底棲藻類在淺水湖泊穩(wěn)態(tài)轉(zhuǎn)換中的作用
發(fā)布時間：2018-08-21 13:27
【摘要】：湖泊不僅是人類淡水資源的主要來源之一,也是維護(hù)良好生態(tài)環(huán)境和促進(jìn)可持續(xù)發(fā)展的重要因素。近年來,因經(jīng)濟(jì)的快速發(fā)展,資源利用強(qiáng)度加大,導(dǎo)致我國湖泊水體富營養(yǎng)化問題日趨嚴(yán)重。武漢東湖作為典型的淺水富營養(yǎng)化湖泊,其沿岸帶生長了大量的底棲藻類,它們作為湖泊重要的初級生產(chǎn)者,在湖泊穩(wěn)態(tài)轉(zhuǎn)換過程中的作用十分重要。因此,在2012.3~2013.10期間,我們以底棲藻類為研究對象,開展野外東湖圍隔實驗和室內(nèi)實驗。東湖圍隔實驗主要測定了水體中底棲藻類生物量及環(huán)境因子;底棲藻類滯留的總磷及各形態(tài)磷的含量;分析了底棲硅藻的種類組成及其與環(huán)境因子之間的關(guān)系。室內(nèi)實驗主要測定了底棲藻類和苦草對不同濃度豬糞廢水中化學(xué)需氧量(COD)、氮和磷等營養(yǎng)物質(zhì)的去除效果,底棲藻類、苦草和浮游藻類生物量,底棲藻類和苦草滯留的總磷及各形態(tài)磷的含量及苦草過氧化氫酶活性和丙二醛的含量。為期一年的野外實驗結(jié)果表明:圍隔中底棲藻類葉綠素a(Chl a)含量,滯留的鈣磷含量比大湖(對照)高,但鐵/鋁磷含量低于對照,這說明底棲藻類對水中營養(yǎng)鹽的吸收和對磷的賦存形態(tài)均對湖泊從藻型到草型的轉(zhuǎn)換起到了積極的作用。圍隔水體中所有化學(xué)因子要明顯低于對照,水中浮游藻類生物量顯著下降,表明圍隔對水質(zhì)修復(fù)作用明顯。當(dāng)圍隔水體中TP含量在0.02-0.05 mg/L時,圍隔水體發(fā)生了穩(wěn)態(tài)轉(zhuǎn)換,沉水植被覆蓋度逐漸增加。圍隔和對照水體中底棲硅藻的種類組成及其分布比較研究表明:圍隔和對照水體中底棲硅藻共有148種,其中圍隔水體的硅藻優(yōu)勢種類數(shù)要高于對照,且不同季節(jié)優(yōu)勢種不同;圍隔和對照水體中底棲硅藻生物量均值分別為8.4×109和2.1×1010 cells/m2。極小曲殼藻(Achnanthes minutissima)是所有樣點的絕對優(yōu)勢種,其相對豐富度最高為65%。圍隔水體中底棲硅藻主要為纖細(xì)橋彎藻(Cymbella gracilis),近緣橋彎藻(Cymbella affinis),Gomphonema truncatum,橄欖形異極藻(Gomphonema olivaceum)等清水優(yōu)勢種,其中彎棒桿藻(Rhopalodia gibba)和扁圓卵形藻(Cocconeis placentula)的出現(xiàn)對圍隔內(nèi)沉水植被的恢復(fù)起到了一定的指示作用;而對照中主要為谷皮菱形藻(Nitzschia palea),窄異極藻(Gomphonema parvulum),偏腫橋彎藻(Cymbella ventricosa)及隱頭舟形藻(Navicula cryptocehala)等耐污優(yōu)勢種。對底棲硅藻的優(yōu)勢種類和環(huán)境因子的關(guān)系進(jìn)行了典型對應(yīng)分析(CCA),結(jié)果顯示:圍隔水體中的底棲硅藻種類組成主要受到氮和磷等營養(yǎng)物質(zhì)的影響,而大湖的硅藻種類組成主要受到氮和pH的影響。室內(nèi)模擬實驗表明,底棲藻類、苦草、底棲藻類-苦草對高濃度豬糞廢水的COD、氮磷均存在顯著的去除效果。其中COD的最大去除率均大于86%;底棲藻類-苦草混合培養(yǎng)對高、中濃度豬糞廢水中磷、氮的平均去除率均大于62%和70%,高于二者單獨培養(yǎng)的處理組。底棲藻類和苦草對水中磷的滯留作用明顯,滯留的總磷的主要形態(tài)為無機(jī)磷。底棲藻類、苦草和浮游藻類Chl a含量的變化以及苦草的CAT、MDA含量變化表明,高濃度的豬糞廢水會對苦草產(chǎn)生短期的逆境脅迫,但底棲藻類的存在可以減緩高濃度氮磷對苦草的脅迫效應(yīng),在中濃度氮磷且有底棲藻類存在的條件下,有利于苦草的恢復(fù)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.
【學(xué)位授予單位】：中南民族大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X524
，
本文編號：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.
【學(xué)位授予單位】：中南民族大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X524
，
本文編號：2195877
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