Adsorption of Edifenphos pesticide using polypyrrole modified zeolite composite

Today, due to the growing population and increasing agricultural and food production, the use of toxins and organophosphate and organochlorine pesticides, especially Edifenphos, is increasing in the agricultural sector. One of the most effective ways to remove such toxins is to use the adsorption method. Therefore, the present study investigated the removal of Edifenphos fungicide from aqueous solution using polypyrrole composite on natural perlite zeolite. It is notworthy that each experiment was performed in a discontinuous system. For this purpose, after removing possible impurities in perlite through heating at 550 °C and then activating perlite with 0.06 N sulfuric acid, PPy/perlite nanocomposite was prepared. The structure of the adsorbents synthesized was identified using X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. Then, the effect of experimental parameters of pH, contact time, adsorbent mass, and temperature on adsorption was studied. The results showed that the optimal conditions for adsorption of Edifenphos by PPy/Perlite were pH 6, contact time 18 min, and adsorbent amount of 0.3 g/100 ml. Examination of the effect of temperature also showed that increasing the temperature has a positive effect on the removal efficiency. Finally, the study of the process thermodynamics showed a spontaneous and endothermic process

In Vitro Evaluation of Antibacterial Effects of Aqueous and Alcoholic Extracts of Echinops dichorus L. on Escherichia coli

The use of antibiotics as major drugs in infectious diseases has always been associated with two problems of side effects and drug resistance. The compounds found in various plants have been used as a treatment method since the past until today because medicinal plants possess side effects compared to other drugs. Given that different species of Echinops dichorus L. plant have indicated good antimicrobial effects, in this study antimicrobial effects of ethanol and aqueous extracts of Echinops dichorus L. plant have been investigated by disk diffusion method and determining the minimum inhibitory concentration (MIC) on the 24-hr culture of Escherichia coli (E. coli) standard strain. Echinops dichorus L. plant was dried after collection and its ethanol and aqueous extracts of were prepared by maceration method. Afterward, the concentrated and dried samples were stored in clean containers under standard conditions for further tests. The antibacterial effect of different concentrations of the extracts was determined by agar diffusion and compared with penicillin, gentamicin, and tetracycline antibiotics. Ethanol and aqueous extracts possessed a MIC of 31.25 µg/ml (diameter of the bacterial growth inhibition (halo): 12 mm) and 125 µg/ml (diameter of the bacterial growth inhibition (halo): 10 mm), respectively, as anti-microbial effect against E. coli

Investigation of the Performance of Zeolitic Adsorbent Modified with Cu Nanoparticles for Desulfurization of Hydrocarbon Fuel

Sulfur is one of the elements in fossil fuels that is converted to sulfur dioxide, which is one of the most important air pollutants, when burned in a car engine. In the present study, the adsorption capacity of an organic sulfurized compound from a diesel fuel model containing 300 ppm thiophene was evaluated using x13 zeolite modified with 3% by weight of copper metal. Moreover, the effect of three parameters of contact time (15, 30, 60, and 120 min), adsorbent value (0.5, 1, 2.5 and 3.5 g) and temperature (25, 40, 50 and 60 °C) was assessed in a discontinuous system. In order to activate the adsorbent surface cations, x13 zeolite was washed with deionized water and 0.1 M copper nitrate salt and then copper nanoparticles were loaded on it. The maximum adsorption capacity was 2.5 g of adsorbent at 60 min at room temperature, and the amount of thiophene for adsorption modified with copper nanoparticles increased from 300 to 138 ppm. The adsorption results showed that an increase of more than 2.5 g of adsorbent would not cause a significant change in the adsorption efficiency. In addition, FT-IR, SEM and N2 physisorption studies showed that the adsorbent would maintain its regular structure after nanoparticle loading. Finally, the modified zeolite showed better performance for desulfurization of the diesel fuel model

Petroleum Wastewater Treatment

Petroleum hydrocarbons in refinery wastewater are considered the main cause of pollution. Wastewater from oil refineries contains large amounts of oil and fat in the form of suspended particles, light and heavy hydrocarbons, phenol, and other dissolved organic substances, which cause environmental pollution if they are discharged into the environment without treatment. Usually, conventional methods of treating petroleum wastes have a lot of costs; due to the existence of sufficient area for the construction of solar distillation ponds and suitable sunlight, as well as a large number of sunny days near the equator, the solar distillation method can be used. Membrane bioreactors based on biological decomposition and biological transformation of oils and waste oil materials have provided new solutions for the biological treatment of these wastewater. In addition to these methods, Fenton’s advanced oxidation methods, electrochemical coagulation method, and membrane filtration method are mentioned in this chapter

Copper Removal From Paper Mill Wastewater Using Polymer Nanofiber

The aim of this research work is to investigate sorption characteristic of synthesized polypyrrole / polyaniline (PPy / PANI) nano fiber for Cu (II) removal from paper mill wastewater. The sorption is carried out by batch method. The structural characterization of this sorbent was performed by SEM and FTIR analysis. The optimum conditions of copper sorption from paper mill wastewater onto PPy / PANI were found to be: pH=6, contact time 12 min and 0.4 g of sorbent in 100 ml in wastewater. The kinetic studies showed that the sorption process was well described by the pseudo second order kinetic model. Also, Langmuir isotherm provided the best fit to the equilibrium data. Also the effect of temperature on the process was found that the temperature has positive effect on the process. Thermodynamic parameters showed that the sorption of copper onto nano fiber were feasible, spontaneous and endothermic under studied conditions

Electrospun Polymeric Substrates for Tissue Engineering: Viewpoints on Fabrication, Application, and Challenges

Electrospinning is the technique for producing nonwoven fibrous structures, to mimic the fabrication and function of the native extracellular matrix (ECM) in tissue. Prepared fibrous with this method can act as potential polymeric substrates for proliferation and differentiation of stem cells (with the cellular growth pattern similar to damaged tissue cells) and facilitation of artificial tissue remodeling. Moreover, such substrates can improve biological functions, and lead to a decrease in organ transplantation. In this chapter, we focus on the fundamental parameters and principles of the electrospinning technique to generate natural ECM-like substrates, in terms of structural and functional complexity. In the following, the application of these substrates in regenerating various tissues and the role of polymers (synthetic/natural) in the formation of such substrates is evaluated. Finally, challenges of this technique (such as cellular infiltration and inadequate mechanical strength) and solutions to overcome these limitations are studied