生物降解实验中的接种物标准化研究

针对降解实验中接种物采集困难、活性差异大、实验可重复性及结果可比性差的问题展开接种物标准化研究。对多来源的接种物在实验室可控条件下进行驯养,驯养后生长状态良好的活性污泥分别固定于灭菌麸皮和藻酸钙凝胶等2种微生物载体上,形成2种固定化接种物(分别简称为Bran及Ball)。对上述固定化接种物进行微生物活性、适应性、降解能力以及稳定性研究:通过2种固定化接种物与商品化接种物Polyseed对葡萄糖-谷氨酸(GGA)五日生化需氧量(BOD5)的结果与活菌细胞数的关系,确认3种接种物在降解实验中的用量可控制在相同数量级;比较不同批次及保存时间的2种固定化接种物、相同批次不同保存时间的Polyseed以及污水处理厂曝气池污泥为接种物对苯胺及二甘醇的快速生物降解实验(OECD301F)结果,发现Ball及Bran较Polyseed及新鲜采集活性污泥的微生物适应性及降解能力更佳。此外,在较长保存期内2种固定化接种物活性相对稳定。2种固定化接种物初具成为标准化接种物的必要条件。

Study of inoculum standardization for biodegradation test

The aim of this study was to solve the problems of biodegradation test caused by inoculum, including sampling difficulties, differences of the activities, worse repeatability and comparison of results. Inoculum of multiple sourcing was domesticated under controlled laboratory conditions, well grown sludge was immobilized to two different carriers (sterile bran and calcium alginate gel) to form two immobilized inocula (named Ball and Bran). The activity, adaptation, biodegradability and stability of the above two immobilized inocula were investigated. The relationships between BOD₅ values of GGA (Glucose-Glutamic Acid) and the living bacteria number of two immobilized inocula and Polyseed were established, and the results indicated that the living bacteria number used in biodegradation test could be maintained at the same level. The ready biodegradability of aniline and diethylene glycol were evaluated by OECD 301F with two immobilized inocula, Polyseed and activated sludge which was newly collected from aeration tank of sewage treatment plant. Both of the adaptation, biodegradability and the reproducibility of Ball and Bran are better than using Polyseed and new collected activated sludge. In addition, the living bacteria numbers of two immobilized inocula were also determined and were relatively stable during their shelf period. The two immobilized inocula could be initially identified as standardized inocula with their better activity, adaptation, biodegradability and stability during relatively long shelf period.