Removal Reverse osmosis Packing material Optimization Air treatment Photocatalytic degradation Continuous reactor Clofibric acid Azo dye Fouling Oxidation Electrochemical oxidation Electrocoagulation Adsorption Azo dyes Kinetics Persulfate Toxicity Biodegradation Absorption Metronidazole Cleaning Carbon felt electrode Organic solvent nanofiltration Wastewater Hydrophobic VOC Membrane Volatile organic compound Dyes Pesticides PH Fixed bed Biosorption Electro-Fenton Central composite design Water treatment Ultrafiltration Antibiotics Isotherms Combined process Wastewater treatment Activated carbon Partition coefficient Combined processes Ionic liquids Cyclic voltammetry Graphite felt Activated sludge VOC Sulfamethazine Mass-transfer Ageing Biofiltration Mineralization Fermentation Tetracycline Characterization Heavy metals Silicone oil Biodegradability Polyamide Aqueous-solution Chemical oxidation Pollution TiO2 Nanofiltration Degradation Modelling Chemical scrubbing Advanced oxidation processes Prediction Modeling Simulation Kinetic modeling Filtration Volatile organic compounds Biological treatment Microfiltration Soil Toluene Methylene blue VOCs Mass transfer Ozone Magnetite Nanoparticles Isotherm Synergetic effect Biomass DFT Kinetic models Electro-Fenton process Response surface methodology Phenol Sorption Kinetic Water Advanced oxidation process Batch study Photocatalysis