Enhancement of Detoxification of Petroleum Hydrocarbons and Heavy Metals in Oil-Contaminated Soil by Using Glycine-β-Cyclodextrin.

Wei Zhang,Qiu-Ya Niu,Yuan-Qiang Tang,Guang-Ming Zeng,Yun-Guo Liu,Ji-Lai Gong,Xiao-Fei Tan,Cui Lai

doi:10.3390/ijerph16071155

Wei Zhang, Qiu-Ya Niu + Show 6 more

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https://doi.org/10.3390/ijerph16071155

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Abstract

Soil contamination with petroleum hydrocarbons and heavy metals is a widespread environmental problem. In recent years, cyclodextrin has attracted research interest because of its special hole structure that can form inclusion complexes with certain small molecules. However, the solubility of β-cyclodextrin (β-CD) in water is low and it crystallizes easily, leading to its low utilization in practice. In this experiment, we connected β-CD with glycine under alkaline conditions to prepare glycine-β-cyclodextrin (G-β-CD), which is water soluble, has stronger coordinating ability with heavy metals, and is more suitable for treating oil-contaminated soil. The results show that G-β-CD provides better desorption of petroleum hydrocarbons and heavy metals in soils with low organic matter content (1%) and NaNO3 of 0.25 mol/L at 70 g/L G-β-CD under mildly acidic (pH 5–6) conditions. The results indicate that petroleum hydrocarbons and heavy metals were removed simultaneously by means of pretreatment with G-β-CD, and the results can provide a theoretical basis for remediation of petroleum-contaminated soil.

Highlights

Oil-contamination of soil is a serious environmental problem
The soil used for the experiment was collected from a typical location in a production station at the No 4 oil production plant of Zhongyuan Oilfield, where oil production wells were stable for more than one year
In view of these results, one can conclude that G-β-CD could simultaneously increase the apparent

Summary

Introduction

Oil-contamination of soil is a serious environmental problem. 8 million tons is produced during oil exploitation and lost during refining, transporting, and draining of waste oily water. This lost oil slowly leaches into the soil and groundwater [1,2]. These harmful elements will enter the human body through the food chain, harming human health. Petroleum hydrocarbons and heavy metals produce synergistic effect in soils that exacerbate the toxicity and damage to the environment, making treatment more difficult [3,4]

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