微生物燃料电池同步脱氮除磷及产电性能研究

发布时间：2018-05-07 18:02

本文选题：微生物燃料电池 + 溶解氧　；参考：《华南理工大学》2015年博士论文

【摘要】：微生物燃料电池(Microbial fuel cell,MFC)能够有效处理污水同时实现产能,近年来广受关注。本课题结合MFC研究现状,以提高MFC电能输出和污水处理能力为目标,研究了反应器构型、阴极室溶解氧、外加磁场对MFC脱氮除磷和产电性能的影响,并对氨氮燃料MFC产电性能和氨氮抑制作用做了研究,最后用MFC结合微波法处理实际污水——垃圾渗滤液。主要成果如下:单室MFC和双室MFC都有脱氮除磷效果,但去除效率和机理均不同。单室MFC中总磷(Total phosphorus,TP)和总氮(Total nitrogen,TN)去除率分别为43.9%和53.8%,且主要是以在阴极表面形成针状磷酸铵镁晶体的形式被去除的。双室MFC阳极室对TP和TN去除不明显,其阴极表面也没有形成磷酸铵镁晶体。双室MFC阴极室中TP去除率达到了94%,是化学沉降和微生物吸收共同作用的结果,阴极室中形成的化学沉淀物是磷酸化合物、碳酸化合物和羟基化合物等物质的混合物。双室MFC中大部分的NH4+-N都在阴极室中被氧化成了NO2--N,但TN去除量较少。单室MFC和双室MFC中化学需氧量(Chemical oxygen demand,COD)去除率分别为66%和79%。单室MFC和双室MFC的最大输出电压、最大面积功率密度、内阻、库伦效率分别为443和524 m V、560和528 m W/m2、181和227Ω、35%和51%。阴极室溶解氧是MFC产电和污水处理的重要影响因素。阴极室溶解氧由3.5 mg/L下降至2.0 mg/L时,MFC最大输出电压、库伦效率、最大面积功率密度分别由521 m V、52.48%、530 m W/m2下降至303 m V、23.09%、178 m W/m2。4种阴极室溶解氧条件下MFC中TP去除率均85%,其中约80%是被化学沉降作用去除的,约4%-17%是被微生物吸收作用去除的。当阴极室溶解氧浓度为3.5和2.8 mg/L,TN去除率很低,大部分NH4+-N都在阴极室被氧化成了NO2--N;当阴极室溶解氧浓度为2.5和2.0 mg/L,TN去除率85%。COD去除率受阴极室溶解氧影响较小,阳极室中COD的去除率70%,阴极室中COD的去除率5%。4种阴极室溶解氧条件下MFC阴极室中生成的化学沉淀物是磷酸化合物、碳酸化合物和羟基化合物的混合物。给MFC外加低强度的稳恒磁场会提高其产电性能和污水处理能力。当MFC外加50 m T的磁场时,MFC的最大输出电压、TP去除率、COD去除率分别由523±2 m V、~93%、~80%上升至553±2 m V、~96%、90%,同时启动时间和库伦效率分别由16 d和~50%下降至10 d和~43%。外加磁场对TN去除无明显促进作用,但磁场MFC中NH4+-N转化率更高,硝化反应也进行的更彻底。MFC的启动速度和输出电压受磁场方向影响较小。磁场对MFC产电及污水处理效果的影响是快速、可逆、不可持续的。如将外加磁场突然从MFC撤离,会对MFC产电及COD去除起反作用,但对氮磷去除及氮的转化没有反作用。氨氮可作为MFC的间接电子供体,但不能作为直接电子供体。当MFC中无有机碳源时,以NH4Cl、KNO2、KNO3、KNO2和Na NO3、NH4Cl和Na NO3为氮源,MFC均无电压输出,且MFC中氮元素的量和形态都无明显变化。以NH4Cl(20 m M)和KNO2(10 m M)混合物为氮源时,MFC有少量电压输出,且最大输出电压随着KNO2浓度的增加由18.1 m V上升至32.5 m V,出水中NH4+-N和NO2--N浓度大幅度降低,并含有一定量的NO3--N。证实了MFC中厌氧氨氧化(Anaerobic ammonium oxidation,ANAMMOX)反应的发生,MFC产电是厌氧氨氧化菌(ANAMMOX bacteria,An AOB)和一些异养产电菌协同完成的,NH4+-N是产电过程中的间接电子供体。另外,MFC电压输出滞后ANAMMOX反应一段时间,进一步表明NH4+-N是MFC间接电子供体。NH4+-N扩散和NH3挥发是MFC中NH4+-N损耗的重要途径,相比无电压输出MFC,有电压输出MFC中扩散和挥发等作用消耗的NH4+-N量更多。在一定浓度范围内,提高氨氮浓度有助于增加MFC电压输出、最大功率密度和COD去除率。当氨氮浓度大于100 m M时,MFC中微生物活性受到严重抑制,MFC产电性能和污水处理效果显著下降。当氨氮浓度为50 m M时,MFC输出电压和COD去除率分别达到最大值555 m V和82%。当氨氮浓度为100 m M时,MFC最大功率密度达到最大值602 m W/m2。随着微波辐照时间的延长和功率的增大,垃圾渗滤液的p H、五日生化需氧量(Five days biochemical oxygen demand,BOD5)、BOD5/COD逐渐增大,垃圾渗滤液的可生化性能逐渐增强,电导率、COD、NH4+-N值逐渐减小。选择BOD5/COD0.3经微波法前处理后的垃圾渗滤液为MFC燃料,MFC的启动速度加快了,输出电压和最大面积功率密度增大了,内阻增大了,库伦效率降低了,脱氮除碳效果明显增强。垃圾渗滤液的BOD5/COD值越高MFC产电性能不一定会更好,MFC的产电性能还与电导率等其它因素有关。垃圾渗滤液微波处理前后,MFC中TP去除效果差别不大。较优微波前处理条件为微波功率210 W辐照15 min和微波功率350 W辐照5min。
[Abstract]:Microbial fuel cell (MFC) can effectively deal with sewage and realize production capacity. In recent years, the subject is concerned with the present situation of MFC research. In order to improve the capacity of MFC power output and sewage treatment, the effects of reactor configuration, cathode chamber dissolved oxygen and magnetic field on the performance of nitrogen and phosphorus removal and electricity production of MFC are studied. The effect of ammonia nitrogen fuel MFC production and ammonia nitrogen inhibition was studied. Finally, the actual sewage - garbage leachate was treated with MFC combined with microwave method. The main results are as follows: single room MFC and double chamber MFC have the effect of denitrification and phosphorus removal, but the removal efficiency and mechanism are different. The total phosphorus (Total phosphorus, TP) and total nitrogen (Total nitrogen, TN) in single room MFC are different. The removal rates are 43.9% and 53.8%, respectively, which are mainly removed from the form of acicular magnesium phosphate on the cathode surface. The removal of TP and TN in the double chamber MFC anode chamber is not obvious, and the surface of the cathode has not formed magnesium ammonium phosphate. The removal rate of TP in the double chamber MFC cathode chamber is 94%, which is the common effect of chemical deposition and microbial absorption. As a result, the chemical precipitates formed in the cathode chamber are mixtures of phosphoric acid compounds, carbonates and hydroxyl compounds. Most of the NH4+-N in the double chamber MFC is oxidized to NO2--N in the cathode chamber, but the removal of TN is less. The removal rate of chemical oxygen demand in single chamber MFC and double chamber MFC (Chemical oxygen demand, COD) is 66%, respectively. The maximum output voltage of 79%. single chamber MFC and double chamber MFC, maximum area power density, internal resistance, Kulun efficiency 443 and 524 m V respectively, 560 and 528 m W/m2181 and 227 Omega, 35% and 51%. cathode chamber dissolved oxygen are important factors affecting the MFC production and sewage treatment. The maximum output voltage of the cathode chamber dissolved oxygen from 3.5 mg/L to 2 mg/L, the maximum output voltage of MFC. The maximum area power density decreased from 521 m V, 52.48%, 530 m W/m2 to 303 m V, 23.09%, 178 m W/m2.4 cathode chamber dissolved oxygen in MFC 85%, of which about 80% were removed by chemical deposition, and 4%-17% was removed by microbial absorption, when the concentration of dissolved oxygen in the cathode chamber was 3.5 and 2.8 mg/L. The removal rate is very low, most of the NH4+-N are oxidized to NO2--N in the cathode chamber; when the concentration of dissolved oxygen in the cathode chamber is 2.5 and 2 mg/L, the 85%.COD removal rate of the TN removal rate is less affected by the dissolved oxygen in the cathode chamber, the removal rate of COD in the anode chamber is 70%, and the removal rate of COD in the cathode chamber 5%.4 is produced in the cathode chamber of the cathode chamber in the MFC cathode chamber under the condition of dissolved oxygen. The sediment is a mixture of phosphoric acid compounds, carbonates and hydroxyl compounds. The low strength and stability of the magnetic field for MFC will improve its electrical performance and sewage treatment ability. When MFC plus 50 m T magnetic field, the maximum output voltage of MFC, TP removal rate, COD removal rate from 523 + 2 m V, ~93%, ~80% to 553 + 2 m, 90%, simultaneously, simultaneously, simultaneously, 90%, simultaneously, simultaneously, 90%, simultaneously, simultaneously, 90%, simultaneously, simultaneously, 90%, simultaneously, simultaneously, simultaneously, 90%, simultaneously, simultaneously The starting time and Kulun efficiency decreased from 16 D and ~50% to 10 D and ~43%. applied magnetic field to TN removal, but the NH4+-N conversion rate in magnetic field MFC was higher. The starting speed and output voltage of the nitrification reaction were less affected by the direction of the magnetic field. The effect of magnetic field on the output of MFC and sewage treatment was fast. Speed, reversibility, unsustainable. If the external magnetic field is suddenly evacuated from MFC, it will react to MFC production and COD removal, but has no reaction to nitrogen and phosphorus removal and nitrogen conversion. Ammonia nitrogen can be used as an indirect electron donor for MFC, but not as a direct electron donor. When MFC has no organic carbon source, NH4Cl, KNO2, KNO3, KNO2 and Na NO3, NH4Cl and Na NO3 is a nitrogen source and MFC has no voltage output, and there is no obvious change in the amount and form of nitrogen elements in MFC. When the mixture of NH4Cl (20 m M) and KNO2 (10 m M) is the nitrogen source, MFC has a small amount of voltage output, and the maximum output voltage rises to 32.5 with the increase of KNO2 concentration from 18.1 m. The quantitative NO3--N. confirmed the reaction of anaerobic ammonia oxidation (Anaerobic ammonium oxidation, ANAMMOX) in MFC, and MFC production was completed by anaerobic ammonia oxidizing bacteria (ANAMMOX bacteria, An AOB) and some heterotrophic bacteria, and NH4+-N was an indirect electron donor in the process of electricity production. One step indicates that NH4+-N is an important way for the.NH4+-N diffusion and NH3 volatilization of the MFC indirect electron donor and the NH4+-N loss in MFC. Compared with the non voltage output MFC, the amount of NH4+-N consumed by the diffusion and volatilization in the voltage output MFC is more. In a certain concentration range, the increase of ammonia nitrogen concentration is helpful to increase the output of MFC voltage, maximum power density and COD. When the concentration of ammonia is greater than 100 m M, the microbial activity in MFC is severely inhibited, the output of MFC and the treatment effect of wastewater decrease significantly. When the ammonia nitrogen concentration is 50 m M, the maximum value of MFC output voltage and COD removal rate is 555 m V and 82%. when ammonia nitrogen concentration is 100 m. The maximum power density reaches the maximum value of 602 With the prolongation of microwave irradiation time and increasing power, the P H of landfill leachate, Five days biochemical oxygen demand, BOD5, BOD5/COD gradually increased, the biodegradability of the landfill leachate increased gradually, the conductivity, COD, NH4+-N value gradually decreased. When the liquid is MFC fuel, the starting speed of the MFC is accelerated, the output voltage and the maximum area power density increase, the internal resistance is increased, the efficiency of Kulun is reduced, the effect of denitrification and removal of carbon is obviously enhanced. The higher the BOD5/COD value of the landfill leachate is, the power production performance of the MFC is not necessarily better. The electrical property of MFC is also related to other factors such as electrical conductivity and other factors. Landfill leachation Before and after microwave treatment, the effect of TP removal in MFC was not very different. The best microwave pretreatment conditions were microwave power 210 W irradiation 15 min and microwave power 350 W irradiation 5min.

【学位授予单位】：华南理工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：X703;TM911.45

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