Polystyrene Magnetic Nanocomposites as Antibiotic Adsorbents

Abstract

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/Fe3O4 magnetic nanocomposite (abbreviated as P(St-b-AAc)/Fe3O4)) was achieved for environmental applications, and particularly for the removal of antibiotic compounds. For this reason, the synthesis of the P(St-b-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 Fe3O4 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 (R2 = 0.9995), while the kinetics were better fitted to second-order kinetic equation (R2 = 0.9973).

Chromatin extracted from common carp testis as an economical and easily available adsorbent for ethidium bromide decontamination

“…The Langmuir isotherm model is defined by the following equation [ 37 ]： where q e is the equilibrium adsorption volume (mg·g −1 ), Q is the monolayer saturation adsorption volume (mg·g −1 ), c e is the EtBr concentration in the working fluid at adsorption equilibrium (mg·L −1 ), and k L is a constant related to the temperature or enthalpy change of the adsorption process. The Freundlich isotherm model is defined by the following equation [ 38 ]： where k F and n are Freundlich constant related to the temperature or enthalpy change of the adsorption process. The Dubinin-Radushkevich isotherm model is defined by the following equation [ 39 ]: where K ad is the isotherm constant with respect to Dubinin-Radushkevich; q s is the theoretical adsorption amount; and ε is the Polanyi potential, which is calculated as follows [ 40 ]: for the parameters in Dubinin-Radushkevich equation, the value of the average adsorption energy ( E ) can be calculated, which represents the free energy used for the transfer of 1 mol of ions from the solution to the surface of the adsorbent, and it can be calculated from the following equation [ 41 ]: …”

Investigation of synergetic effect of adsorption and photocatalysis for the removal of tetracycline by BiFeO3 immobilized on copolymer seeds

“…Porous polymeric materials with tunable pore size and controllable morphology have been effectively used as matrices for the deposition of fine particles [8,9]. It is well known that the styrene-divinylbenzene co-polymers are mechanically and chemically stable as well as they have high adsorption abilities towards many organics [10,11]. Also, their distinct features of including abundant surface functional groups enable them to be applied as efficient adsorbents for binding organic molecules [12].…”

Barium/Cobalt@Polyethylene Glycol Nanocomposites for Dye Removal from Aqueous Solutions

“…Adsorption is widely used in water and wastewater treatment [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ], which is one of the most effective technology [ 29 , 30 , 31 , 32 , 33 , 34 ]. Adsorption process between liquid and solid phase is strongly affected from temperature [ 35 ].…”