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The air filtration materials with high efficiency, low resistance, and extra antibacterial property are crucial for personal health protection. Herein, a tree-like polyvinylidene fluoride (PVDF) nanofibrous membrane with hierarchical structure (trunk fiber of 447 nm, branched fiber of 24.7 nm) and high filtration capacity is demonstrated. Specifically, 2-hydroxypropyl trimethyl ammonium chloride terminated hyperbranched polymer (HBP-HTC) with near-spherical three-dimensional molecular structure and adjustable terminal positive groups is synthesized as an additive for PVDF electrospinning to enhance the jet splitting and promote the formation of branched ultrafine nanofibers, achieving a coverage rate of branched nanofibers over 90% that is superior than small molecular quaternary ammonium salts. The branched nanofibers network enhances mechanical properties and filtration efficiency (99.995% for 0.26 µm sodium chloride particles) of the PVDF/HBP-HTC membrane, which demonstrates reduced pressure drop (122.4 Pa) and a quality factor up to 0.083 Pa-1 on a 40 µm-thick sample. More importantly, the numerous quaternary ammonium salt groups of HBP-HTC deliver excellent antibacterial properties to the PVDF membranes. Bacterial inhibitive rate of 99.9% against both S. aureus and E. coli is demonstrated in a membrane with 3.0 wt% HBP-HTC. This work provides a new strategy for development of high-efficiency and antibacterial protection products.
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Antibacterianos , Escherichia coli , Nanofibras , Polímeros , Polivinilos , Staphylococcus aureus , Nanofibras/química , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Escherichia coli/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Polivinilos/química , Polímeros/química , Polímeros/farmacología , Polímeros/síntesis química , Membranas Artificiales , Pruebas de Sensibilidad Microbiana , Filtros de Aire , Compuestos de Amonio Cuaternario/química , Compuestos de Amonio Cuaternario/farmacología , Filtración/métodos , Tamaño de la Partícula , Polímeros de FluorocarbonoRESUMEN
In order to reduce the consumption of sand and gravel resources, the use of loess can reduce transportation costs and realize the in-situ construction of spongy in areas with rich loess resources. But the collapsibility and low permeability of loess make it unable to be directly used as the filler of bioretention cells. In this study, sulfoaluminate cement (SAC) mixed with a small amount of basalt fiber was considered to be used for loess modification, and the physicochemical properties and nutrient removal effect of SAC-modified loess as filler in bioretention cells were comprehensively evaluated. The results showed that when the SAC dosage was 15% and the basalt fiber addition was 0% (S15B0) and 0.6% (S15B6) and the curing time was 14 days, the stability and appropriate permeability can be exhibited, which can preliminarily satisfy the requirements of bioretention cell. SAC made the maximum adsorption capacity of S15B0 and S15B6 for ammonia nitrogen (NH4+-N) and phosphate higher than that of sand by 10.96%-31.51% and 45.92%-76.72%, respectively. The hydration products in SAC modified loess can fill the internal pores of loess particles and provide structural support, and ultimately reduce the accumulated pores, mesoporous pore size (20%) and surface homogeneity. Both S15B0 and S15B6 showed good removal effects of NH4+-N and COD. The TP removal efficiency was stable at 95.43%â¼99.95%. Both the antecedent drying days and the submerged zone have an effect on the nitrogen removal in the bioretention cells, where a longer antecedent drying days is detrimental to the nitrogen removal, and the installation of a submerged zone improves the nitrogen removal. The basalt fiber can enhance the transformation process from nitrate-nitrogen to nitrite-nitrogen in the bioretention cell. Therefore, the modification of SAC can provide a certain idea for the in-situ use of loess as the filler of the bioretention cell.
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Materiales de Construcción , Contaminantes Químicos del Agua/química , Adsorción , Movimientos del Agua , NitrógenoRESUMEN
Cold climates have an adverse effect on the nitrogen-removal capacity of bioretention cells, especially during freeze-thaw cycles (FTCs). To explore the effects of FTCs on the nitrogen removal performance of bioretention cells, this research compared the effects of FTCs on the pore structure and microbial community composition of the filler, and analyzed the nitrogen removal performance of the bioretention cell before (RT), during (FTC) and after (RRT) FTCs. The results demonstrated that RRT filler had a much greater number of pores with equivalent diameter <500 µm than RT filler, and that RRT had a higher pore volume and pore density than RT. Microbial community analysis revealed that the diversity and richness of the microbial community in FTC were lower than in RT, and the relative abundance of Lacunisphaera, Pseudomonas, and Dokdonella decreased significantly. There was no significant difference in microbial community richness between RRT and RT, however RRT diversity was lower. RRT has a higher relative abundance of nitrifying bacteria (Subgroup_10, Bryobacter, etc.) than RT, but a lower relative abundance of denitrifying bacteria (Pseudomonas, Dokdonella, Arenimonas, etc.). The nitrogen removal efficiency of FTC was inhibited, resulting in a decrease of 13.0 ± 4.86%, 19.7 ± 9.17%, and 26.6 ± 1.74% in the removal rates of ammonia nitrogen(NH4+-N), nitrate nitrogen(NO3--N), and total nitrogen(TN) when compared to RT, respectively. RRT improved nitrification and increased NH4+-N removal rate by 10.3 ± 2.69% compared to RT. However, because of denitrification inhibition, the nitrogen removal performance of RRT was not able to reach RT levels, and its NO3--N and TN removal rates decreased by 100 ± 4.70% and 58.3 ± 3.71%, respectively. This study has demonstrated that FTCs can permanently harm the bioretention cell's filler structure and microbial community, resulting in a significant decrease in the nitrogen removal performance of the bioretention cell designed according to warm climate conditions after experiencing FTCs.
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Nitrógeno , Nitrógeno/metabolismo , Congelación , Microbiota , Bacterias/metabolismoRESUMEN
Realizing breathable shape memory fiber-based material with antibacterial and waterproof performances is important for multitiered wearable protection to address the increasing concerns of air pollution. Herein, using an alternating electrospinning-electrospraying technology, we develop a fiber-based membrane with Janus wettability based on a silk fibroin nanofibers-substrate (SFNFs), a polyurethane nanospheres-top layer (PUNSs), and a middle layer of PU nanofibers-mat with in-situ grown silver nanoparticles (PUNFs-AgNPs), which serves separately for skin contact, a self-cleaning physical barrier to resist external aerosol/bacteria (PM2.5 filtration efficiency ~ 98.1%), and a bio-barrier that can sterilize harmful particles and inhibit bacteria proliferation (> 95%). This breathable Janus film (SFNFs/PUNFs-AgNPs/PUNSs, SPAP) with an antibacterial filter shows shape memory stretchability enabled by the thermoplastic PU component, which is mechanically adaptive to human body for wearable protection. This work presents a breathable wearable material for air-filtration and anti-bacteria, promising for applications such as wound dressings, medical masks, protection suits, and multifunctional filters. Graphical abstract: An alternating electrospinning-electrospraying technology was proposed to achieve a silk fibroin-based antibacterial membrane with Janus wettability, as well as good skin affinity and breathability, which serves well as physical and bio-barriers for water resistance, PM2.5 filtration (~98.1%) and bacteria inhibition (efficiency of 95%). This shape memory Janus membrane can adapt mechanically to human body curvatures for functional wearable protections. Supplementary Information: The online version contains supplementary material available at 10.1557/s43578-022-00805-w.
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The sand and gravel fillers used in traditional bioretention cells are expensive and becoming increasingly scarce, and their performance is unstable. It is important to find a stable, reliable, and low-cost alternative filler for bioretention facilities. Using cement as a modified loess filler for bioretention cells is a low-cost and easily obtainable alternative. The loss rate and anti-scouring index of the cement-modified loess (CM) were analyzed under different curing times, cement addition amount, and compactness control conditions. This study found that the stability and strength of the cement-modified loess in water with a density of not less than 1.3 g/cm3, a curing time, of not less than 28 d and a cement addition amount not less than 10% meets the use requirements of the bioretention cell filler. X-ray diffraction and Fourier transform infrared spectroscopy of cement-modified materials with a 10% cement addition and a curing time of 28 days (CM28) and 56 days (CM56). Cement-modified materials with 2% straw and a curing time of 56 days (CS56) showed that the three kinds of modified loess all contain calcium carbonate and that the surface contains hydroxyl and amino functional groups that can effectively remove phosphorus. The specific surface areas of the CM56, CM28, and CS56 samples were 12.53 m2/g, 24.731 m2/g, and 26.252 m2/g, respectively, which are significantly higher than that of sand (0.791 m2/g). At the same time, the adsorption capacity of the ammonia nitrogen and the phosphate that was present in the three modified materials is better than that of sand. CM56, like sand, has rich microbial communities, which can entirely remove nitrate nitrogen in water under anaerobic conditions, indicating that CM56 can be used as an alternative filler for bioretention cells. The production of cement-modified loess is simple and cost-effective, and using modified loess as a filler can reduce the use of stone resources or other on-site materials. Current methods for improving the filler of bioretention cells are mainly based on sand. This experiment used loess to improve the filler. The performance of loess is better than sand, and can completely replace sand as the filler in bioretention cells.
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Arena , Contaminantes Químicos del Agua , Contaminantes Químicos del Agua/análisis , Fósforo , Agua , Nitrógeno , LluviaRESUMEN
The nitrogen removal effect of traditional bioretention cells on runoff rainwater is not stable. The nitrogen removal effect of bioretention cells can be improved by setting up a layered filling structure, but the effect of changes in filling structure on the nitrogen removal process and microbial community characteristics is still unclear. Two types of porosity fillers were set up in the experiment, and a homogeneous bioretention cell and three bioretention cells with layered fillers were constructed by changing the depth range of the upper and lower layers to analyze the influence of the pore variation of different depth fillers on the nitrogen removal process and microbial community characteristics. The experimental results showed that, compared with the homogeneous filing structure, the layered filling structure can strengthen the adsorption of NH4+-N and the conversion of NO3--N, so as to increase the removal rates of NH4+-N and NO3--N by 20.71-81.56% and 9.25%-78.19%, respectively. Although the low porosity filler structure will reduce the nitrification activity and urease activity by 48.63%-66.68% and 8.00%-20.64% respectively, it can increase the denitrification activity by 19.14%-31.92%, thus significantly reducing the nitrate content in the filler. The low porosity filler structure can affect the growth and reproduction of various phylum bacteria such as Proteobacteria, Chloroflexi, Acidobacteria, and genus bacteria such as Nitrospira, Ellin6067, Rhizobacter, Pseudomonas, which can improve the diversity and richness of microorganisms.
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Desnitrificación , Nitrógeno , Lluvia , Nitrificación , BacteriasRESUMEN
There have been numerous summaries of the runoff purification characteristics of bioretention cells in warm climates. However, little has been done on the effects of freeze-thaw cycles (FTCs) that frequently occur in cold regions on bioretention cell performance. Three experimental columns were constructed to simulate the operation of the bioretention cell under the FTCs. The effects of FTCs on the nutrient removal efficiency of different filling bioretention cells were analyzed. The results showed that the ammonia nitrogen (NH4+-N) concentration in the effluent of the wood chip bioretention cell under the T3 conditions (WBCF) (2.35 mg/L) was significantly higher than that of the wood chip bioretention cell operating at room temperature (WBCR) (0.62 mg/L). The effluent NH4+-N concentration of aluminum sludge bioretention cell (ABCF) (0.096 mg/L) under the FTCs was lower than that of WBCF (0.91 mg/L). Under the T3 condition, the effluent nitrate nitrogen (NO3--N) and total nitrogen (TN) concentrations of WBCF (5.33 mg/L and 8.86 mg/L) were higher than those of WBCR (5 mg/L and 6.11 mg/L) at room temperature. Under FTCs conditions, both WBCF and ABCF had high NO3--N removal efficiency (up to 85.87% and 24.75%) at the initial stage of thawing of the filler, and the efficiency gradually decreased with the thawing of the filler. With the increase of FTCs, the NO3--N removal efficiency of WBCF gradually decreased (always higher than 13.6%), while the removal efficiency of ABCF fluctuated wildly (the removal efficiency was primarily negative). The total phosphorus (TP) concentration in the effluent of WBCF (0.11 mg/L) under the T3 conditions was lower than that of WBCR (0.02 mg/L) at room temperature, and the TP concentration of ABCF (0.021 mg/L) in the effluent under the FTCs was slightly lower than that of WBCF (0.031 mg/L). The FTCs have a more significant impact on removing nitrogen pollutants in runoff, but have little effect on phosphorus. Compared with aluminum sludge, wood chips are more suitable for efficient removal of nitrogen pollutants in runoff under the FTCs. The experimental conclusions can provide a reference for the construction of bioretention cells in cold regions.
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Contaminantes Ambientales , Lluvia , Aluminio , Aguas del Alcantarillado , Fósforo , Nitrógeno/análisis , NutrientesRESUMEN
BACKGROUND: Intestinal fibrosis is a common complication of Crohn's disease (CD). Adiponectin reportedly exerts anti-inflammatory effects in various disease models, including colitis models. AIMS: In this study, we aimed to determine the effects of adiponectin on intestinal fibrosis and the underlying mechanisms. METHODS: A murine model of intestinal fibrosis was established by administering increasing doses of 2,4,6-trinitrobenzene sulfonic acid to Balb/c mice via enema for 7 weeks. Primary human fibroblasts were isolated from the colon tissues of patients with CD. The fibroblasts were incubated with transforming growth factor (TGF)-ß1 to establish a fibrosis model in vitro. Pathway inhibitors were used to verify the potential signaling pathways involved in the anti-fibrogenic effect of adiponectin. RESULTS: Compared with the normal mesentery, adiponectin expression was significantly increased in the hypertrophic mesentery of patients with CD. Intraperitoneal injection of adiponectin significantly decreased the activity of myeloperoxidase and the expression of pro-inflammatory cytokines (tumor necrosis factor α and interleukin 6) in the colon of fibrosis model mice, whereas the expression of the anti-inflammatory cytokine interleukin 10 was substantially increased. Moreover, adiponectin treatment inhibited colon shortening, decreased colon weight, and reduced fibrotic protein deposition in the model mice. Adiponectin reduced the phosphorylation of Smad2 and collagen deposition induced by TGF-ß1 in primary human intestinal fibroblasts, with an increase in AMP-activated protein kinase (AMPK) phosphorylation. Furthermore, this phenomenon was reversed by the AMPK inhibitor. CONCLUSIONS: Adiponectin can protect against intestinal fibrosis by enhancing the phosphorylation of AMPK and inhibiting the activity of the TGF-ß1/Smad signaling pathway.
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Proteínas Quinasas Activadas por AMP , Adiponectina , Enfermedad de Crohn , Proteínas Quinasas Activadas por AMP/metabolismo , Adiponectina/metabolismo , Adiponectina/farmacología , Animales , Enfermedad de Crohn/patología , Citocinas/metabolismo , Fibroblastos/metabolismo , Fibrosis , Humanos , Ratones , Fosforilación , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
Thermal stiffening materials that are naturally soft but adaptively self-strengthen upon heat are intriguing for load-bearing and self-protection applications at elevated temperatures. However, to simultaneously achieve high modulus change amplitude and high mechanical strength at the stiffened state remains challenging. Herein, entropy-mediated polymer-mineral cluster interactions are exploited to afford thermal stiffening hydrogels with a record-high storage modulus enhancement of 13 000â times covering a super wide regime from 1.3â kPa to 17â MPa. Such a dramatic thermal stiffening effect is ascribed to the transition from liquid-liquid to solid-liquid phase separations, and at the molecular level, driven by enhanced polymer-cluster interactions. The hydrogel is further processed into sheath-core fibers and smart fabrics, which demonstrate self-strengthening and self-powered sensing properties by co-weaving another liquid metal fiber as both the joule heater and triboelectric layer.
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In recent years, there have been a number of studies on bioretention during hot summer, with only few studies reported during low-temperature winters. The application of bioretention in cold areas still lacks effective guidance. In this study, runoff simulation experiments were conducted to explore the influence of wood chips filler and water treatment residue on the removal of runoff pollutants under different packing gradations and low temperature conditions. Under low temperature, nitrate nitrogen removal rate of wood chips filler decreased from 70% to 90% in autumn to -23%- 35% in winter, the total nitrogen removal rate decreased from 75 to 90% in autumn to 20%-50% in winter, the removal rate of ammonia nitrogen and total phosphorus exceeded 70% during the entire experiment. Water treatment residue filler maintained a high ammonia nitrogen and total phosphorus removal rate during the experiment, with the total phosphorus removal rate above 90% and ammonia nitrogen removal rate above 80%. The bioretention effluent concentration of nitrate and total nitrogen was higher than 7.3 mg/L and 8.5 mg/L, respectively, most of the time. However, at low temperature, the COD removal rate of the two fillers was 25%-50%, which was very poor. Therefore, wood chips filler was observed to be better suited for the removal of nitrate and total nitrogen from the runoff, while water treatment residue had a better effect on the removal of ammonia nitrogen and total phosphorus in winter. Thus, for the application of bioretention in northern China, appropriate fillers should be selected considering the water quality characteristics of the area.
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Contaminantes Químicos del Agua , Purificación del Agua , China , Nitrógeno/análisis , Fósforo/análisis , Lluvia , TemperaturaRESUMEN
The work evaluated the influence of different operating conditions (voltage, ionic strength and mechanical pressure) on algae electro-osmotic dewatering effect and extracellular organic matter (EOM) regionalization. It was found that the algae electro-dewatering effect became better as the voltage and ionic strength increased, but electro-dewatering effect was decreased when ionic strength was more than 0.006gNaCl/gTSS, this indicated that too high ionic strength will reduce algae electro-dewatering effect. In addition, electro-osmosis effect first increases and then weakens when the pressure was increased. The content of dissolved organic materials (DOM) in the filtrate of both electrodes was increased when the voltage and ionic strength enhanced, the DOM content of filtrate at cathode and anode were increased from 42.9 mg/L, 36.7 mg/L to 68.2 mg/L, 85.3 mg/L when ionic strength raised from 0gNaCl/gTSS to 0.01gNaCl/gTSS, this indicated that a large amount of EOM dissolution as the voltage and ionic strength increased. The DOM content of both electrodes did not change significantly when mechanical pressure changed, anodic oxidation can oxidize and decompose macromolecular weight substances into mid-molecular weight and low molecular weight substances.
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Aguas del Alcantarillado , Eliminación de Residuos Líquidos , Electricidad , Electrodos , Concentración OsmolarRESUMEN
Textile has been known for thousands of years for its ease of use, comfort, and wear resistance, which resulted in a wide range of applications in garments and industry. More recently, textile emerges as a promising substrate for self-powered wearable power sources that are desired in wearable electronics. Important progress has been attained in the exploitation of wearable triboelectric nanogenerators (TENGs) in shapes of fiber, yarn, and textile. Along with the effective integration of other devices such as supercapacitor, lithium battery, and solar cell, their feasibility for realizing self-charging wearable systems has been proven. In this review, according to the manufacturing process of traditional textiles starting from fibers, twisting into yarns, and weaving into textiles, we summarize the progress on wearable TENGs in shapes of fiber, yarn, and textile. We explicitly discuss the design strategies, configurations, working mechanism, performances, and compare the merits of each type of TENGs. Finally, we present the perspectives, existing challenges and possible routes for future design and development of triboelectric textiles.
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To assess the status and risk of metal pollution in landscape water body replenished by wastewater treatment plant effluent, the distribution of metals in sediments from three regions [regulation pond (RP), wetland lake (WL), and main lake (ML)] of Harbor Lake, Tianjin, China, was characterized. Higher levels of all metals (except Cr and Pb) were observed in RP sediments. As, Cr, Cu, Ni, Pb, and Zn were mainly bound to organic matter and sulfide (F3) and residual fractions (F4), while the exchangeable and carbonate fraction (F1) and Fe/Mn oxide fraction (F2) were the dominant forms for Cd. Additionally, finding showed that the overall risk of sediments in aquatic systems was affected by both metal toxicity and metal fractionation. Thus, according to a modified risk assessment code (RAC), the potential adverse effect of metals in sediments was medium (although As, Cd, Ni, and Zn had high mobility risks based on the RAC), decreasing in the order RP > WL > ML.
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Monitoreo del Ambiente , Sedimentos Geológicos , Metales Pesados/química , Aguas Residuales/química , Contaminantes Químicos del Agua/química , China , Lagos , Medición de Riesgo , Instalaciones de Eliminación de Residuos , Eliminación de Residuos Líquidos/métodos , Purificación del AguaRESUMEN
OBJECTIVE: To investigate the relationship between the Notch signaling pathway and expression of vascular relevant factors in rabbit deep II degree burn model.⩠Methods: A total of 120 New Zealand white rabbits were randomly divided into a block group, a model group, and a control group. The block group was injected 2 mg/kg γ-secretase inhibitor (GSI) once a day at 1 d before the model establishment, and 1-14 d after the deep II degree burns model establishment. The model group were injected physiological saline at the same time. The control group was only injected with the same amount of saline. The expressions of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 2 (VEGFR-2), matrix metalloprotein 2 (MMP-2) and matrix metalloprotein 9 (MMP-9) were detected by immunohistochemistry.⩠Results: The expressions of VEGF and VEGFR-2 in the model group and the block group were significantly increased within 21 days after modeling, while decreased after 21 days; the expressions of MMP-2 and MMP-9 were decreased within 21 days after modeling, while increased after 21 days, with significant differences compared with the control group (P<0.05). The expressions of VEGF and VEGFR-2 in the model group were higher than that in the block group, and the expressions of MMP-2 and MMP-9 were lower than those in the block group (P<0.05). The expression of VEGFR-2 was positively correlated with VEGF, while MMP-2 and MMP-9 were negatively correlated with VEGF within 21 days after modeling.⩠Conclusion: In the rabbit deep II degree burn model, the Notch signaling pathway was blocked to attenuate the expressions of VEGF and VEGFR-2, and to up-regulate the expressions of MMP-2 and MMP-9.
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Quemaduras/metabolismo , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo , Factores de Crecimiento Endotelial Vascular/metabolismo , Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Animales , Quemaduras/patología , Modelos Animales de Enfermedad , Conejos , Distribución Aleatoria , Transducción de Señal , Factores de TiempoRESUMEN
Phosphorus (P) removal in constructed wetlands (CWs) is often low unless special substrates with high sorption capacities are used. However, the use of special substrates in vertical flow (VF) CWs has not been proved to enhance P sorption. Thus, two VF wetlands were designed to evaluate the potential for enhanced P removal from polluted urban river water, one with slag as substrate and the other as a control with gravel as substrate. Findings from batch experiments showed P sorption capacities of 3.15 gP/kg and 0.81 gP/kg, respectively, for steel slag and gravel. Different organic matter fractions played different roles in P sorption, the effects of which were significant only at high concentrations. Over a 220 days' operation, the VF-slag removed 76.0% of the influent total phosphorus (TP) at 0.159 g/m(2)·d and PO4-P of 70.9% at 0.063 g/m(2)·d, whereas the VF-gravel removed 65.0% at 0.136 g/m(2)·d and 48.6% at 0.040 g/m(2)·d, respectively. Therefore, the merit of using a steel slag substrate in VF wetlands can be significant for the removal of PO4-P.
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Fósforo/aislamiento & purificación , Acero/química , Purificación del Agua/métodos , Humedales , Ácidos Carboxílicos/química , Ríos , Contaminación del Agua/prevención & controlRESUMEN
A pilot-scale municipal sewage sludge deep-shaft aeration system was implemented in Lanzhou, Gansu Province of China. The reactor depth was 60 m with a diameter of 1.0 m and the sludge to be treated came from a wastewater plant in Lanzhou. In order to obtain the optimum operation conditions, analysis was conducted on the transformations of the volatile suspended solids (VSS), temperature, pH, oxidation-reduction potential (ORP) and pathogens in the deep-shaft reactor under different aeration conditions. Attention was paid to how operating conditions affected the removal efficiency of the VSS and the reaction temperature. As a result, higher volatile solids removal was gained at higher temperature, and the temperature could reach 50.8°C for a complete inactivation of bacteria in the first reaction zone when the deep-shaft aeration system was run for about 18 days. The sludge aeration rate was observed as 1.5 to 1.8 L/(h·L sludge) which enabled the volatile solids removal rate to reach 40.1%. The degradation of VSS occurred under a micro-oxygen environment, and the lowest ORP was found to be -256 mV in the digestive process. Not only aerobic bacteria but also anaerobic and facultative bacteria performed their functions in the reactor.
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Reactores Biológicos , Aguas del Alcantarillado/química , Instalaciones de Eliminación de Residuos , Eliminación de Residuos Líquidos/métodos , Aerobiosis , Bacterias Aerobias/metabolismo , China , Calor , Oxígeno/análisis , Proyectos Piloto , Aguas del Alcantarillado/microbiología , Temperatura , Aguas Residuales/química , Contaminantes Químicos del AguaRESUMEN
The characteristics of nitrogen (N) and phosphorus (P) removal were studied during the 2-year operation of a free water surface flow wetland of 900 m² with hydraulic loading of 0.1 m/d to evaluate its potential to treat water from an urban stream polluted with municipal and industrial wastewater. Attention was focused on the removal of dissolved N and P by harvesting plants (local Phragmites australis and Typha orientalis) at the end of each growing season. According to findings, the removals of N and P increased from 47.1% and 17.6%, respectively, in the 1st year to 52.3% and 32.4%, respectively, in the 2nd year. Increments of N and P removal were largely attributable to plant biomass, which increased from an average dry weight of 1.77 kg/m² in the 1st year to 3.41 kg/m² in the 2nd year. The amount of nutrients assimilated by plants in the 2nd year was almost double that of the 1st year. Increasing biomass in the 2nd year also improved redox conditions in the substrate layer, which contributed to increasing the efficiency of N removal. Compared with T. orientalis, P. australis was more competitive and adapted to conditions in the wetland better; it regenerated more vigorously and contributed more to nutrient removal.
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Nitrógeno/metabolismo , Fósforo/metabolismo , Poaceae/metabolismo , Typhaceae/metabolismo , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/metabolismo , Humedales , Biomasa , China , Poaceae/crecimiento & desarrollo , Ríos , Typhaceae/crecimiento & desarrollo , Aguas Residuales/análisis , Movimientos del AguaRESUMEN
A series of large pilot constructed wetland (CW) systems were constructed near the confluence of an urban stream to a larger river in Xi'an, a northwestern megacity in China, for treating polluted stream water before it entered the receiving water body. Each CW system is a combination of surface-and subsurface-flow cells with local gravel, sand or slag as substrates and Phragmites australis and Typha orientalis as plants. During a one-year operation with an average surface loading of 0.053 m(3)/(m(2)·day), the overall COD, BOD, NH3-N, total nitrogen (TN) and total phosphorus (TP) removals were 72.7% ± 4.5%, 93.4% ± 2.1%, 54.0% ± 6.3%, 53.9% ± 6.0% and 69.4% ± 4.6%, respectively, which brought about an effective improvement of the river water quality. Surface-flow cells showed better NH3-N removal than their TN removal while subsurface-flow cells showed better TN removal than their NH3-N removal. Using local slag as the substrate, the organic and phosphorus removal could be much improved. Seasonal variation was also found in the removal of all the pollutants and autumn seemed to be the best season for pollutant removal due to the moderate water temperature and well grown plants in the CWs.
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Contaminantes del Agua/aislamiento & purificación , Purificación del Agua , Humedales , Compuestos Orgánicos/aislamiento & purificación , Proyectos Piloto , Estaciones del Año , Movimientos del AguaRESUMEN
Stormwater runoff is the main source of carbaryl in natural waters; bioretention cells can effectively retain and remove carbaryl from stormwater runoff. However, the accumulation of carbaryl in the bioretention cell impacts its stormwater purification ability, especially nitrogen removal performance. To investigate the mechanisms behind the influence of carbaryl in stormwater runoff on the nitrogen removal performance of bioretention cells, the purification of carbaryl in bioretention facilities was compared under four carbaryl concentrations (0, 0.5, 1.0, and 2.0 mg/L); the effects of carbaryl input on nitrogen removal and the microbial community structure inside the filler were analyzed. After entering the bioretention cell, carbaryl was mainly adsorbed within the filler at a depth of 10-30 cm, and the desorption-adsorption process continued during subsequent rainfall. Carbaryl input negatively affected the denitrification performance of the bioretention cell. The removal rate of nitrate nitrogen (NO3--N) decreased by 61.13-100.09%, and that of total nitrogen (TN) was reduced by 24.82-38.95%. Carbaryl accumulation reduced the abundance and diversity of microorganisms in the bioretention cell. The relative abundance of some denitrifying bacteria genera (Terrimonas, Bdellovibrio, Aquabacterium, Ohtaekwangia, Sphingomonas, and SWB02) also decreased, which was the main reason for the decrease in the nitrogen removal performance.
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Carbaril , Nitrógeno , Contaminantes Químicos del Agua , Desnitrificación , Purificación del Agua/métodosRESUMEN
A woman in her 70s presented with anasarca and exertional dyspnoea. Investigation showed severe hypoalbuminaemia with no urinary or gastrointestinal protein losses. CT thorax reported lung consolidations, and transbronchial lung biopsy demonstrated organising pneumonia. Autoimmune myositis serology was positive for anti-Jo-1, anti-Ro-52, and anti-PM/Scl-100 antibodies. She was diagnosed with anti-synthetase syndrome with organising pneumonia. She was treated with oral prednisolone and oral mycophenolate mofetil with a good clinical response.