功能微生物强化生物流化床工艺处理工业园区废水的研究

本研究采用功能微生物强化生物流化床工艺处理丽水市工业园区废水,研究表明:出水化学需氧量低于50 mg/L,氨氮低于5 mg/L,总氮低于15 mg/L,去除率分别达到85%、85%、60%,出水达到《城镇污水处理厂污染物排放标准(GB 18918-2002)》一级(A)标准。功能微生物强化生物流化床工艺在污水处理中具有很好的应用价值,可用于城镇污水处理厂提标改造等。     

纳米银对污水生物处理系统的影响

纳米银(silver nanoparticles,Ag-NPs)是目前商业化应用最多的纳米材料,因其优越的抗菌性能,广泛使用于纳米技术强化的消费品。释放到环境中的Ag-NPs随污水收集系统进入市政污水处理厂。市场上Ag-NPs产品日益增多,Ag-NPs与污水处理系统中微生物相互作用,可能影响污水处理厂的运行,引起人们广泛关注。污水中Ag-NPs去向和形态变化具有很大的不确定性。本文总结了Ag-NPs抗菌机制以及污水中Ag-NPs暴露对污水生物处理系统去除有机物、氮、磷等微生物的影响。为了降低Ag-NPs在水环境中的风险,今后需要关注的研究方向,包括:研究不同暴露时长下,Ag-NPs在污水中的形态转变,确定各种形态银的数量,寻求控制或消除Ag-NPs对污水处理系统微生物毒性作用的有效措施,为全面评估水体中Ag-NPs的环境风险提供依据。     

污水生物处理中的噬菌体及其功能研究进展

污水生物处理是一种利用微生物分解污水中的污染物、实现污水净化的方法。噬菌体是侵染细菌的病毒,在污水生物处理系统中广泛存在,它们能够特异性地控制微生物菌群,影响污水处理效果和调控污泥性状。因此,研究污水生物处理中噬菌体的分布及其功能具有重要意义。本文介绍了不同污水生物处理中噬菌体的分布,简要分析了噬菌体分离、培养与鉴定方法及其优缺点,详细总结了噬菌体在污水生物处理中的功能,包括：（1）调节微生物群落结构,影响污水处理效果;（2）作为环境监测的指示生物;（3）控制病原菌、污泥膨胀、污泥发泡和膜污染;（4）减少污泥产量,重点分析了影响噬菌体功能的因素,探讨了污水生物处理中噬菌体功能应用存在的问题及其解决方法,最后对噬菌体未来应用的发展方向进行了展望,以期为污水生物处理技术和工艺的开发与应用提供参考,促进污水处理健康发展。     

基于好氧反硝化及反硝化聚磷菌强化的低温低碳氮比生活污水生物处理中试研究

【背景】低碳氮比生活污水很难达标处理,多级A/O工艺、生物强化技术及生物膜技术的有机结合可有效解决这一问题。【目的】开发出一种泥膜共生多级A/O工艺并进行中试研究,驯化出高效脱氮除磷菌剂并对系统进行生物强化。【方法】通过测定中试设备出水及污水处理厂出水化学需氧量(Chemical oxygen demand,COD)、氨氮(NH_4~+-N)、硝氮(NO_3~--N)、总氮(Total nitrogen,TN)、总磷(Total phosphorus,TP)对比分析两种工艺的污染物去除效能,利用高通量测序技术对比生物强化技术对系统微生物群落结构的影响。【结果】中试设备对COD、NH_4~+-N、NO_3~--N、TN、TP的去除效果均优于污水处理厂的处理工艺;驯化的低温好氧反硝化菌TN去除率最大值可达84.21%,驯化的低温反硝化聚磷菌群对磷的去除率最高可达85.75%;利用驯化菌群对中试设备进行生物强化后较好地改善了系统NH_4~+-N、NO_3~--N、TN、TP的去除效果;经生物强化后,具有好氧反硝化和反硝化聚磷功能的Pseudomonas菌群明显增多。【结论】泥膜共生多级A/O工艺对于低碳氮比生活污水的处理具有很好的效果,利用生物强化技术可有效提高低温条件下系统污染物去除效能。     

污水脱氮功能微生物的组学研究进展

生物脱氮是污水处理厂的核心,掌握生物脱氮过程相关微生物代谢特性,对于探索微生物资源和提高污水处理厂脱氮性能具有重要意义。近年来,分子生物学方法不断发展和改进,已被广泛应用于揭示脱氮微生物群落多样性、组成结构和潜在功能等方面,大幅提升了研究者们对污水生物脱氮系统中微生物,尤其是不可培养微生物的代谢机理、抑制调控原理及新型生物脱氮工艺途径的认识。本文对流行的分子生物学方法（16S rRNA基因测序、实时荧光定量PCR技术、宏基因组学、宏转录组学、宏蛋白质组学和代谢组学）进行了介绍,综述了其在硝化细菌、反硝化细菌、完全氨氧化细菌、厌氧氨氧化细菌、厌氧铁氨氧化细菌、硫酸盐型厌氧氨氧化细菌及亚硝酸盐/硝酸盐型厌氧甲烷氧化微生物等方面的研究进展,阐明了这些氮素转化微生物在氮循环过程的代谢途径和酶促反应,并从标准测定方法构建、不同方法的联用及跨学科结合和检测方法的简易化这3个方面展望了分子生物学方法的技术突破及其在污水生物处理系统中的应用前景。本综述从系统角度全面认识脱氮微生物群落及其结构,为未来污水处理生物脱氮微生物的研究提供了新方向。     

异养微生物在金属生物淋滤技术中的应用

生物淋滤技术主要应用于低品位矿石金属选矿、煤气脱硫、废弃物中金属回收和污染介质中金属离子毒性的去除等方面。作为生物淋滤技术中的主体微生物之一,异养微生物可通过其产生的酸性代谢物还原、酸化及络合,提取或者溶解非硫化矿、固体废弃物、污水污泥及土壤中的金属,有助于解决目前的资源短缺问题,还可对污染环境治理提供技术支持,具有重要的理论意义和实践价值。应用于异养微生物淋滤技术中的常见微生物包括细菌(以假单胞菌为主)和真菌(以曲霉菌和青霉菌应用最为广泛)。淋滤过程涉及酸解、络合、还原及碱化等。目前,异养微生物淋滤技术主要应用于生物冶金、固体废弃物处理、污水处理和污染土壤修复等。本文分析了异养微生物金属淋滤过程中的问题,并提出了未来研究的发展方向。     

微生物在污水处理中的原理,作用和应用

未经处理的城市工业废水和生活污水直接排入江,湖,河,海,是造成我国污染的主要原因,本文重点介绍污水处理厂曝气池生物处理的机理,以及微生物,特别是原生动物能指示和预报污水处理厂的净化效能。     

污水处理厂中四环素和磺胺类抗生素抗性基因的分布、传播及去除

近年来,抗生素滥用造成的抗性基因(ARGs)污染问题引起了人们的关注.四环素及磺胺类抗生素由于价格低廉被广泛使用,大量残留的四环素和磺胺通过各种途径进入污水处理厂,并进一步导致ARGs的污染.为深入了解四环素和磺胺类ARGs的污染及治理现状,本研究对污水处理厂中四环素和磺胺类ARGs的分布情况及传播机制进行了综述,并重点讨论了不同污水处理工艺对ARGs的去除效果.在此基础上,从加大污水处理厂ARGs污染调查、改进污水处理工艺以及探讨ARGs传播机制等方面进行了展望.     

污水土地生态处理脱氮技术的中型试验研究

地沟式污水土地生态处理工艺,是自然生态净化与人工工艺相结合的小规模污水处理回用技术。它是采用土壤毛细管浸润扩散原理的浅型土壤处理技术,在人工可控条件下,将污水科学、合理地投配到设计定型的装置内,利用污水的能量,把其所携带的污染物,通过人工基质(土壤、砂、碎石等,填料-水-微生物-植物系统)的物质循环和能量流动,逐级降解;在不同的污染负荷、水力负荷下,完成一系列物理、化学、物理化学和微生物化学、生物化学的反应。通过以贵州典型的黄壤土为主配比的人工土作为处理系统填料的现场中型试验,探讨地沟式污水土地处理系统的脱氮效果及其影响因素。地沟式污水土地生态系统对氨氮和总氮去除效果良好,去除率分别达到84 .7%和70 .7% ,出水氨氮(14 .0 mg/L )和总氮(2 4 .7mg/L ) ,达到建设部颁发的生活杂用水水质标准。对处理系统微生物数量及分布的研究表明:处理系统中氮转化细菌丰富,氨化细菌为10 3～10 6 cfu MPN/g(土壤) (cfu:形成菌落数:MPN:最大可能数量) ,亚硝化菌为10 3～10 6 MPN/g(土壤) ,硝化菌10 4～10 6 MPN/g(土壤) ,反硝化细菌为10 3～10 6 MPN/g(土壤)。由硝化/反硝化实现生物脱氮是土地生态处理系统去除总氮的主要途径;建立土壤、土壤微生物、土壤植被环境以促进硝化作用是提高总     

我国南北区域城市污水处理系统内真菌群落的差异

【背景】微生物是污水处理系统内污染物去除的主体,真菌作为其中不可或缺的一部分,在去除有毒化合物、提高生物转化等方面发挥着重要作用,应引起人们的关注。【目的】明确我国南北区域城市污水处理系统内真菌群落的多样性、组成差异及其影响因素。【方法】采集我国北方23个污水处理厂的90份活性污泥样品和南方37个污水处理厂的121份活性污泥样品,提取上述样本的总DNA,并应用Illumina MiSeq平台进行ITS高通量测序,结合多种数量生态学分析方法对数据进行分析。【结果】我国南北区域城市污水处理系统内真菌群落结构存在显著差异,真菌群落多样性南方显著高于北方;我国南北区域真菌群落的组成差异显著,南方群落以Sordariomycetes和Glomeromycetes为优势菌纲,以Ophiocordycep和Alternaria为优势菌属,北方群落以Tremellomycetes和Saccharomycetes为优势菌纲,以Trichosporon和Saccharomyces为优势菌属,其中Tremellomycetes和Sordariomycetes是常见的病原菌,对下游生物或者人类的健康具有潜在威胁,Trichosporon属的丝状真菌若大量异常增殖会引发污泥膨胀现象,影响系统的稳定运行;地理纬度、年平均气温、进水NH_4~+浓度、进水总氮浓度是导致我国南北区域真菌群落存在差异的重要影响因子。【结论】我国南北区域真菌群落多样性、组成存在显著差异,地理因素、所在城市的气候因素和进水污染物浓度对真菌群落结构影响显著。针对南北区域,应合理调控相应区域内的重要功能菌群,以调控污水处理厂的高效稳定运行,同时密切关注其中的条件致病菌和易引发污泥膨胀的菌群,建立面向种群的优化控制系统以管控风险。     

Impacts of drinking water pretreatments on the formation of nitrogenous disinfection by-products

The formation of disinfection by-products (DBPs), including both nitrogenous DBPs (N-DBPs) and carbonaceous DBPs (C-DBPs), was investigated by analyzing chlorinated water samples following the application of three pretreatment processes: (i) powdered activated carbon (PAC) adsorption; (ii) KMnO(4) oxidation and (iii) biological contact oxidation (BCO), coupled with conventional water treatment processes. PAC adsorption can remove effectively the precursors of chloroform (42.7%), dichloroacetonitrile (28.6%), dichloroacetamide (DCAcAm) (27.2%) and trichloronitromethane (35.7%), which were higher than that pretreated by KMnO(4) oxidation and/or BCO process. The removal efficiency of dissolved organic carbon by BCO process (76.5%)--was superior to that by PAC adsorption (69.9%) and KMnO(4) oxidation (61.4%). However, BCO increased the dissolved organic nitrogen (DON) concentration which caused more N-DBPs to be formed during subsequent chlorination. Soluble microbial products including numerous DON compounds were produced in the BCO process and were observed to play an essential role in the formation of DCAcAm in particular.     

Dissolved organic nitrogen budgets for upland, forested ecosystems in New England

Relatively high deposition ofnitrogen (N) in the northeastern United States hascaused concern because sites could become N saturated.In the past, mass-balance studies have been used tomonitor the N status of sites and to investigate theimpact of increased N deposition. Typically, theseefforts have focused on dissolved inorganic forms ofN (DIN = NH₄-N + NO₃-N) and have largelyignored dissolved organic nitrogen (DON) due todifficulties in its analysis. Recent advances in themeasurement of total dissolved nitrogen (TDN) havefacilitated measurement of DON as the residual of TDN– DIN. We calculated DON and DIN budgets using data onprecipitation and streamwater chemistry collected from9 forested watersheds at 4 sites in New England. TDNin precipitation was composed primarily of DIN. Netretention of TDN ranged from 62 to 89% (4.7 to 10 kgha^{minus 1} yr^{minus 1}) of annual inputs. DON made up themajority of TDN in stream exports, suggesting thatinclusion of DON is critical to assessing N dynamicseven in areas with large anthropogenic inputs of DIN.Despite the dominance of DON in streamwater,precipitation inputs of DON were approximately equalto outputs. DON concentrations in streamwater did notappear significantly influenced by seasonal biologicalcontrols, but did increase with discharge on somewatersheds. Streamwater NO₃-N was the onlyfraction of N that exhibited a seasonal pattern, withconcentrations increasing during the winter months andpeaking during snowmelt runoff. Concentrations ofNO₃-N varied considerably among watersheds andare related to DOC:DON ratios in streamwater. AnnualDIN exports were negatively correlated withstreamwater DOC:DON ratios, indicating that theseratios might be a useful index of N status of uplandforests.     

Mechanisms behind plant diversity effects on inorganic and organic N leaching from temperate grassland

Higher plant diversity reduces nitrate leaching by complementary resource use, while its relation to leaching of other N species is unclear. We determined the effects of plant species richness, functional group richness, and the presence of specific functional groups on ammonium, dissolved organic N (DON), and total dissolved N (TDN) leaching from grassland in the first 4 years after conversion from fertilized arable land to unfertilized grassland. On 62 experimental plots in Jena, Germany, with 1–60 plant species and 1–4 functional groups (legumes, grasses, tall herbs, small herbs), nitrate, ammonium, and TDN concentrations in soil solution (0–0.3 m soil layer) were measured fortnightly during 4 years. DON concentrations were calculated by subtracting inorganic N from TDN. Nitrogen concentrations were multiplied with modeled downward water fluxes to obtain N leaching. DON leaching contributed most to TDN leaching (64 ± SD 4% of TDN). Ammonium leaching was unaffected by plant diversity. Increasing species richness decreased DON leaching in the fourth year. We attribute this finding to enhanced use of DON as a C and N source and enhanced mineralization of DON by soil microorganisms. An increase of species richness decreased TDN leaching likely driven by the complementary use of nitrate by diverse mixtures. Legumes increased DON and TDN leaching likely because of their N\(_{2}\)-fixing ability and higher litter production. Grasses decreased TDN leaching because of more exhaustive use of nitrate and water. Our results demonstrate that increasing plant species richness decreases leaching of DON and TDN.     

Does Anthropogenic Nitrogen Enrichment Increase Organic Nitrogen Concentrations in Runoff from Forested and Human-dominated Watersheds?

Although the effects of anthropogenic nitrogen (N) inputs on the dynamics of inorganic N in watersheds have been studied extensively, “the influence of N enrichment on organic N loss” is not as well understood. We compiled and synthesized data on surface water N concentrations from 348 forested and human-dominated watersheds with a range of N loads (from less than 100 to 7,100 kg N km⁻² y⁻¹) to evaluate the effects of N loading via atmospheric deposition, fertilization, and wastewater on dissolved organic N (DON) concentrations. Our results indicate that, on average, DON accounts for half of the total dissolved N (TDN) concentrations from forested watersheds, but it accounts for a smaller fraction of TDN in runoff from urban and agricultural watersheds with higher N loading. A significant but weak correlation (r ² = 0.06) suggests that N loading has little influence on DON concentrations in forested watersheds. This result contrasts with observations from some plot-scale N fertilization studies and suggests that variability in watershed characteristics and climate among forested watersheds may be a more important control on DON losses than N loading from atmospheric sources. Mean DON concentrations were positively correlated, however, with N load across the entire land-use gradient (r ² = 0.37, P < 0.01), with the highest concentrations found in agricultural and urban watersheds. We hypothesize that both direct contributions of DON from wastewater and agricultural amendments and indirect transformations of inorganic N to organic N represent important sources of DON to surface waters in human-dominated watersheds. We conclude that DON is an important component of N loss in surface waters draining forested and human-dominated watersheds and suggest several research priorities that may be useful in elucidating the role of N enrichment in watershed DON dynamics.     

耕作扰动对喀斯特土壤可溶性有机质及其组分迁移淋失的影响

土壤可溶性有机质(DOM)及其组分淋失特征研究对深入理解干扰作用下土壤碳氮养分损失机制具有重要意义,本研究基于翻耕模拟试验,分析喀斯特石灰土可溶性有机碳(DOC)、可溶性有机氮(DON)、及DOM官能团组分的淋失动态特征及其对不同耕作频率的响应,并探讨其影响因子。结果表明:(1)土壤DOC与DON的淋失量均随翻耕频率的增加而增加,但4个官能团特征参数对翻耕频率响应均不显著;DOC/DON淋失比随翻耕频率的增大而减少,DON占淋溶水可溶性总氮(TDN)比例随翻耕频率增加而增加。(2)DOC和DON月淋失量同时受翻耕处理与季节变化及其交互作用的影响,4个官能团特征参数仅受季节变化的影响;翻耕处理实施后,DOC月淋失量表现为初期大、后期小,各处理间差异性逐渐降低;但DON月淋失量初期小、后期大,各处理间差异性逐渐增大。(3)DOC淋失量与4个官能团特征参数呈显著负相关(P0.05),与Ca~(2+)、NH_4~+-N的淋失量呈显著正相关;DON淋失量与4个官能团参数无显著相关关系,与Mg~(2+)淋失量呈显著正相关关系。以上结果表明耕作扰动会加剧土壤DOM淋失,但淋失组分中稳定性组分没有变化,意味着耕作干扰将导致土壤有机质的持续损失,且由于其淋失组分碳氮比(DOC/DON)随扰动频率增加而降低,DON/TDN比随扰动频率增加而增加,持续的耕作干扰将大大增加水体氮素污染风险。     

Modeling nitrogen removal in water hyacinth ponds receiving effluent from waste stabilization ponds

We developed a dynamic model to predict nitrogen removal in water hyacinth ponds (WHPs) receiving effluent from waste stabilization ponds (WSPs). The model is based on the biofilm reaction on the root surface of plant and pond walls. The model consists of mass balances of six main substrates including: particulate organic nitrogen (PON), dissolved organic nitrogen (DON), ammonium (NH₄⁺), nitrite and nitrate (NOx), soluble chemical oxygen demand (SCOD), and particulate chemical oxygen demand (PCOD). The model, incorporating major nitrogen transformation mechanisms such as hydrolysis, mineralization, and nitrification–denitrification, accounts also for carbon consumption and plant uptake. The model's application to a pilot plant showed good agreement between measured and predicted values. According to the modeling results, in the WHPs, nitrification and denitrification were the predominant nitrogen removal processes occurring simultaneously. Temperature and hydraulic retention time (HRT) had a profound effect on the performance of nitrogen removal while an algae biomass (PCOD) accumulated in the WHPs, was a useful carbon source for denitrification.     

Vertical transport of dissolved organic C and N under long-term N amendments in pine and hardwood forests

At the Harvard Forest, Massachusetts, a long-term effort is under way to study responses in ecosystem biogeochemistry to chronic inputs of N in atmospheric deposition in the region. Since 1988, experimental additions of NH₄NO₃ (0, 5 and 15 g N m^–2 yr^–1) have been made in two forest stands:Pinus resinosa (red pine) and mixed hardwood. In the seventh year of the study, we measured solute concentrations and estimated solute fluxes in throughfall and at two soil depths, beneath the forest floors (Oa) and beneath the B horizons.Beneath the Oa, concentrations and fluxes of dissolved organic C and N (DOC and DON) were higher in the coniferous stand than in the hardwood stand. The mineral soil exerted a strong homogenizing effect on concentrations beneath the B horizons. In reference plots (no N additions), DON composed 56% (pine) and 67% (hardwood) of the total dissolved nitrogen (TDN) transported downward from the forest floor to the mineral soil, and 98% of the TDN exported from the solums. Under N amendments, fluxes of DON from the forest floor correlated positively with rates of N addition, but fluxes of inorganic N from the Oa exceeded those of DON. Export of DON from the solums appeared unaffected by 7 years of N amendments, but as in the Oa, DON composed smaller fractions of TDN exports under N amendments. DOC fluxes were not strongly related to N amendment rates, but ratios of DOC:DON often decreased.The hardwood forest floor exhibited a much stronger sink for inorganic N than did the pine forest floor, making the inputs of dissolved N to mineral soil much greater in the pine stand. Under the high-N treatment, exports of inorganic N from the solum of the pine stand were increased >500-fold over reference (5.2 vs. 0.01 g N m^–2 yr^–1), consistent with other manifestations of nitrogen saturation. Exports of N from the solum in the pine forest decreased in the order NO₃-N> NH₄-N> DON, with exports of inorganic N 14-fold higher than exports of DON. In the hardwood forest, in contrast, increased sinks for inorganic N under N amendments resulted in exports of inorganic N that remained lower than DON exports in N-amended plots as well as the reference plot.     

Shifting stoichiometry: Long-term trends in stream-dissolved organic matter reveal altered C:N ratios due to history of atmospheric acid deposition

Dissolved organic carbon (DOC) and nitrogen (DON) are important energy and nutrient sources for aquatic ecosystems. In many northern temperate, freshwater systems DOC has increased in the past 50 years. Less is known about how changes in DOC may vary across latitudes, and whether changes in DON track those of DOC. Here, we present long-term DOC and DON data from 74 streams distributed across seven sites in biomes ranging from the tropics to northern boreal forests with varying histories of atmospheric acid deposition. For each stream, we examined the temporal trends of DOC and DON concentrations and DOC:DON molar ratios. While some sites displayed consistent positive or negative trends in stream DOC and DON concentrations, changes in direction or magnitude were inconsistent at regional or local scales. DON trends did not always track those of DOC, though DOC:DON ratios increased over time for ~30% of streams. Our results indicate that the dissolved organic matter (DOM) pool is experiencing fundamental changes due to the recovery from atmospheric acid deposition. Changes in DOC:DON stoichiometry point to a shifting energy-nutrient balance in many aquatic ecosystems. Sustained changes in the character of DOM can have major implications for stream metabolism, biogeochemical processes, food webs, and drinking water quality (including disinfection by-products). Understanding regional and global variation in DOC and DON concentrations is important for developing realistic models and watershed management protocols to effectively target mitigation efforts aimed at bringing DOM flux and nutrient enrichment under control.     

河流沉积物氮循环主要微生物的生态特征

微生物驱动的氮循环过程是全球生物地球化学循环的重要组成部分,由于人类活动的影响,氮循环负荷加剧,氮素的生态平衡和微生物的功能特征也相应地受到干扰。河流生态系统是陆地与海洋联系的纽带,因人类活动过量活性氮的输入导致水体富营养化,明显影响着河流的生态功能以及河口沿岸海洋生态系统的平衡。富含微生物的沉积物对氮素的转化和去除起着至关重要的作用。本文主要介绍河流沉积物氮循环主要功能微生物,包括氨氧化细菌、氨氧化古菌、亚硝酸盐氧化菌、反硝化细菌和厌氧氨氧化细菌的群落特征和生态功能,总结氮相关营养盐、溶氧和季节变化等环境因子,以及河道控制管理措施和污水处理厂扰动等条件下氮循环过程主要功能类群的生态特征和响应关系。指出还需深入全面地研究河流沉积物生态系统氮循环过程的驱动机制和微生物的贡献效率,加强城市河流沉积物微生物功能作用的研究及河道生物修复技术的开发。     

Particulate organic matter quality influences nitrate retention and denitrification in stream sediments: evidence from a carbon burial experiment

Organic carbon supply is linked to nitrogen transformation in ecosystems. However, the role of organic carbon quality in nitrogen processing is not as well understood. We determined how the quality of particulate organic carbon (POC) influenced nitrogen transformation in stream sediments by burying identical quantities of varying quality POC (northern red oak (Quercus rubra) leaves, red maple (Acer rubrum) leaves, red maple wood) in stream mesocosms and measuring the effects on nitrogen retention and denitrification compared to a control of combusted sand. We also determined how POC quality affected the quantity and quality of dissolved organic carbon (DOC) and dissolved oxygen concentration in groundwater. Nitrate and total dissolved nitrogen (TDN) retention were assessed by comparing solute concentrations and fluxes along groundwater flow paths in the mesocosms. Denitrification was measured by in situ changes in N₂ concentrations (using MIMS) and by acetylene block incubations. POC quality was measured by C:N and lignin:N ratios and DOC quality was assessed by fluorescence excitation emission matrix spectroscopy. POC quality had strong effects on nitrogen processing. Leaf treatments had much higher nitrate retention, TDN retention and denitrification rates than the wood and control treatments and red maple leaf burial resulted in higher nitrate and TDN retention rates than burial of red oak leaves. Leaf, but not wood, burial drove pore water to severe hypoxia and leaf treatments had higher DOC production and different DOC chemical composition than the wood and control treatments. We think that POC quality affected nitrogen processing in the sediments by influencing the quantity and quality of DOC and redox conditions. Our results suggest that the type of organic carbon inputs can affect the rates of nitrogen transformation in stream ecosystems.