电极面积对老龄垃圾渗滤液为底物的微生物燃料电池性能影响

构建生物阴极型双室微生物燃料电池,处理老龄垃圾渗滤液。研究了阳极与阴极面积比值对微生物燃料电池产电能力和对老龄垃圾渗滤液处理效果的影响。结果表明,阳极与阴极面积比为1:2、2:2、2:1的3组生物阴极型微生物燃料电池输出电压分别为408、452、396mV,最大电功率密度分别为145.73、237.65、136.50mW/m³,内阻分别为350、200、400Ω,COD的去除率分别为21.18%、20.20%、22.31%。3组微生物燃料电池运行30d后,垃圾渗滤液中氨氮、硝酸盐氮、亚硝酸盐氮浓度均下降,其中,氨氮去除率分别为80.88%、73.61%和66.17%,其去除效果与产电性能相关。     

电化学法改性阳极对MFC性能的影响

采用不同质量分数的NH_4NO_3和(NH_4)_2S_2O_8溶液作为电解液,对双室微生物燃料电池的阳极炭布进行改性。以餐厨废水作为阳极底物,以K_3[Fe(CN)_6]和NaCl混合溶液为阴极液,考察不同电解液改性阳极条件下微生物燃料电池的产电性能及污水处理效果。结果表明,采用NH_4NO_3或(NH_4)_2S_2O_8改性炭布作为阳极的微生物燃料电池的发电性能和水处理效果均有改善。其中,采用质量分数为4%的(NH_4)_2S_2O_8溶液作为阳极改性电解液时,微生物燃料电池系统的产电性能达到最佳,其稳态电流密度约为60 m A/m~2,COD去除率约为42.5%。     

固定化微生物处理垃圾渗滤液

重点研究了固定化微生物处理垃圾渗滤液时的处理结果以及主要性能．通过对进水与出水COD及氨氮等指标进行检测分析,研究了固定化微生物对COD和氨氮的高效去除效果．并采用GC—MS对处理前后的垃圾渗滤液组分进行定性分析,同时利用Kjeldahl’s法测定了高效微生物菌群在载体上的生物负载量,最后采用电子显微镜观察了固定化微生物的形态．研究结果表明：采用固定化微生物处理渗滤液,COD和氨氮去除率分别达到98．3％和99．9％．处理后的垃圾渗滤液组分中有机物大量减少,生物负载量为38g·L^-1,丝状微生物较为发达．而且200mg·L^-1以上的氨氮以及150mg·L^-1以上的NH3对硝化菌及亚硝化菌没有抑制作用．在有机负荷较高的情况下,固定化微生物仍具有较好的硝化作用．还在相同条件下与游离微生物性能进行了比较,说明固定化微生物技术在各个方面所表现出的性能较后者具有明显的优势．     

阴极催化剂对微生物燃料电池性能的影响

以不同载量的MnO_2/rGO和Pt/C修饰阴极电极构建了生物阴极型双室微生物燃料电池(MFC),考察了不同阴极催化剂修饰MFC对其产电性能以及老龄垃圾渗滤液主要污染物去除效果的影响。结果表明,以MnO_2/rGO修饰MFC阴极电极材料,能显著提高MFC产电性能及对老龄垃圾渗滤液中污染物去除效果;输出电压为372 mV,功率密度为194 mW/m~3(是未经催化剂修饰MFC的两倍),内阻为264Ω,化学需氧量(COD)和氨氮(NH_3-N)去除率分别为58.68%和76.64%。当MnO_2/rGO载量为.0 mg/cm~2时,MFC性能与负载Pt/C的MFC性能接近,但构建成本却明显降低。     

氧化钙改性高岭土对垃圾渗滤液中氨氮的去除研究

采用氧化钙对高岭土进行改性,并用XRD、SEM和FT-IR对改性高岭土进行了表征。将改性高岭土应用于垃圾渗滤液的处理,考察了改性高岭土投加量、渗滤液初始pH、时间等因素对氨氮去除效果的影响,并对其吸附机理进行了研究。结果表明,氧化钙改性高岭土的产物主要是胶凝材料水化物(硅铝酸钙和含Al的C-S-H凝胶),形貌为蜂窝状;向氨氮含量为3520mg/L、pH为7.53~7.80的垃圾渗滤液中投加160g/L吸附剂,吸附60min,氨氮的去除率达82.66%,吸附量为18.19mg/g。氧化钙改性高岭土对氨氮的吸附符合Langmuir等温模型,动力学上符合准二级动力学方程,其相关系数分别为0.9678,0.9989。同时,该吸附过程包含了膜扩散和颗粒内扩散。     

共基质改善MFC处理链霉素废水及产电性能的研究

以K_3[Fe(CN)_6]和NaCl混合溶液为阴极液,以驯化的人工湖泊底泥为微生物菌种,以链霉素废水为阳极液,构建微生物燃料电池实验系统,研究添加共基质前后微生物燃料电池的废水处理效果与同步发电性能。结果表明,以链霉素废水为阳极液的微生物燃料电池的产电能力及废水处理效果均较差,并且随着链霉素浓度的增大而进一步恶化;但将葡萄糖作为共基质添加至阳极链霉素废水后,微生物燃料电池的产电能力和废水处理效果均显著提高。链霉素浓度为50 mg/L时,未添加共基质的微生物燃料电池处理链霉素废水的COD去除率为52%,产电电流密度为25 m A/m~2,输出电压为4.72 m V;添加共基质后,COD去除率为92%,稳态产电电流密度为300 m A/m~2,稳态输出电压为54 m V。     

La-Ti/SnO2-Sb/RuO2-Co电极制备及其处理垃圾渗滤液研究

以纯钛为基体材料,并以热氧化的方式制备La-Ti/SnO_2-Sb/RuO_2-Co电极,采用X-射线衍射仪(XRD)、扫描电子显微镜(SEM)及X-射线能量色散谱(EDS)对电极涂层表面形貌和晶体结构进行表征。采用制备的La-Ti/SnO_2-Sb/RuO_2-Co电极作为阳极,不锈钢为阴极,构建电化学反应器,对老龄垃圾渗滤液进行降解。结果表明在电流密度为65 mA/cm~2、Cl-浓度为4 500 mg/L、初始pH=9和反应时间为6 h的最佳反应条件下,La-Ti/SnO_2-Sb/RuO_2-Co电极对NH_3-N和COD的去除率分别达到86.5%、61%。     

微生物燃料电池多孔阳极的制备及阳极改性研究

以石墨粉为阳极基体,使用相转换法,制备了一种孔隙梯度分布的多孔阳极材料。将这种阳极组装为双室型微生物燃料电池进行电化学性能测试。另外,在阳极中添加了10%石墨质量比的聚苯胺,对阳极进行改性。相转换的改性方式能够使聚苯胺与阳极颗粒均匀混合,保证了改性的效率。电化学测试结果表明,单纯石墨阳极的功率密度为26.3mW·m~(-2)。而添加了聚苯胺后,功率密度提高到了80.2mW·m~(-2)。阻抗谱测试也显示,添加聚苯胺后的阳极,其欧姆阻抗与界面阻抗均有一定程度的降低。     

垃圾渗滤液的处置及资源化利用现状

分析了我国垃圾无害化处理处置现状,指出卫生填埋存在一系列问题。综述了垃圾渗滤液的组成及性质,对比分析了生物处理技术、物化处理技术以及土地处理技术的机理及其优缺点,其中传统的垃圾渗滤液处理处置工艺不利于垃圾处理行业健康发展。列举说明垃圾渗滤液的资源化利用现状,展望了垃圾渗滤液在能源、农业以及工业领域的应用,提出通过从垃圾渗滤液中提取腐殖酸等物质生产肥料的方式,不仅可以实现垃圾渗滤液的资源化利用,且具有良好的经济效益。     

化学修饰炭黑在微生物燃料电池中的生物产电行为

研究发现微生物燃料电池从启动到稳定运行的过程中往往存在一种现象,就是在高电流密度下,微生物燃料电池的输出电压会出现逆转,从而限制了微生物燃料电池的规模化应用,以及它在污废水处理、脱盐等方面的功能.
　　前期研究发现,微生物燃料电池的性能逆转现象与阳极材料的电容性能有关.电极材料的电容越大,越有利于微生物燃料电池的产电性能稳定,换言之,阳极材料电容不足导致产电性能逆转.但是超级电容活性炭的制作工艺繁琐,成本高,且导电性弱,不能满足微生物燃料电池的应用需求.炭黑的导电能力强、化学稳定性高、成本低,但作为微生物燃料电池的阳极则产生产电性能逆转现象.
　　化学修饰(如酸、碱活化或者添加具有赝电容性质的金属氧化物等)可以提高材料的电容性能.低温条件(80 oC)下,对低电容材料—炭黑进行HNO3和KOH的化学活化处理,并在此基础上,进一步用5%Fe3O4修饰,采用辊压工艺,以质量分数为60%的聚四氟乙烯乳液为粘结剂,制作微生物燃料电池的阳极,与空气阴极构建单室微生物燃料电池系统.采用傅里叶变换红外光谱(FTIR)、比表面积测试、材料表面pH和X射线能量分析光谱(EDX)等手段表征炭黑活化前后的物理、化学性质;接触角润湿性测试表征活化前后电极表面的亲疏水性.电化学循环伏安法测试活化前后,电极的电子存储能力.
　　与蒸馏水的pH相比较,材料表面pH分析表明炭黑材料经化学活化处理后,其表面pH无明显变化; FTIR和EDX测试表明化学活化处理使得炭黑表面引入含O(N)官能团;吸附-脱附曲线分析表明化学活化后,炭黑的比表面积减小,微孔与介孔的体积比增加;接触角测试表明炭黑阳极活化处理后,电极表面亲水性增加;循环伏安测试证实,化学活化后的炭黑阳极电容得到0.1–0.8 F/cm2的增长.结合燃料电池的产电性能测试,发现只有当炭黑阳极电容不小于1.1 F/cm2时,微生物燃料电池的产电逆转现象才会消失.炭黑阳极的化学活化方法为微生物燃料电池的性能稳定提供了一种简便、低成本的方法.     

Municipal Solid Waste Landfill Leachate Treatment and Electricity Production Using Microbial Fuel Cells

Microbial fuel cells were designed and operated to treat landfill leachate while simultaneously producing electricity. Two designs were tested in batch cycles using landfill leachate as a substrate without inoculation (908 to 3,200 mg/L chemical oxygen demand (COD)): Circle (934 mL) and large-scale microbial fuel cells (MFC) (18.3 L). A total of seven cycles were completed for the Circle MFC and two cycles for the larger-scale MFC. Maximum power densities of 24 to 31 mW/m² (653 to 824 mW/m³) were achieved using the Circle MFC, and a maximum voltage of 635 mV was produced using the larger-scale MFC. In the Circle MFC, COD, biological oxygen demand (BOD), total organic carbon (TOC), and ammonia were removed at an average of 16%, 62%, 23%, and 20%, respectively. The larger-scale MFC achieved an average of 74% BOD removal, 27% TOC removal, and 25% ammonia reduction while operating over 52 days. Analysis of the microbial characteristics of the leachate indicates that there might be both supportive and inhibiting bacteria in landfill leachate for operation of an MFC. Issues related to scale-up and heterogeneity of a mixed substrate remain.     

Application of Catalytic Wet Air Oxidation to Treatment of Landfill Leachate on Co／Bi Catalyst

Catalytic wet air oxidation(CWAO) was employed to reduce the organic compounds in landfill leachate and the effects of temperature, oxygen pressure, catalyst dosage, and concentration of the organic compounds on the TOC and CODcr removal rates were studied. The degradation kinetics of landfill leachate was also investigated and an exponential experiential model consisting of four influential factors was established to describe the reduction of the organic compounds in the landfill leachate. Meanwhile, the GC-MS technique was used to detect the components of the organic intermediates for the inference of the decomposition mechanisms of the organic compounds in landfill leachate. The results reveal that the reaction temperature and the catalyst dosage are the most important factors affecting the degradation reaction of the organic compounds and that the principal intermediates confirmed by GC-MS are organic acids at a percentage of more than 88% with no aldehydes or alcohols detected. The decomposition mechanisms of the organic compounds in landfill leachate were inferred based on the GC-MS information as follows;the activated gas phase O2 captured the hydrogen of the organic pollutants to produce free radicals, which then initiated the catalytic reaction. So most of the organic compounds were oxidized into CO2 and H2O ultimately. In general, catalytic wet air oxidation over catalyst Co3O4/Bi2O3 was a very promising technique for the treatment of landfill leachate.     

Comparative Study of Electrochemical Performance and Microbial Flora in Microbial Fuel Cells by Using Three Kinds of Substrates

This work aimed to investigate the distinct electrochemical performance and microbial flora of microbial fuel cells(MFCs)in relation to different single hazardous fed fuels.Three replicate MFCs were inoculated with the same microbial consortium from a coking wastewater treatment plants wherein ammonium chloride(ammoniiim chlo-ride-fed MFC,N-MFC),phenol(phenol-fed MFC,P-MFC)and potassium sulphide(potassium sulphide-fed MFC,S-MFC)were the sole substrates and main components of real coking wastewater.With initial concentrations of am-monium chloride,phenol and potassium sulphide of 0.75,0.60 and 0.55 g/L,the removal efficiencies reached 95.6%,90.6%and 99.9%,respectively,whereas the peak output power densities totalled 697,324 and 1215 mW/m^2.Micro-bial community analysis showed that the respective addition of substrate substantially altered the microbial community structure of anode biofllm,resulting in changes in relative abundance and emergence of new strains and further affecting the electrochemical properties of MFCs.The chemical oxygen demand(COD)removal efficiency of real coking wastewater,in which,the inoculum was the combined biomass from the three MFCs,reached 82.3%.     

Treatment of mature landfill leachate by a continuous modular internal micro-electrolysis Fenton reactor

A modular internal micro-electrolysis Fenton reactor (MIME-Fenton) was specifically designed in order to facilitate the performance of internal micro-electrolysis (IME) technology in the treatment of mature landfill leachate. Excellent COD removal efficiency of 90.9 % by the new reactor of mature landfill leachate was observed in bench-scale treatment, which is 193–399, 415–551, and 226–457 % higher than that of conventional treatments of electrolysis, coagulation–sedimentation, and Fenton, respectively. The innovative concept behind the excellent performance is the novel two-step treatment, similar to the anaerobic–aerobic activated sludge method. It is based on a combination effect of reductive IME and oxidative IME with aeration processes and the integration of electro-aggregation and electro-coagulation. Initial pH and air flow rate were optimized, and the effect of auxiliary in situ regeneration of ferrous iron and generation of H₂O₂ was further investigated. The reactor was also particularly efficient in removal of color and HA, and in improvement of the BOD₅/COD ratio. All these results show that the MIME-Fenton reactor, a new approach of IME, is promising for mature landfill leachate treatment because it is efficient and easy to operate.     

游离氨抑制协同过程控制实现渗滤液短程硝化

采用UASB-SBR生化系统处理高氮晚期渗滤液为研究对象,在获得稳定有机物和氮去除的前提下,考察了采用游离氨(FA)协同过程控制对实现渗滤液长期稳定短程硝化的可行性,建立实现与维持SBR系统内稳定短程硝化的途径及方法.试验结果表明:经过36d的运行,SBR系统的亚硝积累率始终稳定在90%以上,获得了稳定的短程硝化.游离氨和过程控制的协同作用是实现与维持SBR反应器稳定短程硝化的决定因素,以DO,ORP和pH作为渗滤液短程硝化反硝化的过程控制参数是可行的,在充分利用较高FA抑制亚硝酸盐氧化菌活性的前提下,过程控制能够准确判断硝化终点,避免过度曝气破坏短程硝化,从而为氨氧化菌(AOB)的生长创造有利条件,有效抑制亚硝酸盐氧化菌(NOB)的生长并逐渐从系统中淘洗出去,实现了硝化菌种群的优化,荧光原位杂交技术(FISH)检测也证明这一点.在此基础上,通过批次实验考察了微生物种群的反硝化动力学特性,符合Monod动力学方程,NO2--N基质最大比利用速率和半饱和常数分别为0.44gNO2--NgVSS-1d-1和15.8mgL-1.     

Treatment of landfill leachate by immobilized microorganisms

This paper focuses on the outcome and the main performance of the immobilized microbial that treats landfill leachate. Based on the analysis of COD and ammonia-nitrogen of the influent and effluent, research was done on the high removal efficiency of COD and ammonium nitrogen by immobilized microbial. The leachate composition was analyzed qualitatively using GC-MS before and after being treated. Biological loading of efficient microbial flora on the carrier was measured by Kjeldahl’s method. Finally, the patterns of immobilized microbe were observed through scanning electron microscopy (SEM). The results showed that in immobilized microorganisms system, the efficiencies of COD and nitrogen were 98.3% and 99.9%, respectively. There was a great reduction of organic components in effluent. When the immobilized biomass on the carrier was 38 g·L?1 (H2O), the filamentous microorganism was highly developed. There was no inhibitory effect on the nitrobacteria and nitrococcus, when ammonia was over 200 mg·L?1 and NH3 over 150 mg·L?1. At a high organic loading, it still had good nitrification. This paper also compares the performance of immobilized microbial with free microbial under the same condition. The immobilized microbial technology demonstrated better than the latter in all aspects.