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1.
Adsorption technique has attracted considerable attention as a promising alternative for reducing heavy metal ions in water sources. This work is focused on the adsorption of nickel ions using lemon peel biomass chemically modified with titanium dioxide (TiO2) nanoparticles through siloxane bonds. The biomass was characterized by FT-IR and compositional analyses to identify functional groups and elemental composition. From these measurements, it was observed peaks at 1741, 1328, and 1229 cm?1, characteristics of CO, C–O, and C–H stretching bands, respectively. These organic bonds can be related to the existence of cellulose, lignin, and pectin biopolymers, which are present in the lemon peel biomass, as observed from the compositional analyses. After grafting TiO2 nanoparticles onto lemon peel biomass surface, it was observed from FTIR the presence of vibrational bands at 1524, 1054, and 943 cm?1, characteristics of –Ti-O-C, –Si-O-Si, and –Ti-O-Si functional groups. Additionally, the morphology and elemental composition of the lemon peel biomass modified with the titanium dioxide (TiO2) nanoparticles were determined by SEM microscope, observing the presence of C, O, Ti, and Si atoms from the EDS mapping. Batch adsorption experiments were carried out to determine the effect of pH and biomass particle size on adsorption of Ni (II) ions from aqueous solution. From these experiments, maximum adsorption of Ni (II) ions of 78 ± 0.2% was obtained at pH 6.0, while no significant effects were observed for biomass particle size. Furthermore, the modification of biomass with TiO2 nanoparticles increased up to 90 ± 0.1% the Ni (II) ions adsorption, suggesting the potential of the biomass modified with metal oxide nanoparticles for removal of heavy metal ions.  相似文献   

2.
To date, many efforts have been made in order to develop novel cost-efficient materials that can be used to remove heavy metal ions from aqueous solution. The aim of this work was to evaluate the adsorption capacity of nanocomposites prepared from starch and sodium montmorillonite (starch/Na-MMT). To this end, nanocomposites with different starch-to-nanoclay ratio (SN) of 5:1, 10:1 and 10:3 were prepared by intercalation technique in acetic acid solution and used for nickel and cobalt uptake. The characterization techniques of Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) were conducted to determine physicochemical and morphological properties of nanocomposites as well as bean starch. The initial concentration of metal ions, pH and SN ratios were varied to assess how well the starch/Na-MMT nanocomposites could remove cobalt and nickel from aqueous solutions. Experimental results were used to calculate parameters of the Langmuir and Freundlich isotherms. It was found that pH = 4.5, Co = 100 ppm (metal concentration in solution), and SN = 10:1 were the most suitable conditions based on the removal yield (97.1%) and adsorptive favourability for nickel ions. For cobalt, the highest removal yield (78.07%) was achieved using pH = 6, Co = 140 ppm and SN = 10:3. The fitting of the data to the Langmuir and Freundlich isotherms indicated a multilayer adsorption process for both heavy metals. These results showed that the nanocomposite starch/Na-MMT exhibited attractive adsorption properties for its application during wastewater remediation. The incorporation of Na-MMT in the bean starch matrix is strongly encouraged for nickel uptake due to the adsorption efficiencies increase by 35% compared to the unmodified starch.  相似文献   

3.
Oil palm empty fruit bunch (OPEFB) is a solid waste abundantly produced by the palm oil industry. This study aimed to prepare a film adsorbent from OPEFB-based charcoal (OC), embedded into chitosan-ethylenediaminetetraacetic acid (EDTA) matrix (OC/Chi-EDTA) through a simple phase inversion technique for Cd (II) removal. Based on the tensile strength (20.4 kgf/mm2) and adsorption capacity (66.6 mg/g), the material with 0.85 : 0.1: 0.15 was selected as the best film adsorbent using simple additive weighting. Further, the sample was characterized for its functional group, morphology, crystallinity, and thermal behavior. The characterizations revealed the successful preparation of OC/Chi-EDTA with advantageous properties for Cd (II) adsorptive removal such as rough surface morphology and amorphous structure (crystallinity = 41.02). Good thermal stability of OC/Chi-EDTA was also suggested by the Tpeak of the first composite degradation at 298.97°C. At equilibrium, the adsorption isotherm best fitted with the Langmuir isotherm model (R2 = 0.992; root-mean-square error = 2.75), where the maximum adsorption capacity was 283.33 mg/g. Investigation on the adsorption mechanisms found that electrostatic attraction and complexation were responsible for the Cd (II) uptake. At the optimum conditions (contact time = 120 min; pH 7), the adsorption capacity was recorded to be 67.2 mg/g with a removal efficiency of 99.56%. Regeneration studies suggested that OC/Chi-EDTA can be used up to four cycles (removal efficiency > 75%). In conclusion, the OC has been successfully embedded into chitosan-EDTA matrix resulting in a film adsorbent that could perform a high Cd (II) uptake.  相似文献   

4.
The current study was intended to elucidate the cytotoxicity, genotoxicity ability of nickel oxide (NiO) nanoparticles (NPs) and assessment of preliminary mechanism of the toxicity. Characterization studies showed that NiO‐NPs have a particle size of 17.94 (±3.48) nm. The particle size of the NPs obtained by dynamic light scattering method in Milli‐Q and RPMI 1640 media was 189.9 (±17.1) and 285.9 (±19.6) nm, respectively. The IC50 concentration for NiO‐NPs after 24 hours of treatment was estimated as 23.58 μg/mL. Comet and cytokinesis‐block micronucleus assays revealed a significant dose‐ and time‐dependent genotoxic potential of NiO‐NPs. Morphological assessment of the lymphocytes upon exposure to NiO‐NPs showed that the mechanism of toxicity was apoptosis. Reactive oxygen species analysis and lipid peroxidation patterns were aligned with the cytotoxicity and genotoxicity endpoints. Thus, the preliminary mechanism of NiO‐NPs for cytotoxicity on lymphocytes was assumed to be oxidative stress‐mediated apoptosis and DNA damage. Furthermore, these NiO‐NPs are considered a potentially hazardous substance at environmentally significant levels. Further investigations are suggested to understand the immunotoxic effects of NiO‐NPs.  相似文献   

5.
The uptake of Pb(II) from the aqueous solution by Coffee Husk Biomass Waste (CHBW) as a green low cost solid phase adsorbent was critically studied. The chemical composition and the surface morphology of the CHBW were determined and fully characterized by FESEM-EDX. In batch mode, the effect of various analytical parameters e.g. adsorbent dose, contact time and analyte concentration on lead(II) ions retention by the biomass CHBW was performed. The adsorption equilibrium of Pb(II) ions was achieved after 60 min with very high percentage 98%, and an adsorption capacity of 19.02 mg/g lead towards the adsorbent was determined. Sorption kinetics data was fitted well with pseudo-second-order model with good correlation coefficient (R2 = 1) and (qe,cal) 19.23 mg/g, (eqe,exp) 19.07 mg/g. The sorption isotherm fitted better with the Freundlich model (R2 is close to the unity). The Langmuir gives maximum adsorption capacity (qmax) of Pb(II) was 37.04 mg/g. These results indicated that, the coffee husk is an efficient, sustainable, and low-cost adsorbent for Pb(II) uptake from wastewater.  相似文献   

6.
Manufactured nanomaterials have a variety of medical applications, including diagnosis and targeted treatment of cancer. A series of experiments were conducted to determine the pharmacokinetic, biodistribution and biocompatibility of two novel magnetic nanoparticles (MNPs) in the anaesthetized pig. Dimercaptosuccinic acid (DMSA) coated superparamagnetic iron oxide nanoparticles (MF66‐labelled 12 nm, core nominal diameter and OD15 15 nm); at 0.5, or 2.0 mg/kg) were injected intravenously. Particles induced a dose‐dependent decrease in blood pressure following administration which recovered to control levels several minutes after injection. Blood samples were collected for a 5‐h period and stored for determination of particle concentration using particle electron paramagnetic resonance (pEPR). Organs were harvested post‐mortem for magnetic resonance imaging (MRI at 1.5 T field strength) and histology. OD15 (2.0 mg/kg) MNP had a plasma half‐life of approximately 15 min. Both doses of the MF66 (0.5 and 2.0 mg/kg) MNP were below detection limits. MNP accumulation was observed primarily in the liver and spleen with MRI scans which was confirmed by histology. MRI also showed that both MNPs were present in the lungs. The results show that further modifications may be required to improve the biocompatibility of these particles for use as diagnostic and therapeutic agents.  相似文献   

7.
The aim of this work was to define optimum conditions to perform the mechanical and chemical pretreatment of empty fruit bunches (EFBs) and kernel shell (KS). Mechanical pretreatment was based on particle size reduction to 0.5, 1, and 2 mm. For chemical pretreatment, a solution of urea (2, 4, and 6 %w/v) was added to the residues under stirring for 18 h and 80 °C. Then, samples were hydrolyzed with sulfuric acid and the resulting reducing sugars were quantified using the 3,5- dinitrosalicyclic acid method. In addition, Van Soest and FTIR analyzes were performed to characterize the biomass suggesting acceptable cellulose contents (EFBs: 36.47%; KS: 20.06 %) and high lignin values (EFBs: 31.27%; KS: 66.49%). Results showed that the highest amount of TRS for EFBs was 105.3 g/L with urea concentration of 4% w/v and a particle size of 0.5 mm. For the KS, the highest amount of TRS was 98.62 g/L using a urea concentration of 6% w/v and a particle size of 0.5 mm. According to these results, it was concluded that pretreatments of oil palm biomass significantly enhance the performance of lignocellulosic material conversion into reducing sugars.  相似文献   

8.
Two new copper(II) ( 2 ) and nickel(II) ( 3 ) complexes with a new coumarin derivative have been synthesized and structurally characterized. The DNA-binding activities of the two complexes have been investigated by spectrometric titrations, ethidium bromide displacement experiments, CD (circular dichroism) spectral analysis, and viscosity measurements. The results indicate that the two complexes, especially the complex 2 , can strongly bind to calf-thymus DNA (CT-–DNA). The intrinsic binding constants Kb of the complexes with CT-DNA are 2.99 × 105 and 0.61 × 105 for 2 and 3 , respectively. Comparative cytotoxic activities of the two complexes are also determined by MTT assay. The results show that the drugs designed here have significant cytotoxic activity against the human hepatic (HepG2), human promyelocytic leukemia (HL60), and human prostate (PC3) cell lines. Cell apoptosis was detected by Annexin V/PI flow cytometry, and the results show that the two copper complexes can induce apoptosis of the three human tumor cells. In conclusions, the two complexes show considerable cytotoxic activity against the three human cancer and induce apoptosis of the threes.  相似文献   

9.
A magnetic adsorbent was prepared by polydopamine coating and thiourea grafting on carbon-modified discarded fly ash magnetic beads (TPCMFA). The successfully preparation of the TPCMFA was supported by SEM image, XRD, FT-IR and Raman spectroscopy. Batch adsorption experiments reveal that the adsorption of silver ions on this magnetic sorbent TPCMFA agreed with the Langmuir isotherm model, with a maximum absorbability of 94.94 mg g-1. Kinetics data revealed that the adsorption of silver ions on TPCMFA conform to a pseudo-second-order. The TPCMFA achieved remarkable selectivity for Ag (I) that was almost five times higher than that for ions of copper, zinc and nickel. After three cycles, the adsorption capacity of TPCMFA remained at 93.5% of the adsorption capacity of the initial material. These results show that this new magnetic adsorbent prepared from discarded fly ash magnetic beads has promising commercial prospects.  相似文献   

10.
In this study, sericin–alginate particles are produced for use as a biosorbent to remove Cu(II) ions from an aqueous solution in a batch biosorption system. Sericin is a protein present in silkworm cocoons and is considered a byproduct of the silk industry. Its use in the production of biosorbents has emerged as an environmentally friendly alternative. Sericin–alginate particles are characterized using N2 physical adsorption analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, and point of zero charge. Additionally, they are evaluated via kinetic, isothermal, and thermodynamic biosorption tests. Kinetic modeling is performed using Lagergren pseudo-first-order, pseudo-second-order, Weber–Morris intraparticle diffusion, homogeneous solid diffusion, and external liquid-film diffusion models. For equilibrium modeling, the Langmuir, Freundlich, and Temkin isotherm models are applied. The Cu(II) ions biosorption is spontaneous and exothermic, as biosorption capacity decreases with temperature: 87.27 mg g-1 (20 °C), 82.54 mg g-1 (40 °C), and 76.18 mg g-1 (60 °C). Based on kinetic modeling, it is verified that internal mass transfer limits the biosorption rate. The Langmuir isotherm model shows a better fit for the biosorption equilibrium, indicating that biosorption occurs in the monolayer. Tests to evaluate the reusability of sericin–alginate particles are performed. It is discovered that even after five adsorption–desorption cycles, the biosorbent shows excellent biosorption capacity. The obtained results and a comparison of the biosorption capacity of different biomaterials demonstrate the high potential of the sericin–alginate particles as a biosorbent for Cu(II) ions.  相似文献   

11.
This study evaluated the relationship between pregnancy rate and semen cadmium concentration. This prospective and nonrandomized clinical study analyzed 341 male partners of infertile couples undergoing infertility evaluation and management. Semen samples were collected to analyze semen quality and cadmium concentrations. The main outcome was pregnancy during 60-day infertility treatment. Simple linear regression analysis revealed an association between semen cadmium concentration NS sperm count (r = −0.150, P = 0.0416) in nonsmoking subjects (n = 184). In both smokers and nonsmokers, semen cadmium concentrations were significantly higher in non-pregnant patients than in pregnant patients. In nonsmokers, Cox multi-variable fertility ratio analysis demonstrated an association between semen cadmium concentration and fertility (fertility ratio of log semen cadmium = 0.24; 95% confidence intervals (CI) = 0.12–0.47, P < 0.0001) after adjusting for related variables. Each tenfold increase in semen cadmium concentration was associated with a 4.17-fold increase in infertility ratio in nonsmoking patients. In smokers, Cox multi-variable fertility ratio analysis demonstrated that sperm count and semen cadmium concentration are associated with fertility (fertility ratio of log semen cadmium = 0.17; 95% CI = 0.04–0.63, P = 0.0085) after adjusting for related variables. In smokers, each tenfold increase in semen cadmium concentration was associated with a 5.88-fold increase in infertility ratio. In conclusion, low levels of cadmium accumulation in semen may contribute to male infertility by reducing sperm quality.  相似文献   

12.
A simple and new coprecipitation procedure is developed for the determination of trace quantities of heavy metals (lead, cobalt, copper, cadmium, iron and nickel) in natural water and food samples. Analyte ions were coprecipitated by using zirconium(IV) hydroxide. The determination of metal levels was performed by flame atomic absorption spectrometry (FAAS). The influences of analytical parameters including pH, amount of zirconium(IV), sample volume, etc. were investigated on the recoveries of analyte ions. The effects of possible matrix ions were also examined. The recoveries of the analyte ions were in the range of 95–100%. Preconcentration factor was calculated as 25. The detection limits for the analyte ions based on 3 sigma (n = 21) were in the range of 0.27–2.50 μg L−1. Relative standard deviation was found to be lower than 8%. The validation of the presented coprecipitation procedure was performed by the analysis certified reference materials (GBW 07605 Tea and LGC 6010 Hard drinking water). The procedure was successfully applied to natural waters and food samples like coffee, fish, tobacco, black and green tea.  相似文献   

13.
Combined lesser scaup (Aythya affinis) and greater scaup (A. marila) populations have declined steadily from the 1970s. Accompanying the population decline have been two shifts in lesser scaup demographics: a decrease in the proportion of young birds and an increase in male to female ratio. In addition, there are concerns about potential effects of contaminants and trace elements. These metals may influence the stress response and corticosterone secretion. We examined impacts of cadmium, selenium and mercury on the stress response in relation to social status in male lesser scaup near Yellowknife, NWT May to June 2004 and 2005. Kidney cadmium and liver selenium and mercury ranged 0.78–93.6, 2.12–9.64, and 0.56–3.71 μg/g, dry weight, respectively. Results suggest that corticosterone release may be influenced by complex contaminant interactions in relation to body condition and body size. When cadmium was high and birds were in good body condition, there was a negative relationship between liver selenium and corticosterone (R 2 = 0.60, n = 10, P = 0.008) but not in birds with poor body condition (R 2 = 0.07, n = 9, P = 0.50). Unfortunately we were unable to draw any conclusions about metals and social status in relation to corticosterone or glucose and T4. This study emphasizes the complex nature of biological systems and the importance of considering interactions to characterize effects of metals.  相似文献   

14.
Trace exposures to the toxic metals mercury (Hg), cadmium (Cd) and lead (Pb) may threaten human reproductive health. The aim of this study is to generate biologically-plausible hypotheses concerning associations between Hg, Cd, and Pb and in vitro fertilization (IVF) endpoints. For 15 female IVF patients, a multivariable log-binomial model suggests a 75% reduction in the probability for a retrieved oocyte to be in metaphase-II arrest for each μg/dL increase in blood Pb concentration (relative risk (RR) = 0.25, 95% confidence interval (CI) 0.03–2.50, P = 0.240). For 15 male IVF partners, each μg/L increase in urine Cd concentration is associated with an 81% decrease in the probability for oocyte fertilization (RR = 0.19, 95% CI 0.03–1.35, P = 0.097). Because of the magnitude of the effects, these results warrant a comprehensive study with sufficient statistical power to further evaluate these hypotheses.  相似文献   

15.
Formation constants for the cadmium(II), nickel(II) and lead(II) complexes of DL-NN'-dicarboxamidomethyl-NN'-dicarboxymethyl-1,2-diaminopr opane (ICRF 198) and the 1,2-diaminobutane homologue (ICRF 226) have been measured potentiometrically at 37 degrees C and I = 150 mmol dm-3 [NaCl]. In all titrations a competing ligand, known to complex strongly with the metal ion, and having its formation constants predetermined, was employed. The constants are used in computer simulation models to assess the relative efficacy of the agents in mobilizing these metals from plasma proteins into low-molecular-weight complexes and the results are compared to those for known chelating agents. It is shown that the lead mobilizing potential of the agents is greater than either EDTA or D-penicillamine; they are, however, less adept in the removal of cadmium and nickel than other established agents.  相似文献   

16.
In this study, for the first time, TMC/MCC complex nanoparticles as a delivery system and as an adjuvant were developed and evaluated to obtain systemic and mucosal immune responses against nasally administered tetanus toxoid (TT). Nanoparticles were developed by complexation between the oppositely charged chitosan derivatives, N-trimethyl chitosan (TMC, polycationic) and mono-N-carboxymethyl chitosan (MCC, polyampholytic) without using any crosslinker for mucosal vaccination. The cellular viability was found to be higher with TMC/MCC complex compared to that of MCC and TMC alone. Size, zeta potential and morphology of the nanoparticles were investigated as a function of preparation method. Nanoparticles with high loading efficacy (95%) and positively charged surface were obtained with an average particle size of 283 ± 2.5 nm. The structural integrity of the TT in the nanoparticles was confirmed by SDS–PAGE electrophoresis analysis. Cellular uptake studies indicated that FITC-BSA loaded nanoparticles were effectively taken up into the mouse Balb/c monocyte macrophages. Mice were nasally immunized with TT loaded TMC/MCC complex nanoparticles and compared to that of TMC and MCC nanoparticles. TMC/MCC complex nanoparticles were shown to induce both the mucosal and systemic immune response indicating that this newly developed system has potential for mucosal administration of vaccines.  相似文献   

17.
The objective of the present work is to prepare and evaluate ionically complexed Quinapyramine sulphate (QS) loaded lipid nanoparticles and its scale up using geometric similarity principle. Docusate sodium (DS), at a molar ratio of 1:2 of QS to DS, was used to prepare hydrophobic Quinapyramine sulphate-Docusate sodium (QS-DS) ionic complex. Based on the difference in total solubility parameter and polarity of QS-DS complex and different lipids, precirol was selected as a lipid for the preparation of lipidic nanoparticles. The particle size, zeta potential, and % entrapment efficiency (%EE) of QS-DS ionic complex loaded solid lipid nanoparticles (QS-DS-SLN) was found to be 250.10 ± 26.04 nm, ?27.41 ± 4.18 mV and 81.26 ± 4.67% respectively. FTIR studies confirmed the formation of QS-DS ionic complex. DSC and XRD studies revealed the amorphous nature of QS in QS-DS-SLN. The spherical shape of nanoparticles was confirmed by scanning electron microscopy. QS-DS-SLN showed sustained release of QS for up to 60 h. No significant difference was observed in particle size, zeta potential, and % entrapment efficiency of pilot-scale batch prepared by using rotational speed of 700 rpm. In conclusion, ionic complexation approach can be used to increase % EE of charged drugs into lipid nanoparticles.  相似文献   

18.
Optimization of operating and design parameters is needed for the greater application to achieve higher quality, performance, and minimum cost. The paper mainly concentrates on, the optimization of process parameters influencing the deflouridation of water by Analysis of mean (ANOM) approach. The current work mainly aims at the utilization of the Taguchi approach to optimize influencing operating parameters for maximizing the removal of fluoride under batch experimental studies by using biosorbent developed from Saccharum spontaneum, weed plant. The optimum conditions were found at pH 7, sorbate content 5 mg/L, period of contact 120 min, sorbent dosage 10 g/L, and temperature 30 °C. The percent part of various process parameters is obtained in the successive sequence pH 56.21% > initial concentration of adsorbate 33.94% > biosorbent dose 5.49% > contact time 3.35% > temperature 1.01%. The equilibrium study indicates fluoride sorption on Saccharum spontaneum adsorbent fulfill the Langmuir model with parameters ‘a' and ‘b' determined as 1.617 mg/g and 0.473 L/mg. The kinetic study with sorption data suggested the Pseudo-second order kinetic model as best fitting with kinetic rate k2 0.218 g/mg min. The thermodynamic analysis suggested a spontaneous and endothermic nature (ΔH = 16.268 kJ/mol). Characterization of adsorbent was done using BET, SEM, and also by the determination of textual properties. Regeneration of the biosorbent is done for three cycles and is used for fluoride removal.  相似文献   

19.
This study investigated the role of cadmium, a widespread heavy metal in the aquatic environment, on cell volume regulation of digestive cells isolated from the digestive gland of Mytilus galloprovincialis. These cells when exposed to a rapid change (from 1100 to 800 mOsm/kg) of the bathing solution osmolality swelled but thereafter underwent a Regulatory Volume Decrease (RVD), tending to recover the original size. This homeostatic response is altered by cadmium, as suggested by experiments performed both on isolated cells pre-incubated with cadmium (10?5 M) and on cells isolated from animals exposed to sub-lethal concentrations of the metal (40 μg/l for 21 days). It is suggested that cytoskeleton and Na+/K+ATPase are the possible targets of cadmium which impairment is responsible of the altered homeostatic response.  相似文献   

20.
Coconut coir (Cocos nucifera L.), particle size 300–850 μm, has been identified as an adsorbent for safranin-O dye removal from aqueous solution. Bioadsorption efficiency is improved by modifying untreated coconut coir (UCC) with 1 N phosphoric acid (PCC) and 1 N sulphuric acid (SCC). The acid treatment enhances the surface area of adsorbents and accelerates more dye uptake. The adsorption process is optimized by varying the physicochemical conditions like initial pH, adsorbent amount, contact time, initial dye concentration, and temperatures. The adsorption process's optimum pH is 4, 6, and 6, respectively, using UCC, PCC, and SCC adsorbents.In contrast, more than 98% of dye removal has been observed at the lower concentration of dyes up to 200 mg/L at 303 K. Maximum dye removal is possible at 75 mg/L of dye concentration. UCC, PCC, and SCC adsorbents’ adsorption capacity is 80.32 mg/g, 96.81 mg/g, and 89.53 mg/g, respectively, at 303 K temperature. Langmuir and Tempkin model and the pseudo-second-order model are the best-fitted models for isotherm and kinetic study. Thermodynamic parameters indicate the adsorption process is viable, spontaneous, exothermic. 75% glacial acetic acid is the most potent solvent for safranin-O dye extraction from dye loaded biomass. The functional groups and different interactions are identified to establish the adsorption mechanism. The PCC adsorbent has been used for scale-up design. The multiple polynomial regression (MPR) successfully predicts the dye removal efficiency for individual adsorbents. The modeling of the Genetic Algorithm has also been done successfully.  相似文献   

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