阳电极面积对双室微生物燃料电池产电性能及COD的影响

微生物燃料电池(MFC)最具应用前景之一是处理废水的同时能够产生电能.以糖蜜废水作为阳极基质,以金属离子的电镀废水做阴极溶液,研究了双室微生物燃料电池不同电极面积对产电性能和COD的影响.结果发现,当外电阻为300Ω时,小反应器微生物燃料电池(阳极面积为76.8cm2)及大反应器微生物燃料电池(阳极面积为78.15cm2)最大功率密度分别为0.22mW/cm2和0.28mW/cm2.在前200个小时内,小反应器微生物燃料电池在第60个小时时产生最大电压71.1 mV和最大电流189.5 μA,大反应器微生物燃料电池在第190个小时时产生最大电压81.1 mV和最大电流228.1μA.同时,当Zn2+作阴极溶液时,小反应器微生物燃料电池阳极溶液的COD去除率在1.5％到7.02％之间,大反应器微生物燃料电池阳极溶液的COD去除率在0到14.96％之间.     

阳电极面积对微生物燃料电池产电性能的影响

微生物燃料电池（MFC）最具应用前景之一是处理废水的同时能够产生电能。以糖蜜废水作为阳极基质,以金属离子的电镀废水做阴极溶液,研究了双室微生物燃料电池不同电极面积对产电性能和COD的影响。结果发现,当外电阻为300Q时,大反应器微生物燃料电池A．（阳极面积为78．15cm^2）及小反应器微生物燃料电池～（阳极面积为76．8cm^2）最大功率密度分别为0．28mW／cm^2和0．22mW／cm^2。在前200个小时内,A：电池在第60个小时时产生最大电压71．1mV和最大电流189．5μA,A,在第190个小时时产生最大电压81．1mV和最大电流228．1μA。同时,当Zn^2＋作阴极溶液时,小反应器微生物燃料电池阳极溶液的COD去除率在1．5％到7．02％之间,大反应器微生物燃料电池阳极溶液的COD去除率在0到14．96％之间。阴极中Zn^2＋去除率A1中为28．6％,A2为21．2％。     

微生物燃料电池处理CTMP制浆废水的研究

以化学热磨机械浆(CTMP)制浆废水为底物,采用铁氰化钾阴极微生物燃料电池(MFC),对MFC处理CTMP制浆废水的可行性和废水CODCr浓度对MFC产电性能的影响进行研究.结果表明,MFC最大功率密度随废水CODCr浓度的增大而升高,最高为233 mW/m2,CODCr去除率达到54.3％～ 62.4％;当CODCr增大至5200 mg/L以上时,过高的CODCr浓度抑制微生物活性,电池最大功率密度和CODCr去除率分别降低至34.2 mW/m2和32.8％.CTMP制浆废水可以作为MFC底物,在产电的同时实现有效降解,这为废水资源化利用提供了新途径.     

糖蜜废水与电镀废水对微生物燃料电池产电性能的影响

用微生物燃料电池处理电镀废水,在产电的同时,还能析出金属单质.实验室采用Cu(NO3)2和AgNO3代替电镀废水作为阴极电子受体,糖蜜废水为阳极底物,碳纸60为电极材料,考察了0.1 mol/LCu(NO3)2和0.05mol/L AgNO3对电池产电性能的影响.结果表明:在667 h,Cu(NO3)2作为阴极电子受体,最大输出电压达到105.1 mV,最高功率输出密度0.50 mW/cm2,而AgNO3作为电子受体在787 h时,输出电压达到最大值120.2 mV,最高功率输出密度仅为0.41 mW/cm2.研究表明,重金属离子可以作为微生物燃料电池的阴极电子受体,微生物燃料电池(MFC)可以直接将有机废水中的化学能直接转化为电能,同时将重金属还原,具有显著的环境效益和经济效益.     

微生物燃料电池处理OCC制浆废水及其产电性能研究

研究了微生物燃料电池处理OCC制浆废水及同步产电性能,为全面了解实验室研究与实际应用之间的差距,选用自制的和纸厂的两种OCC制浆废水进行比较分析。研究结果表明,阳极室进水为纸厂废水的反应体系在有机物去除及产电方面优于自制废水体系,反应器运行结束时自制废水和纸厂废水的COD_(Cr)去除率分别为81.3%和89.5%;自制废水体系于3个产电平台产生的输出电压分别低于纸厂废水体系,进水COD_(Cr)浓度为1000 mg/L时,两个体系得到的最大功率密度分别为289.9 mW/m~2和303.0 mW/m~2。通过扫描电子显微镜和傅里叶红外光谱分析可知,自制废水体系和纸厂废水体系中阳极优势菌群的表面形态不同,且红外谱图在吸收峰的数量及特定峰的强度上存在差异。     

包装印刷废水处理工艺研究

本文针对包装印刷企业废水量比较少的情况设计了一套小型高效微生物污水处理系统,其对废水中CODcr、BOD5、SS、NH3-N、色度等污染指标去除效果明显,均达到国家污水排放标准。     

味精废水浓缩后挥发组分的分析研究

味精废水是一种难处理的高浓度的有机废水。本文对浓缩后不同时间段挥发组分中CODcr、NH3--N值进行检测和分析,结果表明：当味精废水体积浓缩80％时,挥发组分CODcr值由5710mg／L降到860mg／L,而NH3-N值由45．5mg／L经过一个平台约12．0mg／L又急剧上升到约40．0mg／L,因此浓缩不能超过80％,以75％为最佳。     

微生物燃料电池降解木素磺酸盐并同步产电

以厌氧活性污泥为接种体构建铁氰化钾阴极微生物燃料电池（Microbial fuel cell,MFC）,对木素磺酸盐的降解及产电效果进行了研究。结果表明：经过3个周期连续添加葡萄糖后MFC成功启动,并产生了446mV的电压。以木素磺酸盐为单一底物的MFC经过50h运行,最大功率密度达到177．9mW／m^2,阳极液CODCr和木素磺酸盐去除率分别为;35．5％和46．7％。MFC可以降解木素磺酸盐并同步产电,这为解决造纸废水中生物质能的开发和利用提供了新途径。     

紫外线辐射对活性污泥脱氮除磷效果的影响

本实验通过对比紫外线辐射前后活性污泥对模拟生活污水的处理效果,研究紫外线辐射对活性污泥脱氮除磷效果的影响。结果表明,辐射40s(紫外辐射能量为30.91J)时对实验配置废水的处理效果最好,且效果显著,对CODcr、TP、TN的去除率最高,为96.42%、93.09%、87.79%,分别比辐射前的去除率高5.83%、2.16%、19.51%,辐射60s对NH4+-N的去除率最高,为97.64%,而紫外辐射40s后的其次,为97.29%,高于辐射前3.87%。而最佳辐射时段为辐射后的2～3天。     

基于粒子群算法的微生物燃料电池最大功率跟踪

微生物燃料电池能够在实现污水发电,实现清洁能源的同时,对污水中的微生物进行分解和净化,有较大的发展空间。但微生物燃料电池的输出电压和输出功率,受负载波动的影响都较大,为了充分利用电池系统的产电效能,将电池控制在最大功率输出状态具有实际意义。文章对微生物燃料电池的电化学模型进行了系统的阐述,并将粒子群算法应用于电池最大功率跟踪,在负载变化的情况下,始终实现最大功率输出。     

反硝化除磷工艺研究

研究了反硝化除磷工艺的运行效果。结果表明，此反硝化除磷工艺可以较好地进行除磷脱氮，但是磷的去除对进水氮的浓度有一定的要求。在进水COD 400mg／L，总磷15mg／L，氨氮84mg／L的条件下COD的降低率可达96％以上，氮的去除率稳定在86％～88％，磷的去除率为92%～95%。进水氨氮质量浓度为60mg／L时，磷的去除率为78％，在进水氨氮质量浓度降为44mg／L时磷的去除率降为68％。反硝化除磷比以氧为电子受体的生物除磷可减少耗氧55．5％，剩余污泥的产生量可减少53％，温室气体CO2的产生量可减少体积分数21．4％。     

异养硝化-好氧反硝化菌株的分离、鉴定及其氨氮降解过程初探

该研究采用选择性培养基从汾河底泥中分离筛选异养硝化-好氧反硝化菌,通过形态观察、生理生化试验及分子生物学技术对其进行菌种鉴定,并对其氨氮（NH4+-N）降解过程进行动态监测,测定NH4+-N降解过程中关键酶的基因及酶活。结果表明,分离筛选得到一株异养硝化-好氧反硝化菌,编号为ZH-2,其被鉴定为醋酸钙不动杆菌（Acinetobacter calcoaceticus）。该菌在NH4+-N降解过程中存在NO3--N和NO2--N两种中心代谢产物,其基因组中含有3种关键酶（氨单加氧酶（Amo）、硝酸盐还原酶（Nap）和亚硝酸盐还原酶（Nir））基因,在NH4+-N降解过程,这3种关键酶的比酶活分别为45.69 mU/mg、3.54 mU/mg和6.91 mU/mg。综上,初步确定A. calcoaceticus ZH-2的NH4+-N降解过程是NH4+-N→NH2OH→NO2--N→NO3--N→NO2--N→NO→N2O→N2的经典降解途径,为该菌的进一步推广应用提供了理论依据。     

Ammonia (NH3) and total volatile nitrogen (TVN) in preserved and unpreserved stored,whole fish

Total volatile nitrogen (TVN), ammonia (NH3) and amide-N were analysed in fish stored without and with preservatives. In well preserved fish the increase in NH3-N during storage was accompanied by a parallel decrease in amide-N. It is concluded that NH3 may originate from glutamine and probably also from asparagine. In unpreserved material other sources may dominate.     

Characterization of atmospheric ammonia emissions from a commercial chicken house on the Delmarva Peninsula

A three-dimensional sampling grid using passive collectors was used to characterize the downwind gas-phase ammonia plumes originating from a commercial chicken house on the Delmarva Peninsula in the Chesapeake Bay watershed. Inverse Gaussian plume modeling was used to determine the source strength of the chicken house and the corresponding chicken emission factors. A total of seven field deployments were performed during two different flocks with a sampling duration ranging from 6 to 12.6 h. The deployments occurred during weeks 3, 4, and 5 of the 6-week chicken grow-out period in the months of May-July 2002. The ammonia emission factors ranged from 0.27 to 2.17 g of NH3-N bird(-1) day(-1) with a mean of 1.18 g of NH3-N bird(-1) day(-1). Weighted emissions factors that accounted for the nonlinear increase in ammonia emissions over the 6-week grow-out period were also calculated and ranged from 0.14 to 1.65 g of NH3-N bird(-1) day(-1) with a mean of 0.74 g of NH3-N bird(-1) day(-1). These weighted emission values would correspond to an annual release of approximately 18 x 10(6) kg of NH3-N to the atmosphere from broiler production on the Delmarva Peninsula. This assumes that the emission factors in this study are representative for the entire year with varying meteorological conditions and are representative of all chicken husbandry practices. The Delmarva Peninsula could represent a significant source of nutrient nitrogen to the Chesapeake Bay and Delaware Bay watersheds through atmospheric deposition when considering the size of this annual release rate, the relative short atmospheric lifetime of ammonia due to deposition, and the proximity of the Delmarva Peninsula to the Chesapeake and Delaware Bays.     

Effect of ammonia nitrogen and dissolved organic matter fractions on the genotoxicity of wastewater effluent during chlorine disinfection

Chlorine is a widely used disinfectant which prevents the spread of harmful pathogens when reusing wastewater, but harmful byproducts might be formed and cause adverse ecological and health effects. In this study, the potential effects of chlorination on the genotoxicity of different biologically treated wastewater samples were investigated using the umutest. For the firsttime, ammonia nitrogen (NH3-N) was found to significantly influence genotoxicity during wastewater chlorination. After chlorination, the genotoxicity decreased in wastewater with a low NH3-N concentration (<10-20 mg/L), but it increased notably in wastewater with a high NH3-N concentration (>10-20 mg/L). By fractionating the DOM (dissolved organic matter) in wastewater into different fractions, it was found that the hydrophilic substances (HIS) fraction of DOM was the key fraction involved in decreasing genotoxicity during the chlorination of wastewater with a low NH3-N concentration, while the hydrophobic acids (HOA) fraction of DOM was the key fraction involved in increasing genotoxicity during chlorination of wastewater with a high NH3-N concentration. Furthermore, fluorescence spectroscopy analysis on different fractions indicated that some free or combined aromatic amino acids might produce highly genotoxic byproducts during the chlorination of wastewater with a high NH3-N content, and this was then demonstrated through experiments on the chlorination of free aromatic amino acids.     

Ti/SnO_2-Sb_2O_5-CuO电极制备及其降解模拟高盐印染废水中氨氮的研究

本文采用热分解法制备了Ti/SnO_2-Sb_2O_5-CuO电极,通过SEM、极化曲线及强化寿命测试对电极性能进行检测分析。研究发现相较于Ti/Sn O2-Sb2O5电极,Ti/SnO_2-Sb_2O_5-CuO电极表层更加致密,析氧电位更高,析氯电位更低,电极强化寿命更长。以模拟高盐印染废水中铵态氮作为研究对象,考察了Ti/SnO_2-Sb_2O_5-CuO电极的降解性能,结果表明:50 mg/L氨氮,氯离子浓度10 g/L,氨氮的降解速率和去除效率随氯离子浓度的增加而增加;氯离子浓度≥10 g/L,继续增加氯离子浓度,降解速率和去除效率无明显变化;在2~10 m A/cm2范围内,增加电流密度,降解速率加快,但氨氮的去除率变化不大;Ti/SnO_2-Sb_2O_5-CuO电极对氨氮的去除率可达90%以上,废水中氨氮浓度能降低到3 mg/L以下,达到印染废水的国家排放标准。     

黑土壤种植烤烟的氮肥形态试验初报

2 0 0 0～ 2 0 0 1年连续两年在黑龙江省中等肥力的粘壤土上进行了田间小区试验 ,研究不同形态氮肥配比对烤烟的农艺性状、化学成分和产量品质的影响。结果表明 ,每公顷施纯氮 4 5 0kg ,采用 75 %NO- 3-N 2 5 %NH 4 -N的配比 ,烟叶中钾、还原糖等成分的含量较高 ,与烤烟品质关系密切的化学成分比例适宜 ,产值及上中等烟比例等经济指标最佳。     

Atmospheric emission of reactive nitrogen during biofuel ethanol production

This paper evaluates emissions to the atmosphere of biologically available nitrogen compounds in a region characterized by intensive sugar cane biofuel ethanol production. Large emissions of NH3 and NOx, as well as particulate nitrate and ammonium, occur at the harvest when the crop is burned, with the amount of nitrogen released equivalent to approximately 35% of annual fertilizer-N application. Nitrogen oxides concentrations show a positive association with fire frequency, indicating that biomass burning is a major emission source, with mean concentrations of NOx doubling in the dry season relative to the wetseason. During the dry season biomass burning is a source of NH3, with other sources (wastes, soil, biogenic) predominant during the wet season. Estimated NO2-N, NH3-N, NO3- -N and NH4+ -N emission fluxes from sugar cane burning in a planted area of ca. 2.2 x 10(6) ha are 11.0, 1.1, 0.2, and 1.2 Gg N yr(-1), respectively.     

霞多丽葡萄不同砧穗组合对硝态氮和铵态氮的吸收、分配及利用特性

通过对霞多丽5种砧穗组合植株施用15N标记的硝酸钙和硫酸铵,研究其对硝态氮和铵态氮的吸收、分配和利用特性.结果表明,所有砧穗组合植株对铵态氮的吸收均显著大于硝态氮.不同砧穗组合对氮形态的敏感性存在差异,SO4组合根系供铵处理的Ndff是供硝处理的3.22倍,而3309C和101-14M组合的两种处理差异仅为1.74倍和2.07倍.供氮形态也影响了不同砧木器官对氮的竞争吸收能力,供硝有利于其地上部新生器官的吸收.不同砧穗组合对两种形态氮的吸收利用也有明显不同,以101-14M和3309C组合对两种形态氮的利用率均较高,而SO4组合则更喜好铵态氮,对硝态氮的利用率为最低.两氮形态处理不同砧穗组合各器官的15N分配率均有着相同的趋势,大体为叶＞根＞当年生枝＞砧木茎＞品种茎,多数组合叶的15N分配率达到50％以上.     

Performance of a constructed wetland with a sulfur/limestone denitrification section for wastewater nitrogen removal

The effectiveness of a nonvegetated lab-scale subsurface flow constructed wetland for wastewater treatment had been evaluated with the feed ammonium concentration of approximately 20-40 mg of NH4(+)-N L(-1) and a hydraulic retention time of approximately 10 d. The present system had a nitrification zone plus a sulfur/limestone (S/L) autotrophic denitrification zone followed by an anaerobic polishing zone and was operated with and without aeration. The wetland had only 80% organics removal and no net nitrogen removal when there was no artificial aeration. However, almost 100% organics removal and approximately 81-90% total inorganic nitrogen (TIN = NH4(+)-N + NO2(-0-N + NO3(-)-N) removal were achieved when the oxic zone of the system was aerated with compressed air. S/L autotrophic denitrification contributed 21-49% of total NO3(-)-N removal across the whole wetland and 50-95% across the S/L column. TIN and NH4(+)-N in the effluent were always < 5.5 and < 0.7 mg L(-1), respectively, when the feed had NH4(+)-N < or = 35 mg L(-1). Sulfate removal of approximately 53-69% was achieved in the anaerobic polishing zone. The position of the S/L column was changed (1.78, 2.24, and 2.69 m from the inlet), and no remarkable difference in nitrogen removal was observed. However, without the S/L column, TIN removal decreased to approximately 74%, and the effluent NO3(-)-N increased about two times (9.13 mg of N L(-1)). The present study has demonstrated the possible use of S/L autotrophic denitrification for nitrate removal in a constructed wetland.