Treatment of a sanitary landfill leachate using combined solar photo-Fenton and biological immobilized biomass reactor at a pilot scale

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Vitor J. P. Vilar (Author) FEUP; E.M.R. Rocha (Author) Other; F.S. Mota (Author) Other; Amélia Fonseca (Author) Other; Isabel Saraiva (Author) Other; Rui Boaventura (Author) FEUP

Journal

Title: Water Research

Vol. 45

Pages: 2647-2658

ISSN: 0043-1354

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 63 Citations

ISI Web of Science

Scopus - 82 Citations

Scientific classification

FOS: Engineering and technology > Environmental engineering

CORDIS: Technological sciences > Technology > Environmental technology

Other information

Authenticus ID: P-002-SMX

DOI: 10.1016/j.watres.2011.02.019

Abstract (EN): A solar photo-Fenton process combined with a biological nitrification and denitrification system is proposed for the decontamination of a landfill leachate in a pilot plant using photocatalytic (4.16 m(2) of Compound Parabolic Collectors - CPCs) and biological systems (immobilized biomass reactor). The optimum iron concentration for the photo-Fenton reaction of the leachate is 60 mg Fe2+ L-1. The organic carbon degradation follows a first-order reaction kinetics (k = 0.020 L kJuv(-1), r(0) = 12.5 mg kJuv(-1)) with a H2O2 consumption rate of 3.0 mmol H2O2 kJuv(-1). Complete removal of ammonium, nitrates and nitrites of the photo-pre-treated leachate was achieved by biological denitrification and nitrification, after previous neutralization/sedimentation of iron sludge (40 mL of iron sludge per liter of photo-treated leachate after 3 h of sedimentation). The optimum C/N ratio obtained for the denitrification reaction was 2.8 mg CH3OH per mg N-NO3-, consuming 7.9 g/8.2 mL of commercial methanol per liter of leachate. The maximum nitrification rate obtained was 68 mg N-NH4+ per day, consuming 33 mmol (1.3 g) of NaOH per liter during nitrification and 27.5 mmol of H2SO4 per liter during denitrification. The optimal phototreatment energy estimated to reach a biodegradable effluent, considering Zahn-Wellens, respirometry and biological oxidation tests, at pilot plant scale, is 29.2 kJuv L-1 (3.3 h of photo-Fenton at a constant solar UV power of 30 W m(-2)), consuming 90 mM of H2O2 when used in excess, which means almost 57% mineralization of the leachate, 57% reduction of polyphenols concentration and 86% reduction of aromatic content.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12