【作者】 孙守琴；

【导师】 王定勇；

【作者基本信息】 西南农业大学 ， 环境工程， 2005， 硕士

【摘要】 苔藓植物作为一类监测环境污染的指示植物已得到广泛应用。发达国家在利用苔藓指示监测环境污染方面已做了大量的研究工作,取得了可喜进展,并建立了一些较为实用的技术和方法。我国也有用苔藓来监测大气污染的研究,但所采用的研究方法主要是定性的生态指示法,即采用生态学方法,观察其外部形态来估计大气重金属污染状况,在一定程度上容易受到调查者主观因素的影响;在定量监测方面的研究相对较少,而且监测的对象主要是SO₂等气态污染物,在重金属监测方面的研究很少,在苔藓植物对大气污染物的吸附特性以及污染物对超微结构的影响等方面研究不足,研究范围较为狭窄。因此,用化学分析法定量研究,与用生态指示方法定性研究相结合,并研究苔藓植物对重金属的吸附特性,有利于更好的了解苔藓对大气重金属的吸附规律,在监测大气污染方面有重要意义。 据此,本研究首先通过对苔藓种类、生长状况及分布特征的调查,初步揭示苔藓生态特点与大气污染的相关性。其次通过定量分析比较不同苔藓植物中重金属的含量,分析苔藓对重金属的吸附特性,筛选出了对重金属富集能力强的苔藓品种,以作为用苔藓植物进行大气环境监测的基础。再次采用一种简易的定性和定量识别区域性大气重金属污染的方法——苔袋生物监测方法对重庆市南岸、九龙坡、江北和北碚天生桥大气质量状况进行监测,揭示出监测区域大气污染物干湿沉降规律及大气污染物的时空分布。结果表明: 各调查点苔藓植物的种类、出现频率及多度存在较大差异。其中金佛山、天生桥、龙车寺、北温泉、山耳崖等地苔藓植物种类丰富、生长旺盛;来凤m、槽上等地苔藓植物种类少、长势差。调查区域内最常见的苔藓植物品种有娟藓属、青藓属、麻羽藓属、鳞叶藓属、灰藓属、卷柏藓属等。 各监测点苔藓植物中污染物的含量变化为:青木关>天生桥>北温泉>龙车寺>来凤>山耳崖。由此将各样点按相对污染程度的大小分3级,其中污染区为青木关、天生桥;轻度污染区为龙车寺、北温泉、来凤;清洁区为山耳崖。此外,按污染类型,本实验所调查的6个样点可分为4类,清洁区为山耳崖;汞污染区为北温泉和龙车寺;铜镍污染区为青木关和天生桥;锌污染区为来凤。 不同种类的苔藓对不同污染物的吸附力不同,通过对同一样点中不同苔藓种类对重金属的相对富集能力的比较发现,在本研究所调查样区采集的各种苔藓中,对汞吸附力较强的苔藓种有:卷柏藓属、阔叶小石藓、鳞叶藓属、娟藓属、灰藓属等。对铜吸附力较强的苔藓种有:阔叶小石藓、细叶小羽藓、卷柏藓属、麻羽藓属等。对镉吸附力较强的苔藓种有:阔叶小石藓、拟草藓、鳞叶藓属、青藓属、卷柏藓属、娟藓属、麻羽藓属等。对铅吸附力较强的苔藓种有:青藓属、卷柏藓属、娟藓属、麻羽藓属、阔叶小石藓、拟草藓、鳞叶藓属等。对锌吸附力较强的苔藓种有:阔叶小石藓、薄罗藓属、细叶小羽藓、拟草藓、青藓属、卷柏藓更多还原

【Abstract】 Bryophytes were widely used in the world as one kind of indicative plant sensitive to environmental pollution. Developed countries had done many researches in this field, had reached delightful achievements, and established some practical techniques and measures. In China, the research in this field was weak relatively. There were just some researchs in environgmental monitoring used bryophytes as indicators in recent 10 years, but most were concentrated on qualitative reseach by ecological ingdicating means, which could be influenced easily by the subjective factors of researchers in certain extent. The quantitative research was less, and the monitored objects were mainly gaseous pollutions such as SO2, etc. but less in heavy metals, the reseach scope was confined. So, by combinating quatative chemistry analysis and qualitative ecological indicating, as well as studying the bryophytes’ adsorption characters to heavy metal, we could know the bryophytes’ adsorption rules to heavy metals in atmosphere, which is significant in monitoring atmaspheric pollution.As this, we firstly investigated the bryophytes species, growth status and distributing characters, primarily disclosed relativity between the bryophytes’ ecological charateras and the atmospheric pollution. Secondly, through comparing the heavy metal content in different bryophytes by quantitative analysis, and studying the bryophytes’ adsorption characters to heavy metals, we selected out the bryophyte species which have high accumulative ability to heavy metals. Which could be the base of atmospheric environmental monitoring. Thirdly, we adopted moss-bag technology, one simple method, to identify territorial atmosphere heavy metal pollutants qualitatively and quantitatively, to monitor the atmosphere quality in Nanan district, Jiulongpo district, Jiangbei district in Chongqing, and Tiansheng Road in Beibei, disclosed furtherly the dry and wet deposition of atmospheric contaminants and their spatial-temporal variation in monitored regions. The results showed:The bryophytes’ species, existence frequency and quantity differed heavily in investigated spots. Among them, the bryophytes was enrich and grown well in Golden Buddha Mountain, Tiansheng Road, Longjushi, North Hotspring, the Second Mountain Cliff, but few and grown worse in Laifeng. The most pervasive bryophyte species in investigated districts were Entodon, Brachythecium, Claopodium, Taxiphyllum, Hypnum, Taxiphyllum, etc.Pollutant contents varied as Qingmuguan>Tiansheng Road>North Hotspring>Longjushi> Laifeng>the Second Mountain Cliff. Thereout, according to relative pollution extent, the investigated spots could be sorted into three grades, in them, Tiansheng Road, North Hotspring, Qingmuguan was polluted region, Laifeng was light polluted region, and the Second Mountain Cliffwas clean region. Through clustering analysis, we sorted the six spots into four types, the first type was clean area, it was the Second Mountain Cliff, the second type was Hg polluted area, included North Hotspring and Longjushi, the third type was Cu, Ni polluted area, included Qingmuguan and Tiansheng Road, the fourth type was Zn polluted area, included Laifeng.By comparing accumulative indexes of the bryophytes in same spots, we found the bryophytes which had strong accumulative ability to Hg are Hypum cupressiforme, Brachythecium, Entodon, Claopodium, Racoplium, etc. Which had strong accumulative ability to Cu were Brachythecium, Claopodium, Racoplium, Bryohaplocladium microphyllum, etc. Which had strong accumulative ability to Cd were Brachythecium, Entodon, Weisia planifolia Dix, etc. Which had strong accumulative ability to Pb were Brachythecium, Entodon, Barbula, Weisia planifolia Dix, Racoplium, etc. Which had strong accumulative ability to Zn were Brachythecium, Entodon, Barbula, Weisia planifolia Dix, Racoplium, Leskea, etc. Which had strong accumulative ability to Ni were Brachythecium, Entodon, Taxiphyttum, etc. In them, Weisia planifolia Dix., Taxiphyllum, Bryohaplocladium microphyllum (Hedw.) Broth, Pseudoleskeopsis zippelii (Dozy et Molk.)Broth., Brachythecium, Racoplium, Claopodium, etc. had higher accumulative ability to heavy metals, the common bryophytes’ accumulative ability to heavy metals varied as:Racoplium > Entodon > Claopodium>Taxiphyllum>Brachythecium. And this was the base of selecting bryophyte materials in atmospheric environmental monitor.Correlation analysis showed that the bryophyte species in this study was correlative evidently, and could substitute for each other in environmental monitoring, but must be revised before use.Different bryophytes’ adsorption isotherms were common, that was, the adsorption contents to Hg and Cd increased with the concentration of the balanced solution, and all could be simulated by Liner equation, Freundlich equation and Langmuir equation. In them, the Langmuir equation was the best in simulating the bryophytes’ adsorption character to Hg, and the Langmuir equation was the best in simulating the bryophytes’ adsorption character to Cd (r=0.9617-0.9996). But the bryophytes’ saturation adsorption contents were different with each other, the maximum adsorption content to Hg was 23.702-456.20lmg/g, the maximum adsorption content to Cd was 31.118-259.917mg/g. The Bryophytes’ adsorption ability varied as Isothecium alopecuroides (Dubois)Isov.>Bryhnia trichomitria Dix. et Ther.>Hypnum plumaeforme Wils.>Gollania robusta Broth.>Bazzania yoshinagana (Steph.) Steph. ex Yasuda>Brotherella (Duby)Fleisch>Dicranum nipponense Besch. and Thuidium cymbifolium (Dozy et Molk.) Dozy et Molk>Dicranum sp., In all, the adsorption content of Bazzania yoshinagana (Steph.) Steph. ex Yasuda, Dicranum nipponense Besch., and Dicranum sp. were lower than other species, but within this experimental concentration ranges, all didn’t reach their maximum adsorption content.The bryophytes’ adsorption dynamics to heavy metals could be carved into two stages, that was, the rapid reaction phase and the slow reaction phase. Bryophytes’ adsorption content increased rapidly in the beginning 30 minutes, and almost reach maximum until 2 hours, after that, it increased very slow and almost without change. This illuminated the process of the bryophytes’ adsorption to heavy metal was initiative and rapid. The adsorption contents of Bazzania yoshinagana (Steph.) Steph. ex Yasuda, Dicranum nipponense Besch., and Dicranum sp. to Hg ion were lower than other species, this showed their accumulative abilities were weaker than other species and maybe related to their grown forms.The bryophytes adsorption dynamics to Hg could be generally imitated by exponential (double constent) equation and Elovich equation. But exponential equation imitated Brotherella (Duby)Fleisch, Bryhnia trichomitria Dix. et Ther., Eurhynchium eustegium (Broth.) Dix.’s adsorption dynamics better(r=0.9250~0.9353).Similar to the adsorption process, the bryophytes’ desorption dynamics character to Hg solution could be carved into two stages, that was, the rapid reaction phase and the slow reaction phase. Samely, the rapid reaction phase finished rapidly in the first 2 hours, almost reached it’s maximum. In the slow reaction phase, the dis-adsorption content increase very slow and almost without increase. But under same condition, Bazzania yoshinagana (Steph.) Steph. ex Yasuda, Dicranum nipponense Besch., and Dicranum sp. had larger desorption content. The desorption content of Bazzania yoshinagana (Steph.) Steph. ex Yasuda was 1/4 of it’s adsorption content, The proportions of the desorption contents to their adsorption contents of Dicranum nipponense Besch., and Dicranum sp. were larger than other species. This illuminated the heavy metal ions could be released easier from them and further confirmed their ability of holding Hg ions were lower than other species.In this study, we selected out seven species as the best adsorptive species to heavy metal. They were Thuidium cymbifolium (Dozy et Molk.) Dozy et Molk, Brotherella (Duby) Fleisch, Hypnum plumaeforme Wils., etc. but in reality reseach, we must select bryophytes material referring to the bryophytes’ growth status and distributions.Heavy metal contents in moss-bags hung in all monitored spots were higher than Jinyun Mountain spot, which indicated these spots had been polluted in different content. But in the five monitored spots, the content of Hg Cu Cd, Pb Zn Ni in Jiulongpo district is higher than other spots obviously. Jiangbei and Nanan districts and Tiansheng Road were polluted in certain extent. Atmospheric heavy metal content in monitored spots varied little in monitorred span.The wet and dry deposition of atmospheric pollutants was: in controlled spots, the average deposition speed of Hg was 8.50ug.m~-2.mon~-1, dry deposition accounted for 62%. In Tiansheng Road, the deposition speed of Hg was 12.50 g.m~-2.mon~-1, dry deposition accounted for 59%. In Nanan,更多还原