Peracetic acid for disinfection | WWD
How peracetic acid replaces chlorine in water and wastewater treatment
It is said that perfume is the sense that has the strongest connection with memory. The smell of chlorine reminds me of swimming lessons at the YMCA. I remember the taste of pennies, my curls drying and breaking on the way home in the car, and rule number one when swimming: don’t open your eyes underwater. But I did, of course, because it’s the only way for a 6 year old to win Marco Polo.
I can remember with perfect clarity the fuzzy burning in my eyes after a swimming lesson, and blinking didn’t help. My eyes couldn’t be soaked, my skin was tight, my baby blond hair took on a green tint in the daylight and especially under the fluorescent lights in the locker room. But, my swim coach, parents, and the janitor told me that the pungent smell and sting in my eyes was a strong chemical that worked to keep the whole place clean and safe.
Since it was first used in 1905 to decontaminate drinking water in Britain and stop the typhoid epidemic, chlorination has proven to be effective, otherwise society would not have relied on it so much for over a century. But chlorine, in all its power, has flooded all kinds of water treatment outside of drinking water disinfection, including irrigation water systems, community reservoirs, and municipal wastewater. It is used on a large scale throughout water treatment and then released randomly into the environment.
Historically, chlorine was the scent of the clean for most of the 20th century. The world has come a long way since then and has learned just how toxic it is to aquatic life, and how it disrupts vital ecosystems, the livelihoods of coastal industries, soil health and irrigation in the world. agro-industry, and even municipal surface water.
When chlorine oxidizes organic matter, the reaction creates hazardous disinfection by-products (DBs) including trihalomethanes (THMs) and haloacetic acids (HAAs) which can contaminate surface waters used by communities in their daily lives. . These toxic by-products make the water unsuitable for reintroduction into the environment. Although it offers cost-effective disinfection, it often requires the additional and expensive step of dechlorination after water treatment. The long-term effects of the release of dechlorinated compounds to the environment are unknown. As a result, the US EPA has put in place strict restrictions on the acceptable levels of residual chlorine and DBPs in municipal wastewater effluent water. Less damaging alternatives now exist, and it’s time for the industry to take advantage of these new, sustainable developments in water treatment, and one of those options is peroxyacetic acid, also known as d peracetic acid or PAA.
How PAA disinfects water
Several case studies have been carried out and systematically illustrate the effectiveness of PAA in removing pathogens for human health from water, by neutralizing odorous sulfur compounds without harmful residues. PAA is a chemical-containing disinfectant that has been used for years in operations in Europe, but has only recently gained popularity in the United States.
BioSafe Systems has spent more than 20 years converting chlorine users into AAP advocates and continues to gain momentum in a positive and sustainable direction.
All commercially available PAA products contain a balanced mixture of hydrogen peroxide, water and acetic acid. When PAA breaks down in water, two oxidizing powerhouses, hydrogen peroxyl (HO₂) and hydroxyl (OH) are formed and begin cell lysis. Disinfection occurs when the bacterial cell wall breaks down after contact with the free radicals of the PAA. These compounds remain stable in water, allowing them to target pathogens and bacteria without breaking down or reverting to their precursor composition.
PAA for wastewater treatment
PAA mixes with wastewater in the same way as chlorine, allowing a seamless transition from one chemical to another. PAA does not require additional equipment or expense, making it an easy and economical choice for wastewater treatment operations.
Effective wastewater disinfection has been tried, tested, and proven across the United States, from New Jersey to Kentucky, and even California, which has some of the strictest environmental regulatory laws. PAA products are not bothered by turbidity or the pH levels of the wastewater, making them more effective in turbulent and opaque water than UV light.
UV needs the clarity of the water initially for the disinfectant light to penetrate, and in laboratory tests the visual clarity of the water is noticeable moments after the PAA is introduced into the sample.
Ozone is another alternative to chlorine but requires complex equipment, and the chemical is a highly corrosive and reactive compound. When PAA is used to treat wastewater, its chemistry oxidizes on contact and then breaks down into completely non-toxic components.
To look forward
Attention has been drawn to the harmful chlorine, and the water treatment industry is focusing on alternatives such as PAA. This chemistry is the advancement of scientific solutions that many water treatment workers have been waiting for.
PAA has started to save time, money and stress for businesses and municipalities when complying with compliance regulations. Successful broad-spectrum disinfection in a short period of time, with easy implementation and the absence of by-products, is what has made PAA a desirable and progressive option for water and water treatment. worn.