生物碳结构特性及其联合藻类修复水体研究

发布时间：2018-01-02 08:11

本文关键词：生物碳结构特性及其联合藻类修复水体研究　出处：《河北工程大学》2017年硕士论文　论文类型：学位论文

【摘要】：生物碳是农业废弃生物质经裂解制备的富含有机碳和矿物质、结构复杂的碳材料。生物碳含有丰富的矿物质元素可以为植物生长提供养分,常被用于土壤改良剂。另外生物碳含有丰富的含氧官能团,也常用于污染环境修复。但是关于生物碳的老化过程及其老化过程中溶出物对水生生物的影响的研究还十分少。除此之外,小球藻也常被用作环境修复材料,生物碳与小球藻同时存在时,关于两者的吸附性相互影响的研究还是空白。本文在以下四方面对生物碳进行了研究:采用不同温度制备生物碳,研究其组成结构及物理化学性质;使用水洗方法模拟生物碳老化过程,测定生物碳中主要元素的溶出量,并对老化后生物碳进行表征;使用生物碳滤出液培养小球藻,研究不同滤出液对小球藻生长的影响;生物碳与小球藻联合吸附重金属铅。主要结论如下:(1)随着裂解温度的升高,生物碳的pH值升高,产率逐渐下降,灰分含量增大,生物碳的芳香性增加、极性降低、亲水性下降,且小麦秸秆生物碳的产率和灰分含量均小于水稻秸秆生物碳。(2)生物碳老化过程中,生物碳滤出液的pH值呈下降趋势,生物碳中碳、硅、钾的溶出量先是快速下降,然后逐渐减少,最后溶出量趋于平稳。但是氮的溶出量是先较少溶出,在水洗第8次时迅速上升,在第10次左右均达到最大溶出量后又开始快速下降,在第15次过滤之后的溶出量较平稳。水洗过程将生物碳表面含硅矿物去除了,生物碳的结构被破坏,使得生物碳的表面变得蓬松。(3)生物碳滤出液可以为小球藻提供必需的营养元素,如碳、氮等。有机碳含量和培养液的pH是影响小球藻的主要因素。低温生物碳(WS300和RS300)溶出的有机碳量较大,另外其pH接近中性,较适合小球藻生长。(4)小麦秸秆生物碳和小球藻的等温吸附曲线均符合Langmuir拟合方程。生物碳与小球藻联合吸附比单独吸附的吸附效果好,小球藻的吸附平衡时间较短,在初始溶液中Pb较低时,小球藻基本可以完全吸附Pb。随着初始溶液中Pb浓度的升高,生物碳可以吸附小球藻吸附剩余的Pb,生物碳与小球藻的单独吸附时对Pb的去除率之和约等于联合吸附。
[Abstract]:Biological carbon is a kind of carbon material which is rich in organic carbon and minerals and has complex structure, which can provide nutrients for plant growth. It is often used as a soil modifier. In addition, biological carbon is rich in oxygen-containing functional groups. But there are few studies on the aging process of biological carbon and the effects of dissolved substances on aquatic organisms. In addition, Chlorella vulgaris is also often used as an environmental remediation material. When biocarbon and Chlorella microphylla exist at the same time, the study on the interaction between biocarbon and Chlorella spp is still blank. In this paper, the following four aspects of biological carbon were studied: using different temperatures to prepare biological carbon. Its composition structure and physicochemical properties were studied. The water washing method was used to simulate the biological carbon aging process, to determine the dissolution of the main elements in the biological carbon, and to characterize the aging biological carbon. The effects of different filtrates on the growth of Chlorella vulgaris were studied by using biological carbon filtrate to culture Chlorella vulgaris. The main conclusions are as follows: with the increase of decomposition temperature, the pH value of biological carbon increases, the yield decreases, the ash content increases, and the aromaticity of biological carbon increases. When the polarity decreased and hydrophilicity decreased, and the yield of biomass carbon and ash content of wheat straw were lower than those of rice straw, the pH value of biocarbon filtrate decreased. The dissolved amount of carbon, silicon and potassium in biological carbon first decreased rapidly, then gradually decreased, and finally the amount of dissolved nitrogen tended to be stable. However, the amount of nitrogen dissolved was less, and increased rapidly at the eighth time of washing. After 10 ~ (th) maximum dissolution, it began to decrease rapidly, and after the 15 ~ (th) filtration, the dissolved amount was relatively stable. The structure of the biological carbon was destroyed by the removal of silicon-containing minerals on the surface of the biological carbon during the washing process. Make the surface of biological carbon fluffy. 3) Biocarbon filtrates can provide essential nutrients such as carbon for Chlorella sp. Nitrogen and so on. Organic carbon content and pH of culture medium are the main factors affecting Chlorella vulgaris. Low temperature biological carbon WS300 and RS300) dissolving organic carbon amount is larger, and its pH value is close to neutral. The isothermal adsorption curves of wheat straw biological carbon and Chlorella microphylla all accord with Langmuir equation. The adsorption effect of biocarbon combined with Chlorella vulgaris is better than that of single adsorption. The adsorption equilibrium time of Chlorella microphylla is short. When Pb is low in the initial solution, Chlorella spp can completely adsorb Pb with the increase of Pb concentration in the initial solution. Biocarbon can adsorb the residual Pb of Chlorella microphylla, and the total removal rate of Pb by the single adsorption of biocarbon and Chlorella is about equal to that of the combined adsorption.
【学位授予单位】：河北工程大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X52

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