon.

In order to effectively deodorize, a variety of activated carbon with different properties is usually used, and activated carbon for adsorbing acidic substances, activated carbon for adsorbing alkaline substances and activated carbon for adsorbing neutral substances are set up in the adsorption tower, and the adsorption tower is discharged after the odor is in contact with various activated carbons.