What is phenol?
Phenol, also known as carbolic acid, is an organic compound. Phenols are widely used in domestic products such as disinfectants. Industries also uses them for cleaning and manufacturing certain pesticides and pharmaceuticals. So phenolic compounds are often found in industrial effluent.
Phenol removal from water requires a tertiary technology as primary and secondary processes cannot remove it. Furthermore, phenol contamination can damage biological treatment processes, causing them to become ineffective. This means you need to remove this pollutant before it passes through the biological treatment stage.
Due to their harmful nature, there is legislation to prevent phenolic compounds from causing damage to aquatic ecosystems or entering sources of drinking water.
Phenol (C₆H₅OH) contains a benzene ring, and is easily broken down and removed by our NyexTM system. See case study here.
What is phenol used for?
Key uses of phenol include an ingredient for personal care products, such as antiseptic throat spray (numbing throat spray/carbolic spray), aftershave, hairspray, mouthwash and certain medication. In many applications, it is used for its antiseptic and disinfectant properties. It is also used in the industrial manufacturing of resins, plastics, pesticides and for industrial cleaning. Polyphenols contain multiple phenolics and are often used for food preservation.
Phenol hazards occur through long term exposure to the skin or from vapours and affects the central nervous system. Fatal amounts of phenol can be absorbed through a small area of the skin.
Test for phenol
The test for phenol involves a HPLC (High Performance Liquid Chromatography) technique. The phenol test is used to determine the levels of phenolics in water. It is particularly important when a facility is concerned about phenol contamination in wastewater. Chemicals in this group can be damaging to municipal wastewater treatment plants, particularly the biological processes due to their toxic nature.
This means that phenol detected in wastewater must be removed onsite prior to being sent to the local sewer. The alternative is to face fines, damage to the treatment plant and damage to the aquatic environment.
The phenol structure is mineralised using Arvia’s NyexTM treatment process. Dependent on the type of wastewater, NyexTM treated water can be reused or safely sent to the sewer to avoid an increase in trade effluent charges, or fines.
Sources of Phenol in Wastewater
These pollutants are found in low concentrations in domestic wastewater due to their widespread use in household items. However, sources of phenol in wastewater also include industrial plants like pharmaceutical, agrochemical or facilities manufacturing plastics and resins. In these cases, the effluent has higher concentrations to be managed which is why a specialist tertiary process like NyexTM is required.
Phenol Contamination in Water
Industrial effluent with phenol contamination must be carefully managed. This is to prevent the pollution of sources used for drinking water, as well as the aquatic environment. Due to its harmful nature, phenol treatment in wastewater is extremely important.
We can carry out a phenol test at our onsite laboratory facility to determine the level of phenol contamination in water. We can then confirm the type of treatment process required, size and operating costs, dependent on the flow rates and concentration.
Phenol Removal From Wastewater
The NyexTM process is really effective in removal of phenol from wastewater. The way it works is that firstly the wastewater percolates though our Nyex media. The contaminants are attracted to the media and adsorb to its surface. Next the contaminant is completely mineralised using a low electrical current, which is passed through the bed.
One key benefit of the NyexTM system is that the adsorbent media regenerates inside the system. This means that there is no waste to dispose of. Also the treatment does not need to be interrupted for renewal, like with activated carbon. This means that these harmful compounds can be removed onsite with very little maintenance in comparison to alternative treatment processes. Once the phenol is removed from wastewater, the water is suitable to be reused in-process or for other uses around the facility.
Phenol Removal From Effluent
This common organic compound is found in industrial effluent across various industries. Phenol removal from effluent prior to discharge to the local sewer is essential. This is to prevent damage to the municipal wastewater treatment plant. Because of the damage it can do, effluent is closely monitored by the municipality. Fines are administered if pollutant limits are breached.
Phenol Removal From Drinking Water
Drinking water is closely monitored by the local utilities provider to ensure that organic chemicals are at a safe and acceptable level. Phenol removal from drinking water has been set to a safe limit of 2 mg/L by the Environmental Protection Agency (EPA) in the USA.
Phenol Removal Methods
Effluent containing phenol contamination can be treated using ozone (O3), activated carbon or reverse osmosis. However, ozone can prove to be a complex and ‘scattergun’ treatment approach, particularly when the phenol is present in low concentrations. Compare this with NyexTM which localises the compound for efficient and targeted removal, resulting in lower operational costs.
Dependent on the water quality, activated carbon can be labour intensive as the process must be paused for changing out or regenerating the carbon media. NyexTM carbon-based adsorbent media is regenerated in-situ for a low maintenance phenol removal method.
Reverse osmosis involves water passing through a membrane and pollutants being ‘filtered’ out as a reject side-stream. We are often called in to treat this sort of reject side-stream as it can be much cheaper than incineration.
Read more about technology comparison here.
Phenol Removal by NyexTM
Phenol removal from water requires a specialised tertiary process like the NyexTM-a system which localises the benzene contaminant onto the surface of a patented adsorbent media. A low electrical current is applied to the media bed which oxidises the organic chemical, leaving the clean water to flow from the system. Phenol removal using NyexTM ensures that the water is safe for reuse or compliant for discharge to the sewer or environment.
Phenol Removal by Adsorption and Oxidation
This is the way that the NyexTM system works. One key benefit of the NyexTM system is that the adsorbent media used in this process is simultaneously regenerated inside the system. So, there is very little maintenance and operating cost to consider in comparison with activated carbon. Phenol removal by adsorption in this case is much more efficient and lower maintenance, with lower operational costs as the only input required is electricity to run the NyexTM system.
Phenol Removal by Activated Carbon
This sort of contamination can be managed using an activated carbon process. This option essentially absorbs the pollutant into the internal structure of the carbon, resulting in a clean stream of water. Although phenol removal is achieved, the process must be paused, and the carbon regenerated or replaced for the efficiency of the process to continue. Phenol removal by activated carbon will no longer be possible once the carbon media is ‘spent’. Once the carbon can no longer be regenerated for reuse, it must be sent for incineration or landfill which has damaging environmental consequences.
Phenol Removal by Ozone
Although effective when performed correctly, phenol removal by ozone is not always the most cost-effective option and requires complex chemistry tailored to each specific contaminant. In addition, the dosing of hydrogen peroxide (ozone AOP) can inhibit later treatment steps and render this water unsuitable for reuse. By comparison, NyexTM treated water is safe to be reused as the process requires no chemical dosing. It is also a simple ‘plug and play’ solution, requiring no complex chemistry – just the input of electricity.
View All Articles