title: Ozonation of diesel-fuel contaminated sand and the implications for remediation end-points.
abstract: In this study, we investigate specifically the influence of soil grain size and water content on the degradation of n-alkane fractions and the formation of aldehydes and carboxylic acid during ozonation. 15 g of quartz sand spiked with diesel (25 g kg(-1)) were exposed to ozone for 20 h at concentrations of 10, 30 and 50 mg L(-1), respectively. Results indicated that ozonation of the n-alkanes in fine grain size sand (0.15-0.25 mm) was 1.2 times faster than coarse sand due to higher surface contact area between O3 and sand particles. Soil moisture below 18% w/w did not influence the ozonation efficiency. In contrast the ozonation led to an increase of acidity of the sand samples (pH=3.0) after 20 h treatment. This was due to the formation of carboxylic acid. Formaldehyde, one of the key by-products of ozonation, was always <13 mg kg(-1) after the treatment which is below the industrial soil clean-up target level. While the aldehydes and carboxylic acid further reacted with O3 and their ozonation rate were slower than those of the alkanes suggesting that the hydroxylated by-products accumulated in the sand during the process. Overall the findings demonstrated that not only the alkanes but also aldehydes and carboxylic acid should be considered when defining remediation end-points.
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; National Engineering Research Centre for Distillation Technology, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China.
authors.forename: Xingang
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; Department of Environmental Science and Technology, School of Applied Science, Cranfield University, Cranfield MK43 0AL, UK.
authors.forename: Xingtao
authors.initials: X
authors.lastname: Cao
authors.affiliation: Division of Ocean Science and Technology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
authors.forename: Guozhong
authors.initials: G
authors.lastname: Wu
authors.affiliation: Centre for Defence Chemistry, Cranfield University, Shrivenham SN6 8LA, UK.
authors.forename: Tracey
authors.initials: T
authors.lastname: Temple
authors.affiliation: Department of Environmental Science and Technology, School of Applied Science, Cranfield University, Cranfield MK43 0AL, UK. Electronic address: f.coulon@cranfield.ac.uk.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Coulon
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; National Engineering Research Centre for Distillation Technology, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China. Electronic address: suihong@tju.edu.cn.
authors.forename: Hong
authors.initials: H
authors.lastname: Sui
mesh_terms: D000473:Alkanes / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry; D052918:Environmental Restoration and Remediation; D005742:Gasoline; D006863:Hydrogen-Ion Concentration; D010126:Ozone / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000473:Alkanes; D002264:Carboxylic Acids; D005742:Gasoline; D012989:Soil Pollutants; D014867:Water; D010126:Ozone; D012822:Silicon Dioxide
keywords: Aldehydes; Carboxylic acid; Diesel contamination; Ozone treatment; Soil remediation