Tertiary treatment of pulp mill wastewater by solar photo-Fenton Lucas, Marco S., E-mail: mlucas@utad.pt [Centro de Quimica de Vila Real, Universidade de Tras-os-Montes e Alto Douro, Apartado 1013, 5001-801 Vila Real (Portugal)]; Peres, Jose A.; Amor, Carlos [Centro de Quimica de Vila Real, Universidade de Tras-os-Montes e Alto Douro, Apartado 1013, 5001-801 Vila Real (Portugal)]; Prieto-Rodriguez, Lucia; Maldonado, Manuel I.; Malato, Sixto [Plataforma Solar de Almeria (CIEMAT), Carretera de Senes, Km 4, 04200, Tabernas, Almeria (Spain)] 54 ENVIRONMENTAL SCIENCES; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ENVIRONMENTAL IMPACTS; HYDROGEN PEROXIDE; IRON IONS; LEGAL ASPECTS; PARABOLIC COLLECTORS; PILOT PLANTS; POLYPHENOLS; REMOVAL; SLURRIES; TOXICITY; WASTE WATER; WATER TREATMENT Highlights: Black-Right-Pointing-Pointer We firstly report a real pulp mill wastewater treatment by solar photo-Fenton in a CPC reactor. Fenton reagent experiments were tested firstly. Black-Right-Pointing-Pointer Solar photo-Fenton presents excellent ability to treat the pulp mill wastewater. Black-Right-Pointing-Pointer Experimental conditions were optimised. Black-Right-Pointing-Pointer Biodegradability and toxicity tests (respirometry assays and BOD{sub 5}/COD ratio) were performed during the wastewater treatment. Black-Right-Pointing-Pointer A way to reduce the economic and environmental impact was evaluated. - Abstract: This work reports on pulp mill wastewater (PMW) tertiary treatment by Fenton (Fe{sup 2+}/H{sub 2}O{sub 2}) and solar photo-Fenton (Fe{sup 2+}/H{sub 2}O{sub 2}/UV) processes in a pilot plant based on compound parabolic collectors (CPCs). Solar photo-Fenton reaction is much more efficient than the respective dark reaction under identical experimental conditions. It leads to DOC mineralisation, COD and total polyphenols (TP) removal higher than 90%. The solar photo-Fenton experiment with 5 mg Fe L{sup -1} reaches 90% of DOC mineralisation with 31 kJ L{sup -1} of UV energy and 50 mM of H{sub 2}O{sub 2}. The initial non-biodegradability of PMW, as shown by respirometry assays and BOD{sub 5}/COD ratio, can be changed after a solar photo-Fenton treatment. Experiments with 20 and 50 mg Fe L{sup -1} revealed that solar photo-Fenton can reach the same DOC degradation (90%), however, consuming less H{sub 2}O{sub 2} and time. Diluting the initial organic load to 50% also diminishes the dosage of H{sub 2}O{sub 2} and the necessary reaction time to achieve high DOC removals. Accordingly, solar photo-Fenton can be considered an alternative or complementary process to improve the performance of a biologic treatment and, subsequently, achieve legal limits on discharge into natural waters. Available from http://dx.doi.org/10.1016/j.jhazmat.2012.05.013 Netherlands 2012-07-30 English Journal Article Journal Name: Journal of Hazardous Materials; Journal Volume: 225-226; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA) Medium: X; Size: page(s) 173-181 https://doi.org/10.1016/J.JHAZMAT.2012.05.013 PII: S0304-3894(12)00495-5 [] 225-226 Journal ID: ISSN 0304-3894; CODEN: JHMAD9; Other: PII: S0304-3894(12)00495-5; TRN: NL12S2169108334 NLN 2013-11-21 22154200