Variations in Oil Occurrence State and Properties during High-Speed Stirring Treatment of Oily Sludge.

IF 3.9 3区环境科学与生态学 Q2 ENVIRONMENTAL SCIENCES

Toxics Pub Date : 2024-09-29 DOI:10.3390/toxics12100711

Yuwei Bao, Yimin Zhu, Yang Liu, Jiao Zhao, Xiaojia Tang, Tie Li, Yin Wang, Xianmeng Liu, Hao Zhang

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引用次数: 0

Abstract

Oily sludge (OS) has long been regarded as a hazardous waste, and improper disposal may lead to serious environmental concerns and human health risks. Despite various methods having been proposed and applied to the treatment of OS, the oil occurrence states and properties in sludge are rarely characterized, which may directly link to the selection and effectiveness of treatment methods. Here, confocal laser scanning microscopy (CLSM), X-ray diffraction (XRD), gas chromatography (GC), and four components (SARA) analysis were utilized to characterize the changes in the oil occurrence states and compositions in OS samples before and after high-speed stirring (HSS) treatment. Our results show a substantial reduction in the oil concentration of OS after HSS treatment (from 32.98% to 1.65%), while SARA analysis reveals a similar oil composition before and after treatment, suggesting the broad applicability of HSS in removing oil and its insignificant selectivity towards various hydrocarbon components. This is further supported by the total petroleum hydrocarbon (TPH) analysis results, which show that the separated oil phase has a hydrocarbon composition similar to that of the original OS sample. The CLSM and fluorescence analysis suggest a homogeneous distribution of oil in the sludge, with relatively light components more concentrated in the pore systems between coarse mineral particles, whereas relatively heavy components tend to coexist with clay minerals. After HSS cleaning, both light and heavy components are removed to varying degrees, but light components are preferentially removed while heavy components tend to be retained in the sludge due to adsorption by clay minerals. This is consistent with TPH analysis, where a significant decrease in n-alkanes with lower carbon numbers (n-C14 to n-C20) was observed in the residual sample. Our findings demonstrate the dynamic response of oil occurrence states and compositions to the OS treatment process and highlight the importance of characterizing these fundamental properties prior to the selection of OS treatment methods.

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高速搅拌处理含油污泥过程中的含油状态和特性变化

长期以来，含油污泥（OS）一直被视为危险废物，处置不当可能会导致严重的环境问题和人类健康风险。尽管已经提出并应用了多种方法来处理含油污泥，但很少有人对污泥中油的发生状态和性质进行表征，而这可能直接关系到处理方法的选择和效果。在此，我们利用共焦激光扫描显微镜（CLSM）、X 射线衍射（XRD）、气相色谱（GC）和四组分（SARA）分析来表征高速搅拌（HSS）处理前后 OS 样品中油发生状态和成分的变化。我们的结果表明，经过高速搅拌处理后，OS 中的油类浓度大幅降低（从 32.98% 降至 1.65%），而 SARA 分析则显示处理前后的油类成分相似，这表明高速搅拌在去除油类方面具有广泛的适用性，而且其对各种碳氢化合物成分的选择性并不明显。总石油碳氢化合物 (TPH) 分析结果进一步证明了这一点，该结果表明分离出来的油相具有与原始 OS 样品相似的碳氢化合物成分。CLSM 和荧光分析表明，油类在污泥中分布均匀，相对较轻的成分更集中在粗矿物颗粒之间的孔隙系统中，而相对较重的成分则倾向于与粘土矿物共存。经过 HSS 清洁后，轻质和重质成分都在不同程度上被清除，但轻质成分更容易被清除，而重质成分则由于粘土矿物的吸附作用而倾向于保留在污泥中。这与 TPH 分析结果一致，即在残留样本中观察到碳数较低（n-C14 至 n-C20）的正烷烃显著减少。我们的研究结果表明了油类发生状态和组成对 OS 处理过程的动态响应，并强调了在选择 OS 处理方法之前确定这些基本特性的重要性。

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来源期刊

Toxics Chemical Engineering-Chemical Health and Safety

CiteScore

4.50

自引率

10.90%

发文量

681

审稿时长

6 weeks

期刊介绍： The Journal accepts papers describing work that furthers our understanding of the exposure, effects, and risks of chemicals and materials in humans and the natural environment as well as approaches to assess and/or manage the toxicological and ecotoxicological risks of chemicals and materials. The journal covers a wide range of toxic substances, including metals, pesticides, pharmaceuticals, biocides, nanomaterials, and polymers such as micro- and mesoplastics. Toxics accepts papers covering: The occurrence, transport, and fate of chemicals and materials in different systems (e.g., food, air, water, soil); Exposure of humans and the environment to toxic chemicals and materials as well as modelling and experimental approaches for characterizing the exposure in, e.g., water, air, soil, food, and consumer products; Uptake, metabolism, and effects of chemicals and materials in a wide range of systems including in-vitro toxicological assays, aquatic and terrestrial organisms and ecosystems, model mammalian systems, and humans; Approaches to assess the risks of chemicals and materials to humans and the environment; Methodologies to eliminate or reduce the exposure of humans and the environment to toxic chemicals and materials.