Department of Environmental Engineering, Kunsan National University, Kunsan, 54150, South Korea.
Department of Environmental Engineering, Kunsan National University, Kunsan, 54150, South Korea.
Chemosphere. 2020 Jul;250:126206. doi: 10.1016/j.chemosphere.2020.126206. Epub 2020 Feb 18.
In this study, total petroleum hydrocarbon (TPH) removal from fuel-contaminated field soil was investigated. The influence of the washing method (washing before/after sieving), washing time, soil-to-water ratio, and soil particle size on TPH removal efficiency was evaluated under constant stirring speed. Washing the whole contaminated soil is more efficient than separating the soils into particle size fractions and separately washing the fractions. Particles with differing diameters would be more in contact with each other resulting in detachment of contaminants from the soil particle surface. Effects of soil washing time and soil-to-water ratio on TPH removal were not significant in coarse soil particles (greater than 0.15 mm diameter) but significantly affected TPH removal in fine particles (less than 0.15 mm diameter). This study suggests a threshold washing time of 1 h and a threshold soil-to-water ratio of 1:6 for the whole soil in soil washing. However, soil particles less than 0.075 mm (<75 μm) should be separated after washing to meet the Korean soil TPH limit of less than 500 mg/kg. This study demonstrates the importance of finer soils as debrading media and particle size fraction composition of fuel-contaminated soil in soil washing.
本研究旨在研究从受燃料污染的田间土壤中去除总石油烃（TPH）。在恒定搅拌速度下，评估了洗涤方法（洗涤前/后筛分）、洗涤时间、固液比和土壤粒径对 TPH 去除效率的影响。整体洗涤受污染土壤比将土壤分成粒径分级并分别洗涤分级更有效。不同直径的颗粒会相互更紧密接触，从而导致污染物从土壤颗粒表面脱落。在粗颗粒（大于 0.15 毫米直径）中，土壤洗涤时间和固液比对 TPH 去除的影响不显著，但在细颗粒（小于 0.15 毫米直径）中显著影响 TPH 去除。本研究建议在土壤洗涤中，整个土壤的临界洗涤时间为 1 小时，临界固液比为 1:6。然而，洗涤后应将小于 0.075 毫米（<75μm）的土壤颗粒分离，以满足韩国土壤 TPH 限值低于 500 毫克/千克的要求。本研究表明，细土作为去污介质以及受燃料污染土壤的粒径分级组成在土壤洗涤中非常重要。
