Sorption Of Bisphenol Research Articles

Contrasting impact of phosphorus dissolution on the sorption of bisphenol A and carbamazepine by phosphorus-rich chars

Phosphorus (P)-rich chars produced by phosphoric-acid-assisted pyrolysis are promising carbonaceous remediation agents for soil pollution. Nevertheless, the potential of P species dissolution from P-rich chars has been ignored, and the impact of P dissolution on the sorption of hydrophobic compounds remains greatly unaddressed to date. Herein, the P species dissolution from wood-, cellulose-, and lignin-derived P-rich chars at 200–650 °C were investigated. P release capacity ranged from 0.2 to 0.3 mg·g−1 through cyclic dissolution and the maximum release capacity was 1.6 mg·g−1 through continuous dissolution. Enhanced P dissolution in soil experiment implies that P-rich char can be a potential P source. After P species dissolution, bisphenol A (BPA) sorption increased and carbamazepine (CBZ) sorption decreased onto P-rich chars. The enhanced π-π interaction facilitated BPA sorption, while the declined double charge-assisted H-bond ((±)CAHB) weakened CBZ sorption. Combined with DFT calculations, the binding energy (ΔE) supported the contrasting interfacial sorption processes. Apart from micropore-filling, the contribution of sorption mechanisms followed the sequence of (±)CAHB > π-π interaction > H-bonding. This work not only reveals that P-rich char can serve as a promising phosphatic fertilizer for soil improvement but also casts new light on the sorption mechanisms for hydrophobic compounds.

Aggregation of biochar nanoparticles and the impact on bisphenol A sorption: Experiments and molecular dynamics simulations

The unique properties and environmental implications of biochar nanoparticles (BNPs) have attracted increasing attention. The abundant functional groups and aromatic structures in BNPs may promote the aggregation of BNPs, but the mechanism and implications of this aggregation process remain unclear. Thus, this study investigated the aggregation of BNPs and the sorption of bisphenol A (BPA) on BNPs by combining experimental investigations with molecular dynamics simulations. As the concentration of BNP increased from 100 mg/L to 500 mg/L, the particle size increased from approximately 200 nm to 500 nm, and the exposed surface area ratio in the aqueous phase decreased from 0.46 to 0.05, which confirmed the aggregation of BNPs. The sorption of BPA on BNPs decreased with increasing BNP concentration in both the experiments and molecular dynamics simulations because of BNP aggregation. According to a detailed analysis of the BPA molecules adsorbed on BNP aggregates, the sorption mechanisms were hydrogen bonding, hydrophobic effect, and π-π interactions, which were driven by aromatic rings and O- and N-containing functional groups. The aggregation of BNPs embedded some functional groups in the aggregates and thus inhibited sorption. Interestingly, the steady configuration of the BNP aggregates in the molecular dynamics simulations (2000 ps relaxation) also determined the apparent BPA sorption. BPA molecules were adsorbed in the V-shaped interlayers of the BNP aggregates that acted as semi-closed pores, but could not be adsorbed in the parallel interlayers because of their small layer spacing. This study can provide theoretical guidance for the application of BNPs in pollution control and remediation.

Sorption of bisphenol A onto microplastics and associated environmental risks in comparison to engineered carbonous materials and natural media

Microplastics (MPs) have been proven to be a vector for the migration of hydrophobic organic pollutants in the water system. However, the potential environmental risks of MPs compared with typical environmental materials are still unknown. In this work, the potential risks of MPs (high-density polyethylene (HDPE) and polyamide (PA)), engineered carbonous materials (active carbon (AC), graphene oxide (GO), and multi-walled nanotubes (MWCNTs)), and natural media (Soil and Sediment) were evaluated by comparing their interfacial behaviors to bisphenol A (BPA) under various environmental conditions. The maximum sorption capacities of BPA on those materials followed the order of AC (179 mg/g) > MWCNTs (73.5 mg/g) > PA (69.0 mg/g) > GO (44.1 mg/g) >> Soil (0.601 mg/g) > Sediment (0.164 mg/g) ≈ HDPE (0.163 mg/g). The main sorption mechanisms of BPA on GO were H-bonds and π-π interactions, while those on AC and MWCNTs were π-π interactions. Hydrophobic interaction played a dominant role in the sorption of BPA on Soil, Sediment, and HDPE, whereas PA bound to BPA primarily through H-bonds. Density functional theory (DFT) simulation also confirmed the predominant mechanism of hydrophobic interaction (−6.01 kcal/mol) between BPA and HDPE as well as H-bonds (−8.43 kcal/mol) between BPA and PA. Besides, solution pH, humic acid (HA), salinity, water matrices, and coexisting 17β-Estradiol (E2) played roles in the sorption of BPA. Based on the current abundance of carbonous materials and MPs in real environments, the calculated relative desorbed capacity (RDC) of BPA suggested that the predicted environmental risk of MPs was similar to that of engineered carbonaceous materials but much lower than that of natural media. Our findings highlight that the sorption behaviors and potential risks of MPs in real environments highly depend on the structural properties of MPs, in which surface functional groups are particularly important.

Sorption of Bisphenol A from aqueous solutions by acid activated bentonite clay

Sorption of Bisphenol A from aqueous solutions by acid activated bentonite clay

Sorption of Bisphenol A as Model for Sorption Ability of Organoclays.

The arrangement of bisphenol A molecules into organoclays and their interactions with the intercalated surfactant were studied. The organoclays were prepared via solid-state intercalation of four cationic surfactants, such as dodecyltrimethyl-, tetradecyltrimethyl-, hexadecyltrimethyl-, and didodecyldimethyl-ammonium, as bromide salts, at different loading levels into the interlayers of two natural clays. The natural clays, the prepared organoclays, and the spent organoclays were characterized by X-ray powder diffraction, infrared spectroscopy, and scanning electron microscopy. X-ray powder diffraction measurements showed successive interlayer expansions of the d001 basal spacing due to the intercalation of the cationic surfactants and the bisphenol A sorption. The increased d001 basal spacing of the organoclays after bisphenol A sorption indicates that the molecules are integrated between the alkyl chains of the surfactant in the organoclays interlayers. Infrared spectroscopy was employed to probe the intercalation of the cationic surfactants and the sorbed bisphenol A. New characteristic bands attributed to the bisphenol A phenol rings appear in the range 1518–1613 cm−1 on the infrared spectra of the spent organoclays, proving the presence of bisphenol A in the hydrophobic interlayers. Scanning electron microscopy of the organoclays before and after BPA sorption shows that their morphology becomes fluffy and that the presence of the organic molecules expands the clay structure.

Non-Linear Regression Applied to the Sorption of Bisphenol A on Multi-Walled Carbon Nanotubes in Aqueous Systems.

In the present study, equilibrium parameters of adsorption of bisphenol A (BPA) on multi-walled carbon nanotubes were determined using non-linear Langmuir and Freundlich sorption models and regression methods were applied. In the calculations, some error functions were applied in the non-linear regression analysis, the best fit between the data being obtained, for a minimum error distribution. Non-linear regression analysis and the error distribution suggested Langmuir isotherm model the best one for estimation of equilibrium parameters. The results will be further used in environmental applications for BPA removal from natural waters, taking into account the spontaneous character of the adsorption process, the endocrine disrupting effect of BPA and the reduced toxicological effects of the impregnated sorbents.

Sorption of bisphenol A from aqueous solutions using natural adsorbents: isotherm, kinetic and effect of temperature

Emerging organic micropollutants, such as bisphenol A (BPA), have raised concerns about their negative impact on human health and ecological safety. This review article aims to demonstrate and highlight recent advances in adsorption applications for bisphenol A, a toxic environmental pollutant commonly found in wastewater. There are many reasons to use non-toxic materials and eco-friendly technologies to remove this pollutant from sewage. [1] Several adsorbents previously used have shown significant efficiency and performance for the removal of BPAs, and current research is directed towards the development of low-cost treatment processes using materials such as clays and Chitosan. The properties of the adsorbent can be adjusted by changing their surface for an optimized performance. In addition, the efficiency of the adsorption process depends on various parameters such as solution pH, the pollutant concentration, contact time, temperature, nature and dose of the adsorbent, which are also discussed. In addition, we critically review the isothermal, kinetic and thermodynamic approaches. [2]

Sorption of Bisphenol A in Aqueous Solutions on Irradiated and as-Grown Multiwalled Carbon Nanotubes

In this study, non-irradiated and weathered multiwalled carbon nanotubes (MWCNTs) obtained through irradiation, were studied as adsorbents for BPA, both nanomaterials being characterized before and after the adsorption process. The objectives of our investigation were to compare the characteristics of non-irradiated and irradiated MWCNTs, to evaluate the adsorption capacity of BPA by pristine and irradiated MWCNTs and to determine the variation of the kinetic, sorption and thermodynamic parameters during sorption process using both sorbents.

Preparation of bio‐based keratin‐derived magnetic molecularly imprinted polymer nanoparticles for the facile and selective separation of bisphenol A from water

In this study, new bio-based magnetic molecularly imprinted polymer nanoparticles (∼23nm) were synthesized from keratin extracted from chicken feathers and methacrylate-functionalized Fe3 O4 nanoparticles for its potential application in separation and removal of bisphenol A from water. The prepared magnetic molecularly imprinted polymer was characterized by Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, thermogravimetric analysis, alternative gradient field magnetometry, and energy-dispersive X-ray spectroscopy. The sorption of bisphenol A was investigated by changing the influencing factors such as pH, immersion time, Fe3 O4 nanoparticles dosage, and the initial concentration of bisphenol A. Results illustrated that sorption was very fast and efficient (Qm =600mg/g) having a removal efficiency of ∼98% in 40min of immersion. The adsorption process showed better conformity with the Weber-Morris kinetics and the Freundlich isotherm model. The selectivity of bisphenol A by adsorbent was checked in the presence of hydroquinone, phenol, tetrabromobisphenol, and 4,4'-biphenol as interferences.

Sorption behavior and modeling of endocrine-disrupting chemicals on natural sediments: role of biofilm covered on surface.

The surfaces of natural sediments are ubiquitously coated by biofilms that increase the content of organic matter in sediments. However, it is less understood whether the biofilms act as a sorbent or a barrier of mass transfer from water column to sediment phase. This study focused on the role of biofilms coverage on sediments in the sorption of bisphenol A (BPA), 17α-ethinyl estradiol (EE2), and 4-nonylphenols (4-NP) as model compounds for endocrine-disrupting chemicals (EDCs). The OC-normalized distribution coefficients (k OC) for BPA, EE2 and 4-NP ranged from 10(1.87) to 10(3.09) l/kg, the k OC of EE2 was slightly higher (10(2.23) l/kg) for sediment after H2O2 oxidation than before (10(1.93) l/kg). A two-stage model with a fast section and slow section was employed to describe the sorption process (r (2) > 0.95). The model results showed that the fast sorption section played a main role in the sorption process, while the slow section determined the extent of the reaction (the second-phase partition coefficient (k p2) ranged from 11.7 to 118.9 l/kg). The ratios of the mass transfer rate constant of the two stages for the natural sediment ranged from 6.0 to 7.2, which were somewhat lower than those for soil samples. These results indicated that the biofilm coverage on sediment may act as a barrier in mass transfer from water to sediment and scarcely increased the sorption capacity of sediments.

The sorption of organic contaminants on biochars derived from sediments with high organic carbon content

Biochars were produced using a Dianchi Lake sediment at different temperatures and their sorption characteristics with five organic contaminants (with solubilities varied three orders of magnitude) were compared. Freundlich model showed satisfying fitting results of the sorption isotherms. Distinct decrease of nonlinear factors was observed for all five contaminants with pyrolysis suggesting wider energy distribution of the sorption sites after pyrolysis. No clear trend was observed between Kd and the chemical properties of the five chemicals. Phenanthrene and sulfamethoxazole (SMX) showed increased sorption with increased pyrolysis temperature, while the sorption of bisphenol A (BPA), ofloxacin (OFL) and norfloxacin (NOR) in the original sediment was comparable to those in the thermally treated samples. Electrostatic repulsion played an important role in SMX sorption as suggested by its lowest hydrophobicity-normalized sorption coefficients among the five chemicals. Possible sorption mechanisms were discussed and the sorption of SMX and PHE on the produced biochars were compared with natural adsorbents (including soils, sediments, and inorganic mineral particles).

Sorption of 17α-ethinyl estradiol, bisphenol A and phenanthrene to different size fractions of soil and sediment

The potential for negative effects caused by endocrine disrupting chemicals (EDCs) release into the environment is a prominent concern and numerous research projects have investigated possible environmental fate and toxicity. However, their sorption behavior by size fractions of soil and sediment has not been systematically represented. The sorption of bisphenol A (BPA), 17α-ethinyl estradiol (EE2) and phenanthrene (Phen) by different size fractions of soil and sediment were investigated. Sorption isotherms of EE2, BPA, and Phen by size fractions of soil (SL) and sediment (ST) were well fitted to the Freundlich model. The positive correlation between EE2, BPA and Phen sorption capacity (logKd) of size fractions and their organic carbon (OC) content suggests that OC of size fractions in SL and ST should regulate sorption, while the surface area (SA) of size fractions may not account for sorption of EE2, BPA and Phen. Each size fraction of ST had higher sorption capacity (Kd or KOC) of EE2 and BPA than that of SL due to their difference in the polarity of organic matter (OM) between terrestrial and aquatic sources. Sorption capacity logKd for size fractions of SL and ST did not follow the order: clay>silt>sand due to the difference in OM abundance and composition between the size fractions. Large particle fractions of ST contributed about 80% to the overall sorption for any EE2, BPA, and Phen. This study was significant to evaluate size fractions of soil and sediment as well as their associated OM affecting EE2 and BPA sorption processes.

Sorption of bisphenol A, 17α-ethinyl estradiol and phenanthrene on thermally and hydrothermally produced biochars

Thermal and hydrothermal biochars were characterized, and adsorption of bisphenol A (BPA), 17α-ethinyl estradiol (EE2) and phenanthrene (Phen) was determined to investigate the sorption characteristic difference between the two types of biochars. Thermal biochars were composed mostly of aromatic moieties, with low H/C and O/C ratios as compared to hydrothermal ones having diverse functional groups. Single-point organic carbon-normalized distribution coefficients (log K OC) of EE2 and BPA of hydrothermal biochars were higher than thermal biochars, while Phen log K OC values were comparable among them. X-ray diffraction and solid state nuclear magnetic resonance results suggested that hydrothermal biochars consisted of more amorphous aliphatic-C, possibly being responsible for their high sorption capacity of Phen. This study demonstrated that hydrothermal biochars could adsorb a wider spectrum of both polar and nonpolar organic contaminants than thermally produced biochars, suggesting that hydrothermal biochar derived from poultry and animal waste is a potential sorbent for agricultural and environmental applications.

Influence of the presence of heavy metals and surface-active compounds on the sorption of bisphenol A to sediment

The effects of different heavy metals (Cd, Pb), cationic surfactants cetyltrimethylammonium bromide (CTAB), anionic surfactant sodium dodecylbenzenesulfonate (SDBS) and the chemistry of the solution (pH and ionic strength) on the sorption of bisphenol A (BPA) to sediment were studied. Results showed that the presence of Cd and Pb caused a significant increase on the sorption of BPA to sediment and the sorption isotherms were in good agreement with Freundlich equation. The effect of surfactants on the adsorption of BPA onto sediment was found to strongly depend on the type of the surfactants. The presence of CTAB promoted BPA sorption and the amount of BPA adsorbed onto sediment increased linearly with concentration of CTAB. In contrast, the presence of anionic surfactant (SDBS) caused a slight reduction on the sorption of BPA. It was also found that the sorption behavior of BPA was affected by solution pH and ionic strength. The larger amount of BPA was absorbed with higher ionic strength and lower pH. This study may provide important insights into the understanding of the transport and fate of BPA in the environment.