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1.
干湿交替运行对地下渗滤系统脱氮效果的影响 总被引:4,自引:0,他引:4
利用室内模拟系统,在进水铵氮(NH4+-N)浓度30~37.5mg·L-1、水力负荷0.08m3.m-2.d-1的条件下,考察了干湿交替运行对污水地下渗滤系统脱氮效果的影响,分析了干湿比对基质理化性质、脱氮微生物数量以及基质氧化还原电位(ORP)变化的影响。结果表明,基质渗透率和硝化细菌的数量随干湿比的增加而增加,反硝化细菌的数量则随干湿比的增加而减少,比容积和氨化细菌的数量受干湿比的影响较小,各深度基质层ORP均随干湿交替运行而高低起伏。推荐地下渗滤系统启动期的干湿比3∶1,启动周期为20d;稳定运行期干湿比1∶1,NH4+-N及TN的去除率可分别达到86.9%和79.1%,同时,有机污染物去除效果好,出水水质满足再生利用-景观环境用水水质标准(GB/T18921—2002)。 相似文献
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异养硝化复合菌强化处理含氮废水脱氮性能研究 总被引:1,自引:0,他引:1
针对传统污水处理脱氮工艺过程中工艺流程复杂、处理高氨氮废水效率低等问题,利用三株不同种属的高效异养硝化-好氧反硝化细菌构建异养硝化复合菌YM,探讨其异养硝化-好氧反硝化特性及其生物强化脱氮效能研究,从而为异养硝化菌强化处理高氨氮废水工程应用提供理论依据。结果表明:异养硝化复合菌YM的增殖速率、异养氨氧化、好氧反硝化能力均优于单一菌种,YM强化后的污泥系统氨氧化速率较未强化系统从7.04 mg/L/h提高到12.2 mg/L/h,并且生物强化作用可有效提高污泥系统的抗冲击负荷能力,一定程度上提高了系统的处理能力。研究表明异养硝化菌强化污水脱氮处理具有显著的应用潜能,尤其对于目前尚缺少经济高效处理技术的高污染物浓度废水处理而言,无疑是一条具有高潜在应用价值的新途径。 相似文献
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水体氮素污染日益严重,如何经济、高效地去除水体氮素已成为研究热点。近年来,研究人员已从不同环境中分离到许多同时具有异养硝化和好氧反硝化功能的菌株,此类菌生长迅速,可在好氧条件下同时实现硝化和反硝化的过程,并可用于脱除有机污染物,是一类应用潜力巨大的脱氮菌。目前,异养硝化-好氧反硝化菌的脱氮途径和机制主要是通过测定氮循环中间产物或终产物、测定相关酶活性、注释部分氮循环相关基因及参考自养硝化菌和缺氧反硝化菌的氮循环途径等进行研究,其完整的氮素转化途径和氮代谢机制还需要进一步明确。总结了目前异养硝化-好养反硝化菌的脱氮相关酶系及其编码基因的研究进展,以期为异养硝化-好氧反硝化菌的理论研究及其在污水脱氮处理上的应用提供参考。 相似文献
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从沈阳市南部污水处理厂活性污泥中分离获得同时具备异养硝化和好氧反硝化能力的新型菌株,研究其脱氮特性,为改善污水厂的脱氮处理工艺奠定基础。对菌株进行形态学观察和16S rRNA基因鉴定;分别以NH4Cl、NaNO2、KNO3为唯一氮源探究菌株的脱氮能力;以碳源、C/N比、pH值、温度、转速、接种量(V∶V)等因素对菌株脱氮效果的影响进行研究。获得一株新型异养硝化-好氧反硝化菌株,经16S rRNA基因序列比对为副球菌属(Paracoccus),命名为Paracoccus sp. QD-19。菌株对初始氨氮浓度在300 mg/L以下的低浓度氨氮去除率能够达到100%,去除速率为8.707 mg/(L·h)且在脱氮过程中几乎没有亚硝态氮和硝态氮的积累。以亚硝态氮和硝态氮作为唯一氮源时,对此两种氮源的去除率36 h内均能达到99%,去除速率分别为4.944和5.666mg/(L·h)。确定了去除氨氮的最佳脱氮条件:琥珀酸钠为碳源,C/N比为10,pH值为7,接种量(V:V)为1%,温度为30℃,转速为140 r/min。菌株Pa... 相似文献
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【目的】探究甲烷浓度、温度和氮浓度对好氧甲烷氧化耦合反硝化(AME-D)极限脱氮系统的影响,分析该系统微生物群落结构,并对贵阳某污水处理厂尾水进行应用研究。【方法】采用阶段性实验研究甲烷浓度、温度和氮浓度对系统脱氮效能的影响,通过16SrRNA基因测序技术分析系统中微生物群落结构,利用共焦显微拉曼光谱仪分析实际废水水质变化特征。【结果】甲烷进气比为3%、温度为30°C、氮浓度为20 mg/L时脱氮效果最好,系统的总氮、氨氮和硝酸盐氮平均去除率分别为93.66%、96.13%和92.25%;系统中的主要甲烷氧化菌分别为Methylosarcina(1.84%)、Methylovulum(0.01%)和Crenothrix(0.14%),以及兼性甲烷氧化菌属Methylocystis(1.9%),主要的亚硝化菌为Nitrosomonas(0.008%),硝化菌为Nitrospira (0.42%),反硝化菌为Hyphomicrobium (1.19%)和Pseudomonas (0.61%);采用该系统处理贵阳某污水处理厂尾水时,出水总氮平均浓度达到0.96mg/L,能达到极限脱氮的目的,拉曼光谱分析显示系统对硝酸盐氮和亚硝酸盐氮有较高的去除,甲烷被氧化形成的中间产物可能为醇类或醛类物质,为反硝化菌提供所需碳源。【结论】AME-D极限脱氮由多种微生物协同实现,其功能微生物为甲烷氧化菌、亚硝化菌、硝化菌和反硝化菌,应用研究显示该系统在城镇污水处理系统中具有较大的应用潜力。 相似文献
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通过逐步提高进水中的有机碳源浓度,探讨进水碳氮比(C/N)对基于亚硝化的全程自养脱氮(CANON)型潮汐流人工湿地(TFCW)脱氮效能及其微生物特性的影响.结果表明: 进水C/N可显著影响CANON型TFCW中脱氮功能微生物的数量与活性,进而影响其氮素转化速率.当进水C/N由0.0增至6.0时,TFCW中反硝化功能基因的丰度随之增加,系统反硝化性能提高,TFCW中逐渐形成同步亚硝化、厌氧氨氧化与反硝化(SNAD)耦合反应体系,其脱氮效果得以强化.当进水C/N>6.0时,好氧氨氧化菌活性受到抑制,数量逐渐减少,TFCW中的厌氧氨氧化作用与反硝化作用受阻,系统脱氮性能恶化.当进水C/N为6.0时,TFCW中的SNAD作用可得到最大限度的强化,其总氮(TN)去除率和去除负荷分别达(93.3±2.3)%和(149.30±8.00) mg·L-1·d-1,高于CANON系统中TN去除率的理论值. 相似文献
11.
Seong Jin Lim Yeong Hee Ahn Eun Young Kim Ho Nam Chang 《Biotechnology and Bioprocess Engineering》2006,11(6):538-543
A packed bed reactor (PBR) was fed with nitrate containing synthetic wastewater or effluent from a sequencing batch reactor
used for nitrification. The C source introduced into the PBR consisted of volatile fatty acids (VFAs) produced from anaerobic
acidogenesis of food wastes. When nitrate loading rates ranged from 0.50 to 1.01 kg N/m3·d, the PBR exhibited 100∼98.8% NO3
−-N removal efficiencies and nitrite concentrations in the effluent ranged from 0 to 0.6 NO2
−-N mg/L. When the PBR was further investigated to determine nitrate removal activity along the bed height using a nitrate
loading rate less than 1.01 kg N/m3·d, 100% nitrate removal efficiency was observed. Approximately 83.2% nitrate removal efficiency was observed in the lower
50% of the packed-bed height. When reactor performance at a C/N ratio of 4 and a C/N ratio of 5 was compared, the PBR showed
better removal efficiency (96.5%) of nitrate and less nitrite concentration in the effluent at the C/N ratio of 5. VFAs were
found to be a good alternative to methanol as a carbon source for denitrification of a municipal wastewater containing 40
mg-N/L. 相似文献
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《Journal of Fermentation and Bioengineering》1993,75(4):304-308
Propionate and NH4+ were accumulated in the effluent during anaerobic treatment of five-fold diluted distillery wastewater from shochu making. Propionate could be removed efficiently during biological denitrification by the addition of NO3− (4.2 g/l) to the anaerobically treated wastewater. At a hydraulic retention time of more than 2 h, a TOC removal efficiency of 90% could be achieved. The wastewater was then treated aerobically by biological nitrification. With a hydraulic retention time of more than 14 h the efficiency of reduction of NH4+ could be maintained above 97%. In order to reduce the amount of NO3− addition necessary for the removal of propionate, simultaneous removal of propionate and NH4+ was studied by recirculating the effluent from a nitrification process to a denitrification process using denitrification and nitrification reactors connected in series. At a recirculation ratio of 2, the amount of NO3− that had to be added was reduced to 0.3 g/l of anaerobically treated wastewater, which corresponds to 6.9% of the theoretical value. Under the same conditions except for the addition of NO3− at 1.0 g/l, TOC and BOD in the effluent from the nitrification were 23 and 5 mg/l respectively, which are sufficiently low to allow discharge into river water. Moreover, the NO3− concentration in the effluent decreased with increases in the recirculation ratio. 相似文献
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Effects of hydraulic loading rate on pollutants removal by a deep subsurface wastewater infiltration system 总被引:1,自引:0,他引:1
The subsurface wastewater infiltration (SWI) system proved to be an effective and low-cost technique for decentralized sewage treatment in areas without adequate domestic treatment facilities. Field-scale experiments were conducted through a deep SWI system, with effective depth of 1.5 m, under hydraulic loading rates of 0.040, 0.065, 0.081 and 0.10 m3/m2 d. Taking the hydraulic and treatment efficiencies into consideration, the hydraulic loading rate of 0.081 m3/m2 d was recommended. Under this condition, NH3-N, TN, and COD removal efficiencies were 86.2 ± 3.0, 80.7 ± 1.9 and 84.8 ± 2.1%, respectively. In the effluent, NH3-N concentration declined to 2.3-4.4 mg/L, accounting for 63.2-65.6% of TN. NO3-N concentration increased from 0.2 to 0.3 mg/L in the influent to 2.0-2.5 mg/L in the effluent. The nitrifying bacteria number declined with increased depth, while the amount of denitrifying bacteria increased. The analysis of results about the nitrifying and denitrifying bacteria distribution indicated that the most effective ranges for nitrification and denitrification process were 0.3-0.7 m and 0.7-1.5 m, respectively. 相似文献
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The performance of an intermittently aerated sequencing batch reactor (IASBR) technology was investigated in achieving partial
nitrification, organic matter removal and nitrogen removal from separated digestate liquid after anaerobic digestion of pig
manure. The wastewater had chemical oxygen demand (COD) concentrations of 11,540 ± 860 mg/L, 5-day biochemical oxygen demand
(BOD5) concentrations of 2,900 ± 200 mg/L and total nitrogen (TN) concentrations of 4,041 ± 59 mg/L, with low COD:N ratios (2.9)
and BOD5:COD ratios (0.25). Synthetic wastewater, simulating the separated digestate liquid with similar COD and nitrogen concentrations
but BOD5 of 11,500 ± 100 mg/L, was also treated using the IASBR technology. At a mean organic loading rate of 1.15 kg COD/(m3 d) and a nitrogen loading rate of 0.38 kg N/(m3 d), the COD removal efficiency was 89.8% in the IASBR (IASBR-1) treating digestate liquid and 99% in the IASBR (IASBR-2)
treating synthetic wastewater. The IASBR-1 effluent COD was mainly due to inert organic matter and can be further reduced
to less than 40 mg/L through coagulation. The partial nitrification efficiency of 71–79% was achieved in the two IASBRs and
one cause for the stable long-term partial nitrification was the intermittent aeration strategy. Nitrogen removal efficiencies
were 76.5 and 97% in IASBR-1 and IASBR-2, respectively. The high nitrogen removal efficiencies show that the IASBR technology
is a promising technology for nitrogen removal from low COD:N ratio wastewaters. The nitrogen balance analysis shows that
59.4 and 74.3% of nitrogen removed was via heterotrophic denitrification in the non-aeration periods in IASBR-1 and IASBR-2,
respectively. 相似文献
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Zhaoming Zheng Jun Li Jing Ma Jia Du Wei Bian Yun Li Yanzhuo Zhang Baihang Zhao 《Biodegradation》2016,27(4-6):195-208
The simultaneous partial nitrification, anammox and denitrification (SNAD) process for treating domestic wastewater was investigated in a sequencing batch reactor (SBR). The SBR was operated with air flow rate of 500 L h?1 at 30 °C. Domestic wastewater was used as influent and Kaldnes rings were used as biomass carriers. In the beginning, long aeration condition was implemented to cultivate nitrification biofilm. Afterwards, intermittent aerobic condition was conducted during the cycle operation. The influent organic matter loading rate was improved by reducing the aeration and mixing times. Consequently, when the SNAD biofilm reactor was fed with the organic matter loading rate of 0.77 (kg COD m?3 d?1), the bio-bubbles appeared in the reactor and the total inorganic nitrogen (TIN) removal efficiency decreased. After the organic matter loading rate decreased to 0.67 (kg COD m?3 d?1), the reactor showed excellent nitrogen removal performance. The TIN removal efficiency varied between 80 and 90 %, and the average TIN removal loading rate was 0.22 (kg TIN m?3 d?1). Additionally, the scanning electron microscope (SEM) observation confirmed that the anammox bacteria located in the inner part of the carriers. Finally, the microbial community analysis of 16S rRNA gene cloning revealed that the anammox bacteria on the carriers consisted of three main genuses: Candidatus Brocadia sp., Candidatus Brocadia caroliniensis and Candidatus Brocadia fulgida. 相似文献
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Control of carbon and ammonium ratio for simultaneous nitrification and denitrification in a sequencing batch bioreactor 总被引:1,自引:0,他引:1
《International biodeterioration & biodegradation》2007,59(1):1-7
This study shows how the carbon and nitrogen (C/N) ratio controls the simultaneous occurrence of nitrification and denitrification in a sequencing batch reactor (SBR). Data demonstrated that a low C/N ratio resulted in a rapid carbon deficit, causing an unbalanced simultaneous nitrification–denitrification (SND) process in SBR. When the initial COD/NH4+-N ratio was adjusted to 11.1, the SND-based SBR achieved complete removal of NH4-N and COD without leaving any NO2−-N in the effluent. The nitrogen removal efficiency decreases gradually with increasing ammonium-loading rate to the SND–SBR system. Altogether, data showed that appropriate controls of carbon and nitrogen input are required to achieve an efficient SND–SBR. An established SND technology can save operation time and energy, and might replace the traditional two-stage biological nitrification and denitrification process. 相似文献
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Effect of alum on nitrification during simultaneous phosphorous removal in anoxic/oxic reactor 总被引:1,自引:0,他引:1
J. Rajesh Banu Khac-Uan Do S. Kaliappan Ick-Tae Yeom 《Biotechnology and Bioprocess Engineering》2009,14(4):543-548
Phosphorus and nitrogen are the important eutrophication nutrients. They are removed in the anoxic/oxic reactor through simultaneous
precipitation and biological nitrogen removal. The effect of alum a commonly used simultaneous precipitant on biological nitrification
and denitrification are investigated in the present study. Simultaneous removal of phosphorus was carried out using the coagulant
alum Al2(SO4)3·14H2O at 2.2 mol ratio. Before the start of simultaneous precipitation the nitrification rate of the A/O reactor was found to
be 0.05 g N-NH4
+/g VSS/d. It starts to decrease with increase in coagulant dosage. The nitrification rate for alum dosage 97.13 mg/L was 0.38
g N- NH4
+/g VSS/d. There was no accumulation of nitrate in anoxic tank. The nitrogen removal efficiency of the reactor was affected
and it fell from 88 to 78%. There was a slight decrease in effluent COD from 16∼20 mg/L to 8∼12 mg/L after the introduction
of simultaneous precipitation into the reactor. The usage of alum as a simultaneous precipitant in the anoxic/oxic reactor
was limited due to its inhibition on nitrification. Alum did not have any affect over denitrification process. 相似文献
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J. Rajesh Banu Khac-Uan Do Ick-Tae Yeom 《World journal of microbiology & biotechnology》2008,24(12):2981-2986
In the present study a laboratory scale anoxic/oxic reactor was used to remove the important eutrophication nutrients such
as phosphorus and nitrogen from synthetic domestic wastewater. Phosphorus was removed through simultaneous precipitation and
was carried out using the coagulant ferrous sulphate FeSO4 · 7H2O. Total phosphorus in the effluent was controlled to below 1 mg/l using a ferrous to phosphorus molar ratio of 2.1. pH after
the addition of coagulant plays a major role in determining the molar ratio of the precipitant. Nitrogen was removed biologically
in the anoxic/oxic system and the effect of simultaneous precipitation on nitrification and denitrification was investigated.
The nitrification rate of the system remained unaffected during simultaneous precipitation and varied from 0.046 to 0.059 g N–NH4
+/g VSS/day. Denitrification was complete and was not affected by the coagulation process. The nitrogen removal efficiency
varied from 78% to 85%. COD removal efficiency was not affected during simultaneous precipitation and was varied from 94%
to 98%. The highly efficient nitrogen removal in the presence of simultaneous precipitant ferrous sulphate makes the process
an ideal option for nutrient removal. 相似文献
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限氧自养硝化-反硝化生物脱氮新技术 总被引:10,自引:0,他引:10
限氧自养硝化—反硝化是部分硝化与厌氧氨氧化相耦联的生物脱氮反应过程,通过严格控制溶解氧在0.1~0.3mg·L^-1,实现硝化反应控制在亚硝酸阶段,然后以硝化阶段剩余的NH4^+作为电子供体,在厌氧条件下实现反硝化,该反应过程是完全的自养硝化—反硝化过程,具有能耗低、脱氮效率高、反应系统占地面积小等优点,适用于处理COD/NH4^+—N低的废水,是一种非常有应用前景的生物脱氮技术,文中详细介绍了限氧自养硝化—反硝化生物脱氮反应过程的研究进展,讨论了其微生物学机理及应用前景。 相似文献
20.
Lihua Cui Ying Ouyang Qian Lou Fengle Yang Ying Chen Wenling Zhu Shiming Luo 《Ecological Engineering》2010,36(8):1083-1088
Constructed wetlands are becoming increasingly popular worldwide for removing contaminants from domestic wastewater. This study investigated the removal efficiency of nitrogen (N) and phosphorus (P) from wastewater with the simulated vertical-flow constructed wetlands (VFCWs) under three different substrates (i.e., BFAS or blast furnace artificial slag, CBAS or coal burn artificial slag, and MSAS or midsized sand artificial slag), hydraulic loading rates (i.e., 7, 14, and 21 cm d?1), and wetland operational periods (0.5, 1, and 2 years) as well as with and without planting Canna indica L. The wastewater was collected from the campus of South China Agricultural University, Guangzhou, China. Results show that the percent removal of total P (TP) and ammonium N (NH4+-N) by the substrates was BFAS > CBAS > MSAS due to the high contents of Ca and Al in substrate BFAS. In contrast, the percent removal of total N (TN) by the substrates was CBAS > MSAS > BFAS due to the complicated nitrification/denitrification processes. The percent removal of nutrients by all of the substrates was TP > NH4+-N > TN. About 10% more TN was removed from the wastewater after planting Canna indica L. A lower hydraulic loading rate or longer hydraulic retention time (HRT) resulted in a higher removal of TP, NH4+-N, and TN because of more contacts and interactions among nutrients, substrates, and roots under the longer HRT. Removal of NO3?N from the simulated VFCWs is a complex process. A high concentration of NO3?N in the effluent was observed under the high hydraulic loading rate because more NH4+-N and oxygen were available for nitrification and a shorter HRT was unfavorable for denitrification. In general, a longer operational period had a highest removal rate for nutrients in the VFCWs. 相似文献