Instituto de Ingeniería, Universidad Nacional Autónoma de México, Circuito Escolar, Ciudad Universitaria, 04510 Mexico City, Mexico.
Instituto de Ingeniería, Universidad Nacional Autónoma de México, Circuito Escolar, Ciudad Universitaria, 04510 Mexico City, Mexico.
Sci Total Environ. 2019 Jun 1;667:613-621. doi: 10.1016/j.scitotenv.2019.02.374. Epub 2019 Feb 27.
The rates of oxygenic and carbon fixation photosynthetic processes of a microalgae consortium were simultaneously evaluated under steady-state performance in an bench scale alkaline open-system exposed to outdoor conditions in Mexico City. A synthetic methane-free gaseous stream (SMGS) similar to biogas was used as inorganic carbon source and model of biogas upgrading. The microalgae CO fixation rates were calculated through a novel methodology based on an inorganic carbon mass balance under continuous scrubbing of a SMGS similar to biogas, where the influence of pH and temperature time-depended oscillations were successfully incorporated into the mass balances. The oxygenic activity and carbon fixation occurred at different non-stoichiometric rates during the diurnal phase, in average carbon fixation predominated over oxygen production (photosynthesis quotient PQ≈ 0.5 mol O mol CO) indicating photorespiration occurrence mainly under dissolved oxygen concentrations higher than 10 mg L. The oxygen and inorganic carbon mass balances demonstrated that photorespiration and endogenous respiration were responsible for losing up to 66% and 7% respectively of the biomass grew at diurnal periods under optimal conditions. In favoring photorespiration conditions, the microalgae biomass productivity (CO effectively captured) can be severely decreased. A kinetic mathematical model as a function of temperature and irradiance of the oxygenic photosynthetic activity indicated the optimal operation zone for this outdoor alkaline open-photobioreactor, where irradiance was found being the most influential parameter.
在墨西哥城户外条件下，采用类似于沼气的合成无甲烷气体（SMGS）作为无机碳源和沼气升级模型，在稳定状态下，同时评估了微藻联合体的需氧和固碳光合过程的速率。通过一种新颖的方法，根据连续洗涤类似于沼气的 SMGS 的无机碳质量平衡，计算了微藻的 CO 固定速率，其中成功地将 pH 和温度时间相关的波动纳入了质量平衡中。需氧活性和碳固定在白天阶段以不同的非化学计量速率发生，平均碳固定占主导地位，超过氧气产生（光合作用商 PQ≈0.5 mol O mol CO），表明主要在溶解氧浓度高于 10 mg L 时发生光呼吸。氧气和无机碳质量平衡表明，光呼吸和内源性呼吸分别导致在最优条件下的白天生长的生物量损失高达 66%和 7%。在有利于光呼吸条件下，微藻生物质生产力（有效捕获的 CO）可能会严重降低。作为需氧光合作用活性的温度和光照度的函数的动力学数学模型表明了这种户外碱性开放式光生物反应器的最佳操作区域，其中发现光照度是最具影响力的参数。
