Investigation on the materials and electrochemical properties of chemically disintegrated waste activated sludge for aqueous symmetric supercapacitor

Over the past few decades, the ubiquitous water pollution due to the constant increase in the world’s population and industrial growth has caused several global issues. One of these issues is related to wastewater treatment. Wastewater is usually treated using activated sludge (AS) in aeration tanks. The process is based on the addition of oxygen, which bacteria can use for the degradation of organic substances into water and carbon dioxide. However, the AS technique has the disadvantage of excess waste activated sludge (WAS) that is being generated. From a circular economic perspective, reusing such products becomes an opportunity. We believe that understanding the WAS disintegration process by various oxidants (primarily persulfate) and experimenting with the reagents [e.g., persulfate dose] may not only drastically reduce the WAS volume but possibly also reuse the oxidation products (sulfuric acid, transition metals) formed in this process. These products have the potential to be recovered in supercapacitors, which perfectly fits into the current trend of the European Union, i.e., a circular economy.