吲哚乙酸对周丛生物去除水体中氮磷的影响及机理

Effects and Mechanism of Indoleacetic Acid on the Removal of Nitrogen and Phosphorus from Water by Peripheral Organisms

为探究吲哚乙酸添加的先后顺序和质量浓度对周丛生物去除水体中氮磷的影响及其作用机理,以人工培养的周丛生物为研究对象,分别用预先经过吲哚乙酸培养的周丛生物(预处理组)和未经过吲哚乙酸培养的周丛生物(对照组)在含有不同质量浓度(0、5和10 mg·L^(-1))吲哚乙酸的氮磷污水中培养。结果表明,添加吲哚乙酸提高了周丛生物对水体中氮磷的去除效率,对照组中,添加5 mg·L^(-1)吲哚乙酸的周丛生物在第2天对NH_(4)^(+)-N、PO_(4)^(3-)-P的去除率分别为99.9%、95.0%,第7天对NO_(3)^(-)-N的去除率为99.0%,且对照组比预处理组的去除速率更高,比预处理组快2 d。吲哚乙酸的添加改变了周丛生物的微生物群落结构,总磷脂脂肪酸组成减少,细菌、放线菌以及革兰氏阳性菌(G_(3)^(-))数量增加,溶液叶绿素荧光F_(t)值下降,pH升高。综上所述,添加吲哚乙酸促进了周丛生物中藻类的生长,提高了周丛生物对氮磷的去除效率。

In order to explore the effects and mechanism of the sequence and concentration of adding indoleacetic acid on the removal of nitrogen and phosphorus from the water by peripheral organisms,the artificially cultivated peripheral organisms were as the research object,and the peripheral organisms that had been pre-cultured with indoleacetic acid(pretreatment group)and those that have not been pre-cultured with indoleacetic acid(control group)were cultured in nitrogen and phosphorus sewage with different concentrations of indoleacetic acid(0,5 and10 mg·L^(-1)). The results revealed that the addition of indoleacetic acid improved the removal efficiency of nitrogen and phosphorus by peripheral organisms. In control group,the removal rates of NH_(4)^(+)-N and PO_(4)^(3-)-P by peripheral organisms added with 5 mg·L^(-1) indoleacetic acid were 99.9% and 95.0%,respectively,on the 2^(nd) day,and the removal rate of NO_(3)^(-)-N was 99.0% on the 7^(th) day,whose removal rates were faster 2 d than those of pretreatment group. Indoleacetic acid changed the microbial community structure of peripheral organisms with the total composition of phospholipids fatty acids decreasing,the number of bacteria,actinomycetes and gram-positive bacteria(G^(+))increasing,chlorophyll fluorescence F_(t) reducing and pH increasing. In conclusion,the addition of indoleacetic acid could promote the growth of algae in peripheral organisms and improve the removal efficiency of nitrogen and phosphorus by periplexus organisms.