过氧化氢对铜绿微囊藻的生长及损伤效应研究

发布时间：2017-12-28 20:07

本文关键词：过氧化氢对铜绿微囊藻的生长及损伤效应研究　出处：《四川农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：在社会的不断发展和人类持续不断的活动影响下,水体富营养化现象日趋严重,“水华”和“赤潮”的爆发也日趋频繁,由此而引发的生态环境问题以及藻类的防治问题一直备受全世界的关注。目前,对于藻类的去除技术主要有化学、物理和生物方法,这些方法都有一定的缺陷,不能有效的大规模应用于实际水体除藻。近年来,人们发现一定浓度的过氧化氢能够杀灭藻细胞,并且过氧化氢只含有氢和氧两种元素,对环境污染小,是一种潜在的环保除藻剂。本文以铜绿微囊藻,一种能够引起蓝藻“水华”的特征优势蓝藻为试验材料,以藻细胞数和叶绿素a含量为指标来研究过氧化氢在单一环境因素与复合环境因素以及藻细胞自身因素影响下对铜绿微囊藻生长的影响,以期为蓝藻水华的治理和过氧化氢除藻技术提供更加全面的科学依据。然后从藻细胞氧化与抗氧化能力的角度分析过氧化氢对铜绿微囊藻的损伤效应,以总抗氧化能力(T-AOC)水平、类胡萝卜素和丙二醛(MDA)含量变化为指标来研究过氧化氢对铜绿微囊藻的氧化损伤机制,为过氧化氢除藻的机理提供一定的理论参考。同时,通过对培养基中过氧化氢含量分析来简单探讨过氧化氢除藻之后对水体环境的影响,可在一定程度上为实际应用过氧化氢除藻的环境可行性提供依据。本研究的主要成果有：(1)不同浓度的H202处理藻液,会对藻细胞产生不同程度的毒害作用,H202浓度越大,毒害作用越大。24h之后,铜绿微囊藻藻细胞数、叶绿素a含量、类胡萝卜素含量、蛋白质含量以及T-AOC都有了非常大的减小,而MDA含量显著增加,同时培养基中的H202含量也迅速降低；随着处理时间的增加,毒害作用一直延续,培养基中H202也逐渐被消耗和分解,72h之后,藻细胞各指标含量的数值降得很低,同时MDA含量也增加到最大,藻细胞的损伤效应也达到最大。其中,H202浓度为50mg/L时,能够有效的去除藻细胞,并且对藻细胞的生理指标以及抗氧化能力都有很强的损伤效应,并且72h之后,培养基中H202的含量减少了98%,残留量很低。(2)水体中溶液pH值的大小、温度以及光照都会影响铜绿微囊藻的生长,同时也会对H202的除藻效果产生影响。pH7.5-8.5的微碱性环境条件最适合铜绿微囊藻生长繁殖,而在pH6.5-7.5的中性环境条件下,H202对铜绿微囊藻的去除以及藻细胞叶绿素a含量的降低效果较好,中、碱性(pH7.5～9.5)的环境条件更有利于培养基中H202的消耗与分解。在20～30℃的温度范围内,H202都能有效去除铜绿微囊藻,温度对H202除藻影响差异不大。25001x-45001x的光照下,铜绿微囊藻有较高的生长量,以光照为35001x时,其生长量达到最大；H202去除藻细胞,在短时间内,低光照强度有利于H202去除铜绿微囊藻,但随着时间的增加,光照的影响作用不太明显；在相同的时间内,光照强度越大,培养基中H202的残留量越低。(3)正交试验结果表明,光照、温度、pH和H202浓度四个因素中,对藻细胞去除率影响大小的因素依次是：H202浓度pH光照温度；对藻细胞叶绿素a含量去除影响最大因素也是H202浓度,影响最小的是pH值；而对培养基中H202残留量的影响大小顺序是：H202浓度光照pH温度。结合正交试验与实际情况,确定去除铜绿微囊藻的最佳条件是光照为15001x、H202浓度为50mg/L、pH值为7.5、温度为25℃。(4)铜绿微囊藻自身因素也会对H202的除藻效果产生一定的影响。50mg/L H202处理藻液时,藻液的初始藻细胞数大小对H202除藻影响不大。72h内,初始藻细胞数为1×106～1×107个/ml时,H202除藻的效果差别不是很大,当初始藻细胞数超过2×107个/ml时,相同浓度的H202,除藻效果略有下降。对于不同生长阶段的藻细胞,H202对其生长及损伤效应的影响不一样,对藻细胞的去除效果也不一样。H202对衰亡期藻细胞的损伤效应最大,去除效果也最好,其次是适应期的藻细胞,稳定期和对数期的藻细胞损伤效应差异不显著。H202是一种潜在的除藻剂,本身分解也只产生水和氧气,对环境无污染,可以用H202来杀灭水体中的铜绿微囊藻,这对于蓝藻“水华”的治理意义重大。在实际应用H202除藻时,H202的用量是关键,还要充分考虑光照、pH和温度的影响,同时,也可以根据“水华”爆发的程度来适当的调节H202的施用量。这对于指导实际应用H202除藻具有重要的意义。
[Abstract]:Under the influence of continuous development of society and continuous human activities, the phenomenon of water eutrophication is becoming more and more serious. The outbreak of "bloom" and "red tide" is becoming more frequent. The problem of ecological environment and algae control has been attracting worldwide attention. At present, there are mainly chemical, physical and biological methods for algae removal. These methods have some shortcomings and cannot be applied to algae removal in real water. In recent years, it has been found that a certain concentration of hydrogen peroxide can kill algal cells, and hydrogen peroxide contains only two elements of hydrogen and oxygen, and it has little environmental pollution, and it is a potential environmental protection algicidal agent. In this paper, Microcystis aeruginosa, which can cause the characteristic advantage of blue-green algae bloom cyanobacteria as the experimental material, the number and chlorophyll a content of algal cells to study the influence index of hydrogen peroxide on the growth of Microcystis aeruginosa in a single environment and complex environmental factors and self factors of algal cells under the influence, in order to cyanobacterial blooms governance and hydrogen peroxide removal technology to provide more comprehensive scientific basis. Then the damage effect analysis of hydrogen peroxide from algal cell oxidation and antioxidant ability of Microcystis aeruginosa, the total antioxidant capacity (T-AOC), the level of carotenoid and malondialdehyde (MDA) content as an index to study of hydrogen peroxide on Microcystis oxidative damage mechanism for hydrogen peroxide algae removal mechanism to provide a theoretical reference the. At the same time, by analyzing the content of hydrogen peroxide in the culture medium, we simply discussed the influence of hydrogen peroxide on the water environment after algae removal. It can provide a basis for the practical application of hydrogen peroxide to remove algae. The main results of this study are: (1) different concentrations of H202 can produce different degrees of toxicity to algal cells. The greater the concentration of H202, the greater the toxicity. After 24h, the content of protein and T-AOC of Microcystis aeruginosa algal cell number, chlorophyll a, carotenoid content, have been reduced very large, and the concentration of MDA increased, while H202 content in the medium is rapidly decreased; with the increase of treatment time, toxicity has been extended, after the medium H202 is gradually consumed and decomposition, 72h, numerical indexes of algal cell content drop very low, and the content of MDA is increased to the maximum, the damage effect of algal cells also reached the maximum. Among them, when H202 concentration is 50mg/L, it can effectively remove algal cells, and has strong damage effect on physiological and antioxidant capacity of algal cells. After 72h, the H202 content in culture medium is reduced by 98%, and the residue is very low. (2) the size, temperature and light of the pH value in the water will affect the growth of Microcystis aeruginosa, and also influence the algae removal effect of H202. Micro alkaline conditions pH7.5-8.5 the most suitable for the growth of Microcystis aeruginosa and breeding in neutral pH6.5-7.5 condition, H202 removal of Microcystis aeruginosa by algae and chlorophyll a content decreased better in alkaline (pH7.5 ~ 9.5) environmental conditions more conducive to the decomposition of H202 in culture medium consumption. In the temperature range of 20~30 C, H202 can effectively remove Microcystis aeruginosa, and there is little difference in the effect of temperature on H202 removal of algae. 25001x-45001x under the light of Microcystis aeruginosa growth was higher, in light of 35001x, the growth rate reached the maximum; the H202 removal of algal cells, in a short time, low light intensity H202 is conducive to the removal of Microcystis aeruginosa, but with the increase of time, with less obvious effects of light; at the same time, the greater the light intensity, the lower the residual amount of H202 in the culture medium. (3) the results of orthogonal test showed that light, temperature, pH and concentration of H202 four factors, the factors affecting the removal rate of algae cell size were: H202 concentration pH light temperature; remove the influence biggest factor is the concentration of H202 on chlorophyll a content, the minimum impact value of pH; the medium H202 residues affect the size of the order is: the concentration of H202 light pH temperature. Based on the orthogonal test and the actual situation, the best conditions to remove Microcystis aeruginosa were illumination 15001x, H202 concentration 50mg/L, pH value 7.5, and temperature 25 centigrade. (4) the self factors of Microcystis aeruginosa also have a certain effect on the effect of H202 on algae removal. When 50mg/L H202 treated the algae solution, the number of initial algal cells in the algal solution had little effect on H202 removal of algae. In 72h, when the initial algal cell number is 1 * 106~1 * 107 /ml, the effect of H202 on algae removal is not very different. When the initial algal cell number exceeds 2 * 107 /ml, the same concentration of H202 has a slight decrease in algal removal effect. The effects of H202 on the growth and damage of algal cells at different stages of growth are different, and the effect on the removal of algae cells is different. H202 had the greatest damage effect on algal cells in the decline stage, and the best removal effect was followed. The second is the algal cells in the adaptation phase. There was no significant difference in the effect of algal cell damage between stable phase and logarithmic phase. H202 is a potential algicidal agent. It decomposes itself to produce water and oxygen and pollute the environment. H202 can be used to kill Microcystis aeruginosa in water. This is of great significance for the control of cyanobacteria bloom. In the practical application of H202, the amount of H202 is the key to remove algae, and we should take full account of the influence of light, pH and temperature. At the same time, we can adjust the amount of H202 appropriately according to the degree of "bloom". This is of great significance for guiding the practical application of H202 algae removal.
【学位授予单位】：四川农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52

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