强化生物除磷系统微生物群落结构对水温变化响应的试验研究

Effect of water temperature on the microbial community in an enhanced biological phosphorus removal system

在富集聚磷菌(PAOs)且具有较高磷去除率的强化生物除磷(EBPR)系统中,通过对系统水温的控制,研究了EBPR系统微生物群落结构对温度升高和恢复的响应.结果表明,运行温度上升后,EBPR系统除磷效率急速下降.处理水温为25℃和30℃的系统恢复至20℃运行后能够恢复至原始的良好除磷状态,而处理水温为35℃的系统崩溃(磷酸盐去除率非常低下,难以恢复)后则无法恢复.从DGGE图谱和丰富度指数分析中得出的微生物群落结构可较好地说明EBPR系统除磷率的变化特征.BLAST结果表明,典型的聚糖菌Candidatus Competibacter phosphatis 35℃升温处理后在EBPR系统中的数量明显高于升温实验开始时,而聚磷菌Acinetobacter在35℃升温处理后在系统中消失.水温上升可使得EBPR系统的微生物群落结构发生明显的变化,聚糖菌(GAOs)逐渐替代PAOs成为优势菌群,25℃和30℃升温处理的系统恢复至20℃运行后PAOs能够逐渐恢复,而35℃升温处理的系统微生物群落结构不能恢复至原始的良好状态,导致系统崩溃.

Based on an enhanced biological phosphorus removal（EBPR） system with successful enrichment of phosphorus accumulating organisms（PAOs） and high phosphorus removal rate,the response of microbial community in EBPR system to water temperature variation was measured in this study.Results showed that the phosphorus removal rate decreased dramatically after the water temperature was increased.However,the EBPR system could be restored to its original phosphorus removal rate when the water temperature was adjusted to 20 ℃ after 25 ℃ and 30 ℃ treatment for eight days,while it could not be restored after 35 ℃ treatment.From the analysis of DGGE profile and richness index,the characteristics of the microbial community were in accordance with the regulation pattern of phosphorus removal rate in EBPR system.BLAST results showed that the concentration of Candidatus Competibacter phosphatis,a typical glycogen accumulating organism（GAO）,was significantly higher and Acinetobacter,a traditional PAO,disappeared in the EBPR system after 35 ℃ treatment for eight days.From all the results,we can conclude that increasing the water temperature could result in significant variation of the microbial community,and GAOs dominated in the EBPR system in replace of PAOs.The microbial community could be restored to its original status when the water temperature was adjusted to 20 ℃ from 25 ℃ and 30 ℃ treatment,while it could not be restored for 35 ℃ treatment.