厌氧发酵产挥发性脂肪酸实现太湖蓝藻泥的减量与资源化

采用热碱预处理及厌氧发酵技术实现了太湖蓝藻生产挥发性脂肪酸(VFAs)。结果表明，热碱预处理(T=90 ℃，pH=12)可以促进蓝藻中的固相有机质溶于液相中，溶解性的化学需氧量(SCOD)、碳水化合物和蛋白质相比未预处理分别提高了10.3、12.3和4.8倍。三维荧光光谱(3D-EEM)分析表明，热碱预处理能提高蓝藻可生物利用性，同时降低腐殖酸的含量，有利于后续生物转化。在序批式厌氧发酵产酸运行模式下，平均总挥发性脂肪酸(TVFAs)浓度达到18.64 g·L⁻¹，产酸效率(1 g VSS中VFAs的占比)为46%。半连续运行模式下，平均TVFAs可以达到15.56 g·L⁻¹，产酸效率为26%。蓝藻中溶解性碳水化合物和蛋白质降解率分别为50.43%和47.04%。同时，蓝藻中总悬浮固体(TSS)和挥发性悬浮固体(VSS)的降解率分别为24.5%和43.4%，达到了很好的减量化效果，但残留物中还存在大量有机物未生物转化。

Reduction and resource utilization of cyanobacteria from Taihu Lake via anaerobic fermentation for volatile fatty acids production

A study of thermal-alkaline pretreatment and alkaline fermentation of cyanobacteria collected from Taihu Lake was conducted to produce the volatile fatty acids(VFAs). The results showed that thermal-alkaline pretreatment (T=90 ℃, pH=12) promoted the release of cyanobacteria organics into the liquid and provided enough bioavailable substrates for the subsequent acidogenic fermentation. In comparison with the control, the concentrations of soluble chemical oxygen demand(SCOD), soluble polysaccharides and proteins increased by 10.3, 12.3 and 4.8 times, respectively. 3D excitation-emission matrix (3D-EEM) analysis demonstrated that thermal-alkaline pretreatment could improve the bioavailability of cyanobacteria and reduce the content of humic acid-like organics, which is beneficial to the subsequent acidogenic fermentation. In the sequencing batch tests of acidogenic fermentation, the average total volatile fatty acid (TVFAs) concentration reached 18.64 g·L−1, and the VFAs yield was 46%. In the semi-continuous tests, the average TVFAs reached 15.56 g·L-1 and VFAs yield was 26%, the degradation rates of soluble polysaccharides and proteins in cyanobacteria were 50.43% and 47.04%, respectively, and the reduction rates of total suspended solids (TSS) and volatile suspended solids (VSS) reached 24.5% and 43.4%, respectively, which achieved good volume reduction results. However, a large amount of refractory organic materials was still not biodegraded or biotransformed.