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Marine bacterial community plays a vital role in the formation of the hypoxia zone in coastal oceans. Yet, their dynamics in the seasonal hypoxia zone of the Bohai Sea(BHS) are barely studied. Here, the 16S r RNA gene-based high-throughput sequencing was used to explore the dynamics of their diversity, structure, and function as well as driving factors during the gradual deoxygenation process in the BHS. Our results evinced that the bacterial community was dominated by Proteobacteria, followed b... 相似文献
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IntroductionNitrificationisaprocessinwhichammoniumformofnitrogenisconvertedintonitrateform .Nitrogenuseefficiencyintermsofplantuptakeisgenerallylowandvariesgreatlyunderdifferentsoilandcroppingconditions.MostfertilizerNappliedtosoilsisintheformofammonium orammoniumproducingcompoundssuchasurea,andisusuallyoxidizedrapidlytonitratebynitrifyingmicroorganismsinsoils.Applicationofnitrogenfertilizersmorethanoptimumlevelsleadstolownitrogenrecoveriesandgreaternitrogenaccumulationinthesoilprofile .Theac… 相似文献
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Ground level ozone is responsible for the formation ofsmog, and for a variety of adverse effects on bothhuman and plant life. High concentrations of groundlevel ozone occur during the summer months. This paperdescribes the development of a model to forecast themaximum daily concentration of ozone as a function ofthe maximum surface temperature, for ozonenon-attainment regions in Ohio. The model wasdeveloped by statistical analysis of existing data.Site-specific models were developed initially. Theverification and evaluation of the performancecriteria of the model at each site were explored bycomparing the model with an independent datasetcollected from that site. A generalized statewidemodel was developed from the site-specific models. Theperformance criteria of this model were verified andevaluated by employing the same independent datasetsemployed for the site-specific models. An exceedencemodel to predict the occurrence of ozone exceedencesover 100 ppb has also been presented. 相似文献
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Amit Dhir Nagaraja Tejo Prakash Dhiraj Sud 《Environmental science and pollution research international》2012,19(9):3906-3913
This study evaluates the effect of integrated solar-assisted advanced oxidation process (AOP) and biological treatment on the extent of degradation of effluents from chlorination (C) and first alkaline extraction (E1) stages of soda pulp bleaching in agro-residue-based pulp and paper mill. Biodegradation of the effluents was attempted in suspended mode using activated sludge from the functional pulp and paper industry effluent treatment plant acclimatized to effluents in question. The photocatalytic treatment was employed using zinc oxide (ZnO) in slurry mode for decontamination of effluents in a batch manner and the degradation was evaluated in terms of reduction in chemical oxygen demand. The biological treatment (24?h) of C and E1 effluent resulted in 30 and 57?% of degradation, respectively. Solar-induced AOP of C and E1 effluents resulted in 53 and 43?% degradation under optimized conditions (2.5?g?L?1 ZnO at pH?8.0) after 6?h of exposure. For C effluent, a short duration of solar/ZnO (1?h) prior to biological treatment reduced the time required at biological step from 24 to 12?h for almost same extent (92?%) of degradation. However, sequential biological treatment (24?h) followed by solar/ZnO (2?h) resulted in 85.5?% degradation. In contrast, in the case of E1 effluent, sequential biological (24?h)?Csolar/ZnO (2?h) system effectively degrades effluent to 95.4?% as compared to 84.8?% degradation achieved in solar/ZnO (2?h)?Cbiological treatment (24?h) system. In the present study, the sequencing of photocatalysis with the biological treatment is observably efficient and technically viable process for the complete mineralization of the effluents. 相似文献
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