Alireza Behzadi; Amirhosein Yazdanbakhsh
Abstract
Background and Purpose: In recent years, concerns about the presence of pharmaceutical compounds in the wastewater have been increasing. Various types of residues of the widely used tetracycline family of antibiotic compounds are found in environmental waters in relatively low and persistent concentrations ...
Read More
Background and Purpose: In recent years, concerns about the presence of pharmaceutical compounds in the wastewater have been increasing. Various types of residues of the widely used tetracycline family of antibiotic compounds are found in environmental waters in relatively low and persistent concentrations that have adverse effects on human health and the environment. The aim of this study was to synthesize high specific level organic aerogels to remove Minocycline antibiotics.Material and Methods: In this study, resorcinol formaldehyde aerogel was synthesized using sol-gel process and dried by ambient drying. The aerogel was then modified using graphene and finally the performance of the synthesized samples as adsorbent under various parameters such as solution pH (2 -12), the amount of adsorbent (4-10 mg) and the time of contact of the adsorbent with the antibiotic (3-24 h) were evaluated. Raman spectroscopy, electron microscopy (FE-SEM) and BET tests were used to characterize the samples and then the removal efficiency of Minocycline antibiotic was measured by the samples using UV-Vis analysis.Results: The results of BET test showed that the specific surface area of the resorcinol formaldehyde aerogel sample containing 1wt.% graphene was increased compared to the neat aerogel. Also, according to the results, it was found that the removal percentage of minocycline antibiotic for pure and modified samples is 71.6% and 92.1% at optimal pH of 4 and 6, respectively.Conclusion: Graphene-modified resorcinol formaldehyde aerogel is a suitable adsorbent for removal of Minocycline antibiotic from aqueous solution.
Abolfazl Rahmani Sani; Ahmad Hosseini Bandehgharaei; Mahsa Naeemi; Ameneh Navidzadeh; Elham Agheli
Abstract
Background and aim:Antibiotics are a category of organic pollutants that can cause serious environmental problems through their disposal and uncontrolled release to the environment. The purpose of this study was to investigate the removal of sulfadimethoxine from aqueous solutions using carbon ...
Read More
Background and aim:Antibiotics are a category of organic pollutants that can cause serious environmental problems through their disposal and uncontrolled release to the environment. The purpose of this study was to investigate the removal of sulfadimethoxine from aqueous solutions using carbon nanotubes.
Materials and Methods:The present work was an experimental study in which the effects of different parameters, such as PH, contact time, doses of carbon nanotubes, and different concentrations of sulfadimethoxine, on the removal of antibiotic from solutions were examined. All experiments were carried out in a 100-mL reactor at laboratory temperature (24 ± 2 ° C) using a magnetic stirrer at 350 rpm.
Results:The results showed that the maximum removal efficiency (94.5%) was occurred at pH = 6, adsorbent dosage 0.04 g, contact time of 30 min, and initial concentration of 20 mg/L. The findings on the effect of pH showed that the adsorption capacity increases with increasing pH, and at pH = 6, it reaches its maximum and then decreases again. The extent of removal was increased by increasing the dose of carbon nanotubes and the optimum amount for initial concentration of 100 mg/L (50 mL) was 0.04 g. The amount of absorption increased with increasing contact time and the maximum absorption occurred when the contact time was 30 min. The sulfadimethoxine antibiotic isotherm followed the Langmuir isotherm model (R2 = 0.9800) and the pseudo-second-order kinetic model (R2 = 0.9937).
Conclusion: The results showed that carbon nanotubes have a high potential for removal of sulfadimethoxine from aqueous solutions, due to its properties like its high surface area.
hossein kamani; ayat hossein panahi; Somayeh Talebi; mohamad havangi
Abstract
Background and Objectives: Phenol is one of most common organic pollutants in aqueous environments. Phenol presence in the environment can make some health problems such as carcinogenesis, abnormality of heartbeat, etc for humans and poisonous problems for other organisms. Therefore, this pollutant must ...
Read More
Background and Objectives: Phenol is one of most common organic pollutants in aqueous environments. Phenol presence in the environment can make some health problems such as carcinogenesis, abnormality of heartbeat, etc for humans and poisonous problems for other organisms. Therefore, this pollutant must be removed from polluted effluents to prevent water pollution. Using nanoparticles in adsorption processes is considered as an effective method for contaminants removal. The aim of this study was to investigate the efficiency of magnesium oxide nanoparticles in phenol removal from aqueous solutions. Materials and Methods:In this research, nanoparticles of magnesium oxide were used with size of 43 nm. After the preparation of phenol stock solution, effects of pH،(3- 5- 7- 9- 11)، contact time(10,30, 60, 90, and 120 min)، MgO dosage(20, 40, 60, 80 and 100 mg/L) and initial concentration of phenol (25, 50, 75 and 100 mg/l) Were investigated. Results: Results indicated that the removal efficiency increased with increasing pH, contact time, MgO dosage to a certain range and decreasing initial concentration. Such that the maximum efficiency was equal to 81% in the pH of about 11, initial concentration of 50 mg/L, MgO dosage of 80 mg/l and contact time of 60 min. It was found that adsorption kinetics and equilibrium data follow a pseudo-second-order kinetics model and a Langmuir isotherm model respectively. Conclusion: This study showed that the magnesium oxide nanoparticles have the ability to remove the phenol and can be used effectively in removing phenol from aqueous solution
Ali Naghizadeh
Abstract
Background an Objectives: Natural organic matters because of production of disinfection by products such as trihalomethanes, which are often carcinogenic disinfection, are of particular importance. Carbon nanotubes due to large surface area, and many other applications, are effective adsorbents for the ...
Read More
Background an Objectives: Natural organic matters because of production of disinfection by products such as trihalomethanes, which are often carcinogenic disinfection, are of particular importance. Carbon nanotubes due to large surface area, and many other applications, are effective adsorbents for the removal of natural organic matter. The present study aimed to investigate the removal of natural organic compounds from aqueous solution by single-walled carbon nanotubes and kinetics and equilibrium adsorption process. Methods: in present study, single wall carbon nanotubes used for removal of natural organic matters from aqueous solution. Different variables such as pH of zero point of charge, pH and different concentration of natural organic matters were investigated. Results: pH survey show that with decreasing pH adsorption capacity increased also pH of zero charge was 6.7. Adsorption capacity of single wall carbon nanotubes for initial concentration of natural organic matters of 10, 5 and 3 mg/L were 66.24, 40.63 and 29.77, respectively. Conclusion: Single-walled carbon nanotubes due to features such as high surface area have great potential for the removal of natural organic matter from aqueous solution