Nanocomposite-Based Aminated Polyethersulfone and Carboxylate Activated Carbon for Environmental Application. A Real Sample Analysis

Noof Alenazi, Mahmoud Hussein, Khalid Alamry, Abdullah Asiri
Aminated polyethersulfone (PES-NH 2 ) has been synthesized and used with carboxylated activated carbon (AC-COOH) as an adsorbent using two different methods: in situ and ex situ techniques. The chemical modification of polyethersulfone (PES) to introduce -NH 2 functions was used to overcome the hydrophobicity of PES which maximizes its use in water treatment applications whereas applying AC-COOH to this polymer provides a promising effective method as an adsorbent-separation technique to remove
more » ... dye pollutants from wastewater. The structure and characterization of aminated polyethersulfone with carboxylated activated carbon (PES-NH 2 -AC-COOH) were identified using proton nuclear magnetic resonance ( 1 H-NMR), Fourier transform infrared (FT-IR spectroscopy), X-ray diffraction (XRD), thermal analysis (TA), and a scanning electron microscopy (SEM). The performance of PES-NH 2 in situ and ex situ with AC-COOH was tested for the adsorption of cationic (methylene blue) and anionic (acid red 1) dyes from an aquatic environment. The results of the study showed a better thermal stability for the PES-NH 2 with 20% AC-COOH with both in situ and ex situ techniques as well as an excellent adsorption performance in comparison with the bare PES-NH 2 . The resultant polymers displayed significantly high adsorption rates for the acid red dye (60% and 68%) and methylene blue dye (61% and 88%) by PES-NH 2 with AC-COOH using in situ and ex situ techniques, respectively, in comparison with the control (PES-NH 2 ) which showed lower adsorption rates for both dyes (21% for acid red and 33% for methylene blue). Lastly, the study experimental measurements found the most suitable model to describe the kinetic behavior of the acid red dye adsorption by our developed polymer (by PES-NH 2 with AC-COOH) to be the pseudo-second-order kinetic model. C 2018, 4, 30 2 of 22 cosmetic, and papers productions. In the textile sector, almost 200,000 tons of dye is lost as wastes during the dying processes for the textile synthesis [4] . Most of these waste dyes present in the aquatic environment for a long time due to their high stability to light and temperature. The high demand for the textile products leads to a high demand for synthetic dyes, and wastewaters contaminated with dyes are considered one of the most significant causes for pollutions in the aquatic environment. Additionally, synthetic dyes are considered a great risk because they are highly toxic to the aquatic environment and are carcinogenic to humans. More specifically, azo dyes have been discovered to have mutagenic effects because of their biotransformation derivatives once they enter the body by digestion. The biotransformation of zo dyes occurs via the liver enzymes to form N-hydroxylamine compounds, which have been found to cause damage to DNA. Additionally, dyes have been linked to many health illness issues related to kidneys, brain, liver, as well as central nervous and reproductive systems [4, 5] . There are different techniques to remove these dyes from wastewater including adsorptions techniques. The adsorption method is known to be the most effective and low-cost methods, and there are different types of adsorbents including fly ash, lignite, activated carbon black (AC), sawdust, coal, and wood [6] . Activated carbon is often used as an adsorbent due to its variability and low cost [6, 7] . However, in order to enhance the use of AC as adsorbents, AC particles should be used with polymeric materials [8, 9] . Polyethersulfone (PES) is a well-known polymer that has been applied to various adsorbents-separation techniques including dyes adsorption [6] and other organic compounds adsorption [8] . This wide use of PES is because of its high thermal, mechanical, and chemical properties [4] . However, the hydrophobicity of PES is considered one of the drawbacks that limit its use. The additional of hydrophilic functions to PES (including amino, carboxylic, sulfonic, and so forth) could be an effective method to overcome its hydrophobicity [10] . In this work, PES has been chemically modified to PES-NH 2 in order to improve its hydrophobicity. The structure PES-NH 2 was confirmed using proton nuclear magnetic resonance ( 1 H-NMR) and Fourier transform Infrared (FT-IR) spectroscopy. The AC-COOH fine particles were then fabricated in our lab and they have been used with PES-NH 2 using two methods: the in situ and ex situ techniques. Then, the PES-NH 2 with AC-COOH structures were identified and characterized using FT-IR spectroscopy, X-ray diffraction analysis (XRD), thermal analysis (TA), and scanning electron microscopy (SEM) technique. The performance of PES-NH 2 in situ and ex situ with AC-COOH was tested in order to examine its performance in removing both cationic (methylene blue) and anionic (acid red 1) dyes from the aquatic environment. Because of its high adsorption capacity (q e ) in comparison with methylene blue, an acid red dye was used to test the adsorption capability of the solid phase (SP) of PES-NH 2 -AC-COOH under different parameters including pH, contact time, and temperature. Then, the kinetics behaviors and thermodynamic characteristics of acid red adsorption onto PES-NH 2 in situ and ex situ with AC-COOH were further studied. Finally, two real environmental samples from the Red Sea and tap water were spiked with acid red and used to explore the environmental applications of PES-NH 2 in situ and ex situ with AC-COOH in removing the acid red dye from the aqueous environment. Experimental Materials All chemicals and solvents were used as they were obtained from their companies with no purification. The polyethersulfone (PES) was purchased from Solvay Chemicals Limited, Panoli, India. The deuterated dimethylsulfoxide (DMSO-d 6 ) (99.8%), chloroform (99.8%), dichloromethane (DCM) (99.8%), and acid red were purchased from the Sigma-Aldrich Company, Milwaukee, WI, USA. The potassium iodide (KI), sodium hydroxide (NaOH), Tin (II) chloride (SnCl 2 ), hydrochloric acid (HCl) (37%), sulfuric acid (H 2 SO 4 ) (95-97%), and nitric acid (HNO 3 ) (65%) were all obtained from BDH Ltd., Poole, UK. For the preparation of standard and stock solutions, the deionized water was purchased from Millipore Milli-Q Plus, Milford, MA, USA.
doi:10.3390/c4020030 fatcat:jkoeqcqzenayfbxgilkrrn4xem