可生物降解聚合物在低碳氮质量比含盐废水脱氮处理中的应用研究

利用可生物降解多聚物(BDPs)材料固体颗粒作为反硝化过程的碳源和生物膜载体,进行低碳氮质量浓度比含盐废水的生物脱氮研究,考察碳源、温度、停留时间对反硝化脱氮效果的影响及使用前后可生物降解多聚物颗粒的变化。结果表明,实验条件下,可生物降解多聚物材料颗粒可以作为碳源使用,总氮去除率大于90%;温度对反硝化脱氮影响较大,15℃时的反硝化速率较25℃时降低30%;使用前后固体颗粒质量和表面均发生较大变化,证明其可作为碳源被生物利用。     

改性稻壳为碳源和生物膜载体的反硝化脱氮研究

为探索稻壳作为载体和碳源的脱氮性能以及对水处理工艺的适应性,以质量分数6%的NaOH处理的改性稻壳为反硝化碳源和生物膜载体,对模拟养殖排放水进行了脱氮处理研究。结果表明,改性稻壳的性能优于蔗糖及淀粉,可实现NO3--N和高含量NO2--N的有效去除。其作为缺氧反应器载体时,挂膜容易、有机碳释放稳定,反应器启动后可高效去除NO3--N。在硝化-反硝化系统中,对NH4+-N去除率达90%以上,且无NO2--N、NO3--N和有机物残留,说明此改性稻壳具备较好的供碳能力和微生物吸附能力,适于作为反硝化碳源及载体。     

生物脱氮的研究进展

脱氮是大部分废水处理系统中不可缺少的一环。与物理化学法相比,生物脱氮具有经济有效、操作方便以及无二次污染的优势。综述了各类生物脱氮技术的研究背景、机理及其存在的问题,并作了简单比较。结果表明,全程硝化反硝化应用广泛且稳定可靠。异养硝化-好氧反硝化对碳源需求较高(COD/N10),而短程硝化反硝化可节约大量能源和碳源。厌氧氨氧化脱氮速率高且无外加碳源,但细菌富集和前期启动较为困难。     

不同碳源对微压反应器脱氮除磷的影响研究

为探究适用于MPR的外碳源，实验通过3组微压反应器（MPR）并行运行，分别投加单一碳源，考察淀粉、葡萄糖和乙酸钠对MPR系统脱氮除磷的影响。结果表明，在实验运行条件下以淀粉为碳源能更有效地促进MPR系统的生物脱氮。通过典型周期历时分析发现，淀粉降解缓慢，在运行周期中保证了反硝化对碳源的需求，且具有较好的同步硝化反硝化作用，从而使系统获得了较好的脱氮效果。DO检测结果表明，以淀粉为碳源的MPR系统存在明显的DO分区，为同步硝化反硝化作用奠定了基础。EPS检测结果证实，以淀粉为碳源能促使活性污泥储存更多糖类物质，可为后续反硝化提供碳源。实验结果为MPR工艺外加碳源的选择及其实际应用推广提供借鉴和参考。     

重金属对脱氮副球菌YF1脱氮的影响

硝酸盐污染物与重金属复合污染是养殖水体中常见的难以处理的环境污染形式之一.本文研究不同重金属和硝酸盐共存对脱氮副球菌Paracoccus sp.YF1去除Zn(II)和硝酸盐的影响.结果表明,在单独存在Zn(II)的情况下,菌株的除锌效果不佳,仅为14.2％,在加入Cu(II)后可以促进对Zn(II)的去除,去除率上升...     

秸秆碳源对高硝氮含量水体脱氮效果实验研究

针对高含氮水体往往存在碳源不足,需要补充碳源的问题,以农林废弃物油菜秸秆作为外加碳源,对不同高含氮的水体进行了生物反硝化脱氮实验研究。结果表明,油菜秸秆在NO_3~--N含量相对较低的水体情况下脱氮效果较好,可以作为良好的缓释碳源,当NO_3~--N的质量浓度为20 mg/L时,脱氮效果最好,NO_3~--N负荷为31 mg/(L·d);当NO_3~--N的质量浓度大于30 mg/L时,因秸秆释碳不足,NO_3~--N去除率减小。不同浓度NO_3~--N水体的NO_3~--N去除率差别较大,但脱氮负荷较为接近,说明高含量NO_3~--N水体的脱氮效果主要与秸秆释碳量有关,受碳源影响。     

利用缓释碳源强化生物反硝化脱氮的研究进展

水体硝酸盐污染对生态平衡和人体健康产生严重威胁，利用微生物异养反硝化作用去除水体硝酸盐是目前的主流方法，此过程通常需要投加额外碳源保证反硝化进行完全。传统商业碳源短板日渐显露，缓释碳源作为一种新型固体碳源，兼具经济性和高脱氮性能，受到大量关注。从缓释碳源研究的必要性出发，对其种类与反硝化效果、改性方法与成本分析、反应机制与微生物群落变化进行了全面详细的介绍，总结了缓释碳源在协同处理其他污染物和工艺耦合方面的研究进展，并对其未来研究方向提出建议，以期为缓释碳源促进反硝化脱氮的可行性探究提供全面的参考。     

缓释碳源应用于低碳氮比污水脱氮研究进展

处理低碳氮比（C/N）污水时,生物法脱氮反硝化进程中碳源不足易导致脱氮效率偏低,需通过额外投加碳源进行补偿。外加碳源在污水脱氮过程中应用广泛,其投加量不易控制的缺陷可以通过利用缓释技术进行弥补。归纳了碳源缓释的特点及其在低C/N污水处理中的应用现状,总结了固体缓释碳源的不同类型及其在生物反硝化脱氮中的强化效果,对比分析不同缓释碳源在脱氮方面的优缺点。提出了目前缓释碳源应用的局限性,并对缓释碳源在生物反硝化脱氮领域的发展方向进行了展望。     

反硝化聚磷菌脱氮除磷机理研究

目前水体中氮磷含量较高的问题逐渐严重,利用反硝化聚磷菌来进行脱氮除磷的反硝化除磷工艺为生物脱氮除磷提供了新的方向。本研究以反硝化聚磷机理为基础,采用动态的SBR反应器进行菌种的富集培养,驯化富集反硝化聚磷菌,同时跟踪富集过程中污染物的去除情况。实验结果表明,富集成功后SBR系统内除磷率达到80%以上,总氮及COD的去除率达到90%左右,系统稳定且脱氮除磷效果较好。通过吸磷实验、反硝化脱氮产气实验从富集的活性污泥中,筛选出来4株反硝化聚磷菌。     

不同碳源条件下A/O-MBR的脱氮性能对比研究

碳源是影响脱氮效果的关键因素之一。在A/O-MBR中进行了葡萄糖、乙酸钠和厨余发酵液的脱氮性能对比。结果表明:3种碳源条件下反应器对NH4+-N的去除率都较高,达到98%以上;以葡萄糖为碳源时,反硝化作用不够彻底,TN去除率只有60%,而乙酸钠和厨余发酵液的反硝化作用明显,TN去除率达到80%。通过批式实验得出,葡萄糖的比反硝化速率最低,乙酸钠和厨余发酵液的比反硝化速率较高,且相当;同时,葡萄糖的反硝化COD利用效率也比乙酸钠和厨余发酵液低,说明其脱氮能力低于后两者。     

不同碳源对低温投加氧化还原介体污水生物反硝化脱氮过程的影响

低温污水生物反硝化脱氮效果差,投加氧化还原介体有利于反硝化过程,不同碳源对反硝化脱氮过程有不同影响。本文考察了不同碳源（丙酸钠、甲醇、乙醇及乙酸钠）对低温投加氧化还原介体1,2-萘醌-4-磺酸盐（NQS）污水生物反硝化脱氮过程的影响。以硝态氮、总氮、亚硝态氮浓度、去除率和脱氮速率、化学需氧量（COD）、氧化还原电位（ORP）的变化对不同碳源的影响进行了表征,发现丙酸钠为碳源时的反硝化速率最高,最高为7mgNO_x^--N/（gVSS·h）,分别是甲醇[0.88mgNO_x^--N/（gVSS·h）]、乙醇[2.72mgNO_x^--N/（gVSS·h）]和乙酸钠[1.97mgNO_x^--N/（gVSS·h）]为碳源时的8倍、2.6倍和3.6倍;硝态氮的最大去除率为61.5%,分别是甲醇（8.9%）、乙醇（6.6%）和乙酸钠（15.3%）为碳源时的6.9倍、9.3倍和4倍;总氮的最大去除率为47.4%,分别是甲醇（9.1%）、乙醇（10.3%）和乙酸钠（10.3%）为碳源时的5.2倍、4.6倍和4.6倍。     

Understanding the detrimental effect of nitrate presence on EBPR systems: effect of the plant configuration

The interaction between enhanced biological phosphorus removal (EPBR) and biological nitrogen removal may result in EBPR failure in full‐scale wastewater treatment plants (WWTPs). This work studies one of the common causes of this failure: the presence of nitrate in the anaerobic phase, which may act as an inhibitor for polyphosphate accumulating organisms (PAO) activity or may activate the competition between PAO and denitrifying bacteria for the carbon source. Several batch experiments were performed with different carbon sources (acetic acid, propionic acid and sucrose) at different nitrate concentrations using PAO‐enriched sludge from two different pilot plants: an anaerobic/aerobic sequential batch reactor (SBR) and an anaerobic/anoxic/aerobic (A²/O) continuous plant. The results imply that the operational conditions of the A²/O pilot plant selected a PAO population capable of i) coexisting with nitrate without an inhibitory effect and ii) outcompeting denitrifying bacteria for the carbon source, in contrast to the SBR pilot plant where nitrate had an inhibitory effect on EBPR. Copyright © 2012 Society of Chemical Industry     

固液碳源对反硝化脱氮及污泥产量影响研究

分别用乙酸钠和聚己内酯作为外加碳源,对反硝化滤池中固液碳源对污水厂出水脱氮的反硝化效果和污泥产量进行了对比研究。结果表明,液体碳源的反硝化速率更快,可达到2.19 g/(L·d),氮去除率最高可达到95%以上,固体碳源的反硝化速率低于液体碳源,受HRT的影响更大。固体碳源中NO2^--N几乎不积累,液体碳源更容易积累且积累量与HRT有关,2种碳源中均存在异化性硝酸盐还原成铵反应,但出水NO2^--N和NH4^+-N含量均未超标。固体碳源的出水COD稳定低于50 mg/L,当HRT缩短时,液体碳源出水COD存在超标的风险。液体碳源的浓缩污泥产量和单位污泥产量分别为固体碳源的3倍和1.6倍。使用固体碳源可以有效减少污泥的产生。     

反硝化除磷污泥系统驯化及其性能影响因素研究综述

传统生物脱氮除磷工艺存在碳源竞争、溶解氧需求大和菌群结构竞争等诸多问题,反硝化同步脱氮除磷能够在缺氧条件下以硝酸盐为电子受体,在脱氮的同时进行超量聚磷,实现氮磷同步去除,具有节约碳源、能源、污泥产量低等优点,符合污水处理工艺节能减排的绿色发展理念。反硝化聚磷污泥的驯化是运行反硝化同步脱氮除磷工艺的前提,文中综述了一步法、两步法和三步法这3种主要反硝化聚磷污泥的驯化方式,并对比分析研究进展。其中,一步法驯化具有运行操作简单、驯化速度快的特点;提出温度、pH、碳源种类及浓度、电子受体种类及浓度、污泥浓度、污泥龄的建议范围;同时提出同步反硝化除磷还需对碳源、电子受体等影响因素的作用机理等问题深化研究。     

Nitrate remediation in a novel upflow bio-electrochemical reactor (UBER) using palm shell activated carbon as cathode material

This study investigated the biological denitrification method which is a treatment method able to reduce inorganic nitrate compounds to harmless nitrogen gas. Autohydrogenotrophic denitrifying bacteria were used in this study to prevent any problematic outcomes associated with heterotrophic microorganisms. An upflow bio-electrochemical reactor (UBER) was used to accommodate hydrogenotrophic denitrifying bacteria employing palm shell granular activated carbon (GAC) as the biocarrier and cathode material. Bicarbonate as the external inorganic carbon source was fed to the reactor and hydrogen as the electron donor was generated in situ through electrolysis of water. Central composite design (CCD) and response surface methodology (RSM) were applied to investigate the effects of two operating parameters, namely electric current (I) and hydraulic retention time (HRT), on performance of the UBER. Electric current range of 0-20 mA and HRT range of 6-36 h were examined and results showed that nitrate can be entirely reduced within application of a wide operational range of electric current (10-16 mA) as well as HRT (13.5-30 h). However, increase of pH at cathode zone up to 10.5 inhibited nitrite reduction, and it was not reduced to the satisfactory level.     

外加碳源类型对A2/O-BCO系统脱氮除磷性能的影响

反硝化除磷系统可实现氮、磷的同步去除,但在处理实际低C/N污水时,常需补充碳源以解决碳源不足的问题。采用A²/O-BCO（anaerobic anoxic oxic-biological contact oxidation）反硝化除磷系统,通过投加两种常用的外碳源控制进水C/N在4.3左右,考察碳源类型（丙酸钠、乙酸钠）对A²/O-BCO系统长期运行效果的影响,并采用批次试验进一步探究不同外加碳源条件下活性污泥的内碳源贮存和利用特性。结果表明：碳源种类的变化会改变微生物的底物贮存和利用特性,进而影响系统的脱氮除磷效果。当采用丙酸钠为外加碳源时,PO₄^3--P去除效果稳定在94%左右,实现了磷的高效去除,但TIN的去除率仅为70.82%;而以乙酸钠为外加碳源时,系统TIN的平均去除率可以达到74%,但磷的出水浓度出现波动现象,平均去除率仅为89.90%。碳源转化分析表明,厌氧条件下,进水丙酸钠含量增多,PHV的合成比例增加,相反,乙酸钠含量增多,PHB合成比例增多;缺氧条件下,DPAOs对PHB和PHV的降解效果与其含量相关,丙酸钠作为外碳源时,PHV的降解速率高且微生物产能效率高,因此PO₄^3--P吸收速率较快。此外,本文提出了不同外加碳源条件下系统的优化运行策略。     

SBR法处理垃圾渗滤液的反硝化过程中NO~-_2积累的研究

The nitrite accumulation in the denitrification process is investigated with sequencing batch reactor (SBR) treating pre-treated landfill leachate in anoxic/anaerobic up-flow anaerobic sludge bed (UASB). Nitrite accumulates obviously at different initial nitrate concentrations (64.9,54.8,49.3 and 29.5 mg•L－1) and low temperatures, and the two break points on the oxidation-reduction potential (ORP) profile indicate the completion of nitrate and nitrite reduction. Usually, the nitrate reduction rate is used as the sole parameter to characterize the denitrification rate, and nitrite is not even measured. For accuracy, the total oxidized nitrogen (nitrate + nitrite) is used as a measure, though details characterizing the process may be overlooked. Additionally, batch tests are conducted to investigate the effects of C/N ratios and types of carbon sources on the nitrite accumulation during the denitrification. It is observed that carbon source is sufficient for the reduction of nitrate to nitrite, but for further reduction of nitrite to nitrogen gas, is deficient when C/N is below the theoretical critical level of 3.75 based on the stoichiometry of denitrification. Five carbon sources used in this work, except for glucose, may cause the nitrite accumulation. From experimental results and cited literature, it is concluded that Alcaligene species may be contained in the SBR activated-sludge system.     

反硝化聚磷污泥的基质利用及代谢途径

利用A/ASBR富集反硝化聚磷菌,并利用乙酸和葡萄糖两种基质进行反硝化聚磷实验,跟踪实验过程水中的磷酸盐、硝酸盐、COD与泥中PHA和糖原的变化,研究代谢途径。结果表明：（1）厌氧时磷酸盐的释放将决定PHA的合成,缺氧时PHA的分解一方面作为碳源将NO^-₃-N还原成了N₂,同时产生的ATP为聚磷过程提供能量,因此在研究反硝化聚磷效果时,应重点跟踪ΔPHA,而不是ΔCOD。（2）以葡萄糖为基质时只有先通过发酵型的菌将葡萄糖分解为小分子的挥发性有机酸,才能充分发挥非发酵菌的反硝化聚磷功能。（相似文献   

碳源类型和温度对BAF脱氮性能影响研究

以某钢铁厂的二级出水为研究对象,研究了曝气生物滤池(BAF)系统的挂膜,不同碳源类型和温度对该系统脱氮的影响。结果表明:利用含有硝化菌与好氧反硝化菌的富集菌液进行挂膜,16d基本完成挂膜,氨氮、硝态氮的去除率分别高达90.2%和92.2%。不同碳源类型对系统的脱氮性能影响存在差异,以葡萄糖和乙醇作为碳源时效果最佳,氨氮和硝态氮的去除率均超过85%,总无机氮去除率分别是93.4%、95.6%。乙酸钠为碳源时亚硝态氮的质量浓度积累最高达5.79mg/L,采用其它碳源时亚硝态氮几乎没有积累;当不投加外部碳源时,通过内源呼吸代谢作用进行硝化反硝化效果最差,总无机氮的去除率仅有20.4%。随着温度的上升,硝化和反硝化效果逐渐升高,其中硝化的最适温度是在27.3℃左右,氨氮的去除率高达91.1%,好氧反硝化过程对温度的耐受性比较好,在17.5～33.1℃时,平均去除率大于90%。     

Enhanced biological nutrient removal in modified carbon source division anaerobic anoxic oxic process with return activated sludge pre-concentration☆

A pilot-scale modified carbon source division anaerobic anoxic oxic (AAO) process with pre-concentration of returned activated sludge (RAS) was proposed in this study for the enhanced biological nutrient removal (BNR) of municipal wastewater with limited carbon source. The influent carbon source was fed in step while a novel RAS pre-concentration tank was adopted to improve BNR efficiency, and the effects of an influent carbon source distribution ratio and a RAS pre-concentration ratio were investigated. The results show that the removal efficiency of TN is mainly influenced by the carbon source distribution ratio while the TP removal relies on the RAS pre-concentration ratio. The optimum carbon source distribution ratio and RAS pre-concentration ratio are 60%and 50%, respectively, with an inner recycling ratio of 100%under the optimum steady operation of pilot test, reaching an average effluent TN concentration of 9.8 mg·L?1 with a removal efficiency of 63%and an average TP removal efficiency of 94%. The mechanism of nutrient removal is discussed and the kinetics is analyzed. The results reveal that the optimal carbon source distribution ratio provides sufficient denitrifying carbon source to each anoxic phase, reducing nitrate accumulation while the RAS pre-concentration ratio improves the condition of anaerobic zone to ensure the phosphorus release due to less nitrate in the returned sludge. Therefore, nitrifying bacteria, denitrifying bacteria and phosphorus accumulation organisms play an important role under the optimum condition, enhancing the performance of nutrient removal in this test.