基于EM菌黑臭底泥治理的微生物燃料电池性能研究

针对当今城镇内河黑臭水体治理投资大、效果差的现状,构建了一种利用EM菌进行黑臭底泥治理的新型沉积型微生物燃料电池(SMFC)。主要研究EM菌用于SMFC的可行性,同时对以河水或磷酸盐缓冲液(PBS)作为阴极液的SMFC的性能进行对比。实验结果表明:基于EM菌的SMFC运行良好,不影响污泥产电性能,不仅能有效降解黑臭底泥的臭气,而且同步处理有机物效果更加显著;以河水作为阴极液的SMFC性能比以PBS作为阴极液的SMFC好。以EM菌构成的新型SMFC是河道黑臭底泥治理的新理念、新技术,具有巨大潜力和效益。     

黑臭水体底泥生态风险评价及治理方法研究

底泥污染是造成水体黑臭的重要原因,开展底泥污染生态风险评价,探析底泥污染特征,对底泥污染治理具有重要的指导意义。对茅洲河流域（光明新区）底泥中的营养盐、重金属、难降解有机物污染进行了生态风险评价,结果表明,该区域内底泥污染较为严重,其中总磷含量处于重度污染状态;局部地区存在重金属中等潜在生态风险,可能存在点源或面源污染;难降解有机物主要表现为PAEs和PAHs污染,PAEs检出率为100%,DMP、DEP、DBP含量严重超标,均远大于土壤环境治理标准。根据以上结果,对底泥污染控制、处理处置方法及资源化利用进行了综述,可供类似工程参考借鉴。     

治理感潮河道黑臭的底泥原位修复技术研究

选择典型的珠江流域重污染感潮河道——广州市荔湾区郭村涌为研究对象,结合河道感潮特性,在退潮后的最低水位时采用底泥曝气并投加TRSS稳定剂来消除河道黑臭,以利于河道生态系统的恢复。研究结果表明：底泥曝气可有效氧化底泥中的硫化物,运行一个月后对其去除率达到了86.3%～92.1%,臭味基本被消除;底泥经投加TRSS进行稳定化处理后,Cu、Zn、Cr、Cd等重金属的释放量降低了79.5%～87.2%,且形态更加稳定,经底泥毒性鉴别其浸出量分别降低了66.2%、81.5%、82.2%和78.6%,均低于危险废物毒性鉴别标准值,同时还使磷的释放量降低了约90%;停止投药两个月后,底泥中硫化物的含量稳定在0.035 g/kg以下;维持微碱性、好氧条件（pH≈8,DO〉2 mg/L）,可使表层底泥由黑色变成亮褐色,上覆水体水质稳定,黑臭基本消除。     

黑臭水体产生的原因及治理技术

为了改善城市河道的质量,结合实际,对城市黑臭水体的形成原因进行分析,指出引起黑臭水的因素,包含污水排放不合理、面源污染、合流管道积淤以及底泥悬浮与污染释放问题等多方面因素,并且在分析黑臭水体产生的原因基础上,提出了常见的治理技术,实践可知,针对不同类型的黑臭水体,在治理的过程中选择针对的技术进行处理,取得的效果非常显著。     

浅析生态修复技术治理黑臭水体

详细阐述了黑臭水体主要成因及判别标准,并在此基础上针对性地提出了如物理法、化学法以及生物的生态修复法等手段来治理黑臭水体,希望对治理黑臭水体,改善人居环境有所裨益.     

不同纯生物菌剂对黑臭水体底泥的处理效果

目前黑臭水体底泥通常采用化学或生物方法进行异位治理,生物法由于简单易操作、处理成本较低而被广泛应用,并能够为后续的底泥资源化利用提供条件。为探究更适宜的生物处理方法,明确生物处理过程中的微生物群落变化规律,分别采用不同种类的纯生物菌剂(硝化细菌、反硝化细菌、光合细菌和芽孢杆菌)对黑臭水体底泥进行异位处理,通过投加不同剂量的纯菌剂,比较反应前后底泥中的总氮、总磷、有机质及含水率的变化。结果表明,在常温(20±5)℃下经过30 d的处理,底泥中含水率、总氮和有机质含量都有不同程度的降低。其中,投加量为35 mg/L的反硝化细菌试验组处理效果最好,总氮和有机质去除率分别达到59. 90%和20. 93%。三维荧光光谱分析表明,投加纯生物菌剂处理后,底泥中的大分子有机物浓度降低,小分子物质浓度有不同程度的升高,说明生物菌剂能够提高底泥中微生物的活性,不仅促进了有机物的降解,还为反硝化反应提供了碳源,促进了底泥中总氮的去除。此外,高通量测序也表明,投加菌剂的试验组样本中,都出现了一定丰度的Thiobacillus、Sulfurovum、Sulfuricurvum和Sulfurimonas,且在芽孢杆菌试验组和光合细菌试验组中比例较高,四个菌属总比例分别达到13. 24%和14. 80%。这四个菌属能够参与硫代谢,对于底泥中有机质(如蛋白等)的降解起到重要作用。     

城市黑臭水体治理思路探讨

黑臭水体的产生不但对于城市的景观具有极为严重负面作用,并且会使得周围群众生活的质量降低、损伤群众身体的健康.片面性、表面性以及暂时性的治理措施不会发挥起治根的功能.本文提出城市黑臭水体出现的主要原因,以及内源治理和外源治理以及河流整治与生态修复综合的治理思路,望可以对城市黑臭水体的修复方案制订供给一定参考建议.     

小东江黑臭水体调研及治理研究

茂名市作为农业大市、南方油城,工农业的发展导致水体污染严重,穿城而过的小东江水污染尤为突出。对小东江流域水质及周边环境和污染源进行了调研,并介绍了针对性的综合治理措施,对广东省其他地区乃至全国黑臭水体治理都具有重要的借鉴意义。     

老城区黑臭水体治理经验探讨

城市老城区的人口密度大、建筑物密集、交通拥堵,其内部河道多为人工渠道和自然河流的结合体,本身的生态系统脆弱,受周边环境影响大.针对老城区黑臭水体的特点,论文从点源污染处理、面源污染防治、内源污染清除以及水质提升等多方面对老城区的黑臭水体进行了较详细的分析,总结了老城区黑臭水体存在的问题.并针对以上存在问题,提出了溯源排...     

城市黑臭水体治理技术探讨

介绍了黑臭水体的判别方法,治理路线,提出了常见的几种水体修复方案,并比较了优缺点,根据不同地区的自然环境特点,提出切实可行的治理方案,因地制宜、标本兼治,改善水体环境并长效保持。     

以徐巷浜为例探索城市黑臭水体治理途径

徐巷浜城市黑臭水体整治工程通过实施岸上控源截污、河道清淤、生物治理等项目,基本达到了消除黑臭的工程治理目标。通过对徐巷浜黑臭水体的治理经验总结和探索,结合无锡市的实际情况,探索城市黑臭河道治理途径,为城市黑臭水体治理提供方法和建议。     

The effect of real-time external resistance optimization on microbial fuel cell performance

This work evaluates the impact of the external resistance (electrical load) on the long-term performance of a microbial fuel cell (MFC) and demonstrates the real-time optimization of the external resistance. For this purpose, acetate-fed MFCs were operated at external resistances, which were above, below, or equal to the internal resistance of a corresponding MFC. A perturbation/observation algorithm was used for the real-time optimal selection of the external resistance. MFC operation at the optimal external resistance resulted in increased power output, improved Coulombic efficiency, and low methane production. Furthermore, the efficiency of the perturbation/observation algorithm for maximizing long-term MFC performance was confirmed by operating an MFC fed with synthetic wastewater for over 40 days. In this test an average Coulombic efficiency of 29% was achieved.     

Extracellular biological organic matters in microbial fuel cell using sewage sludge as fuel

The microbial fuel cell (MFC) was applied to produce electricity using sewage sludge as a fuel. The extracellular biological organic matter (EBOM) of sludge, before and after MFC operation, was extracted using ammonium hydroxide whose hydrophobicity was characterized with XAD resin fractionation technique. Following MFC operation, the hydrophilic fraction (HPI) of EBOM was enriched (48.0%-64.5%), the hydrophobic acid (HPO-A) fraction was reduced (32.0%-14.5%), and the dissolved organic carbon (DOC) was removed by 36.8% and the sludge aromaticity decreased by 65.7%. The fluorescence tests indicated that the MFC removed the aromatic proteins-like and soluble microbial byproduct-like materials in sludge. Fourier-transform infrared (FT-IR) results showed that the aliphatic (C-H related) components, hydrocarbon and carbohydrate were easily hydrolyzed and biodegraded in the studied MFC.     

Electricity generation from cysteine in a microbial fuel cell

In a microbial fuel cell (MFC), power can be generated from the oxidation of organic matter by bacteria at the anode, with reduction of oxygen at the cathode. Proton exchange membranes used in MFCs are permeable to oxygen, resulting in the diffusion of oxygen into the anode chamber. This could either lower power generation by obligate anaerobes or result in the loss in electron donor from aerobic respiration by facultative or other aerobic bacteria. In order to maintain anaerobic conditions in conventional anaerobic laboratory cultures, chemical oxygen scavengers such as cysteine are commonly used. It is shown here that cysteine can serve as a substrate for electricity generation by bacteria in a MFC. A two-chamber MFC containing a proton exchange membrane was inoculated with an anaerobic marine sediment. Over a period of a few weeks, electricity generation gradually increased to a maximum power density of 19 mW/m(2) (700 or 1000 Omega resistor; 385 mg/L of cysteine). Power output increased to 39 mW/m(2) when cysteine concentrations were increased up to 770 mg/L (493 Omega resistor). The use of a more active cathode with Pt- or Pt-Ru, increased the maximum power from 19 to 33 mW/m(2) demonstrating that cathode efficiency limited power generation. Power was always immediately generated upon addition of fresh medium, but initial power levels consistently increased by ca. 30% during the first 24 h. Electron recovery as electricity was 14% based on complete cysteine oxidation, with an additional 14% (28% total) potentially lost to oxygen diffusion through the proton exchange membrane. 16S rRNA-based analysis of the biofilm on the anode of the MFC indicated that the predominant organisms were Shewanella spp. closely related to Shewanella affinis (37% of 16S rRNA gene sequences recovered in clone libraries).     

Up-scaling microbial fuel cell systems for the treatment of real textile dye wastewater and bioelectricity recovery

ABSTRACT

In this work the energy recovery in microbial fuel cell was studied by electrically stacking its three individual units into series and parallel arrangements. The power output was higher in parallel stacking by 2.07 and 14.77 times than series and individual units respectively. The rate of degradation of dye wastewater was in order of individual Microbial Fuel Cell (MFC) < series stack < parallel stack. The corn cob biochar was used as an additive in the MFC to improve the efficiency of the individual MFC unit. The addition of 0.5 g corn cob biochar enhanced the power output to 38.6 mW/m² from 0.47 mW/m² in the MFC individual unit without the biochar additive. The simultaneous COD reduction, TDS reduction and decolourisation of dye wastewater achieved are 82.14%, 68% and 74.8% respectively. The current work demonstrates that the dose of biochar and parallel stacking are a framework to achieve enhanced dye removal and bioenergy recovery via microbial fuel cell.     

A single-chamber microbial fuel cell as a biosensor for wastewaters

The traditional 5-day test of the biochemical oxygen demand (BOD₅ test) has many disadvantages, and principally it is unsuitable for process control and real-time monitoring. As an alternative, a single-chamber microbial fuel cell (SCMFC) with an air cathode was tested as a biosensor and the performance analysed in terms of its measurement range, its response time, its reproducibility and its operational stability. When artificial wastewater was used as fuel, the biosensor output had a linear relationship with the BOD concentration up to 350 mg BOD cm⁻³; very high reproducibility; and stability over 7 months of operation.The system was further improved by reducing by 75% the total anolyte volume. In this way a response time close to the hydraulic retention time (HRT) of the biosensor (i.e. 40 min) was reached. When the small volume SCMFC biosensor was fed with real wastewater a good correlation between COD concentration and current output was obtained, demonstrating the applicability of this system to real effluents. The measurements obtained with the biosensor were also in accordance with values obtained with standard measurement methods.     

Nitrogen removal from wastewater using membrane aerated microbial fuel cell techniques

Nitrogen removal mainly relies on sequential nitrification and denitrification in wastewater treatment. Microbial fuel cells (MFCs) are innovative wastewater treatment techniques for pollution control and energy generation. In this study, bench-scale wastewater treatment systems using membrane-aerated MFC (MAMFC) and diffuser-aerated MFC (DAMFC) techniques were constructed for simultaneous removal of carbonaceous and nitrogenous pollutants and electricity production from wastewater. During 210 days of continuous flow operation, when the dissolved oxygen (DO) in the cathodic compartment was kept at 2 mg/L, both reactors demonstrated high COD removal (>99%) and high ammonia removal (>99%) but low nitrogen removal (<20%). When a lower DO (0.5 mg/L) was maintained after day 121, both the MFC-based reactors still had excellent COD removal (>97%). However, the nitrogen removal of MAMFC (52%) was 2-fold higher than that of DAMFC (24%), indicating an enhanced performance of denitrification after DO reduction in the cathodic compartment of the MAMFC. Meanwhile, terminal restriction fragment length polymorphism (T-RFLP) analysis of ammonia-oxidizing bacteria (AOB) population in the MAMFC indicated the diversity of AOB with equally important Nitrosospira and Nitrosomonas species present in the cathodic biofilm after DO reduction. The average voltage output in the MAMFC was significantly higher than that in DAMFC under both DO conditions. The results suggest that MAMFC systems have the potential for wastewater treatment with improved nitrogen removal and electricity production.     

Identifying the microbial communities and operational conditions for optimized wastewater treatment in microbial fuel cells

Microbial fuel cells (MFCs) are devices that exploit microorganisms as “biocatalysts” to recover energy from organic matter in the form of electricity. MFCs have been explored as possible energy neutral wastewater treatment systems; however, fundamental knowledge is still required about how MFC-associated microbial communities are affected by different operational conditions and can be optimized for accelerated wastewater treatment rates. In this study, we explored how electricity-generating microbial biofilms were established at MFC anodes and responded to three different operational conditions during wastewater treatment: 1) MFC operation using a 750 Ω external resistor (0.3 mA current production); 2) set-potential (SP) operation with the anode electrode potentiostatically controlled to +100 mV vs SHE (4.0 mA current production); and 3) open circuit (OC) operation (zero current generation). For all reactors, primary clarifier effluent collected from a municipal wastewater plant was used as the sole carbon and microbial source. Batch operation demonstrated nearly complete organic matter consumption after a residence time of 8–12 days for the MFC condition, 4–6 days for the SP condition, and 15–20 days for the OC condition. These results indicate that higher current generation accelerates organic matter degradation during MFC wastewater treatment. The microbial community analysis was conducted for the three reactors using 16S rRNA gene sequencing. Although the inoculated wastewater was dominated by members of Epsilonproteobacteria, Gammaproteobacteria, and Bacteroidetes species, the electricity-generating biofilms in MFC and SP reactors were dominated by Deltaproteobacteria and Bacteroidetes. Within Deltaproteobacteria, phylotypes classified to family Desulfobulbaceae and Geobacteraceae increased significantly under the SP condition with higher current generation; however those phylotypes were not found in the OC reactor. These analyses suggest that species related to family Desulfobulbaceae and Geobacteraceae are correlated with the electricity generation in the biofilm and may be key players for optimizing wastewater treatment rates and energy recovery in applied MFC systems.     

Efficient electricity generation from sewage sludge using biocathode microbial fuel cell

Microbial fuel cells (MFCs) with abiotic cathodes require expensive catalyst (such as Pt) or catholyte (such as hexacynoferrate) to facilitate oxidation reactions. This study incorporated biocathodes into a three-chamber MFC to yield electricity from sewage sludge at maximum power output of 13.2 ± 1.7 W/m³ during polarization, much higher than those previously reported. After 15 d operation, the total chemical oxygen demand (TCOD) removal and coulombic efficiency (CE) of cell reached 40.8 ± 9.0% and 19.4 ± 4.3%, respectively. The anolyte comprised principally acetate and propionate (minor) as metabolites. The use of biocathodes produced an internal resistance of 36-46 Ω, lower than those reported in literature works, hence yielding higher maximum power density from MFC. The massively parallel sequencing technology, 454 pyrosequencing technique, was adopted to probe microbial community on anode biofilm, with dominant phyla belonging to Proteobacteria (45% of total bacteria), Bacteroidetes (19%), Uncultured bacteria (9%), Actinobacteria (7%), Firmicutes (7%), Chloroflex (7%). At genera level, Rhodoferax, Ferruginibacter, Propionibacterium, Rhodopseudomonas, Ferribacterium, Clostridium, Chlorobaculum, Rhodobacter, Bradyrhizobium were the abundant taxa (relative abundances > 2.0%).     

Performance of Paracoccus homiensis DRR-3 in microbial fuel cell with membranes

This study focuses on the bioelectricity production of Paracoccus homiensis strain DRR-3, a Gram-negative bacterium with Nafion117 and polymer membranes. Among the various electrodes used, carbon paper showed a higher production of 790?mV and 0.13?mA with Nafion 117 membrane and 290?mV and 0.10?mA with salt bridge as a proton exchanger. The scanning electron micrograph of the biofilm attached to the anode revealed the presence of P. homiensis. A major highlight in this study is to reveal the efficiency of the two membranes made of conducting polymers (polyvindylene difluoride [PVDF] and polycarbazole [PCZ]) in the proton transfer. Electrochemical impedance spectroscopy was used to study the anode resistance, total resistance of the microbial fuel cell and to recognise the membrane which facilitates the efficient proton transfer. The PVDF membrane showed a better performance of bioelectricity generation when compared to Nafion and PCZ membrane with a low R_ct value of 45.05?Ω and R_s of 23.61?Ω.