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Jamal Alikhani, Imre Takacs, Ahmed Al-Omari, Sudhir Murthy, Arash Massoudieh
A parameter estimation framework was used to evaluate the ability of observed data from a full-scale nitrification-denitrification bioreactor to reduce the uncertainty associated with the bio-kinetic and stoichiometric parameters of an activated sludge model (ASM). Samples collected over a period of 150 days from the effluent as well as from the reactor tanks were used. A hybrid genetic algorithm and Bayesian inference were used to perform deterministic and parameter estimations, respectively. The main goal was to assess the ability of the data to obtain reliable parameter estimates for a modified version of the ASM...
March 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Qiang He, Yinying Zhu, Leilei Fan, Hainan Ai, Xiaoliu Huangfu, Mei Chen
Emission of nitrous oxide (N2O) during biological wastewater treatment is of growing concern. This paper reports findings of the effects of carbon/nitrogen (C/N) ratio on N2O production rates in a laboratory-scale biological aerated filter (BAF) reactor, focusing on the biofilm during nitrification. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and microelectrode technology were utilized to evaluate the mechanisms associated with N2O production during wastewater treatment using BAF...
March 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Seung-Hoon Lee, Patrick J Megonigal, Hojeong Kang
Salt marshes are unique ecosystem of which a microbial community is expected to be affected by global climate change. In this study, by using T-RFLP analysis, quantitative PCR, and pyrosequencing, we comprehensively analyzed the microbial community structure responding to elevated CO2 (eCO2) and N addition in a salt marsh ecosystem subjected to CO2 manipulation and N addition for about 3 years. We focused on the genes of microbes relevant to N-cycling (denitrification and nitrification), CH4-flux (methanogens and methanotrophs), and S-cycling (sulfate reduction) considering that they are key functional groups involved in the nutrient cycle of salt marsh system...
March 22, 2017: Microbial Ecology
Lukhanyo Mekuto, Seteno Karabo Obed Ntwampe, Margaret Kena, Mhlangabezi Tolbert Golela, Olusola Solomon Amodu
An alkali-tolerant bacterium, Pseudomonas aeruginosa STK 03 (accession number KR011154), isolated from an oil spill site, was evaluated for the biodegradation of free cyanide and thiocyanate under alkaline conditions. The organism had a free cyanide degradation efficiency of 80 and 32 % from an initial concentration of 250 and 450 mg CN(-)/L, respectively. Additionally, the organism was able to degrade thiocyanate, achieving a degradation efficiency of 78 and 98 % from non- and free cyanide spiked cultures, respectively...
June 2016: 3 Biotech
Yilu Sun, Liang Feng, Ang Li, Xuening Zhang, Jixian Yang, Fang Ma
The present study investigated effect of ammonium utilization on aerobic denitrification by Pseudomonas stutzeri T13. Per nitrogen balance calculation, all consumed ammonium was utilized as nitrogen source for cell propagation by assimilation rather than heterotrophic nitrification. Total organic carbon (TOC) and ammonium were necessary substrates to sustain heterotrophic propagation of P. stutzeri T13 at optimum proportion equal to seven. Under aerobic condition, nitrate was utilized as substitute nitrogen source when ammonium was completely exhausted...
March 12, 2017: Bioresource Technology
R K Salis, A Bruder, J J Piggott, T C Summerfield, C D Matthaei
Disentangling the individual and interactive effects of multiple stressors on microbial communities is a key challenge to our understanding and management of ecosystems. Advances in molecular techniques allow studying microbial communities in situ and with high taxonomic resolution. However, the taxonomic level which provides the best trade-off between our ability to detect multiple-stressor effects versus the goal of studying entire communities remains unknown. We used outdoor mesocosms simulating small streams to investigate the effects of four agricultural stressors (nutrient enrichment, the nitrification inhibitor dicyandiamide (DCD), fine sediment and flow velocity reduction) on stream bacteria (phyla, orders, genera, and species represented by Operational Taxonomic Units with 97% sequence similarity)...
March 22, 2017: Scientific Reports
Lei Gao, Weili Zhou, Jungchen Huang, Shengbing He, Yijia Yan, Wenying Zhu, Suqing Wu, Xu Zhang
Three novel floating treatment wetlands, including autotrophic enhanced floating treatment wetland (AEFTW), heterotrophic enhanced floating treatment wetland (HEFTW) and enhanced floating treatment wetland (EFTW) were developed to remove nitrogen from the secondary effluent. Results showed that the analogously excellent nitrogen removal performance was achieved in AEFTW and HEFTW. About 89.4% of the total nitrogen (TN) was removed from AEFTW at a low S/N of 0.9 and 88.5% from HEFTW at a low C/N of 3.5 when the hydraulic retention time (HRT) was 1d in summer...
March 9, 2017: Bioresource Technology
Andreas Bruder, Romana K Salis, Peter E Jones, Christoph D Matthaei
Agricultural land use results in multiple stressors affecting stream ecosystems. Flow reduction due to water abstraction, elevated levels of nutrients and chemical contaminants are common agricultural stressors worldwide. Concurrently, stream ecosystems are also increasingly affected by climate change. Interactions among multiple co-occurring stressors result in biological responses that cannot be predicted from single-stressor effects (i.e. synergisms and antagonisms). At the ecosystem level, multiple-stressor effects can be further modified by biotic interactions (e...
March 21, 2017: Global Change Biology
Yaqian Zhao, Ranbin Liu, Jinhui Zhao, Lei Xu, Caroline Sibille
A novel concept was proposed and preliminarily investigated by embedding alum sludge-based constructed wetland into conventional activated sludge system in terms of Green Bio-sorption Reactor (GBR). This novel GBR inherited the aesthetic value of constructed wetland and owned the robust phosphorus (P) adsorption along with the benefit of carriers' addition (dewatered alum sludge). The preliminary demonstration was conducted in a lab-scale sequencing batch reactor (SBR) system without biological phosphorus removal process...
March 9, 2017: Bioresource Technology
Marcin Zieliński, Agnieszka Cydzik-Kwiatkowska, Magdalena Zielińska, Marcin Dębowski, Paulina Rusanowska, Joanna Kopańska
The study investigated wastewater treatment in an aerobic reactor with activated sludge exposed to static magnetic field (SMF) with mean induction of 8.1 mT. The efficiency of chemical oxygen demand removal was about 90% in a control reactor and an SMF-exposed reactor. Although the nitrification efficiency was higher than 95% in both reactors, the activity of ammonia-oxidizing bacteria was higher in the SMF-exposed reactor. This resulted in shortening of nitrification time to 4 h compared to 8 h in the control reactor...
2017: Water, Air, and Soil Pollution
Petteri Laaksonen, Aki Sinkkonen, Gennadi Zaitsev, Esa Mäkinen, Timo Grönroos, Martin Romantschuk
A traditional sand filter for treatment of household wastewater was constructed in the fall of 2012 at Biolinja 12, Turku, Finland. Construction work was led and monitored by an authorized wastewater treatment consultant. The filter was placed on a field bordered by open ditches from all sides in order to collect excess rain and snowmelt waters. The filter was constructed and insulated from the environment so that all outflowing water was accounted for. Untreated, mainly municipal, wastewater from Varissuo suburb was pumped from a sewer separately via three septic tanks (volume = 1 m(3) each) into the filters...
March 18, 2017: Environmental Science and Pollution Research International
Manyun Zhang, Weijin Wang, Jun Wang, Ying Teng, Zhihong Xu
Agrochemical applications may have side effects on soil biochemical properties related to soil nitrogen (N) mineralization and thus affect N cycling. The present study aimed to evaluate the effects of nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) and fungicide iprodione on soil neutral protease (NPR), alkaline protease (APR), chitinase (CHI), and their functional genes (nprA, aprA, and chiA) related to soil N mineralization. The following four treatments were included: blank control (CK), single DMPP application (DAA), weekly iprodione applications (IPR), and the combined applications of DMPP and iprodione (DI)...
March 17, 2017: Environmental Science and Pollution Research International
Yongkai Chang, Jingfeng Fan, Jie Su, Hongxia Ming, Wen Zhao, Yan Shi, Fengyun Ji, Limei Guo, Shuaijun Zan, Bochao Li, Hao Guo, Daoming Guan
Ammonia-oxidizing bacteria (AOB) play an important role in nitrification in estuaries. The aim of this study was to examine the spatial abundance, diversity, and activity of AOB in coastal sediments of the Liaohe Estuary using quantitative PCR, high-throughput sequencing of the amoA gene coding the ammonia monooxygenase enzyme active subunit, and sediment slurry incubation experiments. AOB abundance ranged from 8.54 × 10(4) to 5.85 × 10(6) copies g(-1) of wet sediment weight and exhibited an increasing trend from the Liaohe Estuary to the open coastal zone...
March 14, 2017: Current Microbiology
Yi Xu, Tengxia He, Zhenlun Li, Qing Ye, Yanli Chen, Enyu Xie, Xue Zhang
The cold-adapted bacterium Pseudomonas putida Y-9 was investigated and exhibited excellent capability for nitrogen removal at 15°C. The strain capable of heterotrophic nitrification and aerobic denitrification could efficiently remove ammonium, nitrate, and nitrite at an average removal rate of 2.85 mg, 1.60 mg, and 1.83 mg NL(-1 )h(-1), respectively. Strain Y-9 performed nitrification in preference to denitrification when ammonium and nitrate or ammonium and nitrite coexisted in the solution. Meantime, the presence of nitrate had no effect on the ammonium removal rate of strain Y-9, and yet the presence of high concentration of nitrite would inhibit the cell growth and decrease the nitrification rate...
2017: BioMed Research International
Bin-Bin Wang, Ya-Wei Gu, Jian-Meng Chen, Qian Yao, Hui-Juan Li, Dang-Cong Peng, Feng He
Different from monomeric substrate, polymeric substrate (PS) needs to undergo slow hydrolysis process before becoming available for consumption by bacteria. Hydrolysis products will be available for the heterotrophs in low concentration, which will reduce competitive advantages of heterotrophs to nitrifiers in mixed culture. Therefore, some links between PS and nitrification process can be expected. In this study, three lab-scale sequencing batch reactors with different PS/total substrate (TS) ratio (0, 0.5 or 1) in influent were performed in parallel to investigate the influence of PS on nitrification process in activated sludge system...
March 6, 2017: Chemosphere
Moomen Soliman, Ahmed Eldyasti
Recently, partial nitrification has been adopted widely either for the nitrite shunt process or intermediate nitrite generation step for the Anammox process. However, partial nitrification has been hindered by the complexity of maintaining stable nitrite accumulation at high nitrogen loading rates (NLR) which affect the feasibility of the process for high nitrogen content wastewater. Thus, the operational data of a lab scale SBR performing complete partial nitrification as a first step of nitrite shunt process at NLRs of 0...
March 1, 2017: Bioresource Technology
Thanh-Tin Nguyen, Xuan-Thanh Bui, Vinh-Phuc Luu, Phuoc-Dan Nguyen, Wenshan Guo, Huu-Hao Ngo
Hollow fiber (HF) and flat sheet (FS) Sponge MBRs were operated at 10-20 LMH flux treating hospital wastewater. Simultaneous nitrification denitrification (SND) occurred considerably with TN removal rate of 0.011-0.020mg TN mgVSS(-1)d(-1). Furthermore, there was a remarkable removal of antibiotics in both Sponge MBRs, namely Norfloxacin (93-99% (FS); 62-86% (HF)), Ofloxacin (73-93% (FS); 68-93% (HF)), Ciprofloxacin (76-93% (FS); 54-70% (HF)), Tetracycline (approximately 100% for both FS and HF) and Trimethoprim (60-97% (FS); 47-93% (HF)...
March 1, 2017: Bioresource Technology
Carolina Reyes, Dominik Schneider, Marko Lipka, Andrea Thürmer, Michael E Böttcher, Michael W Friedrich
In this study, we analysed metagenomes along with biogeochemical profiles from Skagerrak (SK) and Bothnian Bay (BB) sediments, to trace the prevailing nitrogen pathways. NO3(-) was present in the top 5 cm below the sediment-water interface at both sites. NH4(+) increased with depth below 5 cm where it overlapped with the NO3(-) zone. Steady-state modelling of NO3(-) and NH4(+) porewater profiles indicates zones of net nitrogen species transformations. Bacterial protease and hydratase genes appeared to make up the bulk of total ammonification genes...
March 10, 2017: Marine Biotechnology
Jörg Schullehner, Leslie Stayner, Birgitte Hansen
Accurate assessments of exposure to nitrate in drinking water is a crucial part of epidemiological studies investigating long-term adverse human health effects. However, since drinking water nitrate measurements are usually collected for regulatory purposes, assumptions on (1) the intra-distribution system variability and (2) short-term (seasonal) concentration variability have to be made. We assess concentration variability in the distribution system of nitrate, nitrite, and ammonium, and seasonal variability in all Danish public waterworks from 2007 to 2016...
March 9, 2017: International Journal of Environmental Research and Public Health
Haitao Wang, Christopher W Marshall, Minying Cheng, Huijuan Xu, Hu Li, Xiaoru Yang, Tianling Zheng
Transition of populations from rural to urban living causes landscape changes and alters the functionality of soil ecosystems. It is unclear how this urbanization disturbs the microbial ecology of soils and how the disruption influences nitrogen cycling. In this study, microbial communities in turfgrass-grown soils from urban and suburban areas around Xiamen City were compared to microbial communities in the soils from rural farmlands. The potential N2O emissions, potential denitrification activity, and abundances of denitrifiers were higher in the rural farmland soils compared with the turfgrass soils...
March 10, 2017: Scientific Reports
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