底栖藻类在浅水湖泊稳态转换中的作用
发布时间：2018-08-21 13:27
【摘要】：湖泊不仅是人类淡水资源的主要来源之一,也是维护良好生态环境和促进可持续发展的重要因素。近年来,因经济的快速发展,资源利用强度加大,导致我国湖泊水体富营养化问题日趋严重。武汉东湖作为典型的浅水富营养化湖泊,其沿岸带生长了大量的底栖藻类,它们作为湖泊重要的初级生产者,在湖泊稳态转换过程中的作用十分重要。因此,在2012.3~2013.10期间,我们以底栖藻类为研究对象,开展野外东湖围隔实验和室内实验。东湖围隔实验主要测定了水体中底栖藻类生物量及环境因子;底栖藻类滞留的总磷及各形态磷的含量;分析了底栖硅藻的种类组成及其与环境因子之间的关系。室内实验主要测定了底栖藻类和苦草对不同浓度猪粪废水中化学需氧量(COD)、氮和磷等营养物质的去除效果,底栖藻类、苦草和浮游藻类生物量,底栖藻类和苦草滞留的总磷及各形态磷的含量及苦草过氧化氢酶活性和丙二醛的含量。为期一年的野外实验结果表明:围隔中底栖藻类叶绿素a(Chl a)含量,滞留的钙磷含量比大湖(对照)高,但铁/铝磷含量低于对照,这说明底栖藻类对水中营养盐的吸收和对磷的赋存形态均对湖泊从藻型到草型的转换起到了积极的作用。围隔水体中所有化学因子要明显低于对照,水中浮游藻类生物量显著下降,表明围隔对水质修复作用明显。当围隔水体中TP含量在0.02-0.05 mg/L时,围隔水体发生了稳态转换,沉水植被覆盖度逐渐增加。围隔和对照水体中底栖硅藻的种类组成及其分布比较研究表明:围隔和对照水体中底栖硅藻共有148种,其中围隔水体的硅藻优势种类数要高于对照,且不同季节优势种不同;围隔和对照水体中底栖硅藻生物量均值分别为8.4×109和2.1×1010 cells/m2。极小曲壳藻(Achnanthes minutissima)是所有样点的绝对优势种,其相对丰富度最高为65%。围隔水体中底栖硅藻主要为纤细桥弯藻(Cymbella gracilis),近缘桥弯藻(Cymbella affinis),Gomphonema truncatum,橄榄形异极藻(Gomphonema olivaceum)等清水优势种,其中弯棒杆藻(Rhopalodia gibba)和扁圆卵形藻(Cocconeis placentula)的出现对围隔内沉水植被的恢复起到了一定的指示作用;而对照中主要为谷皮菱形藻(Nitzschia palea),窄异极藻(Gomphonema parvulum),偏肿桥弯藻(Cymbella ventricosa)及隐头舟形藻(Navicula cryptocehala)等耐污优势种。对底栖硅藻的优势种类和环境因子的关系进行了典型对应分析(CCA),结果显示:围隔水体中的底栖硅藻种类组成主要受到氮和磷等营养物质的影响,而大湖的硅藻种类组成主要受到氮和pH的影响。室内模拟实验表明,底栖藻类、苦草、底栖藻类-苦草对高浓度猪粪废水的COD、氮磷均存在显著的去除效果。其中COD的最大去除率均大于86%;底栖藻类-苦草混合培养对高、中浓度猪粪废水中磷、氮的平均去除率均大于62%和70%,高于二者单独培养的处理组。底栖藻类和苦草对水中磷的滞留作用明显,滞留的总磷的主要形态为无机磷。底栖藻类、苦草和浮游藻类Chl a含量的变化以及苦草的CAT、MDA含量变化表明,高浓度的猪粪废水会对苦草产生短期的逆境胁迫,但底栖藻类的存在可以减缓高浓度氮磷对苦草的胁迫效应,在中浓度氮磷且有底栖藻类存在的条件下,有利于苦草的恢复重建。
[Abstract]:Lake is not only one of the main sources of human freshwater resources, but also an important factor to maintain a good ecological environment and promote sustainable development. In recent years, with the rapid development of economy and the increasing intensity of resource utilization, the eutrophication of lakes in China has become increasingly serious. A large number of benthic algae grow in the coastal zone, and they play an important role in the steady-state transition of lakes. Therefore, during the period from March 2012 to October 2013, we carried out field and laboratory experiments on benthic algae in the enclosure of East Lake. Biomass and environmental factors, total phosphorus and various forms of phosphorus retained by benthic algae, species composition of benthic diatoms and their relationship with environmental factors were analyzed. Biomass of algae, sedge and phytoplankton, contents of total phosphorus and various forms of phosphorus retained by benthic algae and sedge, and activities of catalase and malondialdehyde in sedge were measured. The results showed that the contents of chlorophyll a (Chl a) and calcium and phosphorus retained by benthic algae in the enclosure were higher than those in the Great Lakes (control), but the contents of iron/aluminum and phosphorus were lower. The results showed that benthic algae absorption of nutrients and phosphorus forms played a positive role in the transformation from algae to grassland. All chemical factors in the enclosure water were significantly lower than those in the control, and the biomass of plankton algae in the water was significantly decreased, indicating that enclosure had a significant effect on water quality restoration. When TP content was between 0.02 mg/L and 0.05 mg/L, the enclosure water changed steadily and the vegetation coverage of submerged water increased gradually. The average biomass of benthic diatoms in the enclosure and control waters was 8.4 *109 and 2.1 *1010 cells/m2, respectively. Achnanthes minutissima was the absolute dominant species with the highest relative richness of 65%. The main benthic diatoms in the enclosure waters were Cymbella gracilis, and the relative benthic diatoms in the contiguous waters were Cymbella gracilis. (Cymbella affinis), Gomphonema truncatum, Gomphonema olivaceum and other dominant species in clear water, including Rhopalodia gibba and Cocconeis placentula, played a certain role in indicating the restoration of submerged vegetation in the enclosure; Nitzia pale was the dominant species in the control. A typical correspondence analysis (CCA) was made on the relationship between the dominant species of benthic diatoms and environmental factors. The results showed that the composition of benthic diatoms in enclosed waters was mainly affected by nitrogen and phosphorus. The results of laboratory simulation experiments show that benthic algae, sedge and benthic algae-sedge all have significant removal effects on COD, nitrogen and phosphorus in high concentration pig manure wastewater. The maximum removal rate of COD is more than 86%; the mixed culture of benthic algae and sedge is high, medium and concentrated. The average removal rates of phosphorus and nitrogen in pig manure wastewater were higher than 62% and 70% respectively, which were higher than those in the two treatments. However, the presence of benthic algae can slow down the stress effect of high concentration of nitrogen and phosphorus on the grass. Under the condition of medium concentration of nitrogen and phosphorus and the presence of benthic algae, benthic algae is conducive to the restoration and reconstruction of the grass.
【学位授予单位】：中南民族大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X524
，
本文编号：2195877
[Abstract]:Lake is not only one of the main sources of human freshwater resources, but also an important factor to maintain a good ecological environment and promote sustainable development. In recent years, with the rapid development of economy and the increasing intensity of resource utilization, the eutrophication of lakes in China has become increasingly serious. A large number of benthic algae grow in the coastal zone, and they play an important role in the steady-state transition of lakes. Therefore, during the period from March 2012 to October 2013, we carried out field and laboratory experiments on benthic algae in the enclosure of East Lake. Biomass and environmental factors, total phosphorus and various forms of phosphorus retained by benthic algae, species composition of benthic diatoms and their relationship with environmental factors were analyzed. Biomass of algae, sedge and phytoplankton, contents of total phosphorus and various forms of phosphorus retained by benthic algae and sedge, and activities of catalase and malondialdehyde in sedge were measured. The results showed that the contents of chlorophyll a (Chl a) and calcium and phosphorus retained by benthic algae in the enclosure were higher than those in the Great Lakes (control), but the contents of iron/aluminum and phosphorus were lower. The results showed that benthic algae absorption of nutrients and phosphorus forms played a positive role in the transformation from algae to grassland. All chemical factors in the enclosure water were significantly lower than those in the control, and the biomass of plankton algae in the water was significantly decreased, indicating that enclosure had a significant effect on water quality restoration. When TP content was between 0.02 mg/L and 0.05 mg/L, the enclosure water changed steadily and the vegetation coverage of submerged water increased gradually. The average biomass of benthic diatoms in the enclosure and control waters was 8.4 *109 and 2.1 *1010 cells/m2, respectively. Achnanthes minutissima was the absolute dominant species with the highest relative richness of 65%. The main benthic diatoms in the enclosure waters were Cymbella gracilis, and the relative benthic diatoms in the contiguous waters were Cymbella gracilis. (Cymbella affinis), Gomphonema truncatum, Gomphonema olivaceum and other dominant species in clear water, including Rhopalodia gibba and Cocconeis placentula, played a certain role in indicating the restoration of submerged vegetation in the enclosure; Nitzia pale was the dominant species in the control. A typical correspondence analysis (CCA) was made on the relationship between the dominant species of benthic diatoms and environmental factors. The results showed that the composition of benthic diatoms in enclosed waters was mainly affected by nitrogen and phosphorus. The results of laboratory simulation experiments show that benthic algae, sedge and benthic algae-sedge all have significant removal effects on COD, nitrogen and phosphorus in high concentration pig manure wastewater. The maximum removal rate of COD is more than 86%; the mixed culture of benthic algae and sedge is high, medium and concentrated. The average removal rates of phosphorus and nitrogen in pig manure wastewater were higher than 62% and 70% respectively, which were higher than those in the two treatments. However, the presence of benthic algae can slow down the stress effect of high concentration of nitrogen and phosphorus on the grass. Under the condition of medium concentration of nitrogen and phosphorus and the presence of benthic algae, benthic algae is conducive to the restoration and reconstruction of the grass.
【学位授予单位】：中南民族大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X524
，
本文编号：2195877
本文链接：https://www.wllwen.com/kejilunwen/huanjinggongchenglunwen/2195877.html
最近更新
教材专著
