Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Biol Trace Elem Res ; 202(2): 615-623, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37198356

RESUMO

In the present study, we reviewed the literature as a systematic review to investigate the concentration of some metals (essential, none essential, and toxic metals) in herbal teas and their health risks. The search extended the literature from the database, including Google Scholar, PubMed, and Scopus, using the terms "herbal teas" combined with "heavy metals, essential metals, thyme, rosemary, chamomile, and tea" also with "iron, zinc, aluminum, chromium, cobalt, nickel, manganese, arsenic, cadmium, and lead" in titles and abstracts. The search was limited to articles published from 2012 to 2023 years. Initially, 212 articles were found; by detailed consideration, only 49 papers fit the inclusion criteria and were selected for further study. The mean of metal concentration, standard deviation, data distribution, and sample size were applied to generate data from the articles. The results indicated that all commonly consumed herbal teas included metals. None of them meet the requirements of the WHO requirements. However, more than 70% of their health risks are acceptable. The risks of arsenic and lead in tea and cadmium in black tea were considerably higher than in others. According to the review results, it is important to prevent heavy metal contamination of herbal teas by modifying cultivation patterns and also to prevent to consumption of low-quality herbal teas.


Assuntos
Arsênio , Metais Pesados , Chás de Ervas , Chás de Ervas/análise , Cádmio/análise , Arsênio/análise , Metais Pesados/análise , Chá
2.
Int J Phytoremediation ; : 1-13, 2023 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-38042992

RESUMO

Herein, the application of granular activated carbon, jujube, and barberry tree stem powder for the removal of gasoline and kerosene from water was investigated. Kerosene removal rates upwards of 68.48, 83.87, and 99.02% were achieved using jujube tree stem powder, barberry tree stem powder, and granular activated carbon, respectively. Besides, gasoline removal rates upwards of 69.35, 55.02, and 95.59% were attained using jujube tree stem powder, barberry tree stem powder, and granular activated carbon, respectively. Isotherm data were further investigated and fitted using Langmuir, Freundlich, and Elovich models. The results indicated that the adsorption onto jujube adsorbent is a multilayer adsorption process over a heterogeneous surface, which is best illustrated by the Temkin (Ave. R2= 0.95) model. It was found that the Temkin isotherm (Ave. R2= 0.81) best describes the properties of barberry stem powder in the adsorption of gasoline and kerosene from water. Moreover, the best models to describe the characteristics of granular activated carbon in the adsorption of gasoline and kerosene from water were Freundlich (Ave. R2= 0.74) and Langmuir (Ave. R2= 0.73) isotherms, respectively. The adsorption kinetics showed that the pseudo-second-order was appropriate in modeling the adsorption kinetics of gasoline and kerosene to the studied adsorbents (R2>0.74).


The objective of this study was to identify the potential of agricultural biowastes derived biosorbents to remove petroleum products from contaminated water. Previously, jujube and barberry tree wastes had not been used to remove petroleum pollutants. Moreover, in this research agricultural wastes were used without any processing or energy consumption and all experiments were performed at water pH, so there was no need to add chemicals to adjust the pH.

3.
Water Sci Technol ; 88(4): 1097-1110, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37651340

RESUMO

In this research, and for the first time, the application of anode Pb/PbO2 (prepared from combined thermal oxidation and electrochemical oxidation method) and steel cathode in a flow sample electrochemical treatment process of vinasse and in the wastewater of alcohol factories, has been investigated. The combination of electrodes of Pb/PbO2 as an anode, steel, and/or graphite as a cathode was used in the proposed electrochemical treatment setup. The efficiency of the proposed electrochemical treatment was determined by the removal percentage of chemical oxygen demand (COD), turbidity and color of vinasse samples. The response surface method (RSM) by Minitab 18 was used to determine the effect of the studied factors as well as to detect the relationship between variables. The results showed that under optimum conditions (Pb/PbO2 electrode as the anode and steel electrode as the cathode, a voltage of 30 V, pH 6.5, and reaction time of 45 min), the percentage reduction values of COD, turbidity and color were 97.7, 77.3 and 92.7%, respectively.


Assuntos
Técnicas Eletroquímicas , Chumbo , Análise da Demanda Biológica de Oxigênio , Eletrodos , Aço
4.
Environ Sci Pollut Res Int ; 29(44): 67014-67025, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35511330

RESUMO

Nanofiltration contributes to the development of advanced treatment of wastewater. An antifouling mixed matrix recycled polyethylene terephthalate (rPET) membrane modified by the hydrophilic ZnO/y-FeOOH nanoparticles (NPs) was fabricated via the electrospinning method. The effect of ZnO/y-FeOOH NPS embedded in rPET as a modifier on the fabrication of nanocomposite membranes was investigated regarding water flux, membrane morphology, permeability, fouling resistance, and COD removal. The surface morphology of the rPET-ZnO/y-FeOOH membrane was evaluated by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), water contact angle (WCA), and porosity and pore structure.Due to the embedding of NPs, the resulting rPET-ZnO/y-FeOOH membrane, with a low WCA of 53.404° angle, conforms significantly improved hydrophilicity and water permeation flux. The FESEM image displayed the distribution of cuboidal and needle-like ZnO and FeOOH NPs on the rPET membrane. The performance of the nanofiltration system related to the removal efficiency of COD was studied. It was deduced that the rPET-ZnO/y-FeOOH membrane had a superior COD removal capability (95.7%) at a pressure of 2 bar. Protein rejection tests were performed on antifouling behavior. The nanocomposite membrane with a high antifouling capability was related to 0.5 wt·% ZnO/y-FeOOH NPs (flux recovery ratio [FRR] = 96.2%, Rr = 90.21%, and Rir = 3.001%). The modification procedure in this study (as a great improving technique) was proposed to fabricate the antifouling nanofiltration membrane.


Assuntos
Incrustação Biológica , Nanopartículas , Óxido de Zinco , Incrustação Biológica/prevenção & controle , Membranas Artificiais , Polietilenotereftalatos , Águas Residuárias , Água/química , Óxido de Zinco/química
5.
J Environ Health Sci Eng ; 19(1): 603-612, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34150261

RESUMO

PURPOSE: Arsenic is a toxic metalloid that is present in the environment as arsenate and arsenite anions. Exposure to arsenic anions caused skin problems, degenerative diseases, kidney, liver, and lung cancer. The synthesized iron nanoparticles (NPs) were examined as a green low-cost adsorbent for the removal of arsenite anions from aqueous solution via batch adsorption procedure. METHODS: Iron NPs were prepared in a single step by the reaction of Fe+3 0.01 M solution with a fresh aqueous solution of 2% w/v pomegranate peel extract (PPE) as both reducing and capping agents. The physicochemical properties of peel were investigated by some experiments and functional groups were determined by the FT-IR spectrum. The electrochemical behavior of PPE was studied using cyclic voltammetry on a glassy carbon electrode as produced a cathodic peak at range 120-400 mV. The progress of nZVI production was monitored by a decrease of 372 nm wavelength UV-Vis spectra of PPE. The 27 adsorption experiments were carried out as a function of solution pH, initial arsenite concentration, mass adsorbent, and contact time according to DOE. RESULTS: The rapid rate of adsorption was observed at 20-60 min, indicating that the principal mechanism dominating the sorption process was reduction and chemical adsorption. The arsenite removal efficiency was found to be dependent on the solution pH, adsorbent dose, and initial concentration, respectively. CONCLUSION: The experimental data show the ability of the synthesized iron NPs to remove arsenate from solution in both synthetic and polluted natural water. The thermodynamic study suggested the spontaneous and endothermic nature of adsorption of arsenite by green synthesized iron NPs. The iron NPs synthesized with PPE increased the removal of arsenite with an increase in the active surface, indicating some chemical interactions between the adsorbent and oxoanions.

6.
Environ Sci Pollut Res Int ; 28(36): 50731-50746, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33973114

RESUMO

The median effective concentration (EC50) is the concentration of a substance expected to produce a specific effect in 50% of the populations with a certain density under defined conditions. This parameter is expressed as an acute toxicity and is obtained via chemical toxicity testing. But, the laboratory work is time-consuming, expensive, and not eco-friendly. Therefore, to predict EC50 for new anionic surfactants, a quantitative structure-activity relationship (QSAR) tool was studied for modeling the EC50 of anionic surfactants on Daphnia magna based on the molecular descriptors. The best model (R2 = 0.901 and F = 118.077, p<0.01) included 3 variables of the number of carbons, hydrogens, and the octanol-water partition coefficient logarithm. The main contribution to the toxicity was the octanol-water partition coefficient logarithm descriptor that had a negative effect on the toxicity of surfactants. The QSAR approach exhibited good results in predicting anionic surfactants EC50, which allows the building of a simple, valid, and interpretable model that can be utilized as potential tools for rapidly predicting the lnEC50 of new or untested anionic surfactants to Daphnia magna.


Assuntos
Daphnia , Poluentes Químicos da Água , Animais , Relação Quantitativa Estrutura-Atividade , Tensoativos/toxicidade , Testes de Toxicidade , Poluentes Químicos da Água/toxicidade
7.
Chemosphere ; 263: 128065, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297070

RESUMO

Dielectric barrier discharge (DBD) plasma has been recently used for removal of synthetic organic compounds (SOCs) from aqueous environments. The removal of SOCs by alone DBD is significantly limited by its high electricity needs and inefficient mineralization, which affects the further application of DBD for SOCs. The combined application of DBD with other technologies and the addition of a supplementary substance for energy-saving were proposed to resolve these problems. The addition of catalysts is considered to be a promising and innovative approach to increase the energy yield of DBD, improve the environment friendly of DBD, develop the variety of goal SOCs, and improve the removal efficiency of DBD system. Despite the increasing use of the coupling form of DBD and catalysts, as catalytic dielectric barrier discharge (CDBD), but it still requires a comprehensive review to summarize the last studies and highlight the future perspectives in this area. Therefore, this work is the first literature review aimed to critically assess the latest developments of catalysts coupling with DBD employed in aqueous environments. Moreover, performance evaluation, energy yield, toxicity, eco-friendly, and future perspectives of the CDBD systems for SOCs removal were discussed and overviewed. The results showed that the coupling of catalysts with DBD presents synergistic effects and had excellent removal performance for aqueous SOCs. Overall, it can be concluded that the essential principles of environmental and economic sustainability have been addressed for the removal of persistent pollutants from aqueous environments in the CDBD systems.


Assuntos
Poluentes Químicos da Água , Catálise , Compostos Orgânicos , Plasma/química , Tecnologia , Poluentes Químicos da Água/análise
8.
Biol Trace Elem Res ; 198(2): 714-720, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32212045

RESUMO

Prosopis cineraria is locally grown which scientific literature present evidence for its anti-inflammatory effect. Monitoring the content of toxic elements is one of the most important aspects to consider medicinal plants' safety before evaluating the pharmaceutical use. The aim of present study was to investigate the level of essential and toxic elements in the leaves, branches, and stem of Prosopis cineraria to assess its health risk. Samples were collected around Bandar Abbas, washed several times, and dried in air for 2 weeks. The dried samples were chopped with stainless steel knife to small pieces and powdered by electrical mortar. Some physical and chemical properties of samples were investigated by chemical methods. Samples were ashed by a programmable electric furnace at 650 °C for 6 h. Then samples were dissolved in 30% HNO3, and the content elements of each sample were determined by inductive coupled plasma optical emission spectrometer (ICP-OES). The tests quality control and the measurement uncertainty were checked through the analysis of certified reference materials of SRM 1515 from NIST and solution standards. Correlation analysis of the obtained results showed a significant difference between leaves, branches, and stem of Prosopis cineraria so that the stem had the high essential and low toxic elements ones in comparison to other parts. The results revealed that the Prosopis cineraria stem is meeting health standards regarding the studied toxic metals.


Assuntos
Prosopis , Anti-Inflamatórios , Irã (Geográfico) , Folhas de Planta
9.
MethodsX ; 6: 1305-1312, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31205863

RESUMO

The entry of toxic organic pollutants and resistant to biodegradation has increased the concern about human health. The use of advanced oxidation (AO) processes to degrade these pollutants has been developing. One of the AO processes is based on the use of hydrogen peroxide in removing resistant organic pollutants. This study aimed to develop a new reactor capable of producing H2O2 in the solution. Therefore, a porous electrode made of stainless steel with the capability of air injection in the electrode center was used. The 30 cm rod graphite electrodes were also used as an anode electrode in a 4000 ml reactor. The effects of variables, including current density (30-40 mA/cm2), time (10-30 min), and electrolyte concentration (12-17 mM/L) on the amount of H2O2 production were evaluated by Box behenken design under response surface methodology using Design expert software. The results of this study showed that H2O2 can be produced at the electrode surface of porous cathode under optimal conditions of 36 mA/cm2 current density, 16 mM/l electrolyte concentration, in 23 min, and in the amount of 34 ppm. Using a porous cathode electrode causes the maximum contact among the solution, water, and air, and increases the production of H2O2. The release of resistant organic compounds to the waste water is a serious problem to the environment. By the application of the Electro-oxidation (EO)reactor with the ability to produce H2O2, this issue is resolved. Furthermore, this technique is applied for non-selective degradation of the toxic organic compounds. •The electro-oxidation process is a useful method for destruction of persistent organic matter from wastewater.•Due to use of porous cathode in this method, contact between the electrode and the sewage is at its maximum level which increases the efficiency and speed of sewage treatment.•This method can produce H2O2 as a high potential oxidant that can reduce persistent organic properties of sewage and make the wastewater suitable for biological treatment.

10.
Food Sci Nutr ; 7(12): 4021-4026, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31890182

RESUMO

Tea grows in the contaminated soils, absorbs the heavy metals, and enters them into the human food chain. The concentrations of Pb, Cd, Cu, As, and Hg of the imported black tea leaves to Hormozgan Province were evaluated by atomic absorption spectrometer. Then, the Hazard Quotient (HQ) and Hazard Index (HI) levels of heavy metal intakes were calculated to estimate the health hazard for consumers. The Pb, Cd, Cu, As, and Hg concentrations in the Sri Lankan and Indian blank tea were 0.14, 0.017, 11.29, 0.057, 0.0076 mg/kg, and 0.21, 0.02, 14.56, 0.067, 0.01 mg/kg, respectively. It was found that except for As concentration in Indian black tea were higher than Sri Lankan black tea. The HQ and HI levels of all studied metals were less than one, but they were higher in Indian black tea compared with the Sri Lankan black tea. The HI of Indian and Sri Lankan black tea samples were 0.061 and 0.048, respectively, which indicated no significant health hazard for tea consumers. The results showed that the consumption of the studied tea could not have any risk of heavy metal exposure.

11.
AMB Express ; 8(1): 172, 2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30334115

RESUMO

Enhanced treatment of ceramic-tile industry wastewater was investigated by modified coagulation-flocculation process using combination of poly-aluminum chloride (PAC) with anionic (A300), cationic polymer (C270) and nonionic polymers. The effects of pH, PAC coagulant dose alone and with polymers dose in various combinations was studied by jar tests. To compare the removal efficiencies of turbidity, total suspended solids (TSS), chemical oxygen demand (COD), and color at different levels, we run multivariate analysis of variance. Regarding the economic evaluation, we applied the incremental cost-effectiveness ratio. PAC had the best performance in pH 7 and in optimal dose of 400 mg/L; so that removal efficiency of wastewater turbidity, TSS, COD and color were 99.63%, 99.7%, 47.5% and 50.38%, respectively. The best removal efficiency for wastewater turbidity, TSS, COD and color were 99.87%, 99.89%, 87.5% and 93.02%, respectively which were obtained by combination of anionic polymer (1.5 mg/L) with PAC (300 mg/L). Furthermore, with combination of PAC + anionic + non-ionic polymers, the removal efficiency for wastewater turbidity, TSS, COD and color were 99.93%, 99.94%, 88% and 94.57%, respectively. The imposed cost for treating one cubic meter of ceramic-tile wastewater treatment by PAC + anionic and PAC + anionic and non-ionic polymers in comparison with PAC alone was reduced to 22.96% and therefore economically more affordable for the tile industry wastewater treatment.

12.
Chemosphere ; 207: 303-312, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29803879

RESUMO

The efficiency of photocatalytic oxidation process in arsenite (As(III)) removal from contaminated water by a new Fe2O3-Mn2O3 nanocomposite under UVA radiation was investigated. The effect of nanocomposite dosage, pH and initial As(III) concentration on the photocatalytic oxidation of As(III) were studied by experimental design. The synthesized nanocomposite had a uniform and spherical morphological structure and contained 49.83% of Fe2O3 and 29.36% of Mn2O3. Based on the experimental design model, in photocatalytic oxidation process, the effect of pH was higher than other parameters. At nanocomposite concentrations of more than 12 mg L-1, pH 4 to 6 and oxidation time of 30 min, photocatalytic oxidation efficiency was more than 95% for initial As(III) concentration of less than 500 µg L-1. By decreasing pH and increasing the nanocomposite concentration, the photocatalytic oxidation efficiency was increased. Furthermore, by increasing the oxidation time from 10 to 240 min, in addition to oxidation of As(III) to arsenate (As(V)), the residual As(V) was adsorbed on the Fe2O3-Mn2O3 nanocomposite and total As concentration was decreased. Therefore, Fe2O3-Mn2O3 nanocomposite as a bimetal oxide, at low doses and short time, can enhance and improve the efficiency of the photocatalytic oxidation and adsorption of As(III) from contaminated water resources. Furthermore, the energy and material costs of the UVA/Fe2O3-Mn2O3 system for photocatalytic oxidation of 1  mg L-1 As(III) in the 1 L laboratory scale reactor was 0.0051 €.


Assuntos
Arsenitos/química , Compostos Ferrosos/química , Compostos de Manganês/química , Nanocompostos/química , Óxidos/química , Raios Ultravioleta , Poluentes Químicos da Água/química , Purificação da Água/normas , Adsorção , Arsenitos/isolamento & purificação , Oxirredução , Processos Fotoquímicos , Projetos de Pesquisa , Titânio/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos
13.
AMB Express ; 7(1): 225, 2017 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-29273952

RESUMO

Pomegranate waste modified with Fe2+ and Fe3+ ions followed with carbonization were used as an adsorbent to remove the Pb2+ ions from aqueous solution. To optimum the highest adsorption efficiency, adsorption experiments were conducted on iron modified carbons by batch technique. The characteristic of composite was studied by scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FT-IR). The best pH for control of chemical adsorption was selected within pH of 6.0-6.5. It was observed that the contact time of 90 min, initial concentration 50.0 ppm, and adsorbent dose, 1.0 g/100 ml solution was found to be optimum conditions. On this condition, the maximum adsorption capacity was obtained 27.5 and 22.5 mg/g for Fe2+ and Fe3+ impregnated pomegranate peel carbons (PPC), respectively. The value of Cid, 1.584 for Fe2+-PPC and 0.552 for Fe3+-PPC, indicates that the effect of the boundary layer is more important in adsorption of Pb2+ by Fe2+-PPC and the pore diffusion is the rate limiting mechanism after 30 min. Thermodynamic parameters of Gibbs free energy, enthalpy, and entropy of Pb2+ adsorption on iron-modified carbons suggest that the adsorption process is favorable and spontaneous under the optimum condition.

14.
Chemosphere ; 188: 470-477, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28898779

RESUMO

Microbial desalination cell (MDC) is a new approach of water desalination methods, which is based on ionic species removal from water in proportion to the electric current generated by bacteria. However, the low current generation and insufficient deionization in this technology have created challenges to improve the process. Here, the performance of MDC using ozone as a new electron acceptor (O3-MDC) was evaluated versus another operated independently with oxygen (O2-MDC). Results showed the maximum open-circuit voltages of 628 and 1331 mV for 20 g L-1 NaCl desalination in O2-MDC and O3-MDC, respectively. The O3-MDC produced a maximum power density of 4.06 W m-2 (about 11 times higher than O2-MDC) while at the same time was able to remove about 74% of salt (55.58% in the O2-MDC). Each cycle of O2-MDC and O3-MDC operation lasted about 66 and 94 h, respectively, indicating a more stable current profile in the O3-MDC. Moreover, sequencing test based on 16S rRNA gene showed that the anode biofilm had more diverse microbial community than anolyte sample. Proteobacteria, Firmicutes and Acidobacteria were from dominant microbial communities in anode biofilm sample. Accordingly, the results revealed that ozone can enhance MDC performance either as a desalination process or as a pre-treatment reactor for downstream desalination processes.


Assuntos
Fontes de Energia Bioelétrica/microbiologia , Ozônio/química , Cloreto de Sódio/análise , Purificação da Água/métodos , Biofilmes/crescimento & desenvolvimento , Eletrodos , Desenho de Equipamento , Íons/química , Consórcios Microbianos/genética , Oxirredução , RNA Ribossômico 16S/genética , Salinidade , Purificação da Água/instrumentação
15.
Biol Trace Elem Res ; 174(1): 65-70, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27147432

RESUMO

Breastfeeding plays an important role in the growth and development of breastfed infants, especially in the first 6 months of their lives. The present study was conducted to determine the nickel concentrations in breast milk of lactating women in Yazd, Iran. One hundred fifty volunteers were selected among nursing mothers referring to health centers in Yazd. In the first month of lactation, milk samples were collected three times, on days 3 to 5 (first), 16 (Second), and 30 (third) after delivery. Nickel concentration of the samples was measured by atomic absorption spectrophotometer. Demographic variables were collected through a questionnaire which was completed by mothers. The mean age of the study group was 27.40 ± 4.66 years. The mean nickel concentrations in breast milk at the first, second, and third samples were 47.3 ± 7.40, 49.9 ± 8.05, and 54.8 ± 7.38 µg/l, respectively. The concentration of nickel in the breast milk of more than 86 % of mothers was higher than the permissible range for it. There was no significant relationship between the mean value of nickel in breast milk and education, age, and job of mothers. High level of nickel in breast milk may be attributed to consumed food and drinking water containing nickel. Monitoring the nickel level in breast milk regularly is recommended.


Assuntos
Aleitamento Materno , Lactação , Exposição Materna , Leite Humano/metabolismo , Níquel/metabolismo , Adulto , Estudos Transversais , Feminino , Humanos , Irã (Geográfico)
16.
Artigo em Inglês | MEDLINE | ID: mdl-23388386

RESUMO

A separation technique which has recently received a sharp increase in research activities is "ion flotation". This technique has four important advantages for treating wastewaters: low energy consumption, small space requirements, small volume of sludge and acting selectively. The present study aims to optimize parameters of ion flotation for cadmium removal in simulated wastewater at laboratory scale. It was obtained on the reaction between Cd(2+) and sodium dodecylesulfate (SDS) collector followed by flotation with ethanol as frother. Test solution was prepared by combining the required amount of cadmium ion, SDS and necessary frother or sodium sulfate solution. All experiments were carried out in a flotation column at laboratory temperature (27°C), adjusted pH = 4 and 120 minutes. The different parameters (namely: flow rate, cadmium, SDS and frother concentrations and ionic strength) influencing the flotation process were examined. The best removal efficiency obtained at a collector-metal ratio of 3:1 in 60 min with flow rate of 150 mL/min was 84%. The maximum cadmium removal was 92.1% where ethanol was introduced at a concentration 0.4% to flotation column with above conditions. The obtained results were promising, as both cadmium and collector were effectively removed from wastewater. Hence, the application of ion flotation for metal ions removal from effluents seems to be efficient.

17.
J Environ Health Sci Eng ; 11(1): 21, 2013 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-24499654

RESUMO

The impact of effective parameters such as iron oxide nanoparticles dosage, contact time and solution pH was optimized for removal of Ag(I) and Ni(II) in the nuclear cooling system and the best conditions were compared. Nearly complete removal (97%) of Ni(II) and Ag(I) were obtained at adsorbent dosage of 40 and 20 g/L, respectively. Experiments showed that 4 hours was a good choice as optimum contact time for two ions removal. The effective parameter was pH, so that maximum removal efficiency was obtained for Ag(I) in acidic pH=3 and for Ni(II) in basic pH=10. It seems that removal of Ag(I) was controlled by adsorption-reduction mechanism, but Ni(II) could place only adsorption. Langmuir and Freundlich model was more suitable for nickel and silver removal by this adsorbent, respectively. Ag(I) and Ni(II) removal efficiency trend by this adsorbent is similar at periods but different in the concentrations, pHs and equilibrium model. The obtained results were very promising, as both Ag(I) and Ni(II) were effectively removed from synthetic wastewater and there was a possibility to remove Ag(I) very fast. Hence, the idea of using nanoparticles for application of metal ions removal from wastewaters seems to be very efficient and quite promising.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...