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1.
Environ Sci Technol ; 58(15): 6725-6735, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38565876

RESUMEN

It is a promising research direction to develop catalysts with high stability and ozone utilization for low-temperature ozone catalytic oxidation of VOCs. While bimetallic catalysts exhibit excellent catalytic activity compared with conventional single noble metal catalysts, limited success has been achieved in the influence of the bimetallic effect on the stability and ozone utilization of metal catalysts. Herein, it is necessary to systematically study the enhancement effect in the ozone catalytic reaction induced by the second metal. With a simple continuous impregnation method, a platinum-cerium bimetallic catalyst is prepared. Also highlighted are studies from several aspects of the contribution of the second metal (Ce) to the stability and ozone utilization of the catalysts, including the "electronic effect" and "geometric effect". The synergistic removal rate of toluene and ozone is nearly 100% at 30 °C, and it still shows positive stability after high humidity and a long reaction time. More importantly, the instructive significance, which is the in-depth knowledge of enhanced catalytic mechanism of bimetallic catalysts resulting from a second metal, is provided by this work.


Asunto(s)
Cerio , Ozono , Oxidación-Reducción , Metales , Catálisis
2.
Sci Total Environ ; 924: 171557, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38460704

RESUMEN

Swine wastewater (SW), characterized by highly complex organic and nutrient substances, poses serious impacts on aquatic environment and public health. Furthermore, SW harbors valuable resources that possess substantial economic potential. As such, SW treatment technologies place increased emphasis on resource recycling, while progressively advancing towards energy saving, sustainability, and circular economy principles. This review comprehensively encapsulates the state-of-the-art knowledge for treating SW, including conventional (i.e., constructed wetlands, air stripping and aerobic system) and resource-utilization-based (i.e., anaerobic digestion, membrane separation, anaerobic ammonium oxidation, microbial fuel cells, and microalgal-based system) technologies. Furthermore, this research also elaborates the key factors influencing the SW treatment performance, such as pH, temperature, dissolved oxygen, hydraulic retention time and organic loading rate. The potentials for reutilizing energy, biomass and digestate produced during the SW treatment processes are also summarized. Moreover, the obstacles associated with full-scale implementation, long-term treatment, energy-efficient design, and nutrient recovery of various resource-utilization-based SW treatment technologies are emphasized. In addition, future research prospective, such as prioritization of process optimization, in-depth exploration of microbial mechanisms, enhancement of energy conversion efficiency, and integration of diverse technologies, are highlighted to expand engineering applications and establish a sustainable SW treatment system.


Asunto(s)
Fuentes de Energía Bioeléctrica , Aguas Residuales , Animales , Porcinos , Estudios Prospectivos , Reactores Biológicos , Tecnología
3.
Water Res ; 245: 120571, 2023 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-37683523

RESUMEN

Phosphite, an essential component in the biogeochemical phosphorus cycle, may make significant contributions to the bioavailable phosphorus pool as well as water eutrophication. However, to date, the potential impacts of coexisting photochemically active substances on the environmental fate and transformation of phosphite in aquatic environments have been sparsely elucidated. In the present study, the effect of zinc oxide nanoparticles (ZnO NPs), a widely distributed photocatalyst in aquatic environments, on phosphite phototransformation under simulated solar irradiation was systematically investigated. The physicochemical characteristics of the pristine and reacted ZnO NPs were thoroughly characterized. The results showed that the presence of ZnO NPs induced the indirect phototransformation of phosphite to phosphate, and the reaction rate increased with increasing ZnO NPs concentration. Through experiments with quenching and trapping free radicals, it was proved that photogenerated reactive oxygen species (ROS), such as hydroxyl radical (•OH), superoxide anion (O2•-), and singlet oxygen (1O2), made substantial contributions to phosphite phototransformation. In addition, the influencing factors such as initial phosphite concentration, pH, water matrixes (Cl-, F-, Br-, SO42-, NO3-, NO2-, HCO3-, humic acid (HA) and citric acid (CA)) were investigated. The component of generated precipitates after the phosphite phototransformation induced by ZnO NPs was still dominated by ZnO NPs, while the presence of amorphous Zn3(PO4)2 was identified. This work explored ZnO NPs-mediated phosphite phototransformation processes, indicating that nanophotocatalysts released into aquatic environments such as ZnO NPs may function as photosensitizers to play a beneficial role in the transformation of phosphite to phosphate, thereby potentially mitigating the toxicity of phosphite to aquatic organisms while exacerbating eutrophication. The findings of this study provide a novel insight into the comprehensive assessment of the environmental fate, potential ecological risk, and biogeochemical behaviors of phosphite in natural aquatic environments under the condition of combined pollution.

4.
Water Sci Technol ; 88(1): 62-74, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37452534

RESUMEN

Efficient degradation of uranium(VI) (U(VI)) in wastewater is an urgent problem because of the chemical toxicity and radiotoxicity. In this study, the Agx-SnS2 photocatalysts were compounded by a simple hydrothermal method, effectively removing U(VI) under visible light in water. Compared with SnS2, the results indicated that Agx-SnS2 would decrease the crystallinity without destroying the crystal structure. Moreover, it has excellent photocatalytic performance on the degradation rate of U(VI). Ag0.5-SnS2 exhibited a prominent photocatalytic reduction efficiency of UO22+ of about 86.4% under optical light for 75 min. This was attributed to Ag-doped catalysts, which can narrow the band gap and enhance absorption in visible light. Meanwhile, the doping of Ag promoted the separation of photoinduced carriers, so that more photogenerated charges participated in the photocatalytic reaction. The stability and reusability were verified by the cycle test and the potential photocatalytic mechanism was analyzed based on the experiment.


Asunto(s)
Luz , Uranio , Catálisis , Uranio/química , Aguas Residuales
5.
Sci Rep ; 13(1): 9145, 2023 06 05.
Artículo en Inglés | MEDLINE | ID: mdl-37277502

RESUMEN

With the rapid economic development of China's coastal areas and the growth of industry and population, the problem of heavy metal contamination in estuarine waters is increasing in sensitivity and seriousness. In order to accurately and quantitatively describe the current status of heavy metal contamination and identify sensitive aquatic organisms with high ecological risks, five heavy metals in eight estuaries of the Pearl River were monitored at monthly intervals from January to December in 2020, and the ecological risks of aquatic organisms induced by heavy metals were evaluated using Risk quotients (RQ) and species sensitivity distributions (SSD) methods. The results showed that the concentrations of As, Cu, Pb, Hg and Zn in estuaries of the Pearl River were (0.65-9.25) µg/L, (0.07-11.57) µg/L, (0.05-9.09) µg/L, (< 0.40) µg/L and (0.67-86.12) µg/L, respectively. With the exception of Hg in Jiaomen water, the other heavy metals in each sampling site met or exceed the water quality standard of Grade II. The aquatic ecological risks of As, Pb and Hg were generally low in the waters of the Pearl River estuary, but individual aquatic organisms are subject to elevated ecological risks due to Cu and Zn. The content of Zn has a lethal effect on the crustaceans Temora Stylifera, and the content of Cu has a serious impact on the mollusks Corbicula Fluminea and has a certain impact on the crustaceans Corophium sp. and the fish Sparus aurata. Heavy metal levels and joint ecological risks (msPAF) in the Humen, Jiaomen, Hongqimen, and Hengmen estuaries were slightly higher than in other estuaries, and the Yamen estuary had the lowest contration of heavy metals and ecological risk. Research findings can serve as a basis for formulating water quality standards for heavy metals and for protecting aquatic biodiversity in the Pearl River Estuary.


Asunto(s)
Copépodos , Mercurio , Metales Pesados , Dorada , Contaminantes Químicos del Agua , Animales , Organismos Acuáticos , Monitoreo del Ambiente , Contaminantes Químicos del Agua/toxicidad , Contaminantes Químicos del Agua/análisis , Sedimentos Geológicos , Ríos , Plomo , Estuarios , Metales Pesados/toxicidad , Metales Pesados/análisis , Medición de Riesgo , China
6.
Environ Sci Pollut Res Int ; 30(31): 76595-76605, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37243771

RESUMEN

The process of phosphine production by phosphate-reducing bacteria Pseudescherichia sp. SFM4 has been well studied. Phosphine originates from the biochemical stage of functional bacteria that synthesize pyruvate. Stirring the aggregated bacterial mass and supplying pure hydrogen could lead to an increase of 40 and 44% phosphine production, respectively. Phosphine was produced when bacterial cells agglomerated in the reactor. Extracellular polymeric substances secreted on microbial aggregates promoted the formation of phosphine due to the presence of groups containing phosphorus element. Phosphorus metabolism gene and phosphorus source analysis implied that functional bacteria used anabolic organic phosphorus, especially containing carbon-phosphorus bonds, as a source with [H] as electron donor to produce phosphine.


Asunto(s)
Fosfinas , Fósforo , Fósforo/análisis , Bacterias/metabolismo , Enterobacteriaceae
7.
Environ Sci Pollut Res Int ; 30(22): 63036-63051, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36952164

RESUMEN

Identifying spatiotemporal variation patterns and predicting future water quality are critical for rational and effective surface water management. In this study, an exploratory analysis and forecast workflow for water quality in Pearl River, Guangzhou, China, was established based on the 4-h interval dataset selected from 10 stations for water quality monitoring from 2019 to 2021. The multiple statistical techniques, such as cluster analysis (CA), principal component analysis (PCA), correlation analysis (CoA), and redundancy analysis (RDA), as well as data-driven model (i.e., gated recurrent unit (GRU)), were applied for assessing and predicting the water quality in the basin. The investigated sampling stations were classified into 3 categories based on differences in water quality, i.e., low, moderate, and high pollution regions. The average water quality indexes (WQI) values ranged from 38.43 to 92.63. Nitrogen was the most dominant pollutant, with high TN concentrations of 0.81-7.67 mg/L. Surface runoff, atmospheric deposition, and anthropogenic activities were the major contributors affecting the spatiotemporal variations in water quality. The decline in river water quality during the wet season was mainly attributed to increased surface runoff and extensive human activities. Furthermore, the short-term prediction of river water quality was achieved using the GRU model. The result indicated that for both DLCK and DTJ stations, the WQI for the 5-day lead time were predicted with accuracies of 0.82; for the LXH station, the WQI for the 3-day lead time was forecasted with an accuracy of 0.83. The finding of this study will shed a light on an effective reference and systematic support for spatio-seasonal variation and prediction patterns of water quality.


Asunto(s)
Contaminantes Químicos del Agua , Calidad del Agua , Humanos , China , Monitoreo del Ambiente/métodos , Ríos , Análisis Espacio-Temporal , Contaminantes Químicos del Agua/análisis
8.
Carbohydr Polym ; 304: 120474, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36641191

RESUMEN

A novel flocculation strategy for simultaneously removing Microcystis aeruginosa and algal organic matter (AOM) was proposed using chitosan-amphoteric starch (C-A) dual flocculants in an efficient, cost-effective and ecologically friendly way, providing new insights for harmful algal blooms (HABs) control. A dual-functional starch-based flocculant, amphoteric starch (AS) with high anion degree of substitution (DSA) and cation degree of substitution (DSC), was prepared using a cationic moiety of 3-chloro-2-hydroxypropyltrimethylammonium chloride (CTA) coupled with an anion moiety of chloroacetic acid onto the backbone of starch simultaneously. In combination of the results of FTIR, XPS, 1H NMR, 13C NMR, GPC, EA, TGA and SEM, it was evidenced that the successfully synthesized AS with excellent structural characteristics contributed to the enhanced flocculation of M. aeruginosa. Furthermore, the novel C-A dual flocculants could achieve not only the removal of >99.3 % of M. aeruginosa, but also the efficacious flocculation of algal organic matter (AOM) at optimal concentration of (0.8:24) mg/L, within a wide pH range of 3-11. The analysis of zeta potential and cellular morphology revealed that the dual effects of both enhanced charge neutralization and notable netting-bridging played a vital role in efficient M. aeruginosa removal.


Asunto(s)
Quitosano , Microcystis , Almidón , Floculación , Floraciones de Algas Nocivas , Cationes
9.
World J Gastroenterol ; 28(46): 6433-6477, 2022 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-36569275

RESUMEN

Hepatectomy is currently considered the most effective option for treating patients with early and intermediate hepatocellular carcinoma (HCC). Unfortunately, the postoperative prognosis of patients with HCC remains unsatisfactory, predominantly because of high postoperative metastasis and recurrence rates. Therefore, research on the molecular mechanisms of postoperative HCC metastasis and recurrence will help develop effective intervention measures to prevent or delay HCC metastasis and recurrence and to improve the long-term survival of HCC patients. Herein, we review the latest research progress on the molecular mechanisms underlying postoperative HCC metastasis and recurrence to lay a foundation for improving the understanding of HCC metastasis and recurrence and for developing more precise prevention and intervention strategies.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Recurrencia Local de Neoplasia/prevención & control , Pronóstico , Hepatectomía/efectos adversos , Estudios Retrospectivos
10.
J Environ Manage ; 321: 116028, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-36104874

RESUMEN

Antibiotics have been recognized as emerging contaminants that are widely distributed and accumulated in aquatic environment, posing a risk to ecosystem at trace level. Constructed wetlands (CWs) have been regarded as a sustainable and cost-effective alternative for efficient elimination of antibiotics. This review summarizes the removal of 5 categories of widely used antibiotics in CWs, and discusses the roles of the key components in CW system, i.e., substrate, macrophytes, and microorganisms, in removing antibiotics. Overall, the vertical subsurface flow CWs have proven to perform better in terms of antibiotic removal (>78%) compared to other single CWs. The adsorption behavior of antibiotics in wetland substrates is determined by the physicochemical properties of antibiotics, substrate configuration and operating parameters. The effects of wetland plants on antibiotic removal mainly include direct (e.g., plant uptake and degradation) and indirect (e.g., rhizosphere processes) manners. The possible interactions between microorganisms and antibiotics include biosorption, bioaccumulation and biodegradation. The potential strategies for further enhancement of the antibiotic removal performance in CWs included optimizing operation parameters, innovating substrate, strengthening microbial activity, and integrating with other treatment technologies. Taken together, this review provides useful information for facilitating the development of feasible, innovative and intensive antibiotic removal technologies in CWs, as well as enhancing the economic viability and ecological sustainability.


Asunto(s)
Contaminantes Químicos del Agua , Humedales , Antibacterianos/metabolismo , Ecosistema , Plantas/metabolismo , Eliminación de Residuos Líquidos , Contaminantes Químicos del Agua/análisis
11.
J Environ Manage ; 321: 115848, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-35987051

RESUMEN

In this study, different management strategies for sewage sludge disposal were evaluated associated with environmental, energy, and economic impact, using life cycle assessment (LCA), cumulative energy demand (CED) and life cycle costing (LCC) approaches. Four scenarios, including mono-incineration, co-incineration in municipal solid wastes (MSW) incineration plant, co-incineration in coal-fired power plant and co-incineration in cement kiln, were assessed. The environmental burdens generated from the sludge incineration contributed primarily to the global warming, followed by eutrophication, marine aquatic ecotoxicity, and human toxicity potential across the four scenarios. Furthermore, mono-incineration scenario appeared to be the most environmentally unfriendly, energy and economy intensive alternative, with the LCA, CED and LCC value of 5.41E-09, 1736 MJ and 1.84 million CNY, respectively. By contrast, co-incineration in cement kiln exhibited the lowest CED (368 MJ), LCC (0.59 million CNY), and environmental burdens (1.02E-09). In addition, the sensitivity analysis indicated that four scenarios were sensitive to the changes in the electricity efficiency and the moisture content contained in sewage sludge, suggesting that it was of great significance to enhance the efficiency of sludge dewatering and thermal drying The findings of this study can provide scientific reference for selecting the optimal strategies for the most environmentally and economically friendly sewage sludge management with optimum energy efficiency.


Asunto(s)
Eliminación de Residuos , Aguas del Alcantarillado , Desecación , Humanos , Incineración , Centrales Eléctricas , Residuos Sólidos
12.
J Environ Manage ; 319: 115771, 2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-35982569

RESUMEN

While nanoscale zero-valent iron modified biochar (nZVI-BC) have been widely investigated for the removal of heavy metals, the corrosion products of nZVI and their interaction with heavy metals have not been revealed yet. In this paper, nZVI-BC was synthesized and applied for the removal of Cr(VI). Batch experiments indicated that the adsorption of Cr(VI) fit Langmuir isotherm, with the maximum removal capacity at 172.4 mg/g at pH 2.0. SEM-EDS, BET, XRD, FT-IR, Raman and XPS investigation suggested that reduction of Cr(VI) to Cr(III) was the major removal mechanism. pH played an important role on the corrosion of nZVI-BC, at pH 4.5 and 2.0, FeOOH and Fe3O4 were detected as the major iron oxide, respectively. Therefore, FeOOH-BC and Fe3O4-BC were further prepared and their interaction with Cr were studied. Combining with DFT calculations, it revealed that Fe3O4 has higher adsorption capacity and was responsible for the effective removal of Cr(VI) through electrostatic attraction and reduction under acidic conditions. However, Fe3O4 will continue to convert to the more stable FeOOH, which is the key to for the subsequent stabilization of the reduced Cr(III). The results showed that the oxide corrosion products of nZVI-BC were subjected to the environment, which will eventually affect the fate and transport of the adsorbed heavy metal.


Asunto(s)
Hierro , Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico , Cromo , Aguas del Alcantarillado , Espectroscopía Infrarroja por Transformada de Fourier , Contaminantes Químicos del Agua/análisis
13.
Environ Pollut ; 306: 119399, 2022 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-35525511

RESUMEN

Carbon dioxide (CO2) is the main anthropogenic greenhouse gas contributing to global warming. In this study, a series of KOH-modified biochars derived from feedstock mixtures (i.e., S3W7 biomass consisting of 70% pine sawdust and 30% sewage sludge; S5W5 biomass consisting of 50% pine sawdust and 50% sewage sludge) at different temperature (i.e., 600-800 °C) were prepared for evaluating CO2 adsorption performance. The KOH-activated biochars prepared with S3W7 biomass displayed larger surface areas and micropore volumes compared to those of S5W5 biochars. In particular, the highest CO2 adsorption capacity (177.1 mg/g) was observed on S3W7 biomass at 700 °C (S3W7-700K), due to the largest surface area (2623 m2/g) and the highest micropore volume (0.68 cm3/g). Furthermore, surface functional groups, hydrophobicity, and aromaticity of biochar and presence of hetero atoms (N) also were actively involved in CO2 adsorption of biochar. In addition, in situ DRIFTS analysis advanced current understanding for the chemical sorption mechanisms by identifying the transformation composites of CO2 on biochars, and characterizing the weakly adsorbed and newly formed mineral species (e.g., carbonates) during the CO2 sorption process. This study may provide an insight into the research of CO2 capture by identifying physical and chemical adsorption, and expand the effective utilization of natural biomass-based biochar for mitigation greenhouse gas emission.


Asunto(s)
Gases de Efecto Invernadero , Aguas del Alcantarillado , Adsorción , Dióxido de Carbono/química , Carbón Orgánico/química , Aguas del Alcantarillado/química
14.
Sci Total Environ ; 826: 154133, 2022 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-35219664

RESUMEN

The environment issues associated with global warming and climate change caused by continuous increase in greenhouse gas emissions have attracted worldwide concerns. As renewable resources with good adsorption property, biochar is an efficient and environmental friendly adsorbsent for CO2 capture. In this study, the CO2 adsorption behavior of biochars derived from feedstock mixtures of 70% pine sawdust and 30% sewage sludge by KOH modification was investigated. The textual properties and functional groups of the pristine biochars have been significantly enhanced after KOH activation. With highly developed microporosity, the specific surface area (SSA) of the KOH-modified biochars increased by 3.9-14.5 times. Furthermore, higher CO2 adsorption capacities of 136.7-182.0 mg/g were observed for the modified biochars, compared to pristine ones (35.5-42.9 mg/g). The development of micropores by KOH activation significantly increased the CO2 adsorption capacity. Meanwhile, the presence of hetero atoms (O and K) also positively influenced CO2 adsorption capacity of biochar. Noticeably, both physical and chemical adsorption played a crucial role in CO2 capture, which was verified by different characterization methods including high resolution scanning electron microscope, X-ray photoelectron spectroscopy and in situ diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. The Findings of this study demonstrate the -significance of chemical sorption by identifying the transformation of CO2 by biochar composites and in situ characterization of weakly adsorbed and newly formed mineral species during the CO2 sorption process. Moreover, BC700K showed 97% recyclability during 10 consecutive adsorption-desorption cycles at 25 °C, 1 bar. The results obtained in the present study may inspire new research interest and provide a comprehensive insight into the research subject to biochars derived from feedstock mixtures for CO2 capture.


Asunto(s)
Dióxido de Carbono , Aguas del Alcantarillado , Adsorción , Dióxido de Carbono/química , Carbón Orgánico/química
15.
Chemosphere ; 286(Pt 3): 131754, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34399263

RESUMEN

The problem of deep oxidation of low concentrations of VOCs in industrial tail gas is exceptionally urgent. The preparation of VOCs ozonation catalyst with a high mineralization rate is still a challenge. In this paper, manganese oxide carriers with different morphologies were synthesized by simple methods and used to catalyze ozone mineralization of toluene after loading Pt nanoparticles efficiently. The conversion of toluene over Pt/MnOx-T catalyst was more than 98 % at ambient temperature, and the mineralization rate of toluene was close to 100 % at 70 °C. Through a variety of characterization methods, the strong metal-support interaction (SMSI) between Pt nanoparticles and carriers was successfully constructed. It was found that SMSI successfully optimized the surface oxygen species and oxygen migration ability of the catalyst, and then realized the high degree of mineralization of toluene at low temperature. This paper guides the subsequent development of Pt-Mn catalysts for catalytic organic pollutants ozonation with high activity.


Asunto(s)
Ozono , Tolueno , Catálisis , Oxidación-Reducción , Oxígeno , Temperatura
17.
Rice (N Y) ; 14(1): 43, 2021 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-34014427

RESUMEN

BACKGROUND: Grain size and weight are important target traits determining grain yield and quality in rice. Wild rice species possess substantial elite genes that can be served as an important resource for genetic improvement of rice. In this study, we identify and validate a novel QTL on chromosome 7 affecting the grain size and weight using introgression lines from cross of Oryza sativa and Oryza minuta. RESULTS: An introgression line 'IL188' has been achieved from a wild species Oryza minuta (2n = 48, BBCC, W303) into O. sativa japonica Nipponbare. The F2 and F2:3 populations derived from a cross between IL188 and Nipponbare were used to map QTLs for five grain size traits, including grain length (GL), grain width (GW), grain length to width ratio (LWR), grain thickness (GT) and thousand grain weight (TGW). A total of 12 QTLs for the five grain traits were identified on chromosomes 1, 2, 3, 6, 7, and 8. The QTL-qGL7 controlling GL on chromosome 7 was detected stably in the F2 and F2:3 populations, and explained 15.09-16.30% of the phenotypic variance. To validate the effect of qGL7, eight residual heterozygous line (RHL) populations were developed through selfing four F2:3 and four F2:4 plants with different heterozygous segments for the target region. By further developing SSR and Indel markers in the target interval, qGL7 was delimited to a ~ 261 kb region between Indel marker Y7-12 and SSR marker Y7-38, which also showed significant effects on grain width and thousand grain weight. Comparing with the reference genome of Nipponbare, stop or frameshift mutations in the exon of the three putative genes LOC_Os07g36830, LOC_Os07g36900 and LOC_Os07g36910 encoding F-box domain-containing proteins may be the candidate genes for qGL7. Scanning electron microscopy analysis of the glume's epidermal cells showed that the cell length and width of NIL-qGL7IL188 was higher than NIL-qGL7Nip, indicating that qGL7 increases grain size and weight by regulating cell expansion. CONCLUSIONS: In this study, we detected 12 QTLs regulating grain size and weight using an introgression line from a cross between Oryza sativa and Oryza minuta. Of these loci, we confirmed and delimited the qGL7 to a ~ 261 kb region. Three putative genes, LOC_Os07g36830, LOC_Os07g36900 and LOC_Os07g36910 encoding F-box domain-containing proteins may be the candidate genes for qGL7. These results provide a basis for map-based cloning of the qGL7 gene and useful information for marker assisted selection in rice grain quality improvement.

18.
Environ Res ; 199: 111330, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34010625

RESUMEN

Cadmium-contaminated wastewater has attracted increasing concerns due to its non-biodegradable properties and high toxicity. To explore eco-friendly and economically feasible strategies, the screened Alcaligenes faecalis K2 were employed for the biomineralization and recovery of Cd2+ from wastewater while producing considerable secretory organo-biominerals (SOBs) as bioadsorbents. At 75 mg/L Cd2+ exposure, 85.5% of Cd2+ was removed by K2, 43.0% of which was fixed in the granular SOBs. SOBs were convenient for separating from the solution. The adsorption capacity of granular sorbent made from SOBs was verified to be greater than 77.1 mg/g. Practically, 89.5% of 75 mg/L of Cd2+ could be stably removed while ereK2 continuously generated SOBs in a moving-bed biofilm reactor (MBBR). To sum up, the production of bioadsorbents can be achieved by K2, while removing Cd with live microorganisms, which was conducive to making full use of materials and improving Cd removal efficiency.


Asunto(s)
Alcaligenes faecalis , Contaminantes Químicos del Agua , Adsorción , Biopelículas , Biomineralización , Reactores Biológicos , Cadmio/análisis , Contaminantes Químicos del Agua/análisis
19.
Environ Res ; 197: 111105, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33839120

RESUMEN

The global escalation and intensification of cyanobacterial blooms require powerful algaecides. This study investigated the algicidal efficacy and mechanism of EA-1 against Oscillatoria. Bacteria EA-1, identified as Enterobacter, was isolated with high algicidal activity against harmful cyanobacteria. Results showed that a complete removal of Oscillatoria was observed within 3 days with the initial Chl-a concentration of 1.74 mg/L. Physiological responses of Oscillatoria revealed that EA-1 induced severe lipid peroxidation and the ultimate decline of antioxidant enzyme activities. Moreover, the contents for both intracellular protein and carbohydrate of each algae cell increased first and then decreased. Scanning electron microscope (SEM) and transmission electron microscopy (TEM) analysis clarified that the possible process of Oscillatoria lysis included the breach of cross wall, followed by the disruption of photosynthetic membrane and incipient nucleus, and the ultimate outflow of inclusion. Confocal laser scanning microscopy (CLSM) analysis illustrated the degradation process of incipient nucleus in Oscillatoria.


Asunto(s)
Cianobacterias , Oscillatoria , Antioxidantes , Acuicultura , Enterobacter
20.
Sci Total Environ ; 768: 144281, 2021 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-33454481

RESUMEN

Owing to its environmental-friendliness, low-cost, and outstanding characteristics, biochar has been widely used for the catalytic degradation of various organic pollutants. In this study, a pre- and post-deashing graphitized biochar (DBC800 and PBC800-A) was prepared and compared with the pristine biochar (PBC800) to activate persulfate (PS) for tetracycline (TC) degradation. The influence of the natural endogenous mineral on the catalytic ability of biochar was investigated. Characterization results show that the inherent endogenous mineral in biochar not only acted as a natural pore-forming agent to promote the formation of the porous structure, but also facilitated the formation of edge defective structures, and altered the surface functional groups, as well as increased the carbonization and graphitization degree of biochar. The PBC800-A exhibited a much higher catalytic efficiency on PS activation and TC oxidative degradation with the reaction rate of 0.06055 min-1, 7.14 times as that of DBC800 (0.00861 min-1) and 4.63 times as that of PBC800 (0.00158 min-1). The endogenous minerals were conducive to the generation of free radicals and promoted the oxidative degradation of TC, which was mainly attributed to the improved carbon configuration. The post-deashing treatment was also found to significantly improve the electron transport efficiency of biochar by removing the residual ash, thereby promoting the generation of singlet oxygen. This study demonstrated that the natural minerals in biochar was beneficial for the degradation of TC, and more alternative natural minerals can be applied to co-pyrolysis with biochar for the remediation of refractory organic pollutants.


Asunto(s)
Carbón Orgánico , Tetraciclina , Minerales , Pirólisis
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