Tertiary treatment of pulp mill wastewater by solar photo-Fenton.
This work reports on pulp mill wastewater (PMW) tertiary treatment by Fenton (Fe(2+)/H(2)O(2)) and solar photo-Fenton (Fe(2+)/H(2)O(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 5mg Fe L(-1) reaches 90% of DOC mineralisation with 31kJ L(-1) of UV energy and 50mM of H(2)O(2). The initial non-biodegradability of PMW, as shown by respirometry assays and BOD(5)/COD ratio, can be changed after a solar photo-Fenton treatment. Experiments with 20 and 50mg Fe L(-1) revealed that solar photo-Fenton can reach the same DOC degradation (90%), however, consuming less H(2)O(2) and time. Diluting the initial organic load to 50% also diminishes the dosage of H(2)O(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.
Centro de Química de Vila Real, Universidade de Trás-os-Montes e Alto Douro, Apartado 1013, 5001-801 Vila Real, Portugal. mlucas@utad.pt
Marco S
MS
Lucas
José A
JA
Peres
Carlos
C
Amor
Lucía
L
Prieto-Rodríguez
Manuel I
MI
Maldonado
Sixto
S
Malato
D001673:Biodegradation, Environmental; D002482:Cellulose; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D010782:Photolysis; D013472:Sunlight; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000528:radiation effects* / Q000633:toxicity
D014874:Water Pollutants, Chemical; D002482:Cellulose; D006861:Hydrogen Peroxide; D007501:Iron