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1.
Sci Rep ; 13(1): 5699, 2023 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-37029158

RESUMO

Due to the ongoing demand for alternative fuels for CI engines, biodiesel-based research has received support globally. In this study, soapberry seed oil produced by transesterification process to creates biodiesel. It is referred to as BDSS (Biodiesel of Soapberry Seed). According to criteria, the oil qualities are recognized, hence, three different blends and pure diesel were tested in CRDI (Common Rail Direct Injection) engines. The blends descriptions are: 10BDSS (10% BDSS + 90% diesel), 20BDSS (20% BDSS + 80% diesel), and 30BDSS (30% BDSS + 70% diesel). The outcomes of the related tests for combustion, performance, and pollution were contrasted with those achieved using 100% diesel fuel. In this case, the mixing has resulted in worse braking thermal efficiency than diesel and lower residual emissions with greater NOx emissions. The superior results were obtained by 30BDSS, which had BTE of 27.82%, NOx emissions of 1348 ppm, peak pressure of 78.93 bar, heat release rate (HRR) of 61.15 J/deg, emissions of CO (0.81%), HC (11 ppm), and smoke opacity of 15.38%.

2.
Sci Rep ; 13(1): 5067, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36977712

RESUMO

Large quantities of vegetable biowaste are generated at marketplaces, usually in highly populated locations. On the other hand, nearby markets, hotels, and street shops generate much cooking oil waste and dispose of them in the sewage. Environmental remediation is mandatory at these places. Hence, this experimental work concentrated on preparing biodiesel using green plant wastes and cooking oil. Biowaste catalysts were produced from vegetable wastes and biofuel generated from waste cooking oil using biowaste catalysts to support diesel demand and Environmental remediation. Other organic plant wastes such as bagasse, papaya stem, banana peduncle and moringa oleifera are used as heterogeneous catalysts of this research work. Initially, the plant wastes are independently considered for the catalyst for biodiesel production; secondary, all plant wastes are mixed to form a single catalyst and used to prepare the biodiesel. In the maximum biodiesel yield analysis, the calcination temperature, reaction temperature, methanol/oil ratio, catalyst loading and mixing speed were considered to control the biodiesel production. The results reveal that the catalyst loading of 4.5 wt% with mixed plant waste catalyst offered a maximum biodiesel yield of 95%.


Assuntos
Recuperação e Remediação Ambiental , Verduras , Óleos de Plantas , Biocombustíveis , Esterificação , Catálise
3.
Sci Rep ; 13(1): 4798, 2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-36959305

RESUMO

The purpose of this study is to conduct an experimental assessment of the impact of RCCI (reactivity regulated compression ignition) on the performance, emissions, and combustion of a CRDI engine. A fuel mix (20% biodiesel, 80% diesel, and a NaOH catalyst) is generated. The produced combination is evaluated for attributes using standards established by the American Society for Testing and Materials (ASTM). The engine research included three distinct kinds of injections: 10% Pen RCCI, 20% Pen RCCI, and 30% Pen RCCI. Increasing the injection pressure increases the brake thermal efficiency, often known as BTE. NOx emissions increased as a consequence of higher injection pressures and improved combustion. However, when the injection rate is increased, the Specific Fuel Consumption (SFC) falls. The CO2 and hydrocarbon emissions, as well as the smoke opacity values, increased as the charge increased. The resultant mixture may be utilized in a CI engine with pre-mixed ignition to improve overall engine performance as well as combustion characteristics.

4.
Environ Res ; 220: 115075, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36566967

RESUMO

Biowaste generation is considerably increasing multiple times recently due to various social and environmental changes like population growth, economic prosperity, globalisation etc. they contain different composition and generated at different stages of their life cycle. Though studies reported for recycle, reproduce and reuse of them, this investigation is unique by focussing to investigate the ideal circumstances for the production of biogas and methane from anaerobic digestion of vegetable waste using response surface methods and artificial neural networks with thermophilic temperature range. Thermophilic temperature of 20.78, organic loading rate of 0.2, pH of 8.81, agitation time of 5.8 and hydro retention time of 3 are the ideal input parameter values for the generation of biogas 3.03 m3 and methane% 186.08 with a desirability of 1. The Response surface model was surpassed by the Artificial Neural Network model.


Assuntos
Biocombustíveis , Metano , Anaerobiose , Temperatura , Redes Neurais de Computação , Reatores Biológicos
5.
Chemosphere ; 312(Pt 1): 137099, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36372332

RESUMO

Pollution of heavy metals is one of the risky contaminations that should be managed for all intents and purposes of general well-being concerns. The bioaccumulation of these heavy metals inside our bodies and pecking orders will influence our people in the future. Bioremediation is a bio-mechanism where residing organic entities use and reuse the squanders that are reused to one more form. This could be accomplished by taking advantage of the property of explicit biomolecules or biomass that is equipped for restricting by concentrating the necessary heavy metal particles. The microorganisms can't obliterate the metal yet can change it into a less harmful substance. In this unique circumstance, this review talks about the sources, poisonousness, impacts, and bioremediation strategies of five heavy metals: lead, mercury, arsenic, chromium, and manganese. The concentrations here are the ordinary strategies for bioremediation such as biosorption methods, the use of microbes, green growth, and organisms, etc. This review demonstrates the toxicity of heavy metal contamination degradation by biotransformation through bacterioremediation and biodegradation through mycoremediation.


Assuntos
Arsênio , Mercúrio , Metais Pesados , Humanos , Metais Pesados/metabolismo , Biodegradação Ambiental , Cromo
6.
Environ Res ; 216(Pt 4): 114763, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36356663

RESUMO

Phenols are of much toxicological and they must be effectively removed from the wastewater from industries as well as sewage treatment. Such removal demands a special and strong composite. So, this piece of research aims to activate Potassium peroxymonosulfate (PPMS) with the large surface area of magnetite nitrogen-fixed porous carbon nanotube composites (Co/CoOx@NCNT). Increases in the graphitization degree and structural control brought about by the incorporation of reduced Graphite oxide (rGO) significantly increased the catalyst activity of Co/CoOx@NCNT. It was found that PPMS activation for phenol removal by Co/CoOx@NCNT was nearly as effective as by homogeneous Co2+, with nearly 100% removal efficiency in 10 min. Both high reusability and high recycling of Co/CoOx@NCNT were accomplished simultaneously by proving the technology of viability in practical applications. The PPMS activation mechanism in the Co/CoOx@NCNT/PPMS system was driven by the electron transmission from contaminants to PPMS through the sp2- hybrid carbon nanotubes and nitrogen system. The selectivity of the Co/CoOx@NCNT/PPMS system to remove diverse organic compounds was determined by batch experiments. Due to the insignificant impact of radicals reactive on pollutant breakdown, the ability to inhibit species (such as Cl- and natural organic materials) from a minor role was significantly decreased. These results not only shed light on the process of PPMS heterogeneous activation but also provided a framework for the balanced project of highly effective nanocarbon-based catalysts for PPMS activation.


Assuntos
Nanotubos de Carbono , Águas Residuárias , Fenol , Nanotubos de Carbono/química , Fenóis , Nitrogênio , Compostos Orgânicos , Fenômenos Magnéticos
7.
Environ Res ; 218: 114984, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36462695

RESUMO

Pharmaceuticals are a new developing pollutant that is threatening aquatic ecosystems and impacting numerous species in the ecosystem. The aim of this study is the green synthesis of TiO2-Fe2O3-Chitosan nanocomposites in conjunction with Moringa olifera leaves extract and its applicability for ibuprofen removal. Various characterization studies were performed for the synthesized nanocomposites. Box-Behnken design (BBD) is employed to optimize pH, agitation speed, and composite dosage. Equilibrium results show that adsorption process matches with Langmuir isotherm, demonstrating adsorption on the nanocomposite's homogenous surface and follows pseudo-first-order kinetics. Using the BBD, pH, adsorbent dose, and agitation speed were examined as adsorption parameters. Ibuprofen elimination was demonstrated to be most successful at a pH of 7.3, using 0.05 g of nanocomposites at a rotational speed of 200 rpm. Thermodynamic parameters for ibuprofen sorption were carried out and the ΔH and ΔS was found to be 76.23 & 0.233. Molecular Docking was performed to find the interaction between the pollutant and the nanocomposite. UV-vis spectra confirm the 243 nm absorption band corresponding to the nanocomposite's surface plasmon resonances. Fourier transform infrared spectroscopy spectra relate this band to a group of nanocomposites. The findings of this work emphasize the importance of TiO2-Fe2O3-Chitosan nanocomposites for removing ibuprofen from wastewater.


Assuntos
Quitosana , Poluentes Ambientais , Nanocompostos , Poluentes Químicos da Água , Águas Residuárias , Ibuprofeno , Ecossistema , Simulação de Acoplamento Molecular , Quitosana/química , Porosidade , Concentração de Íons de Hidrogênio , Termodinâmica , Adsorção , Espectroscopia de Infravermelho com Transformada de Fourier , Nanocompostos/química , Cinética , Poluentes Químicos da Água/análise
8.
Environ Res ; 218: 114824, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36455635

RESUMO

Water treatment is as much important as it is to satisfying 11 worldwide sustainable development goals out of 17. The removal of Azo is much important as they are toxic and their existence in water, air and food can easily affect humans by triggering allergies, forming tumours etc. Azo contained Dyes Production was banned in many countries. This research aims to synthesize composite Nanorods and Nanospheres and characterize and test to remove Azo dyes from the wastewater. This research used a previously reported method to rapidly synthesize chitin magnetite nanocomposites (ChM) by co-precipitation while irradiating with ultrasound (US). Detailed structural characterization of ChM revealed a crystalline phase analogous to magnetite and spherical morphologies; extending the reaction time to 8 min yielded a "nanorod" type morphology. Both the morphologies displayed a nanoscale limit with particles averaging between 5 and 30 nm in size, resulting the superparamagnetic performance and saturation magnetization values between 45 and 58 emu/g. The nitrogen adsorption-desorption isotherms showed that the surface modification of ChMs resulted in a rise of specific surface area and pore size. Anionic azo dyes (methyl orange (MO) and reactive black 5 (RB5)) adsorption on the surface of nanocomposites was also demonstrated to be pH-dependent, with the reaction favoured for surface-modified samples at pH 4 and unmodified samples at pH 8. Adsorption capacity studies showed that molecule size effect and electrostatic attraction were two distinct adsorption processes for unmodified and modified ChMs. Chitin Magnetite nanoparticles appear to be a substitute for traditional anionic dye adsorbents. Additionally, the two key materials sources, chitin, and magnetite are inexpensive and easily accessible.


Assuntos
Nanocompostos , Poluentes Químicos da Água , Humanos , Óxido Ferroso-Férrico , Corantes/química , Quitina , Porosidade , Adsorção , Compostos Azo , Fenômenos Magnéticos , Poluentes Químicos da Água/química , Cinética , Concentração de Íons de Hidrogênio
9.
Chemosphere ; 308(Pt 3): 136530, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36150496

RESUMO

Non-steroidal anti-inflammatory medicines (NSAIDs) like paracetamol and other substances released into the water system pose serious environmental issues. The current work examines the synthesis of a nanocomposite combined with Moringa olifera aqueous leaf extract as a reducing and stabilizing agent for the green synthesis of nanocomposites. Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Thermogravimetric analysis (TGA), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) were used to investigate metal based functional nanocomposites. The absorption band centered at a wavelength of 243 nm, which corresponds to the surface plasmon resonances of the produced nanocomposite, is confirmed in UV-vis spectra. The distinctive band at this particular wavelength is attributed to a particular group of nanocomposites based on the result from the Fourier transform infrared spectroscopy spectra. The spherical with irregularly shaped aggregates was confirmed by transmission electron microscopy, and the average size of nanoparticles was found to be 1 nm. For the elimination of pharmaceutical contaminants such as paracetamol from aqueous solutions, the adsorptive characteristics of nanocomposites were examined. Temperature, pH, adsorbent dosage, and agitation speed were investigated as adsorption parameters using Box-Behnken Design (BBD). The best removal outcomes were found under the following circumstances: temperature at 303.15 K, pH = 7.5, 0.05 g of nanocomposites at 200 rpm. Based on the adsorption study, the kinetics was found to be pseudo first order (R2 > 0.9481) which was validated and fitted by Langmuir isotherm (R2 > 0.9973). The adsorption study confirms that it was adsorbed onto the synthesized nanocomposite and found to be present on the homogeneous surface.


Assuntos
Nanocompostos , Poluentes Químicos da Água , Acetaminofen , Adsorção , Anti-Inflamatórios , Anti-Inflamatórios não Esteroides , Excipientes , Concentração de Íons de Hidrogênio , Cinética , Nanocompostos/química , Extratos Vegetais , Espectroscopia de Infravermelho com Transformada de Fourier , Águas Residuárias , Água/química , Poluentes Químicos da Água/química
10.
J Environ Manage ; 324: 116265, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36179469

RESUMO

Impact of heavy metal (HM) pollution and its understanding on environment as well as human beings has grown a lot during the last few decades. The goal of this study is to create a scientometric study on heavy metal contamination, in the period 1989 to 2020, in order to provide futuristic goals for the new researchers on wastewater treatment. For this, a search was conducted in the Web of Science (WoS) and Scopus databases, related to heavy metal pollution. Totally, 37,154 records were collected during the study period from 1989 to 2020. The findings revealed that China, the United States, and India has most referenced papers across a wide range of trans disciplinary issues such as toxicity, technology, and pollution. As a result, this study concludes that more research on various treatment methods is required in order to obtain high-quality water for consumption and routine activities, with the incorporation of various treatment tasks poses various challenges for the upcoming future studies.


Assuntos
Monitoramento Ambiental , Metais Pesados , Humanos , Monitoramento Ambiental/métodos , Metais Pesados/análise , Poluição Ambiental/análise , China , Índia
11.
Chemosphere ; 308(Pt 2): 135950, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36075361

RESUMO

Nanomaterials mainly nanocomposites possess unique physical and chemical properties which makes them superior and indispensable. Though much research has been focused on the properties and application of nanocomposites, the eco-toxicity assessment is one among top priority, which aims to protect the population of concerned biological component and their ecosystem. With this objective, the present study has undertaken an initiation to evaluate the efficacy of chitosan-silver nanocomposite for methyl orange adsorption property (CS-AgNC) and also assessed the toxicity impact on growth parameters of freshwater Tilapia. Batch in vitro studies showed that all the tested dosages of the nanocomposite were effectively adsorbing maximum concentration of methyl orange. The synthesized nanocomposite was administrated to the tested fishes followed by the determination of various growth, nutritional parameters, gene expression of enzymatic antioxidants and liver, and intestinal tissues histology. Obtained results indicated that nanocomposite treatment was not projected as a toxic impact on all the tested growth, and nutritional parameters. Histology study showed that the exposure of Tilapia to nanocomposite has not shown any detrimental effect on antioxidants gene expression and liver, intestinal tissue architecture. Hence, all these findings indicated that chitosan-silver nanocomposite prepared in our present system was found to be biocompatible which suggested the possible utilization and release of the nanocomposite into the divergent ecosystem without affecting non-target organisms (NTO).


Assuntos
Quitosana , Nanocompostos , Tilápia , Adsorção , Animais , Compostos Azo , Quitosana/química , Ecossistema , Água Doce , Nanocompostos/química , Nanocompostos/toxicidade , Prata/química , Prata/toxicidade
12.
Chemosphere ; 307(Pt 3): 135773, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35944678

RESUMO

This work focuses on the synthesis and characterization of photocatalytic activity of Co-Zn/Al2O3 nanocomposite obtained by calcination of Co-loaded Zn/aluminum layered double hydroxide by wet impregnation method. The catalyst was characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), BET and UV-DRS. The evaluation of catalytic activity was investigated for the degradation of emerging pharmaceutical pollutant caffeine in aqueous solutions under UV irradiation. The process parameters were optimized for the maximum removal of caffeine. A maximum caffeine removal of 92% was obtained with the optimal conditions at the catalytic dosage of 0.5 g/L, contact time of 50 min, initial concentration of 50 mg/L, and pH of 9.5. The batch experimental data coincide well with the pseudo first order kinetic model, the rate constant of 0.012 min-1, with the R2 value of 0.875-0.938. The regeneration study reveals that the catalyst has high stability and maximum removal efficiency. Hence, the synthesized nanocatalyst is considered a potential photo catalyst for removing the pharmaceutical pollutant caffeine from aqueous solutions.


Assuntos
Poluentes Ambientais , Nanocompostos , Alumínio , Cafeína , Catálise , Hidróxidos , Nanocompostos/química , Preparações Farmacêuticas , Espectroscopia de Infravermelho com Transformada de Fourier , Zinco
13.
Chemosphere ; 300: 134612, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35430203

RESUMO

Biosynthesized nanoparticles have sparked a lot of interest as rapidly growing classes of materials for different applications. Plants are considered to be one of the most suitable sources for Green synthesis (GS) as they follow the environment-friendly route of biosynthesis of nanoparticles (NPs). This article focuses on the excavation of Titanium dioxide (TiO2) NP from different parts of plants belonging to a distinct classification of taxonomic groups. During the process of biological synthesis of titanium NPs from plants, the extract derived from plant sources such as from root, stem, leaves, seeds, flowers, and latex possesses phytocompounds that tend to serve as both capping as well as reducing agents. TiO2NP is one of the most commonly used engineered nanomaterials in nanotechnology-based consumer products. This article will provide an overview of the GS and characterization of TiO2NPs from plant extracts of different taxonomic groups. Lastly, this review summarizes the current applications of TiO2NPs.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Biomassa , Extratos Vegetais , Plantas , Titânio
14.
Chemosphere ; 300: 134600, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35427654

RESUMO

The current work investigates the conditional influence on Vigna radiate seed germination in vitro and in vivo using the green chemistry approach for the manufacture of titanium dioxide nanoparticles (TiO2 NPs) from seed extract of Trachyspermum ammi (T. ammi). Ultraviolet spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and X-ray diffraction (XRD) were used to analyze the TiO2 NPs produced. The crystalline nature of TiO2 NP was revealed by XRD data, and TEM investigation revealed an irregularity in TiO2 NP shape with a size of 17.5 nm. UV absorbance at 315 nm for the TiO2 NPs was observed using Ultraviolet-visible spectrophotometer. The antioxidant potential of the synthesized nanoparticle was discovered to be good. In case of seed germination studies, six concentrations (25, 50 100, 150, 200, and 250 µg mL- 1) of TiO2 NPs were examined along with the control on Vigna radiata seeds. Germination parameters such as seed vigor index (SVI), germination percentage (GP), germination value (GV) root length (RL) and shoot length (SL) of the Vigna radiata seedlings were observed and results revealed that the green synthesized TiO2 NPs were significantly improved. The results indicated that the TiO2 NP affected the plant growth more specifically at lower concentration (50 µg mL-1) of TiO2 NPs. Overall, the findings of this present study stipulated that the green TiO2 NP production can enhance the growth of Vigna radiate under in vitro and in vivo conditions.


Assuntos
Ammi , Nanopartículas Metálicas , Vigna , Germinação , Nanopartículas Metálicas/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Sementes , Espectroscopia de Infravermelho com Transformada de Fourier , Titânio/química , Titânio/farmacologia , Difração de Raios X
15.
Chemosphere ; 298: 134121, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35271899

RESUMO

Fossil fuel burning is the exclusive of key causes for greenhouse fume Carbon dioxide (CO2). Magnesium nanocomposites synthesized in combination with graphene were characterized and their performance in adsorbing CO2 is validated. The novelty of this work is the use of magnesium oxide decked MG to capture CO2. The magnesium nanocomposites decked with multilayer graphene (MG) were prepared using a simple combustion process. BET surface area of 1480 m2g-1 makes it desirable for adsorbing CO2 molecules. FTIR analysis after adsorption of CO2 shows peak mid position at 3470.45 cm-1, 1300-1000 cm-1, 1603 cm-1, and 1114.30 cm-1 corresponding to the functional groups R-C-O, R-OH, R-COOH, -alkyne, Si-O-Si, and R-C-O-H shifted, signifying that chemisorption has taken place. The effect of many experimental parameters like adsorbent mass, period, and concentration of CO2 was optimized during the experiments. A maximum of 92.2% of CO2 was adsorbed at a concentration of 5 × 10- 4 M at the optimum contact of 70 min. During the experiment, the saturation point was attained at 70 min. Experiment results were best fitting to Langmuir adsorption isotherm; the maximum monolayer adsorption capacity of MG was 7.067 × 10-3 mol/g/min. The kinetics of CO2 on MG was labeled by Pseudo-second-order and R2 value nearly 0.988.


Assuntos
Poluentes Ambientais , Grafite , Nanocompostos , Poluentes Químicos da Água , Adsorção , Dióxido de Carbono/análise , Poluentes Ambientais/análise , Concentração de Íons de Hidrogênio , Cinética , Magnésio , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise
16.
Environ Pollut ; 292(Pt B): 118376, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34656675

RESUMO

The potential ability of synthesized PPy-Fe3O4-SW nano-composite to remove Methylene Blue (MB) from synthetic textile dye solution was investigated under batch conditions. Through parametric studies, the influence of process parameters namely solution pH, on the effective performance of nano-composite was studied. PPy - Fe3O4- SW nano-composite removed 99.14% of MB at the optimized conditions of pH-10, temperature - 25 °C, initial MB concentration - 50 mg/L, nano-composite dosage - 20 mg and contact time - 20 min. PPy - Fe3O4- SW nano-composite has a maximum sorption capacity of 666.66 mg/g. The kinetics and isotherm study revealed that the chromium adsorption obeys pseudo second order (PSO) model (R2 = 0.9941) and Freundlich isotherm (R2 = 0.9910) respectively. The PSO kinetic constant (K2) was found to be 0.000442 (g/mg) min. The thermodynamic feasibility was confirmed through negative values of standard free energy at all tested conditions. The characteristics of adsorption study were analyzed and the results of FTIR, SEM and EDS confirmed the uptake of MB by PPy-Fe3O4-SW nano-composite.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Fenômenos Magnéticos , Azul de Metileno/análise , Polímeros , Poluentes Químicos da Água/análise
17.
Environ Res ; 204(Pt B): 112132, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34571029

RESUMO

In this experimental investigation, feasibility and performance of a polymer hybrid bio-nano composite were evaluated to remove malachite green (MG) under controlled environment conditions. The polymer hybrid bio-nanocomposite was characterized using FTIR, SEM and EDS. The influence of operating variables, namely effect of pH (2-11), nanocomposite dosage (20-100 mg), initial MG concentration (10- 200 mg/L), contact time (10-120 min) and temperature (298-318 K) were explored. The maximum removal efficiency (RE) of 99.79% was achieved at neutral pH at the dosage level of 50 mg with the initial MG concentration of 150 mg/L in 40 min. The equilibrium results revealed that the adsorption of MG data fitted to Langmuir isotherm (R2 > 0.970) indicating monolayer adsorption. The maximum adsorption capacity of polymer hybrid nanocomposite was found to be 384.615 mg/g. Kinetic studies were performed using five kinetic models and results showed the pseudo second order model fitted very well with the MG adsorption data (R2 > 0.990). The thermodynamic results confirmed that MG adsorption onto polymer hybrid nanocomposite is feasible and (ΔS ͦ = 0.2893 kJ/mol K), spontaneous (ΔH ͦ = 81.103 kJ/mol K) and exothermic (ΔG ͦ < 0). A mechanism is also proposed for the removal of MG using the polymer nanocomposite and identified that electrostatic attraction and hydrogen bonding as the major mechanism for removal of MG. FTIR results confirmed the presence of carboxyl (-COO) and hydroxyl (-OH) groups which helped in effective binding of cationic dye. The overall results revealed that polymer nanocomposite could be used as a potential adsorbent for removing MG from aqueous solution.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Adsorção , Biomassa , Concentração de Íons de Hidrogênio , Cinética , Polímeros , Corantes de Rosanilina , Termodinâmica , Poluentes Químicos da Água/análise
18.
Chemosphere ; 288(Pt 1): 132405, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34597639

RESUMO

In this study, Kaolin clay, a mining material, was used as an abundant and available mineral as zero-valent iron-kaolinite composites for As2O3 removal from the water samples. The composites were made by the sodium borohydrate reduction method. The existence of Fe0 in the produced composites was confirmed by X-ray diffraction (XRD) and Fourier-Transform Infrared Spectroscopy (FTIR) analysis. The membranes are prepared with zerovalent nano Iron-Kaolin and PES. The synthesized composites were then mixed with polyethersulfone to prepare the membranes S1, S2, and S3 with varying compositions. Field Emission Scanning Electron Microscopy (FESEM) analysis of the produced membranes showed the porous structure and the contact angle of membranes increased the hydrophilicity. The membranes were explored for the removal of As2O3 (AsIII) in potable water samples. The filtration studies were carried out using the syringe filtration setup. Analysis of the arsenic (III) solution was carried out, before and after the filtration process using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), which showed a maximum of 50% reduction in its original concentration. The filtered membrane is analyzed for arsenic by Energy Dispersive X-ray (EDX) technique. Thus, the synthesized membrane effectively sieves the arsenic in water samples.


Assuntos
Água Potável , Poluentes Químicos da Água , Purificação da Água , Adsorção , Argila , Ferro , Caulim , Cinética , Polímeros , Sulfonas , Poluentes Químicos da Água/análise
19.
Environ Res ; 201: 111626, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34217718

RESUMO

The present work explains the sorption ability of a novel nano-composite, Polypyrrole -iron oxide-seaweed (PPy - Fe3O4 - SW), for Cr(VI) removal. The influence of operating parameters, namely pH, contact time, nanocomposite dosage, initial Chromium concentration and operating temperature, on the hexavalent chromium removal was studied. The novel nano-composite was analyzed using FTIR, SEM and EDS to confirm the sorption of Cr(VI) and to understand the mechanism of sorption. PPy - Fe3O4- SW nano-composite removed 96.36% of Cr(VI) at the optimized conditions of pH = 2, temperature = 30 °C, initial Cr(VI) concentration = 50 mg/L, nanocomposite dosage = 100 mg and contact time = 30min. PPy-Fe3O4-SW nanocomposite has a maximum sorption capacity of 144.93 mg/g. The kinetic studies revealed that the metal adsorption obeys pseudo second order (PSO) model and the sorption was found to be monolayer in nature as confirmed by Langmuir isotherm (R2 > 0.9985). Electrostatic interaction and ion-exchange are identified as the fundamental mechanisms for Cr(VI) sorption on PPy-Fe3O4-SW composite.


Assuntos
Nanocompostos , Polímeros , Cromo , Cinética , Fenômenos Magnéticos , Pirróis
20.
Environ Res ; 199: 111364, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34033830

RESUMO

This research study reported the feasibility of cadmium removal using green algae, Caulerpa scalpelliformis, under controlled environmental conditions. The algal biosorbent could effectively remove cadmium under broad range of test conditions, namely, initial pH (3-6), adsorbent mass (0.5-2.5 gL-1) and shaking speed (60-100 rpm). The best operating conditions were identified using Central Composite Design under Response Surface methodology and found to be pH - 4.9, adsorbent mass - 2.1 gL-1 and shaking speed - 90 rpm. Equilibrium studies were conducted and monolayer sorption was identified as the mechanism, confirmed by Langmuir isotherm (R2 = 0.9920). The maximum Cd uptake achieved at optimal conditions was 111.11 mg g-1. The kinetic constants of the best fit model (pseudo second order) were determined. The thermodynamic feasibility was verified (ΔG ͦ < 0) and the biosorption process was found to be endothermic (ΔH ͦ > 0). The mass transfer studies shows that the mass transfer coefficient was inversely related to the temperature. Presence of favorable surface functional groups and enhanced surface area confirmed the suitability of the synthesized biosorbent for effective removal of cadmium.


Assuntos
Clorófitas , Poluentes Químicos da Água , Adsorção , Cádmio , Concentração de Íons de Hidrogênio , Cinética , Termodinâmica , Água , Poluentes Químicos da Água/análise
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