共查询到15条相似文献,搜索用时 78 毫秒
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短程硝化--反硝化生物脱氮工艺的研究进展 总被引:2,自引:0,他引:2
短程硝化反硝化生物脱氮工艺是将硝化控制在形成亚硝酸阶段,阻止亚硝酸的进一步硝化,然后直接进行反硝化。本文结合国内外的研究,对短程硝化脱氮技术的实现途径进行了概括和探讨,对该工艺的开发应用(如SHARON工艺、OLAND工艺、CANONT艺和生物膜/活性污泥法结合的短程硝化反硝化工艺)作了简要综述,并指出了该工艺的技术优势和应用价值。 相似文献
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利用反硝化聚磷菌实现城市污水的脱氮除磷 总被引:4,自引:0,他引:4
阐述了反硝化除磷的机理,对现有反硝化除磷工艺进行介绍,并进一步讨论了反硝化除磷的影响因素和未来发展新思路。利用DPBs进行反硝化除磷实现了污水处理的资源化和能源化,代表了当前污水处理可持续发展战略的发展趋势,成为目前脱氮除磷技术研究的热点和重点。 相似文献
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阐述了反硝化除磷的机理,对现有反硝化除磷工艺进行介绍,并进一步讨论了反硝化除磷的影响因素和未来发展新思路。利用DPBs进行反硝化除磷实现了污水处理的资源化和能源化,代表了当前污水处理可持续发展战略的发展趋势,成为目前脱氮除磷技术研究的热点和重点。 相似文献
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孙蕾 《中国环境管理干部学院学报》2015,(3):67-69,73
基于对生物硝化反硝化原理的分析,本实验选用两段SBR工艺生物脱氮技术,解决了高浓度工业废水有机物去除效率高而氨氮去除率不高的难题。同时对其脱氮规律作了研究,找到SBR2是脱氮的关键环节,并分别对SBR2硝化反硝化阶段p H和DO的变化规律进行了研究,得出用这两个参数作为系统自动控制的依据是完全可行的。 相似文献
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This study describes the spatial variability in nitrogen (N) transformation within a constructed wetland (CW) treating domestic effluent. Nitrogen cycling within the CW was driven by settlement and mineralization of particulate organic nitrogen and uptake of NO3-. The concentration of NO3- was found to decrease, as the delta15N-NO3- signature increased, as water flowed through the CW, allowing denitrification rates to be estimated on the basis of the degree of fractionation of delta15N-NO3-. Estimates of denitrification hinged on the determination of a net isotope effect (eta), which was influenced byprocesses that enrich or deplete 15NO3- (e.g., nitrification), as well as the rate constants associated with the different processes involved in denitrification (i.e., diffusion and enzyme activity). The influence of nitrification on eta was quantified; however, it remained unclear how eta varied due to variability in denitrification rate constants. A series of stable isotope amendment experiments was used to further constrain the value of eta and calculate rates of denitrification, and nitrification, within the wetland. The maximum calculated rate of denitrification was 956 +/- 187 micromol N m(-2) h(-1), and the maximum rate of nitrification was 182 +/- 28.9 micromol N m(-2) h(-1). Uptake of NO3- was quantitatively more important than denitrification throughoutthe wetland. Rates of N cycling varied spatially within thewetland, with denitrification dominating in the downstream deoxygenated region of the wetland. Studies that use fractionation of N to derive rate estimates must exercise caution when interpreting the net isotope effect. We suggest a sampling procedure for future natural abundance studies that may help improve the accuracy of N cycling rate estimates. 相似文献
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Nitrification and denitrification rates of Everglades wetland soils along a phosphorus-impacted gradient 总被引:2,自引:0,他引:2
Little information is available on the effect of phosphorus (P) enrichment on nitrogen (N) biogeochemical cycling in wetland soil. Of particular importance are the coupled nitrification-denitrification reactions that regulate the microbially mediated loss of N from wetland systems. Soils from the northern Florida Everglades have been affected by P loading from surface waters over the past 40 years. Elevated P levels have been show to have an effect on the size and activity of the microbial pool and a decrease in the N to P ratio of the microbial biomass. The objective of the study was to determine if P enrichment in soils affected microbial activities related to nitrification and denitrification in these flooded, peat soils. Potential nitrification rates of soil and detritus were determined using constantly stirred reactors under aerobic conditions while denitrification rates were determined from anaerobic incubations of slurry. Nitrification rates showed two distinct linear phases, a slower initial rate, signifying activity of nitrifiers present, followed by a sharp increase in the NH4+ conversion rate indicative of maximum potential rates. Initial rates of nitrification were highest in the surficial detrital layer decreasing with soil depth and did not correlate to soil total P. The potential rates of nitrification were 13 times greater than the initial rates. Potential denitrification rates were highest in the detritus and 0- to 10-cm soil interval with significantly lower values in the 10- to 30-cm soil interval, significantly correlated to total P of the soil. A significant (P < 0.01) relationship was seen between potential denitrification rates and soil total P suggesting an increased rate of N removal from P-enriched regions of the northern Everglades. 相似文献
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Townsend-Small A Pataki DE Tseng LY Tsai CY Rosso D 《Journal of environmental quality》2011,40(5):1542-1550
Nitrous oxide (N?O) is a long-lived and potent greenhouse gas produced during microbial nitrification and denitrification. In developed countries, centralized water reclamation plants often use these processes for N removal before effluent is used for irrigation or discharged to surface water, thus making this treatment a potentially large source of N?O in urban areas. In the arid but densely populated southwestern United States, water reclamation for irrigation is an important alternative to long-distance water importation. We measured N?O concentrations and fluxes from several wastewater treatment processes in urban southern California. We found that N removal during water reclamation may lead to in situ N?O emission rates that are three or more times greater than traditional treatment processes (C oxidation only). In the water reclamation plants tested, N?O production was a greater percentage of total N removed (1.2%) than traditional treatment processes (C oxidation only) (0.4%). We also measured stable isotope ratios (δN and δO) of emitted N?O and found distinct δN signatures of N?O from denitrification (0.0 ± 4.0 ‰) and nitrification reactors (-24.5 ± 2.2 ‰), respectively. These isotope data confirm that both nitrification and denitrification contribute to N?O emissions within the same treatment plant. Our estimates indicate that N?O emissions from biological N removal for water reclamation may be several orders of magnitude greater than N?O emissions from agricultural activities in highly urbanized southern California. Our results suggest that wastewater treatment that includes biological nitrogen removal can significantly increase urban N?O emissions. 相似文献
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Potential nitrification and denitrification on different surfaces in a constructed treatment wetland
Kallner Bastviken S Eriksson PG Martins I Neto JM Leonardson L Tonderski K 《Journal of environmental quality》2003,32(6):2414-2420
Improved understanding of the importance of different surfaces in supporting attached nitrifying and denitrifying bacteria is essential if we are to optimize the N removal capacity of treatment wetlands. The aim of this study was therefore to examine the nitrifying and denitrifying capacity of different surfaces in a constructed treatment wetland and to assess the relative importance of these surfaces for overall N removal in the wetland. Intact sediment cores, old pine and spruce twigs, shoots of Eurasian watermilfoil (Myriophyllum spicatum L.), and filamentous macro-algae were collected in July and November 1999 in two basins of the wetland system. One of the basins had been constructed on land that contained lots of wood debris, particularly twigs of coniferous trees. Potential nitrification was measured using the isotope-dilution technique, and potential denitrification was determined using the acetylene-inhibition technique in laboratory microcosm incubations. Nitrification rates were highest on the twigs. These rates were three and 100 times higher than in the sediment and on Eurasian watermilfoil, respectively. Potential denitrification rates were highest in the sediment. These rates were three times higher than on the twigs and 40 times higher than on Eurasian watermilfoil. The distribution of denitrifying bacteria was most likely due to the availability of organic material, with higher denitrification rates in the sediment than on surfaces in the water column. Our results indicate that denitrification, and particularly nitrification, in treatment wetlands could be significantly increased by addition of surfaces such as twigs. 相似文献