Accelerated remediation of oil-sands process water by complementary pairing of advanced oxidation and biodegradation

北阿尔伯塔省的油砂矿床估计含有1.7万亿桶沥青形式的石油，是世界上最大的原油储量之一。近年来，油砂的开发速度加快，占加拿大能源总产量的很大一部分，据估计，到2020年，油砂的总产量将达到每天200万至300万桶。地表开采每生产1桶石油，需要2至5桶淡水，其中只有一小部分返回自然系统。这是因为油砂过程中产生的水（OSPW）对水生生物具有剧毒，因此必须在工程沉淀池中保留数十年。为了跟上蓬勃发展的工业，需要新的OSPW填海方案来加速其修复并减少对淡水资源的净压力。OSPW的有毒成分是一种复杂的天然有机化合物混合物，这些化合物是从油砂中萃取出来的——环烷酸（NAs）。使用一种高度特异性和敏感性的分析方法，我们将i)表征NAs在OSPW中的微生物活性如何缓慢降解，ii)应用和评估高级氧化技术的有效性，以破坏有毒和生物持久性NA部分，以及iii)确保OSPW中的高级氧化NAs对水生生物（包括鱼类）的毒性较小。初步结果表明，这一策略非常有效，通过与行业密切合作，我们确保将新知识快速转化为实践。这一改进的OSPW补救战略将加强和维持加拿大的能源工业，继续为加拿大人创造财富和就业机会，同时保护支持人类和环境健康的阿尔伯塔省北部脆弱的北方生态系统。

Oil sands deposits of Northern Alberta contain an estimated 1.7 trillion barrels of oil in the form of bitumen, representing among the largest reserves of crude oil in the world. Recent acceleration of their development has resulted in their accounting for a major fraction of Canada's total energy production today and it is estimated that total production from oil sands will be 2-3 million barrels per day by 2020. For every 1 barrel of oil produced by surface mining, between 2 and 5 barrels of freshwater are required and only a small fraction of this is returned to natural systems. This is because oil sands process-affected water (OSPW) is acutely toxic to aquatic organisms and, therefore, must be retained on-site in engineered settling ponds for decades. To keep pace with the booming industry, new OSPW reclamation options are needed to accelerate their remediation and to reduce the net pressures on freshwater resources. The toxic constituents of OSPW are a complex mixture of naturally occurring organic compounds that are co-extracted from the oil sands - naphthenic acids (NAs). Using a highly specific and sensitive analytical method we will i) characterize how NAs slowly degrade by microbial activity in OSPW, ii) apply and assess the effectiveness of advanced oxidation techniques to destroy the toxic and biologically-persistent NA fractions, and iii) ensure that advanced oxidized NAs in OSPW are less toxic to aquatic organisms, including fish. Preliminary results show great promise that this strategy can be effective, and by working closely with the industry we ensure a rapid translation of new knowledge into practice. This improved OSPW remediation strategy will strengthen and sustain Canada's energy industry to continue generating wealth and creating employment for Canadians while simultaneously protecting the fragile boreal ecosystems of Northern Alberta that support human and environmental health.