Activities performed / results achieved:
• SR-eAOP treatment was operated under mild conditions (i.e. neutral pH, ambient temperature and pressure), without catalysts, and without generating secondary waste streams. As a result, lower environmental impacts, toxicity effects and operating costs than for other AOP technologies were observed.
• Development and characterization of a 4-stage solid-state Marx Generator used for the treatment of wastewater. The device employed arrays of series connected MOSFETs triggered via a distributed transformer to minimize jitter.The output of the pulse generator was used to generate plasma in a pin-to-water reactor.
• Development and fabrication of a prototype spray reactor, contributing significantly to the body of knowledge on plasma-based reactors for pollutant degradation, with the research outcomes poised to have a substantial impact on the fields of environmental engineering and sustainable pollution control
• Standalone eAOPs were performed at lab scale using both synthetic and real municipal wastewater effluent. The sequential electro-Fenton was successful for both the regeneration of activated carbon and the removal of the desorbed compounds.
• Pristine and heterojunction based visible light driver BiVO4 photoanodes were fabricated through dip coating, electrodeposition and ultrasonic spray pyrolysis techniques.
• The immobilization of several photocatalysts such as titanium dioxide (TiO2), bismuth vanadate (BiVO4), tungsten trioxide (WO3) was conducted on a fluorine doped tin oxide substrate. A novel hybrid process was tested combining the photoelectrochemical process, enhanced by the addition of peroxymonosulfate (PMS), to remove pharmaceuticals from water. Finally, the transformation products and their eco-toxicity were assessed using EPA generated ECOSAR models and in-vivo bioassays.
• The CWPO, i.e. activation of peroxymonosulfate (PMS) and peroxydisulfate (PDS), was achieved with two heterogeneous catalysts: carbon encapsulated cobalt ferrite (CoFe2O4@C) and carbon-cobalt-iron doped graphitic carbon nitride (g-C3N4/C/Co/Fe). Their catalytic performance was evaluated in electrochemical systems comprised of reticulated vitreous carbon (RVC) cathode and dimensionally stable anode (DSA).
• Various carbonaceous materials were tested as cathode material in an electrochemical system and their efficiency and efficacy towards H2O2 generation were evaluated.
• Dedicated Reversed phase LC-MS/MS methodologies were developed allowing quantification at relevant concentration levels (ng/L to µg/L). SPE methods were developed allowing wastewater sample pretreatment and prooved compatible with 54 of the solutes.
• An online comprehensive two-dimensional liquid chromatography (LC x LC) coupled with high resolution mass spectrometry (HRMS) was developed to elucidate degradation products after treatment with AOPs. The optimized method was also applied to tentatively identify degradation products in treated samples.
• A TRLCxRPLC-HRMS platform was developed allowing more facile analysis of eAOP degradation products. The combination of TRLC with refractive index detection was introduced, allowing more universal (standard free) quantification of compounds.
• A generic predictive retention index model was developed for liquid chromatography coupled to high resolution mass spectrometry.
• Electrochemical degradation of three endocrine disrupting chemicals was studied to assess the effects on biological activity. In vivo models were used to evaluate the estrogenic and thyroid disrupting effects of EDCs and their transformation products (TPs). In vivo models proved to be reliable tools for assessing the endocrine disrupting effects of EDCs and electrochemically generated TPs, including the potential effects of incomplete EDC removal and the generation of toxic TPs.
• The effect of electrochemical advanced oxidation processes (eAOP) pre-treatment on the subsequent anaerobic biological treatment of 2-chlorophenol (DCP) was investigated.
• The environmental performance and cost of four emerging electrochemical advanced oxidation processes (eAOPs) for wastewater treatment was investigated in comparison to a benchmark process: ozonation. The LCA study includes the construction, use, and end-of-life phases of the eAOP and ozonation technologies. This study highlights the need to evaluate emerging technologies early in their development to optimize the technology and its potential impacts.
