Although it might seem like we have an unlimited amount of water, the truth is a lot different. With population growth and climate changes, freshwater resources have significantly dropped. Over the years, the freshwater deficit has become a major challenge worldwide. One of the main reasons is the increase of different pollutants, which makes water purification difficult.
Emerging Water Pollutants
Recently, scientists have discovered new pollutants in surface and drinking water. These new pollutants can’t be removed with conventional treatment technologies. So, besides the contaminants that we already know about, scientists have discovered new particles as well.
With the rise of these new, emerging pollutants, scientists have tried various methods to remove them from water. These methods include chemical oxidation, activated carbon adsorption, and membrane filtration. However, only the chemical oxidation using ozone has proven to be effective.
AOP: How Does It Work?
To better understand chemical oxidation, we should clarify what AOP stands for. It’s an Advanced Oxidation Process that removes pollutants from water by oxidation. In practice, it usually includes processes that include ozone and/or UV light.
Advantages of Advanced Oxidation Treatment
A primary advantage is of removing organic compounds in the aqueous phase. That way, the compounds won’t transfer to other phases. AOP can also remove some heavy metals without adding any new hazardous substances. Additionally, some AOPs can even achieve water disinfection.
Disadvantages of Advanced Oxidation Treatment
AOPs are not perfect, and the primary drawback is the cost. They need a continuous input of expensive chemicals, in the same quantity as the contaminants. Some techniques also require pre-treatment, which additionally increases the final cost.
That’s why AOPs shouldn’t decontaminate large amounts of wastewater. Instead, it should be the final stage of treatment. Before AOP, other treatments should be used.
Further Research
For the past 30 years, Advanced Oxidation Treatments have been decontaminating water. The process has been thoroughly researched. Between 1990 and 2002, AOP seemed to be a new and questionable process. However, after 2002, research on the topic significantly increased.
Around 50% of countries studied only the treatment of industrial water, while drinking water takes as low as 20%. However, in countries such as the United States, the primary concern was drinking water.
Most researchers state that using Advanced Oxidation Processes is of great importance. AOPs perfectly remove bacteria, as well as pesticides and pharmaceutical products. Due to an increasing need for water purification after 2002, the number of research projects in China and Spain also increased.
Conclusion
Using AOPs in treating contaminated water was, at first, a questionable process. However, over the past three decades, research has proven the effectiveness of these processes. Despite the price, AOPs are the best method for removing emerging pollutants in industrial, surface, and drinking water.