利用31P-NMR研究了生物除磷污泥胞外多聚物(EPS)的含磷形态,并对检测方法中的影响因素进行了分析。研究发现,测定的三种污泥EPS中磷的形态有五种,磷酸盐、磷单脂、DNA磷、聚磷末端、焦磷酸盐和聚磷。具有除磷能力的A/A/O和A/A/O-MBR污泥其EPS中主要含的是聚磷,证明了EPS中含磷不仅是依靠吸附磷酸盐或生物聚磷过程磷酸盐的滞留,而且EPS本身可能也参与了生物聚磷过程。同时实验证明,EPS提取过程会对EPS含磷形态产生影响,但提取时间在1h内时影响较小;EPS在储存前需要进行中和,从而避免储存过程不同磷形态之间的转化。EPS含磷形态的31P-NMR测定过程中,EPS样品的pH值对峰的分离和各峰化学位移的稳定性有较大影响,需要控制样品pH>13.0以确保测定过程的准确性。

The present paper investigated phosphorus forms in the extracellular polymeric substances (EPS) using 31P-NMR spectroscopy,and analyzed the influential parameters for this method.The results showed that in the three investigated EPS samples five P forms were identified,including orthophosphate,orthophosphate monoesters,DNA,pyrophosphate and polyphosphate.And in the EPS extracted from A/A/O sludge and A/A/O-MBR sludge polyphosphate was the main phosphorus form.This indicated that P is contained in the EPS not only owing to the adsorption of orthophosphate,but also because EPS acting like the bacteria cells contributes to enhanced biological phosphorus removal. Furthermore the transformation of P forms in the EPS during the EPS extraction was found but limited within 1 h.It was found that with the NaOH solution added the polyphosphate in the EPS would partly convert to pyrophosphate but not go further to orthophosphate,while with pure water added P forms in the EPS were very stable.This means that after neutralization,the transformation of phosphorus forms could be avoided.Since the measurement of 31P-NMR spectroscopy was very sensitive to pH,which could affect the chemical shift of the peaks and cause peaks overlapping,the pH of EPS sample must be raised to 13.0 before the measurement.