微生物燃料电池—流动性电极电容去离子性能研究

发布时间：2018-03-04 12:13

本文选题：流动性电极　切入点：电容去离子　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着淡水资源的匮乏,海水淡化逐渐成为解决水资源危机的重要途径之一,在海水淡化的过程中,处理技术集中在热法和反渗透,但不可避免高能耗及高成本的代价。电容去离子吸附技术作为新启之秀,在水处理除盐应用领域广泛应用,而且具备一定的理论基础,但除盐效率有待提高,流动性电极电容去离子(FCDI)在近几年兴起,由于其操作简单,脱盐率较高而备受关注。本课题主要探索了流动性电极电容去离子脱盐的规律,并提出了微生物燃料电池脱氮产电驱动电容去离子这一观点。本文中对比了四种碳材料作为流动式电极的性能,分析其比表面积、孔结构、官能团及吸附动力学对性能的影响,选择性能良好的碳材料用于流动性电极电容去离子,结果表明:四种碳材料包括活性炭AC80、AC50、AC和石墨稀G400,相同操作条件下,AC80的脱盐率达到64%,而AC的脱盐率为48%,产生差异可能由于AC80微介孔含量较多,孔容丰富,比表面积较大,杂质较少,吸附性能较好。同时对比了各自吸附模型,由于FCDI设备中增加了离子交换膜,避免了同离子效应和阴阳离子的扩散,所以比传统电容去离子脱盐量和脱盐速率大,但离子交换膜的增加和碳材料电极的流动性,也导致离子并非稳定吸附在碳材料上,所以模拟的一级和二级动力学的相关性系数较小。为了考察流动性电容去离子中操作条件对除盐效果的影响,主要从电压、流速比(中间腔室:阴极腔室:阳极腔室)、速率、电极间距、两种碳材料的配比和多级串联等因素考虑。实验证明:电压为1.4V,低流速2.5m L/min,流速比(中间腔室:阴极腔室:阳极腔室)为1:2:2、电极板间距3mm、单一碳材料为AC80时,流动性电极电容去离子设备运行50min后,吸附量达到最大,并且在串联情况下,除盐量比单个模组提高17%左右,但是除盐速率降低,说明离子的路程增加会降低除盐速率。文中还考察了流动性电极电容对不同单一阳离子溶液中离子的去除,针对AC80对不同阳离子的吸附量由大到小依次为KClNaClCaCl_2AlCl_3,说明在单一阳离子溶液中,水合半径越小,吸附量越大。实验通过氮掺杂石墨烯催化阴极,研究了产电脱硝的机理,对比不同溶解氧下微生物燃料电池(MFC)的输出能量,改变燃料电池串并联的方式,驱动流动性电容去离子,结果表明:利用氮掺杂石墨烯催化阴极与裸电极对比,微生物燃料电池电压提升了50%,功率密度提升了80%,产电的性能稳定提升;在除氮过程中,去除率相同时,氨氮的去除时间逐渐缩短,氨氮的去除速率提升。溶解氧(DO)浓度从1mg/L增加4mg/L后,MFC稳定期电压从362m V增加到446m V,产电性能提升。随着溶解氧增大,氨氮加速降解,硝酸盐快速生成,溶解氧为4mg/L时,经75h后,NH_4~+去除率达到91.7%,NO_3~-积累量达到80.9mg/L。比较多级串并联方式的微生物燃料电池,电压和功率密度都得到提升,但并联的产电性能更加稳定,与流动性电极电容去离子技术结合,除盐率达到30%。
[Abstract]:With the scarcity of fresh water, sea water desalination has gradually become one of the important ways to solve the crisis of water resources, in the process of seawater desalination, heat treatment technology focused on the method and the reverse osmosis, but inevitably high energy consumption and high cost. The cost of capacitive deionization technology as a new start and adsorption of the show, in addition to widely used applications of salt water processing, but also has certain theoretical basis, but the desalting efficiency should be improved, the flow of electrode capacitive deionization (FCDI) rise in recent years, because of its simple operation, high desalination rate and concern. This paper mainly explores the fluidity of electrode capacitive deionization desalination law, and put forward the idea of microbial fuel battery nitrogen production electric drive. This paper compares the deionizaion performance of four kinds of carbon materials as electrode flow, analysis of the specific surface area, pore structure, adsorption kinetics and properties of functional groups The effects of carbon materials with good performance for mobile electrode capacitive deionization results showed that four kinds of carbon, activated carbon materials including AC80, AC50, AC and graphene G400, under the same operating condition, AC80 desalination rate reached 64%, while the AC desalination rate was 48%, the difference may be due to dielectric AC80 the hole more content, pore volume rich, larger surface area, less impurity, good adsorption performance. While comparing their adsorption model, because the FCDI device increases the ion exchange membrane, to avoid the same ion effect and ion diffusion, so compared with the traditional capacitive deionization desalination and desalination rate, but increased liquidity the ion exchange membrane and carbon electrodes, also lead ion adsorption in carbon materials is not stable, so the smaller correlation coefficient simulation of grade one and two dynamics. In order to study the liquidity from the capacitor to the operating conditions of the sub The effect of salt effect, mainly from the voltage, velocity ratio (intermediate chamber: cathode chamber: anode chamber), the rate of electrode spacing, considering two kinds of carbon materials and tandem and other factors. The experiment results show that the voltage is 1.4V, low velocity 2.5m L/min, velocity ratio (intermediate chamber: cathode anode chamber: the chamber) for 1:2:2, the distance between the two electrode plates 3mm, single carbon material is AC80, liquid electrode capacitive deionization device running 50min, the adsorption capacity reached the maximum, and in a series of cases, in addition to the amount of salt is 17% higher than a single module, but the desalting rate decreased, indicating an increase in ion distance will reduce the desalination rate. This paper also investigated the removal of ions of different single cations in solution of liquidity for the electrode capacitance, AC80 on the adsorption of different cations in descending order of KClNaClCaCl_2AlCl_3, explained in a single cation solution, the hydration radius is smaller, suction With greater volume. Through the experiment of nitrogen doped graphene cathode catalyst, studied the mechanism of producing electric denitration, comparison of different dissolved oxygen microbial fuel cell (MFC) of the output energy, change the fuel cell series parallel way, driven by liquidity deionizaion results showed that by contrast, nitrogen doped graphene cathode catalyst with the bare electrode, the microbial fuel cell voltage increased by 50%, 80% increase in power density, stable performance to enhance electricity production; in nitrogen removal process, the removal rate of ammonia nitrogen removal at the same time gradually shortened, the removal rate of ammonia nitrogen is promoted. The dissolved oxygen (DO) concentration increased from 1mg/L 4mg/L, MFC phase voltage increases from 362M V to 446m V, the electricity production increased. With the increasing of dissolved oxygen, ammonia nitrate accelerated degradation, rapid formation of dissolved oxygen was 4mg/L, after 75h, the removal rate of NH_4~+ reached 91.7%, the accumulation of NO_3~- reached 80.9mg/L. level The voltage and power density of microbial fuel cell in series and parallel connection have been improved, but the power generation performance of parallel connection is more stable. Combined with mobile electrode capacitor deionization technology, the desalting rate reaches 30%..

【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM911.45

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