摘要近几十年来,重金属污染已经成为全球重要污染问题,怎样有效果地处理环境中 存在的重金属污染已经是目前迫在眉睫需要解决的环境问题。固定化微生物材料吸附 水中的重金属离子是目前非常热门的研究方向。固定化微生物材料利用微生物吸附水 中的重金属离子,不会对环境造成二次污染,而且具有针对性、高效性、化学性能稳 定、污染小、能够长期保持并且重复利用、能够处理高浓度的重金属污染废水等特点。84550
实验发现,短小芽孢杆菌(简称 N2)和泡囊短波单胞菌(简称 S3)不仅能够修 复受重金属污染的土壤,还能够吸附处理重金属污染废水。固定了 N2 菌和 S3 菌的吸 附材料对水中重金属 Zn 离子的吸附效果都有明显提升。海藻酸钠+壳聚糖的载菌凝胶 小球对水中的重金属 Zn2+离子有非常好的吸附效果,一般情况下 S3 菌材料的吸附性 能优于 N2 菌材料。
此外,试验还研究了各种吸附条件(Zn2+初始浓度,吸附时间,温度,pH 值)对 吸附效果的影响。通过实验得出固定化微生物材料在对 Zn2+吸附的最佳条件 pH 6-7, 吸附时间 4 h ,投加量足够的情况下,海藻酸钠+壳聚糖+S3 菌小球的吸附效果最好, 对 Zn2+离子的去除率率能达到 80%。
毕业论文关键词:重金属,生物降解,固定化微生物, Zn2+, 海藻酸钠
Abstract In recent decades, heavy metal pollution has become a globally important pollution problem。 The heavy metals discharged through waste water have seriously destroyed animals,plants and the health of human beings。 In the current, Immobilized microorganism absorbing the heavy metals of water is a very popular research direction。 Immobilized microorganism material use microorganism to absorb the heavy metals of water will not destroy the environment secondly。 It has many advantages,for example targeted, highly effective, stabilized, small pollution, keeping for a long time, recycled, and it can deal with the metal waste water with high concentrations。
In this study, Bacillus pumilus(N2, for short) and Brevundimonas vesicularis stain( S3,
for short) not only can repair the soil polluted by heavy metals, but also can absorb the heavy metals of water。 The adsorption materials fixed with N2 and S3 have significant improvement of absorbing the Zinc ions of the water。 Microbial load gel balls made by Sodium alginate and chitosan have a good effect in absorbing the Zinc ions of heavy metal
wastewater。 In the general case,the adsorption effect of S3 is better than N2。
In addition, the effect of other factors on the adsorption efficiency was studied, including Zn2+ initial concentration, adsorption time, temperature and pH to the bacteria with the acid and the alkali。 Compared by studies, the best adsorption condition of Immobilized microorganism is pH 4-6 and 4 hour absorption time。 In these cases, with enough dosage,the best material is Sodium alginate add chitosan add S3。 It’s removal rate of Zinc ions can be eighty percent。
Key Words: Heavy metals; Bio-degradation; Immobilized microorganism;Zinc ions; Sodium alginate
目 录
第一章 绪论 1
1。1 研究背景及意义 1
1。1。1 重金属污水概况 1
1。1。2 废水中重金属污染的危害 1
1。1。3 水中重金属 Zn 离子的来源和危害 2
1。2 重金属污水的处理技术 2
1。2。1 化学沉淀法 2
1。2。2 活性炭吸附法 海藻酸钠+壳聚糖固定化微生物材料吸附水中重金属Zn离子:http://www.youerw.com/huaxue/lunwen_100415.html