Enhanced pharmaceutical removal from water in a three step bio-ozone-bio process

Abstract

Individual treatment processes like biological treatment or ozonation have their limitations for the removal of pharmaceuticals from secondary clarified effluents with high organic matter concentrations (i.e. 17 mg TOC/L). These limitations can be overcome by combining these two processes for a cost-effective pharmaceutical removal. A three-step biological-ozone-biological (BOB) treatment process was therefore designed for the enhanced pharmaceutical removal from wastewater effluent. The first biological step removed 38% of ozone scavenging TOC, thus proportionally reducing the absolute ozone input for the subsequent ozonation. Complementariness between biological and ozone treatment, i.e. targeting different pharmaceuticals, resulted in cost-effective pharmaceutical removal by the overall BOB process. At a low ozone dose of 0.2 g O/g TOC and an HRT of 1.46 h in the biological reactors, the removal of 8 out of 9 pharmaceuticals exceeded 85%, except for metoprolol (60%). Testing various ozone doses and HRTs revealed that pharmaceuticals were ineffectively removed at 0.1 g O3/g TOC and an HRT of 0.3 h. At HRTs of 0.47 and 1.46 h easily and moderately biodegradable pharmaceuticals such as caffeine, gemfibrozil, ibuprofen, naproxen and sulfamethoxazole were over 95% removed by biological treatment. The biorecalcitrant carbamazepine was completely ozonated at a dose of 0.4 g O/g TOC. Ozonation products are likely biodegraded in the last biological reactor as a 17% TOC removal was found. No appreciable acute toxicity towards D. magna, P. subcapitata and V. fischeri was found after exposure to the influents and effluents of the individual BOB reactors. The BOB process is estimated to increase the yearly wastewater treatment tariff per population equivalent in the Netherlands by less than 10%. Overall, the BOB process is a cost-effective treatment process for the removal of pharmaceuticals from secondary clarified effluents.

Ozonation of Sitagliptin: Removal Kinetics and Elucidation of Oxidative Transformation Products

“…However, ozonation of wastewater treatment plant (WWTP) effluents usually does not lead to a complete mineralization of micropollutants but rather to the formation of oxidative transformation products (TPs). 4 Oxidative transformation through ozonation occurs via two pathways: (i) reactions with ozone and (ii) reactions with intrinsically formed hydroxyl (OH) radicals, e.g., by ozone decay or reactions with organic matter. 5 The direct reaction with ozone is a selective reaction, since ozone primarily attacks electron-rich moieties such as double bonds, amines, and activated aromatic rings.…”

Assessment Impacts of Ozone on Salmonella Typhimurium and Escherichia coli O157:H7 in Liquid Dairy Waste

“…Application of ozone treatment for wastewater treatment at a pilot scale showed significant removal of contaminants such as pharmaceuticals, nitrate, and micropollutants [44][45][46]. Ozone treatment is considered a cost-effective, and eco-friendly method for the removal of various contaminations including mycotoxins in grain products [47], pharmaceutical removal from water [48], and contaminants removal in food products [49].…”

Benefits of ozonation before activated carbon adsorption for the removal of organic micropollutants from wastewater effluents

“…Ozonation is currently the most used oxidation process for OMPs removal in drinking water production and is also recently transferred to the advanced treatment of wastewater effluents (de Wilt et al, 2018;Hollender et al, 2009;Margot et al, 2013;Zimmermann et al, 2011). Bourgin et al (2018) obtained removals higher than 80 % for the 12 OMPs used as indicator substances in the Swiss legislation (Office fédéral de l'environnement, Division Eaux, 2014) over a whole wastewater treatment plant upgraded with an ozonation step (0.55 gO3/gDOC).…”