The in-situ nitrification process continuously requires a stable supply of oxygen. However, the application of conventional oxygen-releasing materials is limited by its high alkalinity and rapid oxygen release rates. In this study, a novel sulfur-based slow-release oxygen material (SOSM) was designed to address these challenges.
View Article and Find Full Text PDFGinkgo biloba leaves (Gbl), as abundant agricultural and forestry residues which contains the quercetin that plays an important role in mediating electron transfer, represent a promising heterotrophic denitrification carbon source. Nonetheless, challenges persist due to concerns over nitrate leaching. This study pioneers the application of pretreated Gbl as external carbon sources for heterotrophic denitrification, with a focus on enhancing carbon bioavailability and mitigating nitrate leaching risks.
View Article and Find Full Text PDFThe multi-soil-layering (MSL) systems is an emerging solution for environmentally-friendly and cost-effective treatment of decentralized rural domestic wastewater. However, the role of the seemingly simple permeable layer has been overlooked, potentially holding the breakthroughs or directions to addressing suboptimal nitrogen removal performance in MSL systems. In this paper, the mechanism among diverse substrates (zeolite, green zeolite and biological ceramsite) coupled microorganisms in different systems (activated bacterial powder and activated sludge) for rural domestic wastewater purification was investigated.
View Article and Find Full Text PDFEcological water replenishment (EWR) changes the recharge conditions, flow fields, and physicochemical properties of regional groundwater. However, the resulting impacts on mechanisms regulating the sources and transformation of groundwater nitrate remain unclear. This study investigated how EWR influences the sources and transformation processes of groundwater nitrate using an integrated approach of Water chemistry analysis and stable isotopes (δN-NO and δO-NO) along with microbial techniques.
View Article and Find Full Text PDFNitrobenzene is a typical organic pollutant of petroleum pollutant, which is a synthetic chemical not found naturally in the environment. Nitrobenzene in environment can cause toxic liver disease and respiratory failure in humans. Electrochemical technology provides an effective and efficient method for degrading nitrobenzene.
View Article and Find Full Text PDFIdentifying the leakage channel and the influencing range is essential for controlling the environmental risks of leachate from the tailings pond. The investigation of leachate pollution in tailings pond has the defect of focusing only on the scope of tailings pond in recent studies. This study innovatively built a comprehensive investigation and accurate verification system for leachate leakage of tailings pond integrated with the aeromagnetic survey, ground penetrating radar, hydrochemistry and isotope coupling methods.
View Article and Find Full Text PDFObjective: The effectiveness of MRI-guided intravenous recombinant tissue-type plasminogen activator (r-tPA) for acute ischaemic stroke (AIS) with an unknown time of onset has been demonstrated by the WAKE-UP Trial. We aim to evaluate its long-term cost-effectiveness from the perspective of Chinese and US healthcare payers.
Methods: A combination of decision tree and Markov model was built to project lifetime costs and quality-adjusted life-years (QALYs) associated with intravenous r-tPA or placebo treatment.
Acute ischemic stroke (AIS) caused by tandem intracranial and extracranial occlusions is not rare. However, optimal strategy between antegrade (extracranial first) or retrograde (intracranial first) approaches still remains elusive. This systematic review and meta-analysis aim to compare the two approaches to provide updated clinical evidence of strategy selection.
View Article and Find Full Text PDFThe discharge of slaughterhouse wastewater (SWW) is increasing and its wastewater has to be treated thoroughly to avoid the eutrophication. The hybrid zeolite-based ion-exchange and sulfur autotrophic denitrification (IX-AD) process was developed to advanced treat SWW after traditional secondary biological process. Compared with traditional sulfur oxidizing denitrification (SOD), this study found that IX-AD column showed: (1) stronger ability to resist NO pollution load, (2) lower SO productivity, and (3) higher microbial diversity and richness.
View Article and Find Full Text PDFIn this study, a woodchip biofilm electrode reactor (WBER) with woodchips embedded anode and cathode was developed, and its denitrification mechanism was analyzed by investigating the denitrification performance, organic matter change, redox environment and microbial community. The results show that the WBER with a carbon rod as anode (C-WBER) had a higher denitrification efficiency (2.58 mg NO- 3-N/(L·h)) and lower energy consumption (0.
View Article and Find Full Text PDFElectrocatalytic properties of anode and the electrolyte composition are important parameters influence the degradation efficiency for aniline wastewater. Ti/RuO-SnO and Ti/RuO-IrO have been fabricated using thermal decomposition method and experiments in electrolyte containing 0.05 M NaSO, 0.
View Article and Find Full Text PDFLandfill leachate is a type of complex organic wastewater, which can easily cause serious negative impacts on the human health and ecological environment if disposed improperly. Electrochemical technology provides an efficient approach to effectively reduce the pollutants in landfill leachate. In this review, the electrochemical standalone processes (electrochemical oxidation, electrochemical reduction, electro-coagulation, electro-Fenton process, three-dimensional electrode process, and ion exchange membrane electrochemical process) and the electrochemical integrated processes (electrochemical-advanced oxidation process (AOP) and biological electrochemical process) for landfill leachate treatment are summarized, which include the performance, mechanism, application, existing problems, and improvement schemes such as cost-effectiveness.
View Article and Find Full Text PDFThe performance and process of the constructed pyrite-based mixotrophic denitrification (POMD) system using pyrite and residual organic matters as the co-electron donors were investigated for simultaneous removal of N and P from secondary effluent. After the batch experiments, 61.80 ± 3.
View Article and Find Full Text PDFThis study presented a novel alternating-anode electrochemical system (AAES) based on single electrolytic cell for the treatment of nitrogen-containing refractory organic wastewater (NOW). The core of AAES lies in the alternating working of iron anode and DSA anode to integrate different electrochemical processes. The biologically treated landfill leachate (BTLL) was selected as a practical NOW for assessing the performance of AAES.
View Article and Find Full Text PDFTo meet the increasing energy consumption around the world and fight global climate change, there is an urgent need to explore renewable energy crops to replace the traditional energy sources. Duckweed () is widely distributed in the world and has high starch and low lignin contents, which is perhaps an ideal feedstock for bioenergy production. To investigate the effects of abscisic acid (ABA) on duckweed biomass and starch accumulation, was cultivated at different ABA concentrations.
View Article and Find Full Text PDFThe humic-like substances were the main organic components in most wastewater (e.g. domestic sewage, toilet wastewater and landfill leachate).
View Article and Find Full Text PDFBiologically treated landfill leachate (BTLL) is typically characterized by significantly high amount of total nitrogen (TN) and chemical oxygen demand (COD), and it has low biodegradability. In this study, a joint electrochemical system (JES) composed of iron anode reactor (IAR) and Ti/RuO anode reactor (TAR) was constructed to remove both TN and COD from BTLL and improve its biodegradability. The IAR and TAR with the same structure but using different anodes.
View Article and Find Full Text PDFEnviron Technol
December 2017
In the present study, a Ti-nano-electrode was fabricated for electrochemical denitrification. Response surface methodology (RSM) was utilized for the optimization of the factors that influence the production of Ti nano-electrodes. Box-Behnken design was applied to develop mathematical models for predicting the best electrochemical nitrate removal geometry.
View Article and Find Full Text PDFIn the present study, a granular chitosan-Fe(III) complex was prepared as a feasible adsorbent for the removal of nitrate from an aqueous solution. There was no significant change in terms of nitrate removal efficiency over a wide pH range of 3-11. Nitrate adsorption on the chitosan-Fe(III) complex followed the Langmuir-Freundlich isotherm model.
View Article and Find Full Text PDFNitrate contaminated water can be effectively treated by simultaneous heterotrophic and autotrophic denitrification (HAD). In the present study, woodchips and elemental sulfur were used as co-electron donors for HAD. It was found that ammonium salts could enhance the denitrifying activity of the Thiobacillus bacteria, which utilize the ammonium that is produced by the dissimilatory nitrate reduction to ammonium (DNRA) in the woodchip-sulfur based heterotrophic and autotrophic denitrification (WSHAD) process.
View Article and Find Full Text PDFJ Colloid Interface Sci
February 2016
This aim of this study was to remove phosphorus from aqueous solution using a Fe-loaded ceramic (Fe-LC) adsorbent prepared by mixing dolomite, montmorillonite, FeSO4·7H2O and starch. Simplex-centroid mixture design method was used to determine the optimum mixture proportions by evaluating both phosphorus adsorption efficiency and adsorbent hardness. The study found that the optimum adsorption capacity and the strength can be achieved with the composition of 3.
View Article and Find Full Text PDFFactors influencing the performance of a continual-flow bioelectrical reactor (BER) intensified by microbial fuel cells for groundwater nitrate removal, including nitrate load, carbon source and hydraulic retention time (HRT), were investigated and optimized by response surface methodology (RSM). With the target of maximum nitrate removal and minimum intermediates accumulation, nitrate load (for nitrogen) of 60.70 mg/L, chemical oxygen demand (COD) of 849.
View Article and Find Full Text PDFIn this study, an integrated two-stage soil infiltration bioreactor incorporated with pyrite-based (mixotrophic) denitrification (SIBPD) was designed for domestic wastewater treatment. Benefited from excellent adsorption ability and water-permeability, soil infiltration could avoid clogging, shorten operating time and lower maintenance cost. Respiration and nitrification were mostly engaged in aerobic stage (AES), while nitrate was majorly removed by pyrite-based mixotrophic denitrification mainly occurred in anaerobic stage (ANS).
View Article and Find Full Text PDFThe aims of the present study were to investigate whether exercise can improve the depression-like behavior caused by estrogen deficiency. Given that decreased level of brain-derived neurotrophic factor (BDNF) in many brain areas including hippocampus and prefrontal cortex is associated with estrogen deficiency-induced depression-like behavior, we also determined whether exercise affects the levels of BDNF and its receptor in hippocampus and prefrontal cortex (PFC). It was found that ovariectomy (OVX) caused an increase in depression-like behavior in rats and a decrease in BDNF level in hippocampus but not in PFC.
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