Over the last few decades, rapid deterioration in water quality especially due to the illegal release of contaminants into water bodies, has led to the deprivation of usable water, the brunt of which is felt most strongly by developing and under-developed nations. Many of these chemicals are persistent organic and bio-refractory pollutants, and dwell in the water bodies for long, causing adverse and irreversible health impacts. These contaminants pose formidable challenges for conventional treatment technologies, which are highly inefficient and thereby result in long residual times. The current study considers strategies for efficient removal of emerging and persistent pharmaceutical contaminants in water.

Physico-chemical treatment technologies, notably, advanced oxidation processes (AOPs), have proven to be very successful in mineralizing such persistent organic pollutants (POPs). Although they are effective in mineralizing POPs, they have their own limitations such as periodic chemical addition, sludge formation, generation of toxic intermediates, and/or safety issues. Transcending these AOPs, is a recent AOP named electroperoxone that circumvents most of these challenges. This work focuses on the investigation of novel electrode materials in electroperoxoneto enhance the generation of reactive oxygen species (ROS) and thereby improve contaminant degradation. However, a key challenge in using AOPs is their high energy consumption which has motivated us to study a treatment train that comprises a biological pre-treatment unit followed by an AOP (electroperoxone). Among biological systems, traditional attached growth biological systems involving biofilms have long been used for treating these contaminants due to the resilience of biofilms. However, existing conventional attached growth wastewater systems are greatly hampered by long start-up times, frequent biofilm sloughing and/or erosion which lead to poor or inconsistent performance. Here, we develop a novel Electrically Bound Biofilm Reactor/process (EBBR)and investigate its efficacy in achieving an improved bacterial adhesion for the removal of organic waste. Consisting of electrodes made from e-waste and scrap metal, this work highlights a sustainable approach for achieving biodegradation.Optimization of the bio-electrochemical setup, electrochemical and material characterization and plausible mechanisms for bio-film attachment and electroperoxone-based contaminant degradation will be discussed. We show that the enhanced biofilm attachment, combined with rapid biofilm start-up times and electroperoxone-based degradation paves way for a sustainable EBBR-Electroperoxone system train.