Innovative approaches for metal removal from petroleum desalter effluent using biological systems

原油蒸馏装置（CDU）上游的原油脱盐和脱水是从原油中除去盐和其它不期望组分的重要单元操作。由该单元操作产生的脱盐器流出物流含有许多污染物，例如烃乳液、重金属、盐（例如氯化物和碳酸盐）、悬浮固体、硫化氢（H2S）、氨和酚类化合物。目前处理脱盐废水的方法包括沉淀以去除污泥和悬浮固体，溶气浮选以去除油和/或膜/反渗透以去除金属。然而，这些技术是低效和昂贵的。脱盐废水中重金属的存在影响生物处理策略。迫切需要一种方法，可以经济地去除生物处理前的重金属。在这个提议中，研究了通过使用特定的生物配体，如金属结合蛋白和金属还原细菌，从脱盐器流中去除重金属。该项目与帝国石油有限公司合作。目前正在进行的项目中的研究工作涉及两个步骤的方法：（i）研究嗜盐酵母Debaryomyces hansenii去除碳氢化合物和乳液，随后（ii）使用嗜盐微藻Dunaliella salina去除剩余的氮和磷，并生产营养品，如β-胡萝卜素和清洁水，用于回收到炼油厂。这些营养保健品正在成为一个新的健康食品领域的宝贵材料。该项目的工业合作伙伴Imperial Oil Limited预计将获得的重大利益是更好地管理废水流，并有很大的潜力将清洁水回收到炼油厂。炼油工业中的水循环利用由于使用了大量的水 ** 而成为一项重大效益。

Desalting and dewatering of crude oil upstream of the crude distillation unit (CDU) is an important unit operation for the removal of salt and other undesirable components from crude oil. The desalter effluent stream arising from this unit operation contains many contaminants such as hydrocarbon emulsions, heavy metals, salts such as chlorides and carbonates, suspended solids, hydrogen sulfide (H2S), ammonia, and phenolic compounds. Current approaches to desalter effluent treatment include sedimentation to remove sludge and suspended solids, dissolved air flotation to remove oil and/or membrane/reverse osmosis to remove metals.**However these techniques are inefficient and expensive. The presence of heavy metals in the desalter effluent impacts biological treatment strategies. An approach is urgently needed which can economically remove the heavy metals before biological treatment. In this proposal, the removal of heavy metals is investigated from desalter streams by using specific biological ligands such as metal binding proteins and metal reducing bacteria. This project is in collaboration with Imperial Oil Limited. The current research efforts in the ongoing project involve a two step approach: (i) investigation of a halophilic yeast Debaryomyces hansenii for the removal of hydrocarbons and emulsions and subsequently (ii) the use of halophilic micro-algae Dunaliella salina to remove the remaining nitrogen and phosphorus and produce nutraceuticals such as beta-carotene and clean water for recycle to the refinery. These nutraceuticals are emerging as valuable materials in a new health food sector.The significant benefit envisioned for the industrial partner in this project, Imperial Oil Limited, will be better management of effluent streams with strong potential for clean water recycle into refinery operations. Water recycling in the refinery industry can be a major benefit due to the large volumes of water**utilized.