高效耐海水型厌氧氨氧化污泥的驯化

Acclimation of a highly-efficient and seawater tolerant anammox sludge

针对部分含海水废水生物脱氮效能较低的问题,研究了梯度盐度海水对淡水厌氧氨氧化污泥的驯化过程.考察了不同海水盐度对厌氧氨氧化反应动力学、厌氧氨氧化菌细胞形态和反应器中菌群变化的影响.结果表明,梯度盐度废水可以成功驯化淡水厌氧氨氧化污泥,通过145d的驯化,其总氮去除速率为2.80kg N/(m3·d).在海水盐度由0提高至10‰、20‰和30‰的过程中厌氧氨氧化反应速率经历了升高、降低、再升高的过程,其中,海水盐度20‰在淡水厌氧氨氧化污泥的驯化过程中是一个临界点.驯化后,厌氧氨氧化菌细胞结构更加不规则,并在细胞壁上出现了类菌毛状结构,经16S r DNA PCR扩增测序鉴定该优势厌氧氨氧化菌为"Candidatus Kuenenia Stuttgartiensis".驯化前后反应器中细菌菌群也发生改变.

The performance of biological nitrogen removal in treating seawater-containing wastewater is not satisfying. Here we report the acclimation of a freshwater-origin anaerobic ammonium oxidation（anammox） sludge by using seawater with increasing salt concentrations. Nitrogen removal performance, morphological characteristics and dominant strains of the bacterial community in the reactor were investigated. After 145 days of acclimation, this freshwater-origin anammox sludge was fully adapted to seawater, with a total nitrogen removal rate（TNRR） reaching 2.80 kg N/（m3·d）. The anaerobic ammonium oxidizing rate first increased, then decreased, and then increased again when the seawater content was gradually increased from 0‰ to 30‰. A seawater content of 20‰ was the critical point during the acclimation. In terms of morphological characteristics, cell shape of the acclimated anammox bacteria was irregular and pilus-like appendages were developed on the cell wall. Change in the bacterial community composition after acclimation was also observed through DGGE.The dominant anammox strain was identified as ＂Candidatus Kuenenia Stuttgartiensis＂ based on the sequence of the 16 S r DNA gene.