An innovative photoreactor, FluHelik, to promote UVC/H2O2 photochemical reactions: Tertiary treatment of an urban wastewater

Sci Total Environ. 2019 Jun 1:667:197-207. doi: 10.1016/j.scitotenv.2019.02.335. Epub 2019 Feb 23.

Abstract

An innovative photoreactor, FluHelik, was used to promote the degradation of contaminants of emerging concern (CECs) by a photochemical UVC/H2O2 process. First, the system was optimized for the oxidation of a model antibiotic, oxytetracycline (OTC), using both ultrapure water (UPW) and a real urban wastewater (UWW) (collected after secondary treatment) as solution matrices. Following, the process was evaluated for the treatment of a UWW spiked with a mixture of OTC and 10 different pharmaceuticals established by the Swiss legislation at residual concentrations (∑CECs <660 μg L-1). The performance of the FluHelik reactor was analyzed both at lab and pre-pilot scale in multiple and single pass flow modes. The efficiency of the FluHelik photoreactor, at lab-scale, was evaluated at different operational conditions (H2O2 concentration, UVC lamp power (4, 6 and 11 W) and flow rate) and further compared with a conventional Jets photoreactor. Both photoreactors exhibited similar OTC removal efficiencies at the best conditions; however, the FluHelik reactor showed to be more efficient (1.3 times) in terms of mineralization when compared with the Jets reactor. Additionally, the efficiency of the UVC/H2O2 photochemical system using the FluHelik photoreactor in reducing the toxicity of the real effluent containing 11 pharmaceuticals was evaluated through zebrafish (Danio rerio) embryo toxicity bioassays. FluHelik scale-up from laboratory to pre-pilot to promote UVC/H2O2 photochemical process proved to be feasible.

Keywords: CECs; FluHelik photoreactor; UVC/H(2)O(2); Urban wastewater; Zebrafish embryo toxicity test.

MeSH terms

  • Hydrogen Peroxide / chemistry*
  • Photochemical Processes
  • Photolysis*
  • Ultraviolet Rays*
  • Waste Disposal, Fluid / instrumentation
  • Waste Disposal, Fluid / methods*
  • Wastewater / analysis
  • Water Pollutants, Chemical / analysis*

Substances

  • Waste Water
  • Water Pollutants, Chemical
  • Hydrogen Peroxide