溶解氧对活性污泥合成可生物降解塑料—PHB的影响

聚-β-羟基丁酸酯（polyhydroxybutyrate,PHB）是一种可完全生物降解和具有良好生物相容性的高分子材料，许多情况下可作为传统塑料的替代品。以活性污泥微生物作为PHB合成菌，研究了动态底物投加方式下，溶解氧对污泥贮存PHB过程的影响。结果表明，PHB的贮存过程相当程度上取决于氧的提供。溶解氧浓度的提高明显加快了底物乙酸的吸收，进而导致更大比例的乙酸被活性污泥贮存为PHB。试验中，溶解氧浓度由饱和浓度的10%提高到70%，PHB的产率由0.36 C mmol/C mmol 提高到0.56 C mmol/C mmol，PHB的胞内含量也由26%提高到37%。试验证明溶解氧是控制活性污泥合成PHB工艺的重要因素。

Effect of dissolved oxygen on polyhydroxybutyrate production by activated sludge submitted to dynamic feeding regime

Polyhydroxybutyrate(PHB) was produced by activated sludge submitted to dynamic feeding regime. The conversion of acetate into PHB was investigated with variety of dissolved oxygen concentration. The results showed that the PHB metabolism was considerable dependent on dissolved oxygen. Acetate uptake rate increased significantly with increasing dissolved oxygen concentration, which resulted in a higher proportion of acetate was converted into PHB (YPHB/S was 0.56 C mmol/C mmol with highest 70% of saturation, as opposed to 0.36 C mmol/C mmol with lowest 10% of saturation). The PHB content enhanced by 10% with increasing dissolved oxygen concentration from 10% to 70% of saturation. This study indicated that oxygen management was important to improve PHB production by activated sludge.