Application of Powdered Activated Carbon Water Purification Technology in Water Treatment

1.Properties of powdered activated carbon and water purification principle

1.1 Properties of powdered activated carbon

Powdered activated carbon is an adsorbent with strong adsorption capacity. Its entire microporous structure is relatively developed, which is the main reason for its strong adsorption performance. Activated carbon is also mainly composed of many irregular collections of microcrystals with a graphite-type layered structure. Since the particles of the entire activated carbon are smaller and have more microporous structures, the activated carbon has a larger specific surface area and has the unique advantage of effectively adsorbing chemical substances. The use of powdered activated carbon can not only effectively reduce the content of dissolved organic matter in the water body, but also remove odors from the water, thereby effectively improving the quality of the entire water.

1.2 Water purification principle of powdered activated carbon

The water purification of powdered activated carbon is mainly formed through the interaction between molecules. According to physics, there is a certain interaction force between molecules. Therefore, after one molecule in a substance is adsorbed by activated carbon, other molecules have the possibility of being adsorbed by activated carbon into its molecular gaps. This is the basis for activated carbon powder to achieve effective adsorption of pollutants. In addition, the adsorption of powdered activated carbon also includes two processes, namely: slow diffusion process and rapid diffusion process. Among them, the slow diffusion process means that the carbon particles have large pores. When the solute molecules move into the activated carbon micropores, a certain diffusion resistance will occur, which will cause the entire diffusion process to become slow. At the same time, because powdered activated carbon has a larger specific surface area compared with block activated carbon. Therefore, the unit weight of activated carbon has greater adsorption efficiency and can handle more water resources to be treated.

2.Application of powdered activated carbon water purification technology in water supply treatment

2.1 Removal of trihalomethanes

Trihalomethanes are an important contaminant causing drinking water contamination. The use of powdered activated carbon adsorption technology to remove trihalomethanes is currently the main method used to reduce water resource pollution. During the chlorination and disinfection of drinking water, the main volatile halogenated hydrocarbon compounds generated by the reaction between chlorine and organic matter in the water include chloroform, bromodichloromethane, dibromochloromethane and bromoform. In 1974, Rook first introduced it in drinking water Detected in the water. In animal experiments, it has been proven that it is mutagenic and/or carcinogenic, and some have teratogenic and/or neurotoxic effects, and can cause liver, kidney and intestinal tumors. Activated carbon has a strong adsorption effect on trihalomethanes.

Although powdered activated carbon has a strong adsorption effect on trihalomethanes, its adsorption capacity is not guaranteed to be sufficient to treat drinking water containing high concentrations of trihalomethanes. When using chloride to disinfect drinking water, chloride should be used rationally to avoid excessive concentrations of trihalomethanes produced due to excessive chloride, which may have a certain counterproductive effect on the use of water purification technology. In addition, the concentration of residual chlorine must be reasonably reduced to continuously avoid the generation of more trihalomethanes. Thereby effectively achieving the adsorption effect of trihalomethanes.

2.2 Remove smell and taste substances

Powder activated carbon is more developed due to its entire microporous structure. Therefore, it has strong advantages in removing color, smell and taste. The color, smell, and taste in water are usually mainly caused by the compounds present in the water quality. Therefore, the use of powdered activated carbon can effectively absorb impurities in water. In addition, when using powdered activated carbon, different types of powdered activated carbon have different adsorption effects on odor and taste substances in water. Therefore, we should choose the appropriate powder activated carbon according to the specific water quality conditions.

2.3 Removal of pesticides and herbicides

Water pollution is not only caused by industrial wastewater and domestic pollution, but also agricultural production will have a certain impact on the quality of water use. Among them, pesticides in agricultural production are the main factors causing water pollution. Therefore, when we perform corresponding water treatment operations, we can put a certain amount of powdered activated carbon into the water, which can effectively absorb impurities in the water and achieve the effect of purifying water resources.

2.4 Removal of synthetic organic matter

Organic matter in water is generally caused by industrial production. Although not all organic matter will cause harm to the human body, synthetic organic matter produced in industrial production will have varying degrees of impact on the growth of humans, animals and plants. Using traditional purification treatment methods can only reduce the concentration of compounds in the water. To achieve the purpose of removal, it is far from enough to use traditional water purification treatment methods. Therefore, an appropriate amount of powdered activated carbon can be put into the water to effectively promote its ability to efficiently absorb impurities in the water, thereby continuously improving the quality of water use.