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Wu H.-Z.,Fuzhou University | Qiu L.-F.,Fuzhou University | Su M.-P.,Fuzhou University | Chen Y.-M.,Fujian Provincial Academy of Environmental Science
Environment, Energy and Sustainable Development - Proceedings of the 2013 International Conference on Frontier of Energy and Environment Engineering, ICFEEE 2013 | Year: 2014

This paper reported a study on controlling alkalinity method in partial nitrification to produce the correct influent for anaerobic ammonium oxidation (anammox) process. The start-up of the partial nitrification realized within 8 days at a high temperature (35±0.1 °C) and free ammonia (17.7 mg/L). And the bacteria were almost coccus, so the Ammonium-Oxidizing Bacteria (AOB) affiliated to Nitrosococcus in a preliminary estimate. When the molar ratio of bicarbonate to ammonium was 1:1, the effluent of the Sequencing Batch Reactor (SBR) could be effectively suitable for a subsequent anammox process with the molar ratio of ammonium to nitrite of 1:1. © 2014 Taylor & Francis Group, London. Source


Sun F.,Nanjing University | Kolvenbach B.A.,University of Applied Sciences and Arts Northwestern Switzerland | Nastold P.,University of Applied Sciences and Arts Northwestern Switzerland | Jiang B.,Fujian Provincial Academy of Environmental Science | And 3 more authors.
Environmental Science and Technology | Year: 2014

Contamination by tetrabromobisphenol A (TBBPA), the most widely used brominated flame retardant, is a matter of environmental concern. Here, we investigated the fate and metabolites of 14C-TBBPA in a submerged soil with an anoxic-oxic interface and planted or not with rice (Oryza sativa) and reed (Phragmites australis) seedlings. In unplanted soil, TBBPA dissipation (half-life 20.8 days) was accompanied by mineralization (11.5% of initial TBBPA) and the substantial formation (60.8%) of bound residues. Twelve metabolites (10 in unplanted soil and 7 in planted soil) were formed via four interconnected pathways: oxidative skeletal cleavage, O-methylation, type II ipso-substitution, and reductive debromination. The presence of the seedlings strongly reduced 14C-TBBPA mineralization and bound-residue formation and stimulated debromination and O-methylation. Considerable radioactivity accumulated in rice (21.3%) and reed (33.1%) seedlings, mainly on or in the roots. While TBBPA dissipation was hardly affected by the rice seedlings, it was strongly enhanced by the reed seedlings, greatly reducing the half-life (11.4 days) and increasing monomethyl TBBPA formation (11.3%). The impact of the interconnected aerobic and anaerobic transformation of TBBPA and wetland plants on the profile and dynamics of the metabolites should be considered in phytoremediation strategies and environmental risk assessments of TBBPA in submerged soils. © 2014 American Chemical Society. Source


Li F.,Nanjing University | Wang J.,Nanjing University | Nastold P.,University of Applied Sciences and Arts Northwestern Switzerland | Jiang B.,Fujian Provincial Academy of Environmental Science | And 6 more authors.
Environmental Pollution | Year: 2014

Transformation of ring-14C-labelled tetrabromobisphenol-A (TBBPA) was studied in an oxic soil slurry with and without amendment with Sphingomonas sp. strain TTNP3, a bacterium degrading bisphenol-A. TBBPA degradation was accompanied by mineralization and formation of metabolites and bound-residues. The biotransformation was stimulated in the slurry bio-augmented with strain TTNP3, via a mechanism of metabolic compensation, although this strain did not grow on TBBPA. In the absence and presence of strain TTNP3, six and nine metabolites, respectively, were identified. The initial O-methylation metabolite (TBBPA-monomethyl ether) and hydroxytribromobisphenol-A were detected only when strain TTNP3 was present. Four primary metabolic pathways of TBBPA in the slurries are proposed: oxidative skeletal rearrangements, O-methylation, ipso-substitution, and reductive debromination. Our study provides for the first time the information about the complex metabolism of TBBPA in oxic soil and suggests that type II ipso-substitution could play a significant role in the fate of alkylphenol derivatives in the environment. © 2014 Elsevier Ltd. All rights reserved. Source


Gu J.,Nanjing University | Zhou W.,Nanjing University | Jiang B.,Fujian Provincial Academy of Environmental Science | Wang L.,Nanjing University | And 6 more authors.
Chemosphere | Year: 2016

Little is known about the effects of biochar on the fate and behavior of micropollutants in soil, especially in the presence of soil macrofauna. Using a 14C-tracer, we studied the fate of 2,4-dichlorophenol and phenanthrene, after 30 days in soil in the presence of a biochar (0-5%, dry weight) produced from China fir at 400 °C and/or the earthworm Metaphire guillelmi. Application of the biochar significantly reduced the degradation and mineralization of both pollutants and strongly increased the accumulation of their metabolites in soil. The earthworm had no significant effects on the degradation of parent molecules of the pollutants but it significantly reduced the mineralization of the pollutants independent of the presence of the biochar. Although at an application rate of <1% the biochar strongly sorbed both pollutants, it did not significantly decrease the bioaccumulation of free dichlorophenol and phenanthrene and their metabolites by the earthworm. Our results demonstrate the complex effects of biochar on the fate, transformation, and earthworm bioaccumulation of organic pollutants in soil. They show that biochar application may not be an appropriate strategy for treating soil contaminated with hydrophobic organic pollutants and underline the importance of soil-feeding earthworms in risk assessments of biochar effects on soil remediation. © 2015 Elsevier Ltd. Source


Li F.,Nanjing University | Jiang B.,Fujian Provincial Academy of Environmental Science | Nastold P.,University of Applied Sciences and Arts Northwestern Switzerland | Kolvenbach B.A.,University of Applied Sciences and Arts Northwestern Switzerland | And 6 more authors.
Environmental Science and Technology | Year: 2015

The fate of the most commonly used brominated flame retardant, tetrabromobisphenol A (TBBPA), in wastewater treatment plants is obscure. Using a 14C-tracer, we studied TBBPA transformation in nitrifying activated sludge (NAS). During the 31-day incubation, TBBPA transformation (half-life 10.3 days) was accompanied by mineralization (17% of initial TBBPA). Twelve metabolites, including those with single benzene ring, O-methyl TBBPA ether, and nitro compounds, were identified. When allylthiourea was added to the sludge to completely inhibit nitrification, TBBPA transformation was significantly reduced (half-life 28.9 days), formation of the polar and single-ring metabolites stopped, but O-methylation was not significantly affected. Abiotic experiments confirmed the generation of mono- and dinitro-brominated forms of bisphenol A in NAS by the abiotic nitration of TBBPA by nitrite, a product of ammonia-oxidizing microorganisms (AOMs). Three biotic (type II ipso-substitution, oxidative skeletal cleavage, and O-methylation) and one abiotic (nitro-debromination) pathways were proposed for TBBPA transformation in NAS. Apart from O-methylation, AOMs were involved in three other pathways. Our results are the first to provide information about the complex metabolism of TBBPA in NAS, and they are consistent with a determining role for nitrifiers in TBBPA degradation by initiating its cleavage into single-ring metabolites that are substrates for the growth of heterotrophic bacteria. © 2015 American Chemical Society. Source

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