Microbial characterization of nitrification in a shallow, nitrogen-contaminated aquifer, Cape Cod, Massachusetts and detection of a novel cluster associated with nitrifying Betaproteobacteria.
نویسندگان
چکیده
Groundwater nitrification is a poorly characterized process affecting the speciation and transport of nitrogen. Cores from two sites in a plume of contamination were examined using culture-based and molecular techniques targeting nitrification processes. The first site, located beneath a sewage effluent infiltration bed, received treated effluent containing O2 (>300 microM) and NH4+ (51-800 microM). The second site was 2.5 km down-gradient near the leading edge of the ammonium zone within the contaminant plume and featured vertical gradients of O2, NH4+, and NO3- (0-300, 0-500, and 100-200 microM with depth, respectively). Ammonia- and nitrite-oxidizers enumerated by the culture-based MPN method were low in abundance at both sites (1.8 to 350 g(-1) and 33 to 35,000 g(-1), respectively). Potential nitrifying activity measured in core material in the laboratory was also very low, requiring several weeks for products to accumulate. Molecular analysis of aquifer DNA (nested PCR followed by cloning and 16S rDNA sequencing) detected primarily sequences associated with the Nitrosospira genus throughout the cores at the down-gradient site and a smaller proportion from the Nitrosomonas genus in the deeper anoxic, NH4+ zone at the down-gradient site. Only a single Nitrosospira sequence was detected beneath the infiltration bed. Furthermore, the majority of Nitrosospira-associated sequences represent an unrecognized cluster. We conclude that an uncharacterized group associated with Nitrosospira dominate at the geochemically stable, down-gradient site, but found little evidence for Betaproteobacteria nitrifiers beneath the infiltration beds where geochemical conditions were more variable.
منابع مشابه
Simulation of a Solvent Plume in a Sand and Gravel Aquifer in Cape Cod , Massachusetts Using a 3 - D Numerical Model
AND GRAVEL AQUIFER IN CAPE COD, MASSACHUSETTS USING A 3-D NUMERICAL MODEL by ALBERTO M. LAZARO B.S., Civil Engineering Cornell University, 1995 Submitted to the Department of Civil and Environmental Engineering In Partial Fulfillment of the Requirements for the Degree of MASTER OF ENGINEERING in Civil and Environmental Engineering at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY June 1996 © 1996 Ma...
متن کاملEffect of Dissolved Oxygen and Chemical Oxygen Demand to Nitrogen Ratios on the Partial Nitrification/Denitrification Process in Moving bed Biofilm Reactors
Partial nitrification was reported to be technically feasible and economically favorable, especially for wastewaterwith high ammonium concentration or low C/N ratio. In this study, the effect of dissolved oxygen (DO)and influent ratio of chemical oxygen demand to nitrogen (COD/N) ratio on biological nitrogen removal fromsynthetic wastewater was investigated. Experiments were c...
متن کاملEffect of wastewater COD/N ratio on aerobic nitrifying sludge granulation and microbial population shift.
The effect of COD/N ratio on the granulation process and microbial population succession was investigated. Four identical sequencing batch reactors, R1, R2, R3 and R4, were operated with various initial COD/N ratios ranging from 0/200 to 800/200 (m/m). Ethanol was fed as the source of COD. Aerobic granules were successfully cultivated in R2 and R3, operating with the COD/N ratio of 200/200 and ...
متن کاملStudy on Nitrification and Denitrification of High Nitrogen and COD Load Wastewater in Moving Bed Biofilm Reactor
متن کامل
Nitrogen removal in a single-chamber microbial fuel cell with nitrifying biofilm enriched at the air cathode.
Nitrogen removal is needed in microbial fuel cells (MFCs) for the treatment of most waste streams. Current designs couple biological denitrification with side-stream or combined nitrification sustained by upstream or direct aeration, which negates some of the energy-saving benefits of MFC technology. To achieve simultaneous nitrification and denitrification, without extra energy input for aerat...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of contaminant hydrology
دوره 103 3-4 شماره
صفحات -
تاریخ انتشار 2009