文档介绍：资料
密级:
安全高效絮凝剂的开发
及应用研究
Study on development and application of safe and high-efficient ulant
学院:理学院
专业班级:环境工程0801
学号:080704015
学生姓名:韩洋
指导教师:崔丽(讲师)
2012年 06 月
摘要
由微生物产生具有絮凝活性的高分子絮凝剂称为高分子絮凝剂,其具有对环境和人体无害、易于生物降解等优点,因此在废水处理中日益受到关注和重视。目前我国微生物絮凝剂的发展仍停留在实验室阶段尚未投入到工业生产,其主要原因在于产絮凝剂效率较低、成本较高。本文首先研究能利用常用营养物质配制的培养基而产生絮凝物质微生物的筛选、培养及优化。
本实验首先以花土和树下土为菌种来源,取浸出液经稀释与平面接种,选取表面光滑、粘稠的菌落转接到斜面和液体培养基中,液体培养基经恒温摇床培养后得发酵液,测定发酵液的絮凝和能力,选取表现出絮凝性能的菌株作为粗选菌种。粗选菌种经多次转接、测定,得到絮凝能力较强的优选菌种MBF-3。
得到优选菌种后,本文探讨的主要问题及结论如下:首先,通过正交试验方法确定了最佳C/N为15、、温度为30℃,得出了这三个基础的培养条件对絮凝菌培养的影响大小及规律,从而奠定了培养条件选择基础。其次,通过离心分离的方法得到菌体和上清液,再分别测定菌体悬浊液和上清液的絮凝率从而确定了絮凝活性部分不是菌体而是絮凝菌分泌的胞外物质。第三,通过多组实验确定了投加量、pH值、温度、金属离子对絮凝效果的影响及规律。得出每100ml高岭土悬浊液发酵液和上清液最佳投加量分别为5ml、6ml,最佳絮凝pH值为5~6,最佳絮凝温度为40℃,证明了对絮凝有促进的离子有Ca2+、 Al3+ 、Fe3+。
关键词:微生物絮凝剂;菌株筛选;最佳条件;絮凝效果影响
Abstract
A kind of macromolecular ulant secreted by anisms is called ulant. These kinds of microbial polymers are expected to be useful in ulating wastewater due to their bio-degradability and the harmlessness of their degradation products toward humans and environment. However, the ulants identified so far in laboratories have not yet practically applied in industry because of the high cost and low productivity. In this study the screening, optimization, and prioritization of a new ulant-producting strain were carried out.
These strains were derived from the lixivium of soil which extracted below flowers and trees in the study. Diluted lixiviums were inated on plating mediums. Smooth and ropy bacterial colonies were screened and inated to fluid nutrient mediums. The strains which turned out to be with ulation efficiency by ulation test were chosen as mass-election strains. A plant of optimized strain,MBF-3 with the highest ulation efficiency was chosen out by a mass of inating and test.
We have carried out three aspects of study on the optimized strain. One of them is choosing the optimum situation including C/N which was 15, original pH which was , and temper