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1.
Sci Rep ; 11(1): 9314, 2021 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-33927316

RESUMO

Microbial bioremediation of heavy metals-polluted industrial effluents has been adopted as one of the most effective eco-friendly tool to cope up with the harmful effects of metals. This study was designed to investigate the biosorption potential of marine actinomycetes isolated from the Alexandrian Mediterranean Seacoast, Egypt, with their potential use in metal remediation of industrial effluents. Among the nine marine actinomycetes isolates, Streptomyces rochei ANH showed the highest versatile metal resistance capability with MIC values of 125 mg/l for Cr6+ and 60 mg/l for both Cd2+ and Pb2+. Additionally, scanning electron micrographs showed complete disintegration of Cr6+-treated biomass compared with the control ones where spores remained intact and connected in long chains. The study also aimed to improve the percentage of Cr6+ biosorption by S. rochei ANH biomass using the statistical designs of Plackett-Burman and Box-Behnken where up to 85% of Cr6+ removal was recorded under the following conditions: pH (5), incubation temperature (30 °C), contact time (3 h), agitation speed (90 rpm), initial Cr6+ concentration (50 mg/l) and living biomass concentration (10 mg/ml). The results also showed that the percentage of Cr6+ biosorption by S. rochei ANH decreased gradually beyond these values. Moreover, the results revealed that the use of the biomass of S. rochei ANH is an effective biotechnological agent for the biological treatment of heavy metal-contaminated tannery effluent where the percentages of metal removal were in the following order: Ni2+ (100%) ≥ Cu2+ ≥ Mn2+ ≥ Fe2+ > Pb2+ (95%) ≥ Cd2+ > Cr6+ (86%). Furthermore, the treated effluent exhibited a stimulating effect on the germination process of Lepidium sativum seeds. Therefore, the present study implies that S. rochei ANH can be considered a powerful candidate to mitigate hazardous heavy metals pollution from industrial effluents and improve the water quality for agricultural purposes.


Assuntos
Cromo/isolamento & purificação , Streptomyces , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Irrigação Agrícola , Biodegradação Ambiental , Lepidium sativum , Águas Residuárias/toxicidade
2.
Int J Mol Sci ; 22(6)2021 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-33805783

RESUMO

In anaerobic bioreactors, the electrons produced during the oxidation of organic matter can potentially be used for the biological reduction of pharmaceuticals in wastewaters. Common electron transfer limitations benefit from the acceleration of reactions through utilization of redox mediators (RM). This work explores the potential of carbon nanomaterials (CNM) as RM on the anaerobic removal of ciprofloxacin (CIP). Pristine and tailored carbon nanotubes (CNT) were first tested for chemical reduction of CIP, and pristine CNT was found as the best material, so it was further utilized in biological anaerobic assays with anaerobic granular sludge (GS). In addition, magnetic CNT were prepared and also tested in biological assays, as they are easier to be recovered and reused. In biological tests with CNM, approximately 99% CIP removal was achieved, and the reaction rates increased ≈1.5-fold relatively to the control without CNM. In these experiments, CIP adsorption onto GS and CNM was above 90%. Despite, after applying three successive cycles of CIP addition, the catalytic properties of magnetic CNT were maintained while adsorption decreased to 29 ± 3.2%, as the result of CNM overload by CIP. The results suggest the combined occurrence of different mechanisms for CIP removal: adsorption on GS and/or CNM, and biological reduction or oxidation, which can be accelerated by the presence of CNM. After biological treatment with CNM, toxicity towards Vibrio fischeri was evaluated, resulting in ≈ 46% detoxification of CIP solution, showing the advantages of combining biological treatment with CNM for CIP removal.


Assuntos
Ciprofloxacina/metabolismo , Elétrons , Nanopartículas de Magnetita/química , Nanotubos de Carbono/química , Esgotos/microbiologia , Poluentes Químicos da Água/metabolismo , Adsorção , Aliivibrio fischeri/efeitos dos fármacos , Aliivibrio fischeri/crescimento & desenvolvimento , Anaerobiose/fisiologia , Biodegradação Ambiental , Reatores Biológicos , Ciprofloxacina/isolamento & purificação , Humanos , Nanopartículas de Magnetita/ultraestrutura , Methanobacterium/metabolismo , Methanobrevibacter/metabolismo , Methanosarcinales/metabolismo , Methanospirillum/metabolismo , Testes de Sensibilidade Microbiana , Nanotubos de Carbono/ultraestrutura , Oxirredução , Poluentes Químicos da Água/isolamento & purificação
3.
Int J Biol Macromol ; 179: 366-376, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33647339

RESUMO

A new alternative aerogel was prepared from low-cost chitin and psyllium biopolymers to adsorb crystal violet (CV) dye from liquid media and possibly treat effluents containing other dyes. The aerogel was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), which demonstrated that aerogel has a typical structure of amorphous materials and presented a randomly interconnected porous structure that resembles an open pore network. 2.5 g L-1 of aerogel was able to remove 86.00% of CV from solutions, and the natural pH of the CV solution was considered the more adequate for adsorption. The pseudo-second-order (PSO) model satisfactorily described the adsorption kinetics, and the Freundlich model was suitable to represent the adsorption equilibrium. The maximum experimental capacity achieved was 227.11 mg g-1, which indicates that aerogel is very efficient and competitive with several adsorbents. Tests using a simulated effluent showed that aerogel has excellent potential to treat real colored effluents.


Assuntos
Quitina/química , Corantes/química , Violeta Genciana/isolamento & purificação , Psyllium/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Adsorção , Cinética , Porosidade , Termodinâmica , Água/química
4.
Anal Bioanal Chem ; 413(4): 1107-1116, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33388846

RESUMO

This paper proposes the use of Anoxybacillus flavithermus SO-15 immobilized on iron oxide nanoparticles (NPs) as a novel magnetized biosorbent for the preconcentrations of uranium (U) and thorium (Th). The SPE procedure was based on biosorption of U(VI) and Th(IV) on a column of iron oxide NPs loaded with dead and dried thermophilic bacterial biomass prior to U(VI) and Th(IV) measurements by ICP-OES. The biosorbent characteristicswere explored using FT-IR, SEM, and EDX. Significant operational factors such as solution pH, volume and flow rate of the sample solution, amounts of dead bacteria and iron oxide nanoparticles, matrix interference effect, eluent type, and repeating use of the biosorbent on process yield were studied. The biosorption capacities were found as 62.7 and 56.4 mg g-1 for U(VI) and Th(IV), respectively. The novel extraction process has been successfullyapplied to the tap, river, and lake water samples for preconcentrations of U(VI) and Th(IV).


Assuntos
Anoxybacillus/química , Nanopartículas Magnéticas de Óxido de Ferro/química , Extração em Fase Sólida/métodos , Tório/isolamento & purificação , Urânio/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Células Imobilizadas/química
5.
Anal Methods ; 13(5): 575-594, 2021 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-33507166

RESUMO

Active pharmaceutical ingredients (APIs) are increasingly being identified as contaminants of emerging concern (CECs). They have potentially detrimental ecological and human health impacts but most are not currently subject to environmental regulation. Addressing the life cycle of these pharmaceuticals plays a significant role in identifying the potential sources and understanding the environmental impact that pharmaceuticals may have in surface waters. The stability and biological activity of these "micro-pollutants" can lead to a pseudo persistence, with ensuing unknown chronic behavioural and health-related effects. Research that investigates pharmaceuticals predominantly focuses on their occurrence and effect within surface water environments. However, this review will help to collate this information with factors that affect their environmental concentration. This review focuses on six pharmaceuticals (clarithromycin, ciprofloxacin, sulfamethoxazole, venlafaxine, gemfibrozil and diclofenac), chosen because they are heavily consumed globally, have poor removal rates in conventional activated sludge wastewater treatment plants (CAS WWTPs), and are persistent in the aquatic environment. Furthermore, these pharmaceuticals are included in numerous published prioritisation studies and/or are on the Water Framework Directive (WFD) "Watch List" or are candidates for the updated Watch List (WL). This review investigates the concentrations seen in European Union (EU) surface waters and examines factors that influence final concentrations prior to release, thus giving a holistic overview on the source of pharmaceutical surface water pollution. A period of 10 years is covered by this review, which includes research from 2009-2020 examining over 100 published studies, and highlighting that pharmaceuticals can pose a severe risk to surface water environments, with each stage of the lifecycle of the pharmaceutical determining its concentration. This review additionally highlights the necessity to improve education surrounding appropriate use, disposal and waste management of pharmaceuticals, while implementing a source directed and end of pipe approach to reduce pharmaceutical occurrence in surface waters.


Assuntos
COVID-19 , Mudança Climática , Pandemias , Poluentes Orgânicos Persistentes , Preparações Farmacêuticas , Poluentes Químicos da Água , Animais , Organismos Aquáticos/efeitos dos fármacos , COVID-19/epidemiologia , Indústria Farmacêutica , Ecotoxicologia , União Europeia , Humanos , Poluentes Orgânicos Persistentes/isolamento & purificação , Poluentes Orgânicos Persistentes/metabolismo , Poluentes Orgânicos Persistentes/farmacologia , Preparações Farmacêuticas/isolamento & purificação , Preparações Farmacêuticas/metabolismo , Plantas/efeitos dos fármacos , SARS-CoV-2 , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/farmacologia , Purificação da Água
6.
Chemistry ; 27(2): 660-668, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-32970361

RESUMO

Biowaste-derived substances isolated from green compost (BBS-GC) are environmentally friendly reactants similar to humic substances, which contain multiple functionalities, that are suitable for adsorbing different kinds of pollutants in wastewater. Herein, sodium alginate (derived from brown algae) cross-linked with both Ca2+ ions and BBS-GC in the form of hydrogels and dried films are proposed as green, easy-to-form, and handleable materials for tertiary water treatments. The results show that both hydrogels and films are mechanically stable and can effectively remove differently charged dyes through an adsorption mechanism that can be described by the Freundlich model. BBS-GC-containing gels always performed better than samples prepared without BBS-GC, revealing that such unconventional materials can integrate waste valorization and water decontamination, potentially providing social and environmental benefits.


Assuntos
Alginatos/química , Hidrogéis/química , Águas Residuárias/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Água/química , Adsorção , Química Verde , Phaeophyceae/química , Poluentes Químicos da Água/química
7.
Carbohydr Polym ; 251: 116986, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33142558

RESUMO

Natural biopolymers, polymeric organic molecules produced by living organisms and/or renewable resources, are considered greener, sustainable, and eco-friendly materials. Natural polysaccharides comprising cellulose, chitin/chitosan, starch, gum, alginate, and pectin are sustainable materials owing to their outstanding structural features, abundant availability, and nontoxicity, ease of modification, biocompatibility, and promissing potentials. Plentiful polysaccharides have been utilized for making assorted (nano)catalysts in recent years; fabrication of polysaccharides-supported metal/metal oxide (nano)materials is one of the effective strategies in nanotechnology. Water is one of the world's foremost environmental stress concerns. Nanomaterial-adorned polysaccharides-based entities have functioned as novel and more efficient (nano)catalysts or sorbents in eliminating an array of aqueous pollutants and contaminants, including ionic metals and organic/inorganic pollutants from wastewater. This review encompasses recent advancements, trends and challenges for natural biopolymers assembled from renewable resources for exploitation in the production of starch, cellulose, pectin, gum, alginate, chitin and chitosan-derived (nano)materials.


Assuntos
Biopolímeros , Nanoestruturas , Purificação da Água/métodos , Adsorção , Alginatos , Catálise , Celulose , Quitina , Quitosana , Conservação dos Recursos Hídricos , Química Verde , Nanoestruturas/química , Nanotecnologia , Pectinas , Amido , Águas Residuárias/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
8.
Molecules ; 25(19)2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-33007832

RESUMO

Development of optical materials has attracted strong attention from scientists across the world to obtain low band gap energy and become active in field of solar energy. This challenge, which cannot be accomplished by the usual techniques, has overcome through the current study using non-conventional techniques. This study has used explosive reactions to convert non-optical alumina to series of new optical nanocomposites with very low band gap energy for the first time. In this trend, alumina nanoparticles were prepared and modified by explosive reactions using ammonium nitrate as a solid fuel. By using methanol or ethanol as a source of carbon species, three nanocomposites were produced indicating a gradual reduction of the band gap energy of alumina from 4.34 eV to 1.60 eV. These nanocomposites were obtained by modifying alumina via two different carbon species; core-shell structure and carbon nanotubes. This modification led to sharp reduction for the band gap energy to become very sensitive in sunlight. Therefore, these nanocomposites caused fast decolorization and mineralization of green dyes after illuminating in sunlight for ten minutes. Finally, it can be concluded that reduction of the band gap energy introduces new optical materials for developing optical nano-devices and solar cells.


Assuntos
Nanocompostos/química , Óptica e Fotônica , Energia Solar , Luz Solar , Purificação da Água/métodos , Óxido de Alumínio/química , Compostos Férricos , Nanocompostos/ultraestrutura , Nanopartículas/química , Nanopartículas/ultraestrutura , Naftalenossulfonatos , Espectrometria por Raios X , Análise Espectral Raman , Termogravimetria , Poluentes Químicos da Água/isolamento & purificação , Difração de Raios X
9.
J Chromatogr Sci ; 58(10): 976-984, 2020 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-32893305

RESUMO

Biodiesel consists of various fatty acid methyl esters (FAMEs) that are mainly produced through transesterification of plant oil or animal fat. It is essential for biodiesel to be purified utmostly to meet its product standard before being traded, while the universal purification method has been water washing. However, water washing inevitably causes the residual of FAMEs in wastewater, which represents a loss of industrial profits. For the purpose of determination and monitoring of the FAME profile in wastewater, there is a necessity to develop a fast and reliable approach with small volume of sample in need. Hence, in this study, a combination of dispersive liquid-liquid microextraction (DLLME) and microwave demulsification is applied for the enrichment of residual FAMEs in water, followed by qualitative and quantitative analyses using gas chromatography-mass spectrometry. The results indicate that the optimal extractant in DLLME approach is toluene. And the optimal parameters are 20 mL of water sample, 80 µL of toluene as the extractant, 60 s of ultrasonic irradiation duration, 200 W of microwave power and 2 min of microwave irradiation duration. The standard curves and linear equations obtained with these conditions are used for the quantitative analysis of biodiesel wastewater, which reveals that there was 50.35 mg·L-1 of the total FAME residuals in wastewater. To the best of our knowledge, it is for the first time that the combined technique of DLLME and microwave demulsification is applied in determination of residual FAMEs in water samples. The proposed method corresponds to small volumes of sample and extractant and short analytical period. It also has the potential to be extended to the analysis of other water pollutants.


Assuntos
Biocombustíveis/análise , Ácidos Graxos/análise , Microextração em Fase Líquida/métodos , Águas Residuárias/química , Poluentes Químicos da Água/análise , Ésteres , Ácidos Graxos/química , Ácidos Graxos/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas/métodos , Limite de Detecção , Modelos Lineares , Micro-Ondas , Reprodutibilidade dos Testes , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
10.
IET Nanobiotechnol ; 14(6): 449-456, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32755953

RESUMO

Immobilised magnetic nanoparticles are extensively used owing to their superparamagnetic nature, surface interaction, and binding specificity with the appropriate portentous substances. The present research focuses on the development of a portentous, robust carrier, which integrates the silica-coated amino-functionalised magnetic nanoparticle (AF-MnP) with the plant extracts of Cynodon dactylon (L1) and Muraya koenigii (L2) for the stable and enhanced removal of hazardous hexavalent chromium pollutant in the wastewater. Vibrating sample magnetometer (Ms - 45 emu/g) determines the superparamagnetic properties; Fourier-transform infrared spectroscopy determines the presence of functional groups such as NH2, Si-O-Si, C=C; high-resolution transmission electron microscopy, field emission scanning electron microscope and energy-dispersive X-ray spectroscopy determine the size of the green adsorbents in the range of 20 nm and the presence of elements such as Fe, N, and Si determines the efficacy of the synthesised silica-coated AF-MnP. The AF-MnP-L1 shows the maximum adsorption capacity of 34.7 mg/g of sorbent calculated from the Langmuir isotherm model and the process follows pseudo-second-order kinetics. After treatment, the adsorbents can be easily separated from the solution in the presence of an external magnetic field and are reused for nine cycles after acid treatment with the minimal loss of adsorption efficiency.


Assuntos
Cromo , Nanopartículas de Magnetita/química , Extratos Vegetais , Dióxido de Silício/química , Poluentes Químicos da Água , Cromo/isolamento & purificação , Cromo/metabolismo , Cynodon/química , Concentração de Íons de Hidrogênio , Murraya/química , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Águas Residuárias/química , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/metabolismo
11.
Int J Mol Sci ; 21(13)2020 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-32635635

RESUMO

Heavy metals (HMs) are released into the environment by many human activities and persist in water even after remediation. The efficient filtration of solubilized HMs is extremely difficult. Phytoremediation appears a convenient tool to remove HMs from polluted water, but it is limited by the choice of plants able to adapt to filtration of polluted water in terms of space and physiological needs. Biomasses are often preferred. Aquatic moss biomasses, thanks to gametophyte characteristics, can act as live filtering material. The potential for phytoremediation of Hypnales aquatic mosses has been poorly investigated compared to aquatic macrophytes. Their potential is usually indicated as a tool for bioindication and environmental monitoring more than for pollutant removal. When phytoremediation has been considered, insufficient attention has been paid to the adaptability of biomasses to different needs. In this study the heavy metal uptake of moss Taxiphyllum barbieri grown in two different light conditions, was tested with high concentrations of elements such as Pb, Cd, Zn, Cu, As, and Cr. This moss produces dense mats with few culture needs. The experimental design confirmed the capacity of the moss to accumulate HMs accordingly to their physiology and then demonstrated that a significant proportion of HMs was accumulated within a few hours. In addition to the biosorption effect, an evident contribution of the active simplistic mass can be evidenced. These reports of HM accumulation within short time intervals, show how this moss is particularly suitable as an adaptable bio-filter, representing a new opportunity for water eco-sustainable remediation.


Assuntos
Briófitas , Metais Pesados/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Biodegradação Ambiental , Pectinas/química
12.
Int J Biol Macromol ; 164: 920-931, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32673717

RESUMO

The hydrogels-metal organic frameworks hybrid materials have received increasing attentions in recent years. The pectin hydrogel (PH) was derived from mandarin orange peels by-products and calcium chloride was applied as a cross-linker for incorporation with Fe-TAC metal organic frameworks (MOFs) for the formation of PHM composite on in situ synthesis method. The synthesized PHM composite was characterized by SEM, FT-IR, XRD and N2 adsorption-desorption and investigated for the adsorption of anionic species, Cr(VI) as well as cationic species, Pb(II) ions from aqueous solution. The adsorption kinetics for Cr(VI)/Pb(II) ions removal followed the pseudo-second order kinetic model and the equilibrium adsorption data were well fitted by Langmuir model. The maximum adsorption capacities of Cr(VI)/Pb(II) ions were 825.97 and 913.88 mg g-1, respectively. High swelling capacity (1500.0%) was also characterized for PHM composite after only 400 min and excellent stability for eight cycles with respect to regeneration with 0.1 mol L-1 HCl. The validity of PHM composite for simultaneous removal from real water matrices were confirmed as Cr(VI) (99.73, 99.87 and 99.87%) and Pb(II) (99.02, 98.55 and 98.55%) from tap water, sea water and industrial wastewater samples, respectively.


Assuntos
Cromo/isolamento & purificação , Íons/isolamento & purificação , Chumbo/isolamento & purificação , Pectinas/química , Purificação da Água/métodos , Adsorção , Biomassa , Citrus/química , Água Potável , Frutas/química , Hidrogéis/química , Concentração de Íons de Hidrogênio , Cinética , Estruturas Metalorgânicas , Água do Mar , Temperatura , Termodinâmica , Águas Residuárias , Poluentes Químicos da Água/isolamento & purificação
13.
Chemosphere ; 258: 127152, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32544809

RESUMO

Graphene oxide (GO) has been proved with favorable affinity to U(VI), while some drawbacks such as poor dispersity and low adsorption performance limit its application. Herein, cetyltrimethylammonium bromide (CTAB) modified graphene oxide (MGO) composites were successfully fabricated, characterized and compared with graphene oxide (GO) in the sequestration of U(VI) in aqueous solutions. The results showed that maximum adsorption rate of MGO (99.21%) was obviously higher than that of GO (66.51%) under the same initial condition. Simultaneous introduction of C-H and NO coupled with the enhanced dispersity of GO after modification were mainly responsible for the updated performance verified with multiple characterization techniques. Based on the results of kinetics and isotherms investigations, the experimental data were best described by Pseudo-first-order kinetic model and Redlich-Peterson isotherm model. The results of ΔH, ΔS and ΔG show that adsorptive behaviors of uranyl ion on MGO are endothermic and spontaneous. The study provides a feasible alternative to the chemical modification of GO and enhancing the performance towards uranyl ion removal from solution.


Assuntos
Grafite/química , Urânio/química , Poluentes Químicos da Água/química , Adsorção , Cetrimônio/química , Concentração de Íons de Hidrogênio , Íons , Cinética , Microscopia Eletrônica de Varredura , Modelos Químicos , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo , Urânio/isolamento & purificação , Água , Poluentes Químicos da Água/isolamento & purificação , Poluentes Radioativos da Água/química , Poluentes Radioativos da Água/isolamento & purificação , Difração de Raios X
14.
Biotechnol Prog ; 36(5): e30322, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32475081

RESUMO

Penicillium piscarium can be indicated as promising in the treatment of sites contaminated with uranium. Thus, this research aimed to analyze the P. piscarium dead biomass in uranium biosorption. This fungus was previously isolated from a highly contaminated uranium mine located in Brazil. Biosorption tests were carried out at pH 3.5 and 5.5 in solutions contaminated with concentrations of 1 to 100 mg/L of uranium nitrate. Our results showed that the dead biomass of P. piscarium was able to remove between 93.2 and 97.5% uranium from solutions at pH 3.5, at the end of the experiment, the pH of the solution increased to values above 5.6. Regarding the experiments carried out in solutions with pH 5.5, the dead biomass of the fungus was also able to remove between 38 and 92% uranium from the solution, at the end of the experiment, the pH of the solution increased to levels above 6.5. The analysis of electron microscopy, Energy-dispersive spectroscopy, and X-ray fluorescence demonstrated the high concentration of uranium precipitated on the surface of the fungal biomass. These results were impressive and demonstrate that the dead biomass of P. piscarium can be an important alternative to conventional processes for treating water contaminated with heavy metals, and we hope that these ecofriendly, inexpensive, and effective technologies be encouraged for the safe discharge of water from industrial activities.


Assuntos
Biodegradação Ambiental , Penicillium/metabolismo , Urânio , Poluentes Químicos da Água , Urânio/análise , Urânio/isolamento & purificação , Urânio/metabolismo , Águas Residuárias/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos
15.
Bioprocess Biosyst Eng ; 43(11): 2039-2052, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32594316

RESUMO

In this study, a novel laboratory-scale synchronous enhanced biological phosphorus removal and semi-nitritation (termed as EBPR-SN) combined with anammox process was put forward for achieving nutrient elimination from municipal wastewater at 27 ℃. This process consisted of two 10 L sequencing batch reactors (SBRs), i.e. EBPR-SN SBR followed by Anammox SBR. The EBPR-SN SBR was operated for 400 days with five periods and the Anammox SBR was operated starting on period IV. Eventually, for treating municipal wastewater containing low chemical oxygen demand/nitrogen (COD/N) of 3.2 (mg/mg), the EBPR-SN plus Anammox system performed advanced total inorganic nitrogen (TIN) and P removal, with TIN and P removal efficiencies of 81.4% and 94.3%, respectively. Further analysis suggested that the contributions of simultaneous partial nitrification denitrification, denitrification, and anammox to TIN removal were 15.0%, 45.0%, and 40.0%, respectively. The enriched phosphorus-accumulating organisms (PAOs) in the EBPR-SN SBR facilitated P removal. Besides, the EBPR-SN SBR achieved P removal and provided stable anammox substrates, suggesting a short sludge retention time (SRT 12 d) could achieve synergy between ammonia-oxidizing bacteria and PAOs. These results provided an alternative process for treating municipal wastewater with limited organics.


Assuntos
Reatores Biológicos , Biotecnologia/métodos , Nitrogênio/isolamento & purificação , Fósforo/química , Fósforo/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Amônia/química , Análise da Demanda Biológica de Oxigênio , Desnitrificação , Desenho de Equipamento , Concentração de Íons de Hidrogênio , Nitrificação , Esgotos/microbiologia , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química
16.
Biophys Chem ; 263: 106392, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32417597

RESUMO

An environmental friendly and cost effective method was used for the preparation of silver­iron oxide (α-Fe2O3-Ag) nanocomposite using guava (Psidium guajava) leaf extract, which can be used as an adsorbent for decontamination of chromium (VI) ions from aqueous media. XRD analysis revealed that both Iron oxide and silver nanoparticles are crystalline in nature with face-centered cubic and rhombohedral geometry respectively. The FESEM micrographs of Fe2O3-Ag nanocomposite displayed irregular shaped particles with an average size of 50-90 nm. BET surface area analysis suggests that the prepared Fe2O3-Ag nanocomposites are mesoporous in nature with surface area of 122.72 m2/g. The adsorption of Cr(VI) was pH dependent and maximum adsorption occurred at pH = 4 with maximum adsorption capacity of 71.34 mg/g. Thermodynamic parameters reveals that the Cr(VI) adsorption on Fe2O3-Ag surface is endothermic and spontaneous in nature. The adsorbed Cr(VI) on Fe2O3-Ag surface was recovered and can be reused up to five cycles.


Assuntos
Cromo/isolamento & purificação , Nanocompostos/química , Extratos Vegetais/química , Folhas de Planta/química , Psidium/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Cromo/química , Compostos Férricos/química , Tamanho da Partícula , Porosidade , Prata/química , Propriedades de Superfície , Termodinâmica , Água/química , Poluentes Químicos da Água/química
17.
Chemosphere ; 255: 127005, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32416395

RESUMO

Recovering phosphorus from livestock wastewater could partly mitigate the global phosphorus resource crisis. Crystallization is a promising method for removing phosphorus from wastewater, but the costs of calcium- and magnesium-containing reagents are increasing. Cheap, available, efficient materials are required to replace conventional calcium and magnesium reagents. Here, we describe a new approach to removing and recovering phosphorus from livestock wastewater of a large pig farm, containing a high phosphorus concentration. The effects of the pH, stirring speed, stirring time, and extract dose (containing calcium and magnesium) on phosphorus removal from livestock wastewater were investigated. The product was characterized by X-ray diffractometry, Fourier-transform infrared spectroscopy, and scanning electron microscopy. Under optimized conditions (pH 9.0, stirring speed 200 r/m, stirring time 600 s, Ca 207.62 mg/L, Mg 122.86 mg/L), 92% of the phosphorus was removed from livestock wastewater. The product was mainly the hydroxyapatite (Ca5(PO4)3OH) precursor amorphous calcium phosphate but also contained 1.65% (by mass) magnesium ammonium phosphate (MgNH4PO4·6H2O) crystals. The cost of dolomite to treat 1 m3 of high-phosphorus wastewater was 0.20 yuan (45.9%, 25.9%, and 75.9% lower than for pure MgCl2, MgSO4, and CaCl2, respectively) in 2019. Using dolomite to provide calcium and magnesium effectively decreases the crystallization process cost and should encourage the use of crystallization to remove phosphorus from wastewater.


Assuntos
Carbonato de Cálcio/química , Magnésio/química , Fósforo/isolamento & purificação , Águas Residuárias/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Animais , Fosfatos de Cálcio/isolamento & purificação , Cristalização , Fazendas , Gado/crescimento & desenvolvimento , Estruvita/isolamento & purificação , Suínos
18.
IET Nanobiotechnol ; 14(4): 275-280, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32463017

RESUMO

Lead (Pb) ions are a major concern to the environment and human health as they are contemplated cumulative poisons. In this study, facile synthesis of magnetic iron oxide-tea waste nanocomposite is reported for adsorptive removal of lead ions from aqueous solutions and easy magnetic separation of the adsorbent afterwards. The samples were characterised by scanning electron microscopy, Fourier transform-infrared spectroscopy, X-ray diffraction, and Braunner-Emmet-Teller nitrogen adsorption study. Adsorptive removal of Pb(II) ions from aqueous solution was followed by ultraviolet-visible (UV-Vis) spectrophotometry. About 95% Pb(II) ion removal is achieved with the magnetic tea waste within 10 min. A coefficient of regression R2 ≃ 0.99 and adsorption density of 18.83 mg g-1 was found when Pb(II) ions were removed from aqueous solution using magnetic tea waste. The removal of Pb(II) ions follows the pseudo-second-order rate kinetics. External mass transfer principally regulates the rate-limiting phenomena of adsorption of Pb(II) ions on iron oxide-tea waste surface. The results strongly imply that magnetic tea waste has promising potential as an economic and excellent adsorbent for the removal of Pb(II) from water.


Assuntos
Chumbo , Nanopartículas de Magnetita/química , Nanocompostos/química , Águas Residuárias/química , Poluentes Químicos da Água , Adsorção , Íons/química , Íons/isolamento & purificação , Íons/metabolismo , Cinética , Chumbo/química , Chumbo/isolamento & purificação , Chumbo/metabolismo , Chá , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/metabolismo
19.
Trends Biotechnol ; 38(11): 1292-1303, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32307119

RESUMO

The increasing use and associated loss of phosphorus to the environment pose risks to aquatic ecosystems. Technology for phosphorus removal based on microbial aggregates is a natural, ecologically widespread, and sustainable reclamation strategy. Two main processes dominate phosphorus removal by microbial aggregates: extra- and intra-cellular entrapment. Extracellular phosphorus entrapment relies on extracellular polymeric substances, while intracellular entrapment uses a wider variety of phosphorus-entrapping mechanisms. In microbial aggregates, microalgae-bacteria interactions, quorum sensing, and acclimation can enhance phosphorus removal. Based on these insights, we propose novel avenues for entrapping phosphorus using ecological and genetic engineering, manipulated interactions, and integrated processes to create phosphorus removal technology mediated by microbial aggregates.


Assuntos
Bactérias , Microalgas , Fósforo , Poluentes Químicos da Água , Purificação da Água , Bactérias/metabolismo , Microalgas/metabolismo , Fósforo/isolamento & purificação , Fósforo/metabolismo , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos
20.
J Water Health ; 18(2): 224-228, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32300094

RESUMO

In this study, the effect of Spathiphyllum blandum on the removal of ibuprofen (IB) and conventional pollutants such as chemical oxygen demand (COD), total nitrogen (TN), ammonium (NH4 +-N), total phosphorus (TP), and total suspended solids (TSS) is reported; this, through its use as an emergent vegetation in fully saturated (FS) constructed wetlands (CWs) at mesocosm level treating polluted river water. With the exception of TP and COD, it was found that for TN (12%), NH4 +-N (11%), TSS (19%), and IB (23%), the removals in systems with vegetation were superior to systems without vegetation (p < 0.05). These findings demonstrate the importance of the species S. blandum, in particular, for the removal of ibuprofen, which is an anti-inflammatory drug commonly found in effluents of wastewater treatment plants. Thus, the results obtained provide information that can be used for the design of future efficient large-scale systems using a new ornamental species, mainly under tropical climatic conditions.


Assuntos
Ibuprofeno/isolamento & purificação , Rios/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água , Áreas Alagadas , Compostos de Amônio , Análise da Demanda Biológica de Oxigênio , Nitrogênio , Fósforo , Eliminação de Resíduos Líquidos , Águas Residuárias , Poluição da Água
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