Inactivation of Bacteria E-coli and photodegradation of humic acids using natural sunlight

• Type: Article in International Scientific Journal
• Date: 2009

Authors

Ana I. Gomes (Author) FEUP; João C. Santos (Author) FEUP; Vítor J. P. Vilar (Author) FEUP; Rui A. R. Boaventura (Author) FEUP

Journal

Title: Applied Catalysis B: Environmental

Vol. 88 No. 3-4

Pages: 283-291

ISSN: 0926-3373

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 37 Citations

ISI Web of Science

Scopus - 44 Citations

COMPENDEX

Scientific classification

FOS: Engineering and technology > Other engineering and technologies

CORDIS: Technological sciences

Other information

Authenticus ID: P-003-K21

DOI: 10.1016/j.apcatb.2008.11.014

Abstract (EN): In this work, the disinfection of bacteria Escherichia coli and degradation of humic acids, using sunlight, sunlight + TiO(2) (Degussa P25) in suspension or TiO(2) supported on Ahlstrom paper (NW10) fixed around concentric tubes inside the photoreactor, were investigated in a pilot plant. The inactivation of bacteria E. coli proved to be more efficient (only 1 kJuv/L for 5-log decrease in concentration) when using sunlight and TiO(2) in suspension. However, true disinfection was not achieved under the conditions reported in this work. A first-order model was able to fit the photocatalytic deactivation of E. coli ([TiO(2)] - 50 mg/L) with an inactivation rate constant of 8.21 L/kJ. A Langmuir-Hinshelwood-like model was successfully applied for modelling photolysis and supported-TiO(2) photocatalysis of bacteria E. coli, considering an initial latency period, a classical log-linear behaviour and a tail region. The effect of the flow rate between 5 and 15 L/min was negligible in the inactivation of E. coli in the presence of sunlight and supported TiO(2). The inactivation rate constant increased with the initial concentration of E. coli. Almost no bacterial regrowth was observed in dark conditions during 24 h after illumination of E. coli suspension until complete deactivation. The humic acids (HA) degradation was also investigated by solar photocatalysis with suspended and supported TiO2 and exposure to sunlight-only, in a CPC photoreactor. Supported TiO(2) photocatalysis of HA originated 70% concentration, reduction after Q(UV) approximate to 14 kJ/L, whereas only 20% reduction was obtained by photolysis and slurry photocatalysis. First-order kinetic constants of 0.088 and 0.010 L/kJ were obtained, respectively, for suspended and supported TiO(2).

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9