养殖废水中洛克沙胂的生物电化学转化研究

发布时间：2018-03-05 17:20

本文选题：生物电化学体系　切入点：洛克沙胂　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：洛克沙胂(Roxarsone)作为饲料添加剂被广泛使用,畜禽经喂食后可以抑制肠道病原菌。动物体内大部分的洛克沙胂以原型随粪便排出。未经过恰当处理的养殖粪便废水会进入环境中,产生污染危险。洛克沙胂在厌氧环境中可以还原为3-氨基-4-羟基苯胂酸(HAPA)。而对其在电化学条件下的转化机理尚不清楚。本文通过探究洛克沙胂在生物电化学体系中的生物电化学转化过程来探究洛克沙胂生物转化的新途径。通过构建生物电化学污染物转化实验系统,本文研究了不同底物浓度,产电条件和产电环境共三种不同条件的电化学体系来模拟不同的自然环境条件下洛克沙胂在生物电化学体系中的生物电化学转化过程。主要结论如下:(1)富含有机物条件下洛克沙胂48 h转化了92.5%,生成9.29μmol/L的无机砷。此时希瓦氏菌通过三种方式来转化无机砷:氧化途径,还原途径和甲基化途径。低水平有机物条件下洛克沙胂48 h转化了92.5%,生成1.97μmol/L的无机砷。有机物水平对洛克沙胂转化为HAPA的影响不显著。(2)当生物量一定时,电化学体系的电极面积越大,其产电与电极面积关系越大,而阳极液中悬浮生物量影响越小;当电极面积固定时,生物量越大,其对电化学体系产电的影响就越大。洛克沙胂在电化学体系中的转化迁移过程为:阳极液中的洛克沙胂与附着在电极上的希瓦氏菌接触,在细胞表面被转化为HAPA,进而释放到阳极中,在阳极中与悬浮或附着的的希瓦氏菌接触,在电子的作用下,HAPA在希瓦氏菌细胞内被转化为多种砷产物。(3)在面积为6.3 cm~2-37.5 cm~2电化学串联系统,面积为6.3 cm~2的电极经48h洛克沙胂浓度降低至8.3μmol/L,且其8 h内转化效率提升2.8%;此外,面积为37.5 cm~2的电极经32 h反应,阳极液内洛克沙胂已转化完毕,且其8 h内转化效率提升30.2%。同时,面积为25.0 cm~2-25.0 cm~2电化学并联系统,洛克沙胂经32 h基本转化完成,8 h洛克沙胂转化效率均提升21.8%。此外,50.0 cm~2-0.0 cm~2电化学并联系统,面积为50.0 cm~2的电极反应至32 h时洛克沙胂转化完成,8 h洛克沙胂转化效率提升28.4%;然而,面积为0.0 cm~2的电化学体系反应周期结束时洛克沙胂浓度降低至0.02 mmol/L,且8 h洛克沙胂转化效率降低10%。
[Abstract]:Roxarsone (Roxarsone) is widely used as a feed additive, and livestock and poultry can inhibit intestinal pathogens after feeding. Most of roxarsone in animals is excreted in their faeces by prototyping. Waste water from untreated aquaculture dung enters the environment. Roxarsone can be reduced to 3-amino-4-hydroxyphenylarsonic acid HAPA4 in anaerobic environment, but the mechanism of its conversion under electrochemical conditions is not clear. In this paper, the mechanism of roxarsone in bioelectrochemical system is not clear. To explore a new way of biotransformation of roxarsone. In this paper, we have studied different substrate concentrations, There are three different electrochemical systems of electricity generation and electricity producing environment to simulate the bioelectrochemical transformation of roxarsone in different natural environment. The main conclusions are as follows: 1) rich in organic matter. Under the conditions of roxarsone for 48 h, 92.5% inorganic arsenic was transformed into 9.29 渭 mol/L inorganic arsenic. At this time, Shiva strain transformed inorganic arsenic in three ways: oxidation pathway. Reduction pathway and methylation pathway. Under low organic level, roxarsone was transformed into 92.5% inorganic arsenic at 48 h, resulting in inorganic arsenic of 1.97 渭 mol/L. The effect of organic level on the transformation of roxarsone to HAPA was not significant. The larger the electrode area of the electrochemical system, the greater the relationship between the electrode area and the generation of electricity, while the less the effect of suspended biomass in the anode solution is, the greater the biomass is when the electrode area is fixed. The transformation and migration of roxarsone in the electrochemical system are as follows: the roxarsone in the anodic solution is in contact with the Shiva bacteria attached to the electrode. It is converted to HAPA on the cell surface and released into the anode, where it is in contact with the suspended or attached Shiva bacteria. In a 6.3 cm~2-37.5 cm~2 electrochemical series system, the electrode with an area of 6.3 cm~2 was reduced to 8.3 渭 mol 路L ~ (-1) after 48 h roxarsone concentration, and the conversion efficiency was increased by 2.8% in 8 h. After 32 h reaction of 37.5 cm~2 electrode, roxarsone in anodic solution was converted, and the conversion efficiency was increased by 30.2% within 8 h. Meanwhile, the electrochemical parallel system with an area of 25.0 cm~2-25.0 cm~2 was obtained. The conversion efficiency of roxarsone was increased by 21.8% after 32 h basic transformation. In addition, the 50.0 cm~2-0.0 cm~2 electrochemical parallel system was used to improve the efficiency of roxarsone conversion. At the electrode area of 50.0 cm~2 to 32 h, the conversion efficiency of roxarsone was increased by 28.4when roxarsone was transformed into roxarsone at 8 h. The concentration of roxarsone decreased to 0.02 mmol / L at the end of the reaction cycle with an area of 0.0 cm~2, and the conversion efficiency of roxarsone decreased by 10% at 8 h.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X713

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