【作者】 周礼；

【导师】 张永奎；

【作者基本信息】 四川大学 ， 生物化工， 2006， 硕士

【摘要】 微生物絮凝剂是一种微生物分泌的天然高分子产物,具有无毒、高效和絮凝范围广泛等特点,近年来受到越来越多的重视。本文探讨了PO43-与Ca2+对现有的微生物絮凝剂高岭土评价体系的影响。实验发现这两种无机离子会引起高岭土絮凝,而且絮凝率随这两种无机离子的浓度和pH值的增加而增加,故微生物絮凝剂的絮凝效果不能得到正确的表达。实验表明,当评价体系中助凝剂Ca2+浓度为0.4mmol/L,培养基中PO43-浓度为0.043mol/L时,pH值超过7.0时絮凝率超过80%,pH值达到8.0时絮凝率达到91%。实验结果表明,当培养基中PO43-浓度较高,同时在评价体系中加入一定浓度的助凝剂Ca2+时,现有的微生物絮凝剂高岭土评价体系会受到PO43-与Ca2+的影响,并不能真实地表示微生物絮凝剂的絮凝效果,需要对现有评价体系进行修正。本文从自来水厂活性污泥、荷花池底的淤泥和花园土壤中筛选得到了7株微生物絮凝剂产生菌,它们所产的絮凝剂对高岭土悬浊液均有絮凝效果,并对其中效果较好的两株菌Z-J和Z-4进行了培养基条件优化实验。通过实验,Z-J菌所产絮凝剂对高岭土的絮凝率从81.3%提高到95%;Z-4菌所产絮凝剂对高岭土的絮凝率从80%提高到89%。实验结果表明:(1)对菌种Z-J,适宜的单一碳源为25g/L葡萄糖;对菌种Z-4,适宜的单一碳源为25g/L蔗糖;(2)复合碳源效果优于单一碳源,对菌种Z-J,适宜的复合碳源为蔗糖5g/L,更多还原

【Abstract】 Microbial flocculant is a kind of high molecular substance which is produced by microorganisms. It is nontoxic, high-efficient and widely-used. Nowadays the reserches on microbial flocculant are more and more.The influence of PO43- and Ca2+ was investigated in traditional assay of flocculating efficiency. In this article, when pH exceeded 7.0, with PO43- and Ca2+ and without any microbial flocculant on traditional beaker experiment, the flocculation activity of the two irons enhanced with the increasing of the two irons concentrations and pH. When the Ca2+ concentration was 0.4mmol/L and the PO43- concentration was 0.043mol/L, pH exceeded 7.0, the flocculation activity retained above 80% stably, and when pH was 8.0, the flocculation activity achieved 91%, the mostly. The experiments indicated that the traditional assay of flocculating efficiency could not estimate the flocculation activity correctly when the two irons existed, so it needed some modification.Seven strains were screened and isolated from active sludge from waterworks and soil from a garden and pond. The microbial flocculants produced by them showed high and stable flocculation activity for Gaoling clay suspension. And two of them named Z-J and Z-4, which flocculated Gaoling clay suspension best, was更多还原