State Key Laboratory of Heavy Oil Processing, State Key Laboratory of Petroleum Pollution Control, China University of Petroleum-Beijing, Beijing 102249, China.
Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
Sci Total Environ. 2020 Jul 1;724:138117. doi: 10.1016/j.scitotenv.2020.138117. Epub 2020 Mar 24.
Large quantities of highly polluted point-source wastewaters (EDWs) are generated from electric desalting process of heavy oils (HOs), resulting in severe impacts on the efficiency of wastewater treatment plants in petroleum refineries. In the present study, a comprehensive chemical analysis and characterization of EDWs of two typical Chinese heavy oils, Liaohe heavy oil (LHO) and Karamy heavy oil (KHO), were investigated using Daqing light oil (DLO) as a control. The HO-EDWs (LHO-EDW and KHO-EDW) show high pollutants contents with complicated compositions, more polar dissolved organic pollutants (DOPs), strong emulsion stability and high acute biotoxicity towards Vibrio fischeri, compared to DLO-EDW. LHO-EDW and KHO-EDW have nearly equal pollutants contents but different compositions and distributions, where more types of DOPs exist in KHO-EDW. Large amounts of biologically recalcitrant aromatic compounds, as well as heteroatomic compounds such as CHO, CHOS and CHON species, extensively distribute in HO-EDWs. The organic nitrogen compounds (e.g., anilines and NO, NOS) in KHO-EDW most probably contribute to and thus leading to elevated levels of acute biotoxicity. Additionally, highly dispersed colloidal, micron-sized particles and polar compounds promote the emulsification and stabilization of HO-EDWs. These results can guide the development of pretreatment technologies for HO-EDWs, thus improving the treatment and management of heavy oil refineries' wastewater streams.
大量高度污染的点源废水（EDW）是由重油（HO）的电脱盐过程产生的，这对炼油厂废水处理厂的效率造成了严重影响。在本研究中，使用大庆轻油（DLO）作为对照，对两种典型的中国重油，辽河重油（LHO）和卡拉姆重油（KHO）的 EDW 进行了全面的化学分析和特性研究。与 DLO-EDW 相比，HO-EDW（LHO-EDW 和 KHO-EDW）具有更高的污染物含量、更复杂的组成、更多的极性溶解有机污染物（DOP）、更强的乳化稳定性和对发光菌 Vibrio fischeri 的高急性生物毒性。LHO-EDW 和 KHO-EDW 的污染物含量几乎相等，但组成和分布不同，KHO-EDW 中存在更多类型的 DOP。大量生物难降解的芳香族化合物以及含杂原子的化合物，如 CHO、CHOS 和 CHON 类，广泛分布在 HO-EDW 中。KHO-EDW 中的有机氮化合物（如苯胺和 NO、NOS）可能会导致急性生物毒性升高。此外，高度分散的胶体、微米级颗粒和极性化合物促进了 HO-EDW 的乳化和稳定。这些结果可以指导 HO-EDW 的预处理技术的发展，从而改善重油炼油厂废水的处理和管理。
