Agarwal Ashutosh, Zhou Yufeng, Liu Yu
Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore, 637141, Singapore.
School of Mechanical & Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
Environ Sci Pollut Res Int. 2016 Dec;23(23):23876-23883. doi: 10.1007/s11356-016-7601-5. Epub 2016 Sep 15.
In this study, a novel chemical-free approach for cleaning oil-contaminated sand with self-collapsing air microbubbles (MBs) with diameter less than 50 μm was developed without the use of chemicals, such as surfactants and alkalis. Diesel and rotary-vane pump oil-contaminated fine and medium sands were treated with MBs to study the effect of oil viscosity and sand grain size on oil removal with MBs. About 95 % of diesel removal was achieved for 24 h old 10 % (w/w) diesel-contaminated medium sand in contrast to only 70 % removal from fine sand after 40-min treatment with MBs. While rotary-vane pump oil removal exceeds that of diesel after 40-min treatment with MBs, combination of mechanical stirring with MBs significantly enhanced the oil removal rate, whereby 95 % diesel removal was achieved from fine sand in 30 min in contrast to only 52 % diesel removal with MBs alone. A possible MBs cleaning mechanism for oil-contaminated sand was also proposed. This study provides experimental evidence for the applicability of self-collapsing MBs as a novel chemical-free approach for cleaning oil-contaminated sand.
在本研究中，开发了一种新型的无化学药剂方法，即使用直径小于50μm的自塌陷空气微泡（MBs）来清洁受油污染的沙子，且不使用表面活性剂和碱等化学药剂。用MBs处理受柴油和旋片泵油污染的细砂和中砂，以研究油的粘度和砂粒尺寸对MBs除油效果的影响。对于24小时龄期的10%（w/w）受柴油污染的中砂，用MBs处理24小时后柴油去除率约为95%，而用MBs处理40分钟后，细砂中的柴油去除率仅为70%。在用MBs处理40分钟后，旋片泵油的去除率超过了柴油，而机械搅拌与MBs相结合显著提高了除油率，由此在30分钟内从细砂中实现了95%的柴油去除率，相比之下仅用MBs时柴油去除率为52%。还提出了一种受油污染沙子的MBs清洁机制的可能性。本研究为自塌陷MBs作为一种新型的无化学药剂方法用于清洁受油污染的沙子的适用性提供了实验证据。
