Activated Carbon Filters: What Do They Remove from Water?

What is activated carbon?

Activated carbon consists of small black beads or solid black porous sponges that have undergone some additional processing to make it easier to selectively capture impurities. First, inject heat, steam or chemicals into it, which creates millions of small holes in the carbon, which greatly increases the surface area. This activation process creates more pores for the carbon to capture and absorb a wider range of pollutants, making the carbon more effective as a filter medium.

Each carbon particle has a large surface area, so that the pollutants can be exposed to the active sites in the filter medium to the greatest extent, so that more pollutants can be absorbed/removed.

How do the activated carbon filters work?

Physical adsorption is the main way for activated carbon to filter out specific substances. When liquid or air comes into contact with activated carbon, intermolecular forces draw molecules into millions of pores and sacs on the surface of activated carbon.

In addition to physical adsorption, activated carbon also promotes chemical reactions. A common example involves the chlorine molecule. When chlorine comes into contact with activated carbon, both molecules will react to form chloride ions, which effectively removes the chlorine in the water.

The amount of pollutants that activated carbon removes from air or water depends on many different factors, including the type and amount of pollution, the acidity and temperature of the water or air, and the time the water or air is in contact with the activated carbon.

The specific type of activated carbon also determines the level of filtration provided. Carbon molecules with large pores trap large and heavy molecules, such as those found in organic chemicals. Small and fine pores will absorb smaller and lighter pollutants. Activated carbon manufacturers often label their products by their adsorption potential. Although it is safe to ingest activated carbon, after proper and thorough treatment, no carbon remains in the drinking water.

What do the activated carbon filters remove and reduce?

  1. Pesticides

Pesticides are substances used to control pests, including weeds that end up in groundwater, lakes, rivers, oceans, and sometimes tap water (despite treatment). Activated carbon has been tested to remove the 14 most common pesticides, including chlordane, chlordone (CLD/ketone), glyphosate (rounded), heptachlor and lindane.

  1. Herbicide

Herbicides are also commonly called herbicides, which are substances used to control harmful plants. The tested activated carbon can remove the 12 most common herbicides, including 2,4-D and atrazine.

  1. Pharmaceuticals

The widespread use of drugs has led to relatively continuous discharge of drugs and their metabolites into wastewater. Current observations indicate that extremely low levels of drug exposure in drinking water are highly unlikely to cause significant adverse risks to human health, because the drug concentration detected in drinking water is several orders of magnitude lower than the minimum therapeutic dose. Drugs may be released into water sources from wastewater from poorly controlled production or production facilities (mainly those related to generic drugs). A high-quality carbon block filter (such as TAPP 2) can remove 95% of the drug.

  1. Microplastics

Microplastics are the result of plastic waste from various sources. For many reasons, it is difficult to determine the exact impact of microplastics on human health. There are many different types of plastics, and different chemical additives that may or may not be present. When plastic waste enters waterways, it will not degrade like natural materials. Conversely, exposure to sunlight, the reaction to oxygen and the degradation of physical elements such as waves and sand can cause plastic fragments to break down into tiny pieces. The smallest microplastic identified in the public report is 2.6 microns. A 2 micron carbon block (such as TAPP 2) will remove all microplastics larger than 2 microns.

  1. Chlorine (Cl)

Most public tap water in Europe and North America is strictly regulated, tested, and certified for drinking. However, for safety reasons, the addition of chlorine may worsen its taste and smell. Activated carbon filters perform well in removing chlorine and related undesirable tastes and odors. A high-quality activated carbon filter can remove 95% or more of free chlorine.

  1. Chlorine by-product

Regarding tap water, the most common concern is chlorine by-products (VOC), such as THM, which is determined to be potentially carcinogenic. Activated carbon removes these activated carbons more effectively than any other filtration technology. According to EPA regulations, it removes the 32 most common chlorine by-products.

  1. Chloride (Cl-)

Chloride is a natural mineral that helps maintain proper blood volume, blood pressure and pH of body fluids. However, excessive chloride in the water may cause a salty taste. Chloride is a natural component of tap water and does not have any negative effects on health. This is part of the process of chlorinating harmful bacteria and viruses in drinking water. It does not need to be filtered or removed, but activated carbon can usually reduce chloride by 50-70%.

  1. Perfluorooctane sulfonic acid

PFOS is a synthetic chemical used in fire extinguishing foams, metal coatings and antifouling agents. Over the years, it has ended in the environment and drinking water sources, and several major incidents have occurred in North America and Europe. According to a 2002 study by the OECD Environment Agency, "Perfluorooctane sulfonic acid has persistence, bioaccumulation and toxicity to mammals." Activated carbon has been found to effectively remove PFOS, including PFAS, PFOA and PFNA.

  1. Phosphate (PO43-)

Phosphate, like nitrate, is essential for plant growth. Phosphate is a strong corrosion inhibitor. High concentrations of phosphate do not have any health hazards to the human body. Public water supply systems (PWS) usually add phosphates to drinking water to prevent lead and copper from leaching out of pipes and fixtures. High-quality charcoal filters can usually remove 70-90% of phosphate.

  1. Lithium (Li +)

Lithium is naturally present in drinking water. Although lithium content is very low, it is actually an antidepressant. It has no harmful effects on the human body. Lithium can be found in continental brine, geothermal water, and oil and gas field brines. Charcoal filters (such as TAPP) can reduce this element by 70-90%.