为去除重金属离子筛选和驯化微藻的试验研究

发布时间：2018-12-13 13:48

【摘要】：目前,水体重金属污染已成为一个世界性的环境问题,引起了全社会的共同关注。传统的重金属处理方法在回收重金属方面尚存在较大的困难且容易产生二次污染,而新的重金属处理方法技术操作水平较高如纳米技术、光催化技术。近十几年来,在废水处理领域,研究人员利用非活性藻(藻粉)吸附处理重金属进行了大量研究,但利用活性藻类吸附处理重金属的研究鲜有报道。本研究选用斜生栅藻(Scenedesmus Obliquus)、莱茵衣藻(Chlamydomonas Reinhardtii)、微绿球藻(Nannochloropsis Oculataa)、普通小球藻(Chlorella Vulgaris)、蛋白核小球藻(Chlorella Pyrenoidosa)、FACHB-2(Chlorella Protothecoides)、小球藻 F5(Chlorella)、小球藻(Chlorella sp.)、杜氏盐藻(Dunaliella Salina)用于去除重金属离子微藻的筛选和驯化的试验研究,最后研究和分析了驯化前/后重金属砷离子对藻类油脂含量的影响。目前,关于这9种微藻的研究较多并且原料丰富,具有很高的商业价值。主要研究成果如下:(1)在藻类的筛选试验中,通过对藻类的生长情况、叶绿素a含量以及重金属去除率的结果进行分析,得出重金属砷离子对不同的微藻产生不同程度的抑制作用。低浓度的重金属砷离子对斜生栅藻、小球藻的叶绿素a的合成有促进作用,而较高浓度的砷离子会抑制叶绿素a的合成,其余几种藻叶绿素a含量随着砷离子浓度的增加而下降。9种藻类在不同的重金属砷离子浓度中,其吸附效率规律也不尽相同。普通小球藻、FACHB-2、蛋白核小球藻、微绿球藻、小球藻F5、盐藻、莱茵衣藻,随着砷离子浓度的的增加,藻类对砷离子的去除率R下降:而小球藻及斜生栅藻对砷离了去除率R随着砷离子浓度的增加先上升后下降。(2)藻类的驯化试验分为两个阶段,分别为砷离子浓度为1mg/L时的低浓度驯化阶段和砷离了浓度为2mg/L时的高浓度驯化阶段。经过驯化,提高了藻类本身对重金属的耐受性使得重金属对自身的危害降到最低,进而达到积累重金属的作用。从对比试验1可知,经过驯化的微藻比未驯化的微藻吸附重金属的能力普遍提高了 50%左右。从对比试验2可知,经过驯化的微藻比未驯化的微藻吸附重金属的能力提高了 70%左右。(3)5种微藻油脂含量不同,其中小球藻F5油脂含量最高。重金属砷离子对藻类的油脂的积累产生不同的影响,小球藻、斜生栅藻、普通小球藻,其体内油脂积累量随着重金属浓度的增加而增加,但是增加的幅度有所不同。小球藻F5、微绿球藻其体内油脂积累量随着重金属浓度的增加而减小。驯化后小球藻、小球藻F5、微绿球藻、普通小球藻驯化后体内油脂的含量低于驯化前的藻种,其生物体内的油脂积累与其生长曲线也呈现明显的相反趋势。而斜生栅藻驯化后不仅耐受性得到提高,其体内积累的油脂含量也增加。综上所述,不同的微藻对重金属砷离子具有不同的耐受性及吸附能力。通过驯化试验,藻类对重金属的耐受性及去除率均有不同程度的提高。驯化后的微藻体内的油脂含量与未驯化的微藻体内油脂含量存在差别,其中斜生栅藻的油脂含量达到了空白对照组的水平,因此驯化不仅可以提高斜生栅藻对重金属的耐受性和吸附能力,还可以提高其体内油脂的积累,为新型生物柴油油脂提供原料。总的来说,本试验为后续重金属废水的治理研究提供了科学基础及可行的技术手段。利用藻类处理水环境中的重金属污染,具有非常广阔的发展前景。
[Abstract]:At present, the heavy metal pollution of the water body has become a worldwide environmental problem, which causes the common concern of the whole society. The traditional heavy metal treatment method still has great difficulty in the recovery of heavy metal and is easy to produce secondary pollution, and the new heavy metal treatment method has high technical operation level such as nano technology and photocatalysis technology. In recent ten years, in the field of wastewater treatment, researchers have studied the heavy metals by using non-active algae (algae powder). This study was selected from the group consisting of Scenedesmus Obliqueus, Chlamydomonas reinhardtii, Nannachloropsis Oulataa, Chlorella Vulgaris, Chlorella Pyrenoidosa, FACHB-2 (Chlorella Protocols), Chlorella sp. F5 (Chlorolla), and Chlorella sp. In this paper, Dunaliella Salina (Dunaliella Salina) was used to study the screening and acclimatization of the micro-algae of heavy metal ions. At present, there are many studies on these 9 kinds of microalga, and the raw materials are rich and have high commercial value. The main research results are as follows: (1) In the algae screening test, the results of the growth of the algae, the content of chlorophyll a and the removal rate of heavy metals are analyzed, and the effect of the heavy metal arsenic ion on the different micro-algae is obtained. the low concentration of the heavy metal arsenic ions can promote the synthesis of the chlorophyll a of the slant-growing grid algae and the chlorella, and the higher concentration of the arsenic ions can inhibit the synthesis of the chlorophyll a, The chlorophyll a content of the remaining algae decreased with the increase of the concentration of arsenic ions. The adsorption efficiency of the nine species of algae was different in different concentrations of heavy metal and arsenic ions. Chlorella, FACHB-2, Chlorella pyrenoidosa, Micrococcus pluvialis, Chlorella F5, Dunaliella, and Chlamydomonas reinhardtii, with the increase of the concentration of arsenic ions, the removal rate of the arsenic ions decreases by the algae: The removal rate of the arsenic from the chlorella and the slant-green algae decreased with the increase of the concentration of the arsenic ions. (2) The acclimatization test of the algae is divided into two stages: the low-concentration acclimation stage and the high-concentration acclimatization phase when the concentration of the arsenic ions is 1 mg/ L and the concentration of arsenic at the concentration of 2mg/ L. Through the domestication, the tolerance of the algae itself to the heavy metal is improved, so that the harm of the heavy metal to the heavy metal is reduced to the lowest, and the heavy metal can be accumulated. As can be seen from the comparative experiment 1, the ability of the acclimated microalga to adsorb the heavy metal by the unacclimated microalga is generally improved by about 50%. It can be seen from the comparative experiment 2 that the ability of the acclimated microalga to adsorb the heavy metal by the unacclimated microalga is improved by about 70%. (3) The content of the five microalga oils was different, and the content of the oil and fat of the chlorella was the highest. The heavy metal arsenic ion has different effects on the accumulation of the oil and fat of the algae, and the amount of the oil in the body is increased with the increase of the heavy metal concentration, but the increase is different. The accumulation of oil and fat in Chlorella F5 and Micrococcus pluvialis decreases with the increase of heavy metal concentration. After the domestication, the content of oil in the body of Chlorella, Chlorella F5, Micrococcus pluvialis and Chlorella vulgaris is lower than that of the pre-acclimated algae species, and the accumulation of oil and fat in the living body and its growth curve also show the opposite tendency. and the content of the oil accumulated in the body is also increased. In conclusion, different micro-algae have different resistance and adsorption capacity to heavy metal arsenic ions. The tolerance and removal rate of the heavy metals were improved by the acclimatization test. the oil content of the domesticated micro-algae is different from that of the unacclimated micro-algae, and the oil content of the oblique-raw-grid algae reaches the level of the blank control group, so that the acclimatization not only can improve the tolerance and the adsorption capacity of the oblique-growing grid algae to the heavy metal, can also improve the accumulation of the oil in the body and provide the raw material for the novel biological diesel oil and fat. In general, this test provides a scientific basis and a feasible technical means for the study of the subsequent heavy metal wastewater treatment. The method has a very wide development prospect by using algae to treat heavy metal pollution in the water environment.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703;X173

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