Institute of Geoscience, Federal University of Bahia (UFBA), Rua Barão de Jeremoabo, s/n, Campus Ondina, 40170-115, Salvador, Bahia, Brazil.
Institute of Geoscience, Federal University of Bahia (UFBA), Rua Barão de Jeremoabo, s/n, Campus Ondina, 40170-115, Salvador, Bahia, Brazil.
Environ Res. 2024 Nov 15;261:119672. doi: 10.1016/j.envres.2024.119672. Epub 2024 Jul 23.
Microalgae cultures have emerged as a promising strategy in diverse areas, ranging from wastewater treatment to biofuel production, thus contributing to the search for carbon neutrality. These photosynthetic organisms can utilize the resources present in wastewater and fix atmospheric CO to produce biomass with high energy potential. In this study, the removal efficiency of Polycyclic Aromatic Hydrocarbons (PAHs), CO fixation and lipid content in the biomass produced from microalgae grown in airlift photobioreactor were evaluated. Four mesoscale cultures were carried out: Control (Seawater + Conway medium), Treatment A (Oil Produced Water + Poultry Effluent Water), Treatment B (Poultry Effluent Water + Seawater) and Treatment C (Oil Produced Water, Seawater and nutrients). The impact of biostimulation, through the addition of nutrients, on PAHs removal efficiency (up to 90%), CO fixation rate (up to 0.20 g L d) and the composition of the generated biomass was observed. Primarily, the addition of nitrates to the culture medium impacted CO fixation rate of the microalgae. In addition, a direct correlation was observed between PAHs removal and lipid accumulation in the biomass, up to 36% in dry weight, demonstrating microalgae's ability to take advantage of the organic carbon (PAHs) present in the culture medium to generate lipid-rich biomass. The concentration of polysaccharides in the biomass obtained did not exceed 12% on a dry weight basis, and the Higher Heating Value (HHV) ranged between 17 and 21 MJ kg. Finally, the potential of generating hydrogen through pyrolysis was highlighted, taking advantage of the characteristics of biomass as a conversion route to produce biofuels. These results show that microalgae are effective in wastewater treatment and have great potential in producing biofuels, thus contributing to the transition towards more sustainable energy sources and climate change mitigation.
微藻培养已成为从废水处理到生物燃料生产等多个领域的一种有前途的策略，从而有助于寻找碳中性。这些光合生物可以利用废水中的资源，并固定大气中的 CO，以产生具有高能量潜力的生物质。在这项研究中，评估了在气升式光生物反应器中生长的微藻产生的生物质中多环芳烃（PAHs）的去除效率、CO 固定和脂质含量。进行了四个中规模培养：对照（海水+康威培养基）、处理 A（采油污水+禽畜废水）、处理 B（禽畜废水+海水）和处理 C（采油污水、海水和养分）。通过添加养分进行生物刺激对 PAHs 去除效率（高达 90%）、CO 固定率（高达 0.20 g L d）和生成生物质的组成的影响进行了观察。首先，向培养基中添加硝酸盐会影响微藻的 CO 固定率。此外，还观察到 PAHs 去除与生物质中脂质积累之间存在直接相关性，最高可达干重的 36%，这表明微藻能够利用培养基中存在的有机碳（PAHs）来生成富含脂质的生物质。获得的生物质中多糖的浓度在干重基础上不超过 12%，高热值（HHV）在 17 至 21 MJ kg 之间。最后，强调了通过热解产生氢气的潜力，利用生物质作为转化途径生产生物燃料的特点。这些结果表明，微藻在废水处理方面非常有效，并且在生产生物燃料方面具有巨大的潜力，从而有助于向更可持续的能源和气候变化缓解方向过渡。
