Publications by authors named "Razieh Khaksefidi"

3 Publications

  • Page 1 of 1

Polystyrene Magnetic Nanocomposites as Antibiotic Adsorbents.

Polymers (Basel) 2020 Jun 9;12(6). Epub 2020 Jun 9.

Department of Chemistry, International Hellenic University, Kavala 65404, Greece.

There are different ways for antibiotics to enter the aquatic environment, with wastewater treatment plants (WWTP) considered to be one of the main points of entrance. Even treated wastewater effluent can contain antibiotics, since WWTP cannot eliminate the presence of antibiotics. Therefore, adsorption can be a sustainable option, compared to other tertiary treatments. In this direction, a versatile synthesis of poly(styrene-block-acrylic acid) diblock copolymer/FeO magnetic nanocomposite (abbreviated as P(St--AAc)/FeO)) was achieved for environmental applications, and particularly for the removal of antibiotic compounds. For this reason, the synthesis of the P(St--AAc) diblock copolymer was conducted with a reversible addition fragmentation transfer (RAFT) method. Monodisperse superparamagnetic nanocomposite with carboxylic acid groups of acrylic acid was adsorbed on the surface of FeO nanoparticles. The nanocomposites were characterized with scanning electron microscopy (SEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) analysis. Then, the nanoparticles were applied to remove ciprofloxacin (antibiotic drug compound) from aqueous solutions. The effects of various parameters, such as initial drug concentration, solution pH, adsorbent dosage, and contact time on the process were extensively studied. Operational parameters and their efficacy in the removal of Ciprofloxacin were studied. Kinetic and adsorption isothermal studies were also carried out. The maximum removal efficiency of ciprofloxacin (97.5%) was found at an initial concentration of 5 mg/L, pH 7, adsorbent's dosage 2 mg/L, contact time equal to 37.5 min. The initial concentration of antibiotic and the dose of the adsorbent presented the highest impact on efficiency. The adsorption of ciprofloxacin was better fitted to Langmuir isotherm (R = 0.9995), while the kinetics were better fitted to second-order kinetic equation (R = 0.9973).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/polym12061313DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7362001PMC
June 2020

Degradation of furfural in aqueous solution using activated persulfate and peroxymonosulfate by ultrasound irradiation.

J Environ Manage 2020 Jul 22;266:110616. Epub 2020 Apr 22.

Department of Environmental Health Engineering, Iranshahr University of Medical Sciences, Iranshahr, Iran. Electronic address:

Furfural is a toxic compound that can cause many problems for human health and the environment. In this study, we addressed the degradation of furfural in aqueous solution using the activated persulfate (SPS) and peroxymonosulfate (PMS) through the ultrasonic (US) wave. Besides, the effect of various parameters (pH, oxidizing dose, initial furfural concentration, US frequency, Inorganic anions concentration, and scavenger) on SPS + US (SPS/US) and PMS + US (PMS/US) processes were examined. The results showed, in order to furfural removal, the US had excellent efficiency in activating SPS and PMS, as in SPS/US and PMS/US processes, 95.3% and 58.4% of furfural (at 25 mg/L concentration) was decomposed in 90 min, respectively. The furfural degradation rate increased with increasing oxidizing dose and US frequency in both SPS/US and PMS/US processes. Considering the synergistic effect, the best removal rate has occurred in the SPS/US process. In the SPS/US and PMS/US processes, furfural removal increased at natural pH (pH 7), and the presence of inorganic anions such as NO and Cl had negative effects on furfural removal efficiency. Also CO and HCO acted as a radical scavenger in the SPS/US process but these anions in the PMS/US process produced more SO radicals, and subsequently, they increased the furfural degradation rate. The results also showed that the predominant radical in the oxidation reactions is the sulfate radical. This study showed that the SPS/US and PMS/US processes are promising methods for degrading organic pollutants in the environment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jenvman.2020.110616DOI Listing
July 2020

UV Activation of Persulfate for Removal of Penicillin G Antibiotics in Aqueous Solution.

ScientificWorldJournal 2017 8;2017:3519487. Epub 2017 Aug 8.

Department of Environmental Health Engineering, Faculty of Health, Zahedan University of Medical Sciences, Zahedan, Iran.

Penicillin G (PG) is one of the most widely consumed antibiotics around the world. Release of PG in environment may lead to contamination of water resources. The aim of the present work is to assess feasibility of applying UV-activated persulfate process in removal of PG from aquatic environments. The study examined the effect of pH (3-11), persulfate initial concentration (0.5-3 mM), reaction time (15-90 minutes), and initial concentration of PG (0.02-0.14 mM) on PG decomposition. Also, the pseudo-first-order kinetic model was used for kinetic analysis of PG removal. The results indicated that UV-activated persulfate process can effectively eliminate PG from water. The highest PG removal efficiency was obtained as 94.28% at pH 5, and the decomposition percentage was raised by increasing persulfate dose from 0.5 to 3 mM and the reaction time from 15 to 90 minutes. Besides, the removal efficiency decreased through increasing the initial concentration of PG. UV-activated persulfate process effectively decomposes PG and eliminates it from water.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2017/3519487DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5591921PMC
August 2018