超低界面张力纳米乳液处理含油作业废物的研究

Study on Treatment of Oil-bearing Wastes

作业区含油作业废物无害化处理多采用高温热解和化学萃取等集中建站方法,处理设备庞大,能耗高,废物收集环境风险高,纳米乳液在常温下可将油相从含油废物中快速脱附,为作业现场含油废物的随产生随处理提供了良好的工艺基础。室内研究选用不同配比下的表面活性剂、助表面活性剂和水的混合物,与正辛烷按(1∶9)^(5∶5)比例混合,在10~100 Hz频率超声波震荡后得到Winsor IV型单相纳米乳液NR-A。使用激光粒度仪测得纳米乳液NR-A粒径D90为11 nm,吊环法测得油水界面张力仅为1.35 m N/m,体系Zeta电位大于-50 m V,为热力学稳定的分散体系。在含油废物中加入纳米乳液NA-R后,快速传质作用和超低界面张力可将含油废物的油相在低能耗状态下从固相上剥离脱附。室内评价表明,纳米乳液NA-R与页岩气含油钻屑混合后,在0.5%加量下常温搅拌20 min,油相脱附率达到95.7%,脱附后油相可回用作配浆基油,实现了含油废物的安全高效资源化治理。

High temperature thermal decomposition and chemical extraction are commonly used in the innocent treatment of oilbearing wastes in operation areas. These treatments require the construction of a plant for the centralized processing of the wastes and gigantic equipment with high energy consumption is required. In collecting the wastes, environmental risks have to be considered. Nano emulsion at normal temperatures can rapidly separate oil from oil-bearing wastes, providing a good base for the ＂treatment while producing＂ of oil-bearing wastes. In laboratory study, a mixture of a surfactant, a secondary surfactant and water in different rations was further mixed with n-octane in a ratio between 1∶9 and 5∶5. The final mixture was agitated with supersonic wave at frequencies between 10-100 Hz to obtain a Winsor IV type single phase nano emulsion NR-A. The particle size, D90, of the NR-A emulsion measured on a laser particle size analyzer was 11 nm, and the interfacial tension between oil and water, as measured with the Du Nouy method, was only 1.35 m N/m. The Zeta potential of the emulsion system was greater than 50 m V, indicating that the system was a thermodynamic dispersion. Adding the NR-A into oil-bearing wastes, the oil phase of the wastes can be desorbed from the solids under low energy consumption through fast mass transfer and ultra-low interfacial tension. Laboratory evaluation showed that when 0.5% NA-R was mixed with oil-bearing wastes from shale gas drilling, after agitation at room temperature for 20 min, 95.7% of the oil-on-waste was desorbed from the wastes. The desorbed oil can be used as the base oil for mixing oil base drilling fluids, realizing the efficient treatment and recycling of oil-bearing wastes.