Adsorption Of Sulfamethoxazole Research Articles

Adsorption of sulfamethoxazole on polypyrrole decorated volcanics over a wide pH range: Mechanisms and site energy distribution consideration

• SED theory was firstly applied for SMX adsorption on mineral adsorbent. • pH application range of volcanic rock was broadened to 5–11. • The different adsorption ability and mechanism between VR and PPy-VR was analyzed. • High-energy adsorption centers of PPy-VR was related to π-π EDA and ion exchange. As a widely used antibiotic, sulfamethoxazole (SMX) has attracted increasing research attention. However, acidic condition was normally required for efficient SMX removal, and the energy variation of adsorption system is not fully elucidated. In this study, based on a typical mineral adsorbent of volcanic rock (VR), anion exchange was introduced by Polypyrrole (PPy) modification to overcome the electrostatic repulsion in alkaline environment, and site energy distribution (SED) theory was applied to explore adsorption behavior and mechanism on SMX from an energy perspective. The batch adsorption experiments and a series of complementary characterization were combined, confirming that pore filling and hydrogen bonding are the dominant adsorption mechanisms for SMX removal by VR. While the adsorption distinction between PPy supported VR (PPy-VR) and VR could be explained by electrostatic attraction, π-π electron donor-acceptor interaction (π-π EDA) and ion exchange, which further explained the wide pH application potential of modified sorbent. Moreover, Dubinin-Ashtakhov (DA) model was used to calculate the energy distribution, and PPy-VR exhibited a stronger adsorption affinity ( E m = 8.55–11.57KJ/mol) and energy heterogeneity ( δ e *=2.15–2.57) for SMX. The high-energy adsorption centers increased significantly (92.63%) after modification, which mainly attributed to π-π EDA and ion exchange introduced by PPy loading. The surface modification method provides a feasible idea for the improvement of application environment of adsorbents, and the analysis of SED is expected to promote the understanding of the connection between site energy and adsorption mechanism.

Sulfamethoxazole Adsorption by Polyamide 6 Microplastics: Environmental Impact, Simulated Gastrointestinal Fluid and Desorption Mechanism

Sulfamethoxazole Adsorption by Polyamide 6 Microplastics: Environmental Impact, Simulated Gastrointestinal Fluid and Desorption Mechanism

Adsorption properties of heavy metals and antibiotics by chitosan from larvae and adult Trypoxylus dichotomus

Chitosan was prepared by hydrothermal deacetylation from multi-step protein purification chitin based on Trypoxylus dichotomus, for treating heavy metals and antibiotics. Chitosan with higher deacetylation degree and lower molecular weight were synthesized. The adult chitosan was composed of nanofibers arranged more evenly, showing higher yield, thermal stabilities and antimicrobial properties. The adsorption capacities of Cu2+ and Fe3+ were 462 and 270 mg/g, lower than 934 mg/g of Pb2+. Levofloxacin and tetracycline hydrochloride adsorption capacity were 26 and 22 mg/g, lower than 67 mg/g of sulfamethoxazole. In addition, compared with single pollutants, the adsorption of sulfamethoxazole and Pb2+ can increase by 6% and 5% when they act as composite contaminants. The adsorption procedure can be well described by pseudo-second-order kinetics and Langmuir isothermal model, indicating it a homogeneous monolayer chemisorption. Therefore, the Trypoxylus dichotomus source chitosan prepared by hydrothermal deacetylation has potential applications in the adsorption of complex pollutants.

Adsorption properties of sugarcane bagasse and corn cob for the sulfamethoxazole removal in a fixed-bed column

Natural adsorbents are a good alternative to remove antibiotic residues from wastewater. In this study, the adsorption capacity of sulfamethoxazole (SMX) onto sugarcane bagasse (SB) and corn cob (CC) in a continuous fixed-bed was compared. Brunauer Emmett Teller, Fourier transform infrared (FTIR), Boehm titration, and point of zero charge (pHpzc) were used to characterize both adsorbents. The adsorption capacity (qe) and the removal percentage of SMX (% R) were investigated at different different flow rates (2, 5, and 7 mL min− 1) and adsorbent masses (4 and 6.4 g), and a constant initial concentration of 5 mg L− 1. The results of the characterization showed that SB has a morphology with more dispersed particles and a specific surface higher than CC (2.6 > 1.2 m2 g− 1). Boehm titration indicates that both the surface of SB and CC have a greater amount of acid groups, which is in agreement with FTIR and pHpzc results. The continuous fixed-bed experiments showed that % R and qe of SMX are higher with SB in all the tests. The highest qe and maximum % R was 0.24 mg g− 1 and 74% with SB, and 0.15 mg g− 1 and 65% using CC. In most cases, the qe of both adsorbents decreased with the increase of flow rate and bed height. An analysis suggests that hydrogen bonds could be the main factor favoring the SMX adsorption with SB. Finally, the intraparticle diffusion was the rate-controlling step, predominating the pore-volume diffusion resistance.

Surface imprinted polymer on a metal-organic framework for rapid and highly selective adsorption of sulfamethoxazole in environmental samples

The demand for the removal of pollutants in aqueous solution has triggered extensive studies to optimize the performance of adsorbents, but the adsorption rate and selectivity of adsorbents have been overlooked. Hierarchically ordered porous vinyl-functionalized UIO-66 was used as supporter to prepare a surface molecular imprinted polymer (MIP-IL@UIO-66). The UIO-66 with large specific surface area significantly increased the number of active site of polymer, and so the MIP-IL@UIO-66 can achieve the rapid and highly selective adsorption of sulfamethoxazole (SMZ) in water. The structure and morphology of MIP-IL@UIO-66 was examined using scanning electron microscopy, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption isotherms, thermogravimetry, X-ray photoelectron spectroscopy, and X-ray powder diffraction. Results indicate that the presented MIP-IL@UIO-66 has an ultrafast equilibrium rate (equilibrium time, 10 min), large adsorption capability (maximum capacity, 284.66 mg g−1), excellent adsorption selectivity (selectivity coefficient, 11.36), and good reusability (number of cycles, 5 times) via equilibrium adsorption experiments. Subsequently, as a novel solid phase extraction (SPE) adsorbent, the adsorption performance of SMZ onto MIP-IL@UIO-66 was better than that of a commercial SPE adsorbent. A MISPE column combined with high-performance liquid chromatography (HPLC) was presented to detect SMZ in water, soil, egg, and pork samples with recoveries of 91–106%. Hydrogen bonds, electrostatic and π-π interactions, and molecular memory were attributed to recognizing the SMZ of MIP-IL@UIO-66.

Cyclodextrin polymers and salts: An Eco-Friendly combination to modulate the removal of sulfamethoxazole from water and its release

This study is aimed to validate water-insoluble cyclodextrin-epichlorohydrin polymer (β-EPI) use to remove, by adsorption, sulfamethoxazole (SMX) from water and then release it via an environmentally friendly treatment so that the adsorbent can be recycled according to one of the objectives of the European Project Life “Clean up” (LIFE 16 ENV/ES/000169).SMX adsorption experiments on β-EPI polymer in-batch were performed, varying different experimental parameters of the process, such as contact time, pH values, and so on.The adsorption process, exothermic and driven by enthalpy, occurs both through the formation of inclusion and association complexes, involves mainly hydrophobic and hydrogen bonds, has a rate-controlling step depending on both pollutant concentration and adsorbent dose and can be described by the Freundlich and Dubinin-Radushkevich models which confirm the polymer surface heterogeneity and the physical nature of the adsorption. The presence of salts gives rise to a general decrease in the SMX sorption, mainly in the case of bromide, which was used to promote the SMX desorption and regenerate the adsorbent. The overall results indicate that β-EPI polymer is not only capable of removing SMX by adsorption with short contact times and a qmax = 10 mg/g but it is also easily regenerated using a 0.5 M solution of sodium bromide without any loss in the adsorption performance and with obvious economic and environmental advantages. The polymer as synthesized, with SMX adsorbed and regenerated was characterized by FT-IR, SEM and DSC.

The thermodynamics, kinetics, and isotherms of sulfamethoxazole adsorption using magnetic activated carbon nanocomposite and its reusability potential

The thermodynamics, kinetics, and isotherms of sulfamethoxazole adsorption using magnetic activated carbon nanocomposite and its reusability potential

Investigation of the Adsorption of Sulfamethoxazole by Degradable Microplastics Artificially Aged by Chemical Oxidation.

In this study, three different types of microplastics were aged by the thermal activation K2S2O8 method to investigate the adsorption behavior for sulfamethoxazole (SMX) in aqueous solution. The effects of pH, salinity and humic acid (HA) on adsorption behavior were also investigated. At the same time, the morphology and functional groups of microplastics before and after adsorption were characterized. As the aging time increased, the adsorption capacity of the microplastics also increased significantly. Whether it was pristine or aged, polylactic acid (PLA) had the highest adsorption capacity. The adsorption capacity of microplastics was the largest under acidic conditions, and its adsorption capacity decreased significantly in alkaline solutions. The presence of salinity inhibited the adsorption of SMX on polyethylene terephthalate (PET) and PP, but the adsorption capacity of PLA increases when salinity was above 10‰. The adsorption of SMX on microplastics was promoted by HA. When the concentration of HA was 20mg/L, the adsorption capacity of PLA and PET decreased. Kinetic and isotherm fits were applied to the adsorption process. The increase in sorption capacity was related to the development of holes and cracks and the enhanced number of surface oxygen-containing functional groups. The adsorption kinetics to pristine microplastics conformed to a pseudo-first-order kinetic model, while the kinetics of the aged microplastics conformed to a pseudo-second-order kinetic model. It implies that the adsorption of SMX by aging microplastics involves multiple processes. The adsorption isothermal adsorption process of SMX by microplastics accorded with Freundlich model, belonging to multi-layer adsorption.

Adsorption removal of sulfamethoxazole from water using UiO-66 and UiO-66-BC composites

The adsorption removal of anti-inflammatory drugs from water by diverse materials has drawn great attention. This study investigated the adsorption of sulfamethoxazole (SMX) by two types of materials, UiO-66 and UiO-66-BC composites. Highly porous MOF composites with functional groups were synthesized by combining UiO-66 with corncob-based biochar at different molar ratios. SEM results showed that macroporosity of UiO-66-BC composites was increased by increasing the ratio of biochar. It was found that UiO-66-BC composites displayed highly improved adsorption performance of SMX relative to pristine UiO-66. UiO-66-BC (5%) had the highest SMX adsorption capacity, about 2.4 times those of pristine UiO-66. It was the high surface area of UiO-66 and redundant functional groups of biochar that increased the adsorption performance of composites. Moreover, UiO-66-BC can be reused and displayed the competitive adsorption efficiency after successive adsorption, which made it a potential adsorbent for the removal of SMX from water.

Aminated chitosan/cellulose nanocomposite microspheres designed for efficient removal of low-concentration sulfamethoxazole from water

The ppt to ppb sulfamethoxazole (SMX) entering natural water bodies and possibly present in drinking water is not significantly removed and remain persistent and toxic by conventional adsorbents. Aminated chitosan/cellulose nanocomposite microspheres (ACNM) were prepared by in-situ solid phase grafting methods for low concentration of SMX removal. The physical and chemical properties of ACNM were characterized by SEM, FTIR and XRD etc. 10 mg L−1 SMX was used to simulate the low concentration of SMX in the aqueous phase, SMX adsorption on ACNM could reached the equilibrium within 30 min. The adsorption process was better kinetically fitted with the pseudo-second-order kinetic model and Langmuir isothermal model, suggesting that monolayer chemical adsorption was the dominant adsorption process. The removal efficiency of SMX reached 99.18%, and the adsorption capacity was 13.59 mg g−1. The adsorption mechanism was also studied. ACNM retained 96.8% of the initial adsorption capacity after 3 cycles. Column adsorption experiments were studied to determine the best adsorption conditions.

Mathematical modeling and numerical simulation of sulfamethoxazole adsorption onto sugarcane bagasse in a fixed-bed column

Having rigorous mathematical models is essential for the design and scaling of adsorption columns. In this study, the dynamic behavior of the sulfamethoxazole adsorption on sugarcane bagasse was studied and compared using analytical models and a theoretical mechanistic model. Initially, fixed-bed column tests were carried out at different flow rates and bed heights. Then, the experimental data were fitted with the most widely used analytical kinetic models, and their fit and fixed-bed parameters were compared with the mechanistic model. Of all analytical models analyzed, the Log-Gompertz model was the one that had the best agreed with experimental data. Although some analytical models fitted the experimental data accurately, their usefulness was questionable. Their parameters did not show a clear relationship with the change in operating conditions, and in certain cases had different behavior from that observed in experimentation. Conversely, the mechanistic model not only predicted the breakthrough curves with great accuracy in the initial and transition stage (R2 > 0.92; SSE < 0.06), but it also estimated relevant parameters. Additionally, the effects of the global mass transfer coefficient (Ki) and the axial dispersion coefficient (Dz) on breakthrough curves were studied using the mechanistic model. Increasing Ki increased the slope of the breakthrough curves with a faster adsorption rate. Similarly, high values of Dz produced lower adsorption capacities of the adsorbent; and it was established that the axial dispersion is relevant in SMX adsorption on SB. The theoretical model presented can be used for the design, scaling, and optimization of adsorption columns.

Fast microwave-assisted synthesis of magnetic molecularly imprinted polymer for sulfamethoxazole

A fast and simple strategy based on the microwave technique for the preparation of magnetic molecularly imprinted polymers (MMIPs) is proposed for the selective determination of sulfamethoxazole (SMX). The MMIPs were synthesized at 70 °C in 20 min, being much faster than the conventional techniques. A computational approach based on density functional theory was used to design the MMIP and compare the two most used monomers in MIPs, including methacrylic acid (MAA) and acrylamide (AM). Then, two different MMIPs were prepared using AM and MAA as monomers. The resultant materials were characterized with X-ray diffraction, thermogravimetric analysis, scanning/transmission electron microscopy, and Fourier-transform infrared spectroscopy. Besides, the adsorption characterizations suggested that the adsorption of SMX followed the pseudo-second-order model in the kinetic study and the Sips model in the isotherm study. The experimental results corroborated the computational approach. Furthermore, Both MMIPs demonstrated good selectivity. The MMIP-AM and MMIP-MAA were applied as adsorbents in magnetic dispersive solid-phase extraction combined with UV–visible spectroscopy to quantify SMX. The obtained limits of detection and quantification were lower than 0.59 and 1.77 μM, respectively for both MMIPs. The sensitivity of both MMIPs was in the range of 0.021–0.023 (SI). Our findings revealed that there is no significant difference in the analytical parameters between MMIP-AM and MMIP-MAA. However, the application of both MMIPs in a real sample (tap water) showed that the recovery values of SMX obtained with MMIP-AM (68–70%) were lower than that with MMIP-MAA (80–90%) suggesting that MMIP-MAA is more appropriate for SMX determination.

Preparation, characterization and adsorption properties of tetraalkylphosphonium organobeidellites

New intercalated clay materials based on the combination of four systematically selected alkylphosphonium organocations and beidellite (Bd) were prepared. Particularly, tetraethyl-, tetrabutyl-, tetrahexyl- and tetraoctyl- phosphonium cations were used in the synthesis. The samples were characterized by X-ray diffraction, thermal analysis, infrared spectroscopy and elemental carbon analysis. Further, calculations based on density functional theory method including dispersion corrections (DFT-D3) were carried out in a prediction of stability and detailed characterization of the structure and interactions of the beidellite intercalated models corresponding to four tetraalkylphosphonium cations used in experiment (4PX-Bd; X = 2, 4, 6, 8 / ethyl-, butyl-, hexyl-, octyl-). Calculated interlayer distances (d001) for all four models agreed well with experimental data continuously growing with a length of the alkyl chains of the 4PX cations. The structural stability of 4PX-Bd intercalates also increased with the size of the 4PX cations. Calculated vibrational spectra obtained from ab initio molecular dynamics were in a good agreement with experimental IR spectra. Further, a sorption capacity of synthetized organobeidellites was probed by loading sulfamethoxazole drug and quantified by liquid chromatography method. Adsorption of sulfamethoxazole was the most effective using tetraoctylphosphonium-modified beidellite.

Author Response to Comment on: Dynamic Adsorption of Sulfamethoxazole from Aqueous Solution by Lignite Activated Coke.

The authors would like to thank the comment by Diego M. Juela for contributing to helpful scientific discussions and correction suggestions, and to also express thanks to the editors.

Comments on "Dynamic Adsorption of Sulfamethoxazole from Aqueous Solution by Lignite Activated Coke".

This paper presents a brief discussion with regard to the fixed-bed modeling results of a recent paper by Li et al. published in this journal.

On disclosing the role of mesoporous alumina in the ozonation of sulfamethoxazole: Adsorption vs. Catalysis

Ordered mesoporous alumina (MA) and Fe-doped MA were synthesized by evaporation-induced self-assembly and tested for the ozonation of sulfamethoxazole (SMX). The synthesis methodology produced MA whose surface and structural properties exceeded those of commercial types displaying a BET surface area of 263 m2/g, a pore volume of 0.8 cm3/g and aligned cylindrical pores of c.a. 10 nm. The ozonation of SMX (20 mg/L) was performed in a semibatch stirred tank reactor at: T = 22 °C, [O3]gas = 10 mg/L, Qgas = 42 L/h NTP, [solid] ≈ 1 g/L, t = 120 min. Single ozonation achieved fast and complete SMX removal and mineralized up to 35% of the organics at neutral pH. The addition of MA or Fe-doped MA did not affect the removal rate of SMX, but did achieve a remarkable TOC removal up to 86% at acid pH. However, under the selected operating conditions, ferric species did not improve the removal of organic matter. Then, the adsorption and catalytic contribution of MA was evaluated in specifically-designed experiments. While SMX adsorption was low, its oxidation intermediates did adsorb onto MA surface. Despite the high ability of the materials to decompose ozone, the results revealed that the by-products adsorption is the prevailing process for the TOC removal. After four successive reuses, MA reduced its adsorption performance due to chemisorption of carboxylates. Nevertheless, the worn material was regenerated by direct ozonation in gas phase. In addition, primary transformation products were identified by LC–ESI–TOF–MS and the scavenging effect of the water matrix was assessed using bottled water and a real secondary wastewater.

Adsorption of sulfamethoxazole by wheat straw-derived biochars in seawater

The excessive use of antibiotics in mariculture have resulted in high pollution burdens of antibiotics in marine environment. Biochars, as promising adsorbents, have been widely used in organic pollutant adsorption because of their good adsorption performance and stability. However, adsorption characteristic of antibiotics in seawater by biochar is not well known. Thus, the batch experiment for the adsorption of sulfamethoxazole (SMX) was conducted using wheat straw-derived biochars and graphite (GR) under different initial concentration of SMX and different addition of adsorbent in seawater. The results showed that the wheat straw-derived biochars produced at 700 °C was the optimal adsorbent with the maximum removal rate (R) of 70.3%, the maximum adsorption capacity (Qe) of 1.03 mg g-1 and the maximum adsorption coefficient (Kd) of 0.182 L g-1. The Qe values increased with increasing the initial concentration of SMX, while R and Kd values of SMX decreased. The R values of SMX increased with the increasing dosage of adsorbents, while Qe and Kd values of SMX decreased. These findings will shed new light on the environmentally-friendly and low-cost adsorbent for controlling the antibiotic pollution in marine environment.

Comparison of sulfamethoxazole adsorption by activated carbon and biochar in seawater

Antibiotics, a type of emerging contaminants in marine environment, have posed serious threats to human health and ecological function. Biochar has been widely used in the remediation of multiple pollutants due to low cost and good adsorption characteristics. However, the adsorption characteristics of biochar for antibiotics in seawater are still unclear. Therefore, a coconut shell activated carbon (AC) and a sludge biochar produced at 700 °C (SB700) were selected to carry out batch adsorption experiments of sulfamethoxazole (SMX) under different adsorbent dosage and different initial concentration of SMX. These results showed that the maximum removal rate (R) of AC and SB700 was 99.9% and 97.9%, the maximum adsorption capacity (Qe) was 13.7 mg g-1and 1.6 mg g-1, and the maximum adsorption coefficient (Kd) was 2142 L g-1and 5.1 L g-1, respectively. Compared with SB700, AC showed the excellent performance in SMX adsorption. This study provided theoretical support and experimental basis for the development of highly efficient antibiotic adsorbents in marine ecosystem.

Effects of thiol functionalization of a waste-derived activated carbon on the adsorption of sulfamethoxazole from water: Kinetic, equilibrium and thermodynamic studies

An activated carbon was produced from paper mill sludge (AC-P) and functionalized with thiol groups (AC-MPTMS) for the adsorptive removal of the antibiotic sulfamethoxazole (SMX) from buffered solutions prepared in ultrapure water (pH 8) and real wastewater samples. The physicochemical properties of the two materials (AC-P and AC-MPTMS) showed differences mainly in specific surface area (SBET), in the type of oxygen functional groups and in the relative percentage of sulphur groups. The adsorption results showed a decrease in the Langmuir adsorption capacity (qm) upon an increase on temperature (15, 25 and 35 °C), varying between 113 ± 7 and 42.5 ± 0.6 mg g−1 for AC-P and between 140 ± 20 and 28.0 ± 1.5 mg g−1 for AC-MPTMS. Pseudo-second order model presented the best fit for the kinetic studies, with rate constants (k2) increasing with temperature and varying from 0.005 ± 0.002 to 0.013 ± 0.004 g mg−1 min−1 for AC-P and from 0.006 ± 0.002 to 0.03 ± 0.01 g mg−1 min−1 for AC-MPTMS. Both adsorbents showed very similar thermodynamic parameters, with the adsorption process being spontaneous (−26 kJ mol−1 ≤ ΔG° ≤ −40 kJ mol−1), endothermic (69 kJ mol−1 ≤ ΔH° ≤ 78 kJ mol−1), and entropically favorable (356 ≤ ΔS° ≤ 365 J mol−1 K−1). The performance of AC-MPTMS in the removal of SMX was tested in wastewater, where the material displayed lower SMX adsorption velocity and capacity than in buffered aqueous solution (pH 8) due to competitive matrix effects.

Unveiling the correlation of Fe3O4 fractions upon the adsorption behavior of sulfamethoxazole on magnetic activated carbon

Magnetic particles (MPs) assisted powdered activated carbon (PAC) is a promising composite material for adsorption removal of micropollutants. The fractional amount of Fe3O4 impacts the balance between adsorption capacity and magnetic property of magnetic activated carbons (MPACs), and therefore it affects the extent of sulfamethoxazole (SMX) removal. Here, five MPACs with different mass ratios of Fe3O4: PAC (1:1, 1:2, 1:4, 1:6, and 1:8) were prepared using a hydrothermal method and characterized by various spectroscopic methods. The spherical shaped MPs were monolayerly deposited on PAC with fewer pores blocked when the mass ratio of Fe3O4 was comparatively low (≤ 20%). MPAC6 (14.3 wt% of Fe3O4) had the best overall performance, with good Langmuir adsorption capacities for SMX (173.0 mg g−1) and excellent magnetic properties (9.0 emu g−1). Corresponding adsorption kinetics fitted well with the pseudo second-order kinetic model. The negative ΔG0 (−25.6 to −27.2 KJ mol−1) and ΔH0 (−9.14 KJ mol−1), and positive ΔS0 (0.55 KJ mol−1 K−1) properties indicated the spontaneous and exothermic nature of the adsorption process accompanied by an increase in entropy. The strong cation-assisted electron donor-acceptor and hydrophobic interactions were contributed to a high extent of SMX removal in the pH range of 2–4. Formation of negative charge-assisted H-bonds was responsible for the adsorption of hydrophilic SMX− on negatively charged MPAC6 in alkaline solution. Desorption and regeneration experiments showed SMX removal was still 92.3% in the 5th cycle. These findings give valuable insights into the interactions between SMX and MPACs and guide for choosing sustainable magnetic adsorbents for environmental applications.