Solar-chemical treatment of groundwater contaminated with petroleum at gas station sites: ex situ remediation using solar/TiO(2) photocatalysis and Solar Photo-Fenton.
Groundwater samples contaminated by BTEX (benzene, toluene, ethylbenzene, xylene isomers and TPHs (total petroleum hydrocarbons) were treated with advanced oxidation processes (AOPs), such as TiO(2) photocatalysis and Fe(2+)/H(2)O(2) exposed to solar light (37 degrees N and 128 degrees E) with an average intensity of 1.7 mW/cm(2) at 365 nm. These AOP processes showed feasibility in the treatment of groundwater contaminated with BTEX, TPH and TOC (Total Organic Carbon). Outdoor field tests showed that the degradation efficiency of each contaminant was higher in the Fe(2+)/H(2)O(2) system without solar light compared to the TiO(2)/solar light and H(2)O(2)/solar light systems. However, the TiO(2)/solar light and the Fe(2+)/H(2)O(2)/solar light systems showed significantly enhanced efficiencies in the degradation of BTEX, TPH and TOC with the additional use of H(2)O(2). Near complete degradation of BTEX and TPH was observed within 2 and 4 hrs, respectively, however, that of TOC was slower. Without pretreatment of the groundwater, fouling of the TiO(2), due to the ionic species present, was observed within 1 hr of operation, which resulted in the inhibition of further BTEX, TPH and TOC destruction. The degradation rate of n-alkanes with carbon numbers ranging from C10 to C15 was relatively greater than that of n-alknaes with carbon numbers ranging from C16 to C20. From this work, the AOP process (Fe(2+)/H(2)O(2)/solar light and TiO(2)/H(2)O(2)/solar light) illuminated with solar light was identified as an effective ex situ technique in the remediation of groundwater contaminated with petroleum.
Cho
Ii-Hyoung
IH
New Town Development Division, Gyeonggi Innovation Corporation, Kwandong University, Korea.
Kim
Young-Gyu
YG
Yang
Jae-Kyu
JK
Lee
Nae-Hyun
NH
Lee
Seung-Mok
SM
D002244:Carbon / Q000378:metabolism; D002384:Catalysis; D002849:Chromatography, Gas; D005296:Ferrous Compounds / Q000737:chemistry*; D006838:Hydrocarbons / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000737:chemistry; D007700:Kinetics; D010578:Petroleum / Q000378:metabolism*; D010777:Photochemistry; D016082:Solar System; D014025:Titanium / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification / Q000379:methods
D005296:Ferrous Compounds; D006838:Hydrocarbons; D010578:Petroleum; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D002244:Carbon; D006861:Hydrogen Peroxide; D014025:Titanium