Federal University of Bahia, Department of Environmental Engineering, R. Prof. Aristídes Novis, 2- Federação, 40210-630, Salvador, BA, Brazil.
Salvador University, R. Dr. José Peroba, 251 - Stiep, 41770-235, Salvador, BA, Brazil.
Chemosphere. 2021 Oct;281:130775. doi: 10.1016/j.chemosphere.2021.130775. Epub 2021 May 13.
The objective of the present work is to evaluate the potential of the removal of PAHs and metal sorption for the treatment of petroleum produced water using a photobioreactor system with Nannochloropsis oculata microalgae. A set of photobioreactors with different gradients of produced water concentration diluted in saline water was designed, establishing five gradients (v/v): 0, 25, 50, 75 and 100%. These concentrations were established to test the removal of PAHs. The microalgal growth was monitored daily, noting the adaptation of microalgae to the addition of produced water as a culture medium, with cell growth of 5.24 × 10 cells mL from 25% (v/v), 4.09 × 10 cells mL from 50% (v/v), 2.77 × 10 cells mL from 75% (v/v), and 1.17 × 10 cells mL from 100%. The total removal efficiency of PAHs in the produced water was 94%. Organic compounds such as naphthalene, benzo(a)pyrene, benzo(b)fluoranthene, and acenaphthylene showed higher removal percentages, between 89 and 99% efficiency in produced water. Iron and zinc were the metals detected in the water produced, and iron reduced from 1.57 ± 0.08 mg L to <0.1 mg L after 28 days of cultivation, whereas zinc increased by 0.23 ± 0.05 to 3.90 ± 0.46 mg L. The PAHs removal may have occurred in two ways, by intracellular bioaccumulation or biodegradation by oxidoreductase enzymes. 0.2 g of dry biomass with maximum extraction of oil obtained 3.07% and generation of 3.70% of protein was considered as value-added products for biodiesel and bioplastics.
本工作旨在评估使用含有微藻眼点拟微绿球藻（Nannochloropsis oculata）的光生物反应器系统去除多环芳烃（PAHs）和金属吸附以处理采出水的潜力。设计了一组具有不同生产用水浓度梯度的光生物反应器，用盐水稀释，建立了五个梯度（v/v）：0、25、50、75 和 100%。这些浓度用于测试多环芳烃的去除。每天监测微藻的生长情况，观察微藻对生产用水作为培养基的适应情况，25%（v/v）时细胞生长为 5.24×10^6 个细胞/mL，50%（v/v）时为 4.09×10^6 个细胞/mL，75%（v/v）时为 2.77×10^6 个细胞/mL，100%（v/v）时为 1.17×10^6 个细胞/mL。采出水中多环芳烃的总去除效率为 94%。萘、苯并（a）芘、苯并（b）荧蒽和苊烯等有机化合物的去除率较高，在采出水中的去除效率为 89%至 99%。水中检测到的金属为铁和锌，经过 28 天的培养，铁从 1.57±0.08mg/L 降至<0.1mg/L，而锌从 0.23±0.05mg/L 增加到 3.90±0.46mg/L。多环芳烃的去除可能通过细胞内生物积累或氧化还原酶的生物降解两种方式进行。从 0.2g 干生物量中获得了最大 3.07%的油提取量和 3.70%的蛋白质生成量，被认为是生物柴油和生物塑料的增值产品。
