Wu Shuhui, Yao Xue, Wang Xiao, Yuan Wenyan, Li Qiuhong, Niu Xiaoyin, Ma Yanfei
School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo 255000, China.
School of Resource and Environmental Engineering, Shandong University of Technology, Zibo 255000, China.
Toxics. 2024 Dec 2;12(12):880. doi: 10.3390/toxics12120880.
The solid phase composition in oily sludge (OS) is a key factor affecting the oil-solid separation of OS. In this paper, the effects and mechanisms of solid-phase particle factors on the oil content of residue phase were investigated in order to improve the oil-solid separation efficiency. Flotation experiments were carried out on single-size sand and mixed-size sand OS consisting of three particle sizes at room temperature without adding flotation reagents. The effects of different-size particles as solid phase composition of OS and flotation parameter settings such as flotation temperature (Tp), flotation time (Tt), impeller speed (Rs) and liquid-solid ratio (L/OS) on the oil-solid separation efficiency were investigated. The experimental results showed that the oil content of residue phase decreased with the increasing of solid-phase particle size for single-size sand OS, and the optimal flotation conditions were Tp of 50 °C, Tt of 25 min, Rs of 1450 r/min and L/OS of 12:1. The oil-solid separation was more pronounced for mixed-size sand OS with a complex particle composition, while different particle compositions of the solid phase in OS promoted oil-solid separation. Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FT-IR) characterisation of OS before and after flotation confirmed the relative advantage of coarse particle OS in the oil-solid separation process. The classical first-order model was well fitted to the flotation kinetic process of single-size sand and mixed-size sand OS. The response surface methodology (RSM) method was used to determine the Rs as the main control factor of the flotation process, and the oil content of residue phase in mixed-size sand OS was optimised to 2.63%. This study provides important process parameters and theoretical basis for the efficient treatment of OS.
含油污泥（OS）中的固相组成是影响其油-固分离的关键因素。本文研究了固相颗粒因素对残余相含油率的影响及作用机制，以提高油-固分离效率。在室温下，不添加浮选剂，对单粒径砂和由三种粒径组成的混合粒径砂含油污泥进行浮选实验。研究了不同粒径颗粒作为含油污泥固相组成以及浮选温度（Tp）、浮选时间（Tt）、叶轮转速（Rs）和液固比（L/OS）等浮选参数设置对油-固分离效率的影响。实验结果表明，对于单粒径砂含油污泥，残余相含油率随固相颗粒粒径的增大而降低，最佳浮选条件为：浮选温度50℃、浮选时间25 min、叶轮转速1450 r/min、液固比12:1。对于颗粒组成复杂的混合粒径砂含油污泥，油-固分离更为明显，含油污泥中不同的固相颗粒组成促进了油-固分离。浮选前后含油污泥的扫描电子显微镜（SEM）和傅里叶变换红外光谱（FT-IR）表征证实了粗颗粒含油污泥在油-固分离过程中的相对优势。经典一级模型能很好地拟合单粒径砂和混合粒径砂含油污泥的浮选动力学过程。采用响应面法（RSM）确定Rs为浮选过程的主要控制因素，并将混合粒径砂含油污泥的残余相含油率优化至2.63%。本研究为含油污泥的高效处理提供了重要的工艺参数和理论依据。
