Ozonation of diesel-fuel contaminated sand and the implications for remediation end-points

Xingang Li; Xingtao Cao; Guozhong Wu; Tracey Temple; Frédéric Coulon; Hong Sui

doi:10.1016/j.chemosphere.2014.03.005

Ozonation of diesel-fuel contaminated sand and the implications for remediation end-points

Chemosphere. 2014 Aug:109:71-6. doi: 10.1016/j.chemosphere.2014.03.005. Epub 2014 Apr 12.

Authors

Xingang Li¹, Xingtao Cao², Guozhong Wu³, Tracey Temple⁴, Frédéric Coulon⁵, Hong Sui⁶

Affiliations

¹ 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.
² 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.
³ Division of Ocean Science and Technology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
⁴ Centre for Defence Chemistry, Cranfield University, Shrivenham SN6 8LA, UK.
⁵ Department of Environmental Science and Technology, School of Applied Science, Cranfield University, Cranfield MK43 0AL, UK. Electronic address: f.coulon@cranfield.ac.uk.
⁶ 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.

PMID: 24873709
DOI: 10.1016/j.chemosphere.2014.03.005

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.

Keywords: Aldehydes; Carboxylic acid; Diesel contamination; Ozone treatment; Soil remediation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Alkanes / chemistry
Carboxylic Acids / chemistry
Environmental Restoration and Remediation*
Gasoline*
Hydrogen-Ion Concentration
Ozone / chemistry*
Silicon Dioxide / chemistry*
Soil Pollutants / chemistry*
Time Factors
Water / chemistry

Substances

Alkanes
Carboxylic Acids
Gasoline
Soil Pollutants
Water
Ozone
Silicon Dioxide