本文選題：小球藻 + 鎘��； 參考：《西北農林科技大學》2015年碩士論文

【摘要】：重金屬污染是危害最嚴重的水污染之一,對重金屬廢水和污染的水體進行處理和修復至關重要。傳統(tǒng)的重金屬污水的處理效率較低、成本較高、容易再次形成污染,而生物吸附則是一種高效、廉價的重金屬處理方法,大量研究表明藻類對很多種金屬都具有較強的吸附能力。本研究主要涉及兩方面:一方面是以小球藻(Chlorella vulgaris)為研究材料,通過分析其在不同鎘濃度下的生長情況,色素(葉綠素a、葉綠素b、類胡蘿卜素)、可溶性蛋白、過氧化氫(H2O2)以及超氧化物陰離子(O2·-)含量的變化,并測定過氧化氫酶(CAT)、過氧化物酶(POD)和超氧化物歧化酶(SOD)活性的變化,判斷小球藻對鎘的耐受性。另一方面,通過研究小球藻活藻和死藻在不同接觸時間、不同初始金屬濃度、不同藻生物量以及在自然污水的不同條件下對重金屬鎘的吸附情況,確定小球藻對鎘的吸附能力,同時對小球藻對鎘吸附的動力學和熱力學進行分析,為受重金屬污染的水體利用藻類的生物修復提供理論依據。試驗結果如下:1、在不同鎘濃度(0 mg·L-1、0.5 mg·L-1、1 mg·L-1、3 mg·L-1、5 mg·L-1、7 mg·L-1)的影響下,鎘對小球藻的抑制主要是在高濃度(3-7 mg·L-1)下,并且隨著濃度的增大,對小球藻生長的抑制程度逐漸增大,小球藻生物量隨著鎘濃度的增大逐漸減少,在鎘濃度為5 mg·L-1時,小球藻還可以生長,但在鎘濃度為7 mg·L-1時,小球藻幾乎不能生長。隨著鎘濃度的上升,葉綠素a、葉綠素b、類胡蘿卜素的含量均減少,不同濃度的鎘對葉綠素a、類胡蘿卜素的含量均有顯著影響(P≤0.05);而對葉綠素b影響不顯著(P0.05)�？扇苄缘鞍缀侩S著鎘濃度的上升先逐漸增大,其含量在鎘濃度上升到3mg·L-1時達到最大,之后隨著鎘濃度的上升其含量逐漸減小。過氧化氫和超氧化物陰離子含量隨著鎘濃度的增大逐漸增大,且在高濃度下含量顯著增加。隨著鎘濃度的增大,CAT、SOD、POD的活性逐漸增大,SOD和CAT活性在鎘濃度為0.5 mg L-1時達到最大值,POD活性在鎘濃度為5 mg L-1時達到最大值,隨著鎘濃度的繼續(xù)增大,酶活性都逐漸減小。表明小球藻對鎘有很好的耐受性。2、小球藻對鎘的吸附受不同接觸時間的影響。以100 mg·L-1作為初始鎘濃度,死藻和活藻對重金屬鎘的吸附主要是在前5分鐘內完成,在吸附5分鐘時,活藻和死藻對重金屬鎘的吸附效率分別達到95.2%和96.8%,其吸附量分別為10.54 mg·g-1和10.77mg·g-1。隨著時間的增加,死藻和活藻的吸附效率都逐漸增大,在吸附到105分鐘時達到吸附平衡,此時死藻和活藻的吸附效率分別達到98.1%和96%,吸附量為10.88 mg·g-1和10.64 mg·g-1。因此可知,死藻對重金屬鎘的吸附效率和吸附量要稍高于活藻。3、小球藻對鎘的吸附作用受不同初始鎘濃度的影響。以5 mg·L-1、10 mg·L-1、50 mg·L-1、100 mg·L-1、150 mg·L-1作為初始鎘濃度,在5 mg·L-1的鎘濃度下,吸附平衡后,死藻和活藻對重金屬鎘的吸附效率分別達到89.7%和85.7%,吸附量為0.50 mg·g-1和0.48mg·g-1,隨著初始鎘濃度的增大,活藻和死藻的吸附效率和吸附量逐漸增大,在初始濃度為10-150 mg·L-1時,藻的吸附效率變化不大,但在初始濃度為150 mg·L-1時,死藻和活藻的吸附效率有輕微的下降,但其吸附效率也分別達到96.4%和96.1%,吸附量分別達到16.87 mg·g-1和16.02 mg·g-1。4、小球藻對鎘的吸附作用受不同藻量的影響。不同藻生物量干重分別為0.18 mg、1.8 mg、18 mg,在藻生物量為0.18 mg時,吸附達到平衡后,死藻和活藻的吸附效率分別達到89.5%和87.3%,單位藻量的吸附量分別達到99.39 mg·g-1和97 mg·g-1,死藻的吸附效率明顯高于活藻,隨著藻生物量的增加,死藻和活藻的吸附效率都逐漸增大,但單位藻量的吸附量下降,在藻生物量為18 mg時,死藻和活藻對重金屬鎘的吸附效率可以達到95.5%和95.3%,單位藻量的吸附量為1.06 mg·g-1和1.05 mg·g-1�？梢钥闯�,此時死藻與活藻的吸附效率的差異不大。5、在自然污水中,小球藻對鎘也有較高的吸附效率,但對鎘的吸附量下降。在楊凌地區(qū)選取了某果廠、高干渠、后河和渭惠渠四處的污水,四個地區(qū)初始鎘濃度的大小順序為渭惠渠后河高干渠某果廠,在這四處污水樣中,死藻和活藻對重金屬鎘的吸附效率都隨鎘濃度的增加逐漸增大,且死藻的吸附效率高于活藻,本次研究中,在污水中,死藻與活藻的吸附效率最低分別為85.1%和61.6%,吸附量分別為0.009 mg·g-1和0.006 mg·g-1,最高可分別達到96.4%和90.8%,吸附量為0.053 mg·g-1和0.050 mg·g-1。6、小球藻對重金屬鎘吸附的動力學和熱力學分析,利用偽一階、偽二階和Elovich動力學方程對活藻和死藻對鎘的吸附進行動力學分析,結果表明死藻的吸附符合偽二階動力學方程,活藻的吸附則是符合偽一階動力學方程;利用2個二參數的熱力學方程(Langmuir和Freundlich方程)和2個三參數的熱力學方程(Spis和Khan方程)對吸附的熱力學進行分析,結果表明,死藻和活藻都符合三參數的Sips等溫線模型。
[Abstract]:Heavy metal pollution is one of the most serious water pollution, it is very important to treat and repair heavy metal wastewater and polluted water body. The treatment efficiency of heavy metal wastewater is low, the cost is high, and it is easy to form the pollution again. The biological absorption is a high efficiency and low price heavy metal treatment method. A large number of studies show that algae are Many kinds of metals have strong adsorption capacity. This study mainly involves two aspects: one is using Chlorella vulgaris as the research material, by analyzing its growth in different concentrations of cadmium, pigment (chlorophyll a, chlorophyll b, carotenoid), soluble protein, H2O2, and superoxide anion (O2). The changes in content and changes in the activity of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) were measured to determine the tolerance of Chlorella to cadmium. On the other hand, the different initial metal concentration, different algae biomass and different conditions in natural sewage were studied at different contact time of Chlorella living algae and dead algae. The adsorption capacity of cadmium by Chlorella was determined, and the kinetics and thermodynamics of cadmium adsorption on Chlorella were analyzed in order to provide a theoretical basis for the bioremediation of algae contaminated by heavy metals. The results were as follows: 1, at different concentrations of cadmium (0 mg. L-1,0.5 mg. L-1,1 mg, L-1,3 mg. L-1,5 m) Under the influence of G. L-1,7 mg. L-1, the inhibition of cadmium to Chlorella was mainly at high concentration (3-7 mg. L-1), and with the increase of concentration, the inhibition of chlorella growth gradually increased. The biomass of Chlorella decreased gradually with the increase of cadmium concentration. When the concentration of cadmium was 5 mg. L-1, Chlorella could also grow, but the concentration of cadmium was 7 mg L. At -1, Chlorella could hardly grow. With the increase of cadmium concentration, the content of chlorophyll a, chlorophyll b and carotenoid decreased. The contents of cadmium on chlorophyll a and carotenoid were significantly affected by different concentrations (P < 0.05); but the effect on chlorophyll b was not significant (P0.05). The content of soluble protein increased gradually with the increase of cadmium concentration. The content of hydrogen peroxide and superoxide anion increase gradually with the increase of cadmium concentration, and the content of hydrogen peroxide and superoxide anion increases with the concentration of cadmium. The activity of CAT, SOD, POD increases gradually with the increase of cadmium concentration, and the activity of SOD and CAT increases with the increase of cadmium concentration. The maximum value was reached when the concentration of cadmium was 0.5 mg L-1. The activity of POD activity reached the maximum when the concentration of cadmium was 5 mg L-1. As the concentration of cadmium continued to increase, the enzyme activity decreased gradually. It indicated that Chlorella had a good tolerance to cadmium, and the adsorption of Chlorella on cadmium was affected by different contact time. 100 mg. L-1 as the initial cadmium concentration, dead algae and living algae. The adsorption of cadmium on heavy metals was achieved in the first 5 minutes. At 5 minutes, the adsorption efficiency of cadmium by living algae and dead algae reached 95.2% and 96.8% respectively. The adsorption capacity of the heavy metal cadmium was 10.54 mg. G-1 and 10.77mg g-1. respectively. The adsorption efficiency of dead algae and living algae increased gradually, and reached the absorption in 105 minutes. With equilibrium, the adsorption efficiency of dead algae and living algae reached 98.1% and 96%, respectively, and the adsorption amount was 10.88 mg. G-1 and 10.64 mg. G-1., therefore, the adsorption efficiency and adsorption capacity of dead algae to cadmium were slightly higher than that of living algae.3. The adsorption of Chlorella on cadmium was affected by different initial cadmium concentration. 5 mg. L-1,10 mg. L-1,50 mg. L-1100 mg L-1150 mg / L-1 as the initial cadmium concentration, the adsorption efficiency of cadmium in dead algae and living algae reached 89.7% and 85.7% respectively at the concentration of cadmium in 5 mg. L-1. The adsorption capacity was 0.50 mg g-1 and 0.48mg. G-1 respectively. With the increase of initial cadmium concentration, the adsorption efficiency and adsorption capacity of living algae and dead algae increased gradually, at the initial concentration of 10. When -150 mg / L-1, the adsorption efficiency of algae changed little, but when the initial concentration was 150 mg. L-1, the adsorption efficiency of dead algae and living algae decreased slightly, but the adsorption efficiency reached 96.4% and 96.1% respectively, and the adsorption capacity reached 16.87 mg g-1 and 16.02 mg. G-1.4 respectively. The adsorption of Chlorella on cadmium was affected by different algae quantity. The dry weight of the biomass was 0.18 mg, 1.8 mg and 18 mg respectively. When the algae biomass was 0.18 mg, the adsorption efficiency of dead algae and living algae reached 89.5% and 87.3% respectively. The adsorption capacity of unit algae reached 99.39 mg. G-1 and 97 mg g-1 respectively. The adsorption efficiency of dead algae was significantly higher than that of living algae. The adsorption efficiency increased gradually, but the adsorption capacity of unit algae decreased. When the biomass of algae was 18 mg, the adsorption efficiency of cadmium in dead algae and living algae could reach 95.5% and 95.3%. The adsorption capacity of unit algae was 1.06 mg. G-1 and 1.05 mg. G-1.. The difference of adsorption efficiency between dead algae and living algae was not.5, in natural sewage. Chlorella also had high adsorption efficiency to cadmium, but the adsorption of cadmium decreased. In the Yangling area, a certain fruit plant, the high dry canal, the back River and the Wei Hui canal were selected. The order of the initial cadmium concentration in the four regions was a certain fruit plant in the Weihui river high dry canal, and the adsorption effect of dead algae and living algae on the heavy metal cadmium in the four polluted water samples With the increase of cadmium concentration, the adsorption efficiency of dead algae is higher than that of living algae. In this study, the adsorption efficiency of dead algae and living algae is 85.1% and 61.6%, respectively, the adsorption capacity is 0.009 mg. G-1 and 0.006 mg. G-1 respectively, the highest can reach 96.4% and 90.8% respectively, the adsorption amount is 0.053 mg. G-1 and 0.050 mg g-1.6, pellet. Kinetic and thermodynamic analysis of cadmium adsorption on heavy metals, the adsorption of cadmium on living algae and dead algae was analyzed by pseudo first order, pseudo two order and Elovich kinetic equation. The results showed that the adsorption of dead algae conformed to pseudo two order kinetic equation, and the adsorption of living algae was in accordance with the pseudo first order kinetic equation, and the thermal power of 2 two parameters was used. The thermodynamic equations (Langmuir and Freundlich equations) and 2 three parameters thermodynamic equations (Spis and Khan equations) were used to analyze the thermodynamics of adsorption. The results showed that both dead algae and living algae were in accordance with the three parameter Sips isotherm model.

【學位授予單位】：西北農林科技大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：X173;X703

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