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Ruijiao Xi, Xi-En Long, Sha Huang, Huaiying Yao
Nitrification inhibitors and urease inhibitors, such as nitrapyrin and N-(n-butyl) thiophosphoric triamide (NBPT), can improve the efficiencies of nitrogen fertilizers in cropland. However, their effects on ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) across different soil pH levels are still unclear. In the present work, vegetable soils at four pH levels were tested to determine the impacts of nitrification and urease inhibitors on the nitrification activities, abundances and diversities of ammonia oxidizers at different pHs by real-time PCR, terminal restriction fragment length polymorphism (T-RFLP) and clone sequence analysis...
December 2017: AMB Express
S F Balvert, J Luo, L A Schipper
New Zealand agriculture is predominantly comprised of pastoral grazing systems and deposition of animal excreta during grazing has been identified as a major source of nitrous oxide (N2O) emissions. Nitrification inhibitors have been shown to significantly reduce nitrous oxide emissions from grazing pastoral systems, and some plants have been identified as having nitrification inhibiting properties. Brassica crops are one such example as they contain the secondary metabolite glucosinolate (GLS) whose hydrolysis products are thought to slow soil nitrogen cycling...
June 17, 2017: Science of the Total Environment
J A Parada-Albarracín, J Pérez, M A Gómez
Two experimental submerged membrane bioreactors (MBR) at the industrial scale with different membranes (microfiltration and ultrafiltration) were used to analyse the influence of the small flagellates on the lack of significance of the sludge biotic index (SBI). Also, with these systems, flagellates were analysed as bioindicators in the activated sludge of MBRs. Both facilities were operated in parallel with a pre-denitrification system for a period of nearly two years and fed with real pretreated urban wastewater...
June 14, 2017: Water Research
Wenyong Hu, Yu Zhou, Xiaobo Min, Jingyi Liu, Xinyu Li, Lin Luo, Jiachao Zhang, Qiming Mao, Liyuan Chai, YaoYu Zhou
In this study, a combined Aerobic-Fenton-Anoxic/Aerobic system was designed for the remediation of raw landfill leachate in a pilot-scale experiment. This system included: i) a granular sludge biological oxidation procedure that achieves the accumulation of nitrite nitrogen (NO2(-)-N) under aerobic conditions; ii) a Fenton process that improves the biodegradability of the bio-treated leachate; and iii) an activated sludge biological oxidation component under anoxic and aerobic conditions. Additionally, a shortcut nitrification and denitrification pathway was achieved...
June 19, 2017: Environmental Technology
G Schwob, M Roy, S Manzi, T Pommier, M P Fernandez
Since the mid twentieth-century, subalpine grasslands undergo a progressive encroachment by Alnus viridis shrubs. Thanks to its rapid vegetative reproduction, its nitrogen fixing symbiosis with Frankia and its ectomycorrhizal cohorts, green alders are vigorous colonizers that quickly form mosaic of alder patches that evolves into a close canopy shrub community. To better understand how alder encroachment might influence microbial communities in this successional sequence, symbiont distribution, microbial richness and community structure in both soils and nodules were analyzed at three successional stages: grassland, mosaic and forest...
June 15, 2017: Environmental Microbiology
Qibin Wang, Qiuwen Chen, Jing Chen
The removal of total nitrogen in wastewater treatment plants (WWTPs) is often unsatisfactory for a variety of reasons. One possible measure to improve nitrogen removal is the addition of external carbon. However, the amount of carbon addition is directly related to WWTP operation costs, highlighting the importance of accurately determining the amount of external carbon required. The objective of this study was to obtain a low nitrate concentration in the anoxic zone of WWTPs efficiently and economically by optimizing the external carbon source dosage...
June 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
K J Murray, W J Parker, L M Bragg, M R Servos
The potential for integrated fixed film activated sludge (IFAS) processes to achieve enhanced transformation of pharmaceuticals relative to conventional activated sludge (CAS) processes was assessed. Previous studies have focused on direct comparisons of parallel reactors with and without fixed film carriers and little information is available on the impacts of how varying operating parameters impact the differences in observed pharmaceutical compound (PC) transformation capabilities between CAS reactors and those equipped with both an activated sludge (AS) and fixed film carriers...
June 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Biju Prava Sahariah, J Anandkumar, Saswati Chakraborty
In this study, stability of two sequential moving bed bioreactor systems for phenol shock load (PSL) applications was assessed in presence of thiocyanate and ammonia. The systems were operated in anaerobic-anoxic-aerobic continuous (CMBR: R1-R2-R3) and semi-continuous (FMBR: B1-B2-B3) mode. Both systems were exposed to 3000 mg phenol/L (PSL-I) and 3500 mg phenol/L (PSL-II) for 3 days each from initial 2500 mg phenol/L without any intermediate concentration at 6 days HRT. The effect of PSL-I on R1 was reversible within 10-12 days...
June 15, 2017: Environmental Technology
Sarra E Hinshaw, Corianne Tatariw, Nikaela Flournoy, Alice Kleinhuizen, Caitlin Bailey Taylor, Patricia Sobecky, Behzad Mortazavi
Salt marshes play a key role in removing excess anthropogenic nitrogen (N) loads to nearshore marine ecosystems through sediment microbial processes such as denitrification. However, in the Gulf of Mexico the loss of marsh vegetation due to human-driven disturbances such as sea level rise and oil spills can potentially reduce marsh capacity for N removal. In order to investigate the effect of vegetation loss on ecosystem N removal, we contrasted denitrification capacity in marsh and subtidal sediments impacted by the Deepwater Horizon oil spill using a combination of (29)N2 and (30)N2 production (isotope pairing), denitrification potential measurements (acetylene block), and quantitative PCR (qPCR) of functional genes in the denitrification pathway...
June 15, 2017: Environmental Science & Technology
Na Sun, Chenghao Ge, Hafiz Adeel Ahmad, Baoyu Gao, Shou-Qing Ni
A permanent microbial stratified nitrogen removal system coupling anammox with partial nitrification (SNAP) in a sequencing batch biofilter granular reactor (SBBGR) was successfully constructed for the treatment of ammonia-rich wastewater. With a nitrogen loading rate of 0.1kgNm(-3)·d(-1), the maximal ammonia and total nitrogen removal efficiencies could reach up to 96.08% and 84.86% on day 108, respectively. The pH, DO profiles revealed a switch of functional species (AOB and anammox) at a typical intermittent aeration cycle...
June 1, 2017: Bioresource Technology
Shusong Zhang, Xingbin Sun, Yueting Fan, Tianlei Qiu, Min Gao, Xuming Wang
A new strain of Diaphorobacter polyhydroxybutyrativorans (strain SL-205) was recently isolated and identified. SL-205 can utilize nitrate and nitrite for denitrification and ammonium for nitrification using poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) as the carbon source under aerobic conditions. SL-205 removed 99.11% of NH4(+)-derived N (83.90mg/L), 95.02% of NO3(-)-N (308.24mg/L), and 84.13% of NO2(-)-N (211.70mg/L), with average removal rates of 1.73mg NH4(+)-N/(L·h), 6.10mg NO3(-)-N/(L·h), and 4...
May 31, 2017: Bioresource Technology
Devrim Coskun, Dev T Britto, Weiming Shi, Herbert J Kronzucker
Although the global nitrogen (N) cycle is largely driven by soil microbes, plant root exudates can profoundly modify soil microbial communities and influence their N transformations. A detailed understanding is now beginning to emerge regarding the control that root exudates exert over two major soil N processes - nitrification and N2 fixation. We discuss recent breakthroughs in this area, including the identification of root exudates as nitrification inhibitors and as signaling compounds facilitating N-acquisition symbioses...
June 7, 2017: Trends in Plant Science
Nina Van de Moortel, Rob Van den Broeck, Jan Degrève, Raf Dewil
In this paper, a new and innovative technique, glow discharge plasma, is introduced for the treatment of activated sludge, whereby its effect on sludge solubilization, settleability, floc structure and biomass activity for carbon removal and nitrification is investigated. The obtained results are compared to the use of ultrasound for activated sludge treatment, a technique known for its potential to enhancing biomass activity. Results indicate that ultrasound is up to 9 times more efficient in solubilizing activated sludge and disrupting the sludge floc...
May 24, 2017: Water Research
Yongyuan Yang, Zhenguo Chen, Xiaojun Wang, Lei Zheng, Xiaoyang Gu
A zeolite biological aerated filter (ZBAF) with continuous feeding was successfully applied for achieving stable partial nitrification. Excellent nitrite accumulation (higher than 98.0%) and high nitrite/nitrate production rate (NPR) (approximately 0.760kg/m(3)/d) were obtained with increase influent ammonium concentration from 250 to 550mg/L within a nitrogen loading rate (NLR) of 0.854-1.200kg/m(3)/d. Owning to the adsorption of zeolite to ammonium, free ammonia (FA) concentration could remain at an appropriate range for inhibition of nitrite oxidizing bacteria (NOB) and dominance of ammonia-oxidizing bacteria (AOB), which should be responsible for the excellent partial nitrification realized in ZBAF...
May 29, 2017: Bioresource Technology
Yunlong Yang, Linxiang Xie, Xin Tao, Kaihui Hu, Shaobin Huang
Artificial municipal wastewater was treated successfully by the bioaugmentation of Bacillus sp. K5 capable of simultaneous nitrification and denitrification (SND) within a sequencing batch reactor (SBR). During the long-term operation, the bioaugmentation system exhibited an excellent and steady COD and NH4+-N removal without nitrite and nitrate accumulation. The average removal efficiency for COD and NH4+-N achieved to 98% and 95%, respectively. PCR-DGGE, SEM and FISH revealed that the introduced Bacillus sp...
2017: PloS One
Nur Adlin, Norihisa Matsuura, Yuki Ohta, Yuga Hirakata, Shinya Maki, Masashi Hatamoto, Takashi Yamaguchi
This study proposes a biological nitrogen removal system for freshwater aquaria consisting of a down-flow hanging sponge (DHS) and an up-flow sludge blanket (USB). DHS-USB systems can perform nitrification and denitrification simultaneously, reducing ammonia (NH3) and nitrate (NO3(-)) toxicity in the water. The performance of the system was evaluated using on-site fresh water aquaria at ambient temperature (23-34°C) over 192 days. NH3 and nitrite (NO2(-)) were maintained at a detection limit of 0.01 mg N L(-1) and NO3(-) was maintained below 10 mg N L(-1), despite limited water exchange...
June 13, 2017: Environmental Technology
Biju Prava Sahariah, J Anandkumar, Saswati Chakraborty
A synthetic wastewater containing various pyridine concentrations (25-250 mg/L) was treated in a sequential anaerobic(B1)-anoxic(B2)-aerobic(B3) fed batch moving bed reactor (FMBR) system. Pyridine was associated with phenol (1500 mg/L), SCN(-) (800 mg/L), COD (5400-5430 mg/L) and NH4(+)-N (500 mg/L) at hydraulic retention time (HRT) of 6 (B1: 3; B2 and B3: 1.5 each) days. In B1, pyridine removal was 10-12% with influent concentration 25-100mg/L and beyond it was zero. Removal of phenol (53-39%) and COD (33-22%) occurred in B1 but pyridine above 50 mg/L inhibited the COD and phenol removal...
June 8, 2017: Environmental Technology
Seonghyeon Cho, Jinsoo Kim, Sungchul Kim, Sang-Seob Lee
We screened and identified a NH3-N-removing bacterial strain, Bacillus sp. KGN1 and a PO4(3-)-P removing strain, Vibrio sp. KGP1, from 960 indigenous marine isolates from seawater and marine sediment from Tongyeong, South Korea. We developed eco-friendly high-efficiency marine sludge (eco-HEMS), and inoculated these marine bacterial strains into the marine sediment. A laboratory-scale sequencing batch reactor (SBR) system using the eco-HEMS for marine wastewater from land-based fish farms improved the treatment performance as indicated by 88...
June 7, 2017: Environmental Technology
Devrim Coskun, Dev T Britto, Weiming Shi, Herbert J Kronzucker
The nitrogen (N)-use efficiency of agricultural plants is notoriously poor. Globally, about 50% of the N fertilizer applied to cropping systems is not absorbed by plants, but lost to the environment as ammonia (NH3), nitrate (NO3(-)), and nitrous oxide (N2O, a greenhouse gas with 300 times the heat-trapping capacity of carbon dioxide), raising agricultural production costs and contributing to pollution and climate change. These losses are driven by volatilization of NH3 and by a matrix of nitrification and denitrification reactions catalysed by soil microorganisms (chiefly bacteria and archaea)...
June 6, 2017: Nature Plants
Mohammad Waqas, Talal Almeelbi, Abdul-Sattar Nizami
In the Kingdom of Saudi Arabia (KSA) and Gulf region, a very small amount of municipal solid waste (MSW) is treated for compost production. The produced compost through traditional methods of compost piles and trenches does not coincide with the international standards of compost quality. Therefore, in this study, a continuous thermophilic composting (CTC) method is introduced as a novel and efficient technique for treating food waste into a quality compost in a short period of time. The quality of the compost was examined by degradation rates of organic matter (OM), changes in total carbon (TC), ash contents, pH, dynamics in ammonium nitrogen (NH4-N) and nitrate nitrogen (NO3-N), and nitrification index (NI)...
June 3, 2017: Environmental Science and Pollution Research International
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