反硝化除磷系统中PHB红外光谱解析及其与磷去除率的相关性

为快速、准确测定生物除磷系统中微生物细胞内w(PHB)(PHB为poly-β-hydroxy butyrate,聚-β-羟基丁酸酯)并及时预测PO₄3--P去除率,采用红外光谱法对微生物细胞内PHB的转化规律进行解析,并结合气相色谱法建立w(PHB)的快速测定模型,研究w(PHB)减少量与PO₄3--P去除率的相关性. 结果表明:反硝化除磷系统中微生物细胞内PHB的特征峰位于波数1 730 cm-1处,PHB特征峰的吸光度与w(PHB)的增减趋势相同. 采用PLS(partial least squares,偏最小二乘法)对反硝化除磷系统中微生物细胞内PHB特征峰吸光度与w(PHB)建立PLS模型,对w(PHB)的校正和预测时的相关系数(R2)分别达到0.963 0、0.951 4,其均方根误差分别为0.031 0、0.037 9. 根据预测结果,进一步建立了反硝化除磷缺氧段w(PHB)减少量与PO₄3--P去除率的相关关系,相关系数为0.979 0. 研究表明,利用PLS模型对反硝化除磷系统中PHB红外光谱解析能够快速、准确地表征反硝化除磷系统中微生物细胞内w(PHB)的变化,并能进一步预测PO₄3--P去除率. 

Infrared Spectrum Analysis of PHB and the Correlation between PHB Reduction and Orthophosphate Removal Rate during Denitrifying Phosphorus Removal

In order to create a model to detect intracellular PHB (poly-β-hydroxy butyrate) rapidly and accurately, and to make timely predictions of the orthophosphate removal rate in a biological phosphorus removal system, infrared spectra were probed into the intracellular PHB transformation during denitrifying phosphorus removal. Correlation was established between PHB reduction and orthophosphate removal rate by means of both infrared spectra and gas chromatography. The results of the infrared spectrum analysis indicated that, in the denitrifying phosphorus removal system, an intracellular PHB characteristic peak was found at 1730 cm-1, and the absorbance of PHB characteristic peak was positively correlated with the variation of PHB content. A model (PLS model) was established between the absorbance and PHB content through partial least squares; the correction and prediction coefficients of the model for the PHB content were 0.9630 and 0.9514 respectively, and the root mean square errors were 0.0310 and 0.0379 respectively. Based on the predictions, the correlation between PHB reduction and orthophosphate removal rate was established, with the coefficient 0.9790. The results showed that the PLS model established through infrared spectra and gas chromatography could characterized intracellular PHB variation rapidly and accurately in the biological phosphorus removal system and provide timely predications for phosphorus removal rate.