CO₂ 体积分数调控胞外有机物特性诱导小球藻自絮凝的实验研究

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中图分类号：TK6 文献标志码：A

Abstract： To address the challenges of high chemical flocculant costs， high environmental risks， and low self-flocculation efficiency in microalgae harvesting，this study systematically investigates the mechanism of inducing self-flocculation of Chlorella vulgaris by regulating the CO2 concentration， with a focus on the key regulatory role of extracellular organic matter （EOM） in the process. Three CO2 concentration cultivation conditions （about 0.04% ， 15% ，and 25% ）are employed，and parameters such as EOM characteristics， pH and concentrations of inorganic salts are analyzed to comprehensively evaluate the self-flocculation behavior of Chlorella oulgaris and its influencing factors under different cultivation conditions. The experimental results indicate that the CO2 concentration significantly affects the secretion of EOM， thus altering the self-flocculation efficiency of Chlorella vulgaris. Compared to the 15% and 25% CO2 concentration cultivation groups，the protein and polysaccharide concentrations secreted per unit biomass of Chlorella vulgaris cultiuated at approximately 0.04% （20 CO2 concentration increase by 4 to 7 times and 3 to 5 times，respectively，with the highest self-flocculation efficiency reaching 86% . After the removal of EOM， the self-flocculation efficiency of Chlorella vulgaris decreases by 13% to 24% after 12 hours，further validating the critical regulatory role of EOM in the self-flocculation process. In contrast，variations in pH and inorganic salt concentrations have a negligible effect on selfflocculation efficiency. From the perspective of CO2 supply，this study reveals the interconnection mechanism among CO2 ，EOM， and self-flocculation， providing experimental references for optimizing low-cost， high-efficiency liquid-solid separation processes for microalgae.

Keywords： Chlorella vulgaris;self-flocculation; CO2 concentration；extracellular organic matter

近年来，随着化石燃料储量的日益减少以及全球环境污染问题的日益严峻，可再生能源和碳资源利用技术受到越来越多的关注[1-2]。（剩余17802字）