Adsorption Of Tetrabromobisphenol A Research Articles

Efficient Adsorption Removal of Tetrabromobisphenol A from Water by Using a Magnetic Composite Fe3O4/GO/ZIF-67

Tetrabromobisphenol A (TBBPA) is a kind of widely used brominated flame retardant (BFR), which is proven to be harmful to ecological systems and public health. It is very important to remove TBBPA from the environment. In our study, a magnetic composite named Fe3O4/GO/ZIF-67 was synthesized by a coprecipitation method and applied in the highly efficient adsorption of TBBPA from water. Static adsorption experiments demonstrated that the adsorption capacity could reach 232 mg·g−1 within 120 min, which is much higher than those reported in the other literature. The experimental results show that the adsorption of TBBPA on Fe3O4/GO/ZIF-67 followed Langmuir and pseudo-second-order kinetic adsorption models. The main mechanisms for these adsorptions were identified as hydrogen bonds between OH groups in TBBPA and COOHs of Fe3O4/GO/ZIF-67, and π-π stacking between Fe3O4/GO/ZIF-67 and TBBPA. This study provides a method with great promise for the design and synthesis of better adsorbents for the removal of TBBPA from the water environment.

Insights into the influence of polystyrene microplastics on the bio-degradation behavior of tetrabromobisphenol A in soil

Soil contamination by emerging pollutants tetrabromobisphenol A (TBBPA) and microplastics has become a global environmental issue in recent years. However, little is known about the effect of microplastics on degradation of TBBPA in soil, especially aged microplastics. In this study, the effect of aged polystyrene (PS) microplastics on the degradation of TBBPA in soil and the mechanisms were investigated. The results suggested that the aged microplastics exhibited a stronger inhibitory effect on the degradation of TBBPA in soil than the pristine microplastics, and the degradation efficiency of TBBPA decreased by 21.57% at the aged microplastic content of 1%. This might be related to the higher TBBPA adsorption capacity of aged microplastics compared to pristine microplastics. Aged microplastics strongly altered TBBPA-contaminated soil properties, reduced oxidoreductase activity and affected microbial community composition. The decrease in soil oxidoreductase activity and relative abundance of functional microorganisms (e.g., Bacillus, Pseudarthrobacter and Sphingomonas) caused by aged microplastics interfered with metabolic pathways of TBBPA. This study indicated the importance the risk assessment and soil remediation for TBBPA-contaminated soil with aged microplastics.

Insight into the interaction of tetrabromobisphenol A with sediment-derived dissolved organic carbon in a multiphase system by direct immersion solid phase microextraction

Tetrabromobisphenol A (TBBPA), a ubiquitously used commercial brominated flame retardant (BFR), has been widely detected in aquatic environments, and has aroused much attention due to its potential adverse effects on aquatic organisms. However, current research on the environmental fate and transport of TBBPA in the sediment–dissolved organic carbon (DOC)–water polyphase system is lacking. In this study, the sorption behavior of TBBPA in a water–DOC–sediment system was investigated using the direct-immersion solid-phase microextraction (DI-SPME) method, and the free dissolved concentration (Cw-SPME) and DOC adsorption concentration (CDOC) of TBBPA in water were measured by applying this DI-SPME approach. In addition, the effects of pH, ionic strength, and soluble organic concentration on the adsorption of TBBPA in the multiphase system were evaluated. The adsorption kinetics experimental results show that the adsorption behavior of TBBPA on sediments conforms to a linear model, suggesting that it could be mainly absorbed by sediments. The solid–water partition coefficient (Kd) of TBBPA was artificially reduced 1.54 times using the traditional liquid–liquid extraction method because the sorption behavior of the DOC was ignored, which could be accurately corrected using the DI-SPME method. The logKd and logKOC of TBBPA in the multiphase system were 4.12 ± 0.25 and 6.48 ± 0.25, respectively. Finally, the interference experiment revealed that the sorption behavior of TBBPA was affected by the pH, ionic strength (calcium ion), and humic acid concentration, apart from the lead ion concentration itself.

Adsorption behaviors and bioavailability of tetrabromobisphenol A in the presence of polystyrene microplastic in soil: Effect of microplastics aging

Microplastics, a kind of emerging pollutant, have become a global environmental research hotspot in recent years due to its wide distribution in soil and its impact on soil ecosystems. However, little information is available on the interactions between microplastics and organic contaminants in soil, especially after microplastic aging. The impact of polystyrene (PS) microplastic aging on the sorption of tetrabromobisphenol A (TBBPA) in soil and the desorption characteristics of TBBPA-loaded microplastics in different environments were studied. The results showed a significant increase of 76.3% in adsorption capacity of TBBPA onto PS microplastics after aging for 96 h. Based on the results of characterization analysis and density functional theory (DFT) calculation, the mechanisms of TBBPA adsorption changed mainly from hydrophobic and π-π interactions on pristine PS microplastics to hydrogen bond and π-π interactions on aged PS microplastics. The presence of PS microplastics increased the TBBPA sorption capacity onto soil-PS microplastics system and significantly altered the distribution of TBBPA on soil particles and PS microplastics. The high TBBPA desorption over 50% from aged PS microplastics in simulated earthworm gut environment suggested that TBBPA contamination combined with PS microplastics might pose a higher risk to macroinvertebrates in soil. Overall, these findings contribute to the understanding of impact of PS microplastic aging in soil on the environmental behaviors of TBBPA, and provide valuable reference for evaluating the potential risk posed by the co-existence of microplastics with organic contaminants in soil ecosystems.

Adsorption and Removal of Tetrabromobisphenol A by Adsorption on Functionalized Mesoporous Silica Nanotubes: Isotherms, Kinetics, Thermodynamics, and Optimization via Box-Behnken Design.

In pursuit of environmental safety, a novel and efficient method-dispersive solid-phase extraction based on functionalized mesoporous silica nanotubes (FMSNT nanoadsorbent)-was developed to remove tetrabromobisphenol A (TBBPA) from water samples. Characterization and comprehensive analysis of the FMSNT nanoadsorbent, including maximum adsorption capacity of 815.85 mg g-1 for TBBPA and its water stability, confirmed its potential. Subsequent analysis revealed the impact of multiple factors, for instance pH, concentration, dose, ionic strength, time, and temperature, on the adsorption process. The findings revealed that the adsorption of TBBPA followed the Langmuir and pseudo-second-order kinetics models while primarily driven by hydrogen bond interactions between bromine ions or hydroxyl groups of TBBPA and amino protons around the cavity. The novel FMSNT nanoadsorbent showed high stability and efficiency even after five times of recycling. Moreover, the overall process was identified as chemisorption, endothermic, and spontaneous. Finally, the Box-Behnken design was applied to optimize the results, confirming good reusability even after five cycles.

Quantitative SERS Detection of TBBPA in Electronic Plastic Based on Hydrophobic Cu-Ag Chips.

Tetrabromobisphenol A (TBBPA) was one of the most widely used brominated flame retardants. However, it easily contaminates nature and harms the environment and human health during its production and use. Therefore, it is necessary to strictly control the content of TBBPA in electronics. Surface-enhanced Raman spectroscopy has the advantages of being fast and sensitive, but it is difficult to obtain the SERS spectra of TBBPA because the hydrophobic TBBPA molecule is difficult to approach with the hydrophilic surface of common noble metal SERS substrates. In the present work, a hydrophobic Cu-Ag chip was developed for the SERS detection of TBBPA. The integration of the hydrophobic interaction and the Ag-Br bonding promoted the adsorption of TBBPA on the Cu-Ag chip, allowing for SERS detection. It was observed that both the hydrophobicity and bimetallic composition of the Cu-Ag chip played important roles in the SERS detection of TBBPA. Under the optimized conditions, the low limit of detection of the established SERS method for TBBPA was 0.01 mg L−1, within a linear range of 0.1–10 mg L−1. Combined with ultrasonic-assisted extraction, the substrate could be used for the quantitative determination of TBBPA in electronic products. Compared with the HPLC-UV method used as a national standard, the relative error of the SERS method for quantifying the TBBPA content in a mouse cable and shell was ±3% and ±7.7%, respectively. According to the SERS results, the recovery of TBBPA in the spiked mouse shell was 95.6%.

Adsorption behaviour of tetrabromobisphenol A on sediments in Weihe River Basin in Northwest China

Tetrabromobisphenol A (TBBPA) is adsorbed on sediments in river environments, and various environmental factors have distinct effects on its adsorption behaviour. Investigating the adsorption behaviour of TBBPA on the sediments in Weihe River Basin is critical for protecting the water environment and providing a theoretical basis for the prevention and control of brominated flame retardant pollution. In this study, the adsorption behaviour of TBBPA on Weihe River sediment was investigated by conducting batch equilibrium experiments, and the effects of pH, dissolved organic matter, and ionic strength on the adsorption of TBBPA were discussed. The obtained results revealed that rapid adsorption was the main mechanism of the TBBPA kinetic adsorption process. The isothermal adsorption behaviour of TBBPA was well fitted by Freundlich model (R2 99.21%) than Langmuir model (R2 98.59%). The adsorption capacity for TBBPA is 34.13 mg/kg. The thermodynamic results revealed that the adsorption process of TBBPA by the sediment was a spontaneous endothermic reaction. The increase in pH and ionic strength inhibited the adsorption of sediments on TBBPA. With the increase in the humic acid concentration, the adsorption of TBBPA initially increased and subsequently decreased. Synchrotron radiation-Fourier transform infrared spectroscopy indicated that the adsorption mechanism of TBBPA on the surface of sediment was mainly π–π and hydrogen bonds. The obtained results are useful for understanding of TBBPA migration and transformation in river water bodies.

Facile synthesis of polyoxometalate-modified metal organic frameworks for eliminating tetrabromobisphenol-A from water

Removal of tetrabromobisphenol-A (TBBPA) from wastewater is of significance to protect the aquatic life. The present study reports the facile preparation of polyoxometalate-modified metal-organic framework (MOFs) materials for TBBPA removal from water. The polyoxometalate-modified MOFs exhibited significantly higher affinity towards TBBPA than the control MOFs. The experimental data were fitted with the Langmuir, Freundlich and Dubinin-Radushkevich models. The TBBPA adsorption onto modified MOFs fitted the pseudo-second-order kinetic model. The equilibrium adsorption isotherms showed that the adsorption of TBBPA can be fitted by the Langmuir model. The maximum adsorption capacity of adsorbent composites reached 3.65 mg/g, with 95 % removal of TBBPA. The thermodynamic parameters indicated that adsorption was spontaneous. A blue shift of phosphorus peaks obtained from XPS spectra implied the formation of intrinsic chemical bonding between TBBPA and MOFs composites. Moreover, response surface methodology was employed to characterize the TBBPA adsorption in the co-existence of different factors. BPA had strong competition for TBBPA adsorption in a wide range of pH, but not at the middle level of Ca2+ concentration. Polyoxometalate-modified MOFs can easily be recycled using a simple organic solvent washing. This study provides a novel strategy for developing cost effective adsorbents to remove TBBPA from contaminated water.

Enhanced adsorption of tetrabromobisphenol a (TBBPA) on cosmetic-derived plastic microbeads and combined effects on zebrafish

Microplastics (MPs) pollution and its potential environmental risks have drawn increasing concerns in recent years. Among which, microbeads in personal care and cosmetic products has becoming an emerging issue for their abundance as well as the knowledge gaps in their precise environmental behaviors in freshwater. The present study investigated the sorption process of tetrabromobisphenol A (TBBPA), the most widely applied and frequently encountered flame retardant in aquatic environments, on two sources of polyethylene (PE) particles (pristine PE particles and microbeads isolated from personal care and cosmetic products). Significantly enhanced adsorption capacity of microbeads was observed with up to 5-folds higher than the pristine PE particles. The sorption efficiency was also governed by solution pH, especially for the cosmetic-derived microbeads, indicating the strong adsorption of TBBPA on PE was dominated by both hydrophobic and electrostatic interactions. Additionally, combined effects on redox status of zebrafish were evaluated with two environmental relevant concentrations of PE particles (0.5 and 5 mg L−1) using integrated biomarker response (IBR) index through a 14-d exposure. Co-exposure induced significant antioxidative stress than either PE or TBBPA alone when exposed to 0.5 mg L−1 of MPs. After 7-d depuration, the IBR value for combination treatments [TBBPA + PE (L)] was 3-fold compared with that in MP-free groups, indicating the coexistence might exert a prolonged adverse effects on aquatic organisms. These results highlight the probability of risk from microbead pollution in freshwater, where toxic compounds can be adsorbed on microbeads in a considerable amount resulting in potential adverse effects towards aquatic organisms.

Efficient removal of tetrabromobisphenol A using microporous and mesoporous carbons: The role of pore structure

Abstract Tetrabromobisphenol A (TBBPA) is a widely used flame retardant yet a persistent pollutant in the environment. In this study, various microporous and mesoporous carbon-based materials were synthesized and their adsorption performance toward TBBPA was systematically evaluated. The adsorbents were characterized by transmission electron microscope, scanning electron microscope, X-ray diffraction, Raman spectroscopy, N2 adsorption/desorption and Zeta potential measurements. TBBPA adsorption over coal-based activated carbon (F300), coconut-shell-based activated carbon (AC) and CMK-3 followed Freundlich adsorption model, while TBBPA adsorption over zeolite-templated carbon (ZTC), single-walled carbon nanotube (SWNT) and multiwalled carbon nanotube (MWNT) could be well described by both Freundlich model and Langmuir model. Compared with F300 and AC, TBBPA diffusion on ZTC and CMK-3 is faster because of their ordered pore structure and higher average pore size. The surface-area-normalized adsorption capacity of TBBPA was higher on ZTC, AC and F300 than on CMK-3, SWNT and MWNT, which can be attributed to the stronger micropore-filling effect with the microporous carbonaceous materials. The presence of humic acids had little effect on TBBPA sorption over ZTC, F300, CMK-3 and AC, while suppressed TBBPA adsorption on SWNT and MWNT were observed. In the column adsorption test, ZTC was capable of continuously treating synthetic wastewater stream, indicating that ZTC had great potential to be used as an effective adsorbent for TBBPA removal.

Tetrabromobisphenol A adsorption by active carbon: influential factors and kinetics

Frequency detection and environmental risk of Tetrabromobisphenol A （TBBPA）in aqueous system attracted many concerns. Nevertheless, mutual interactions between TBBPA and natural or synthetic chemical materials has not be clearly revealed. In this study, influential factors, adsorption behavior and mutual dynamism of active carbon (AC) and TBBPA were comprehensively explored. It was found that chemical sorption efficiency of AC reached more than 90%. The adsorption behavior can be depicted by Langmuir and Freundlich isotherms, whose kinetic could be well described by pseudo-first-order kinetic model. The chemisorption of AC is mainly single molecular layer mode for TBBPA adsorption, during which presence of SO42-, HCO3- and humic acid significantly inhibited TBBPA sorption capability. Proper temperature and pH promoted the adsorption efficiency of TBBPA. The obtained results demonstrated that AC adsorption is one feasible and effective technique for enhanced treatment technique for TBBPA containing wastewater.

Synthesis and characterization of Ag‐loaded p‐type TiO2 for adsorption and photocatalytic degradation of tetrabromobisphenol A

A p-type TiO2 with Ti vacancies (D-TiO2 ) was synthesized by a facile solvothermal treatment, and Ag/TiO2 with different Ag loading amount was prepared through a photo-reduction deposition method. The samples were characterized through scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The adsorption and photocatalytic characteristics of tetrabromobisphenol A (TBBPA) on D-TiO2 and Ag/TiO2 were investigated. The adsorption of TBBPA on Ag/TiO2 was significantly enhanced and was five times greater than that of pure TiO2 . The increase in pH significantly inhibited the adsorption of TBBPA. The 2%-Ag/TiO2 nearly completely degraded TBBPA in 10min under UV-Vis light (λ>360nm), and the apparent reaction rate constant (kapp ) reached 0.63min-1 . The significantly enhanced UV-Vis light catalytic properties of the Ag/TiO2 in comparison with that of TiO2 were attributed to the increased adsorption capacity and electron transfer ability of the Ag/TiO2 . Free radical trap experiments results showed that holes and superoxide radicals play a major role in the catalytic degradation of TBBPA by Ag/TiO2 . Moreover, the Ag/TiO2 catalyst exhibits high stability during TBBPA degradation even after three cycles. PRACTITIONER POINTS: Ti-defected TiO2 and Ag/TiO2 were synthesized using a solvothermal and photo-reduction deposition, respectively. Ag/TiO2 exhibited outstanding adsorption and photocatalytic activity for TBBPA removal under UV-Vis light. Holes and superoxide radicals play a major role inthe photocatalytic degradation of TBBPA.

Preparation of magnetic core-shell Fe3O4@polyaniline composite material and its application in adsorption and removal of tetrabromobisphenol A and decabromodiphenyl ether

Present study described a magnetic adsorption and removal method with prepared magnetic core-shell Fe3O4@polyaniline microspheres for the removal of two typical BFRs, tetrabromobisphenol-A (TBBPA) and decabromodiphenyl ether (BDE-209) from water samples. Magnetic core-shell Fe3O4@polyaniline microspheres were prepared by a hydrothermal and two step polymerization method with cheap iron salts and aniline, which were characterized with transmission electron microscopic (TEM) and scanning electron microscopy (SEM). The results showed that the Fe3O4@polyaniline microspheres earned a clear thickness shell of polyaniline (about 50 nm) and a saturation magnetization of 40.4 emu g−1. The Magnetic core-shell Fe3O4@polyaniline exhibited excellent adsorption capability and removal rate to TBBPA and BDE 209. The adsorption of TBBPA and BDE 209 all followed pseudo-second order kinetics and agreed well to the Freundlich adsorption isotherms model. The negative Gibbs free energy change (ΔG0) and positive standard enthalpy change (ΔH0) for TBBPA and BDE-209 suggested that the adsorption was spontaneous and endothermic in nature. These results demonstrated that Fe3O4@PANI was a good adsorbent and would have a good application prospect in the removal of pollutants from environmental water.

Facile synthesis of hydroxyl enriched microporous organic networks for enhanced adsorption and removal of tetrabromobisphenol A from aqueous solution

Here we report the rational design and facile synthesis of hydroxyl-enriched microporous organic networks (MON-OH and MON-2OH) for enhanced and efficient adsorption and removal of a typical brominated flame retardant tetrabromobisphenol A (TBBPA) from aqueous solution. Introducing of hydroxyl groups into MONs’ networks lead to the significant improvement of their hydrophilicity and adsorption capacity for TBBPA. Rely on the good hydrophobicity and predesigned hydrogen bonding sites, the synthesized MON-2OH gave a large adsorption capacity of 326.8 mg g−1 for TBBPA, which is much higher than MONs and many other reported sorbents. The adsorption of TBBPA on MON-2OH followed Langmuir and pseudo-second-order kinetic adsorption models. The TBBPA adsorption capacity was independent on ionic strength (0–30 mg g−1), humic acid (0–40 mg g−1) and pH (5.0–8.0). MON-2OH also gave good stability and reusability and owned good practicability for the removal of TBBPA from wastewater samples. Efficient adsorption and removal of other biphenol pollutants was also achieved on MON-2OH. The adsorption mechanisms of TBBPA on MON-2OH were also well elucidated. This work provides a promising way to design and synthesize efficient adsorbents for TBBPA, which may also promote the design, synthesis and application of functionalized MONs in environmental and material science.

Core–Shell Magnetic Amino-Functionalized Microporous Organic Network Nanospheres for the Removal of Tetrabromobisphenol A from Aqueous Solution

Development of functional porous materials for efficient elimination of environmental pollutants is of great importance in green chemistry and environmental protection. Here we report the design, synthesis, and application of a core–shell magnetic amino-functionalized microporous organic network nanosphere (Fe3O4@MON-NH2) for efficient magnetic adsorption of a typical brominated flame-retardant tetrabromobisphenol A (TBBPA) from aqueous solution. By integration of the hydrophobic networks and hydrogen binding sites within MON-NH2, the synthesized core–shell Fe3O4@MON-NH2 nanospheres gave good adsorption for TBBPA. The adsorption equilibrium of TBBPA (50 mg L–1) on Fe3O4@MON-NH2 was achieved within 1 min, showing ultrafast adsorption kinetics of Fe3O4@MON-NH2 for TBBPA. The adsorption of TBBPA on Fe3O4@MON-NH2 followed the pseudo-second-order kinetics and Langmuir adsorption models, giving a maximum adsorption capacity of 135.9 mg g–1 at 25 °C. The adsorption of TBBPA on Fe3O4@MON-NH2 was a spontaneous and endothermic process controlled by positive entropy. Encouraged by the large adsorption capacity, rapid adsorption kinetics, and the small effect of pH (5–10), dissolved organic matter, and ionic strength on the adsorption, the application of Fe3O4@MON-NH2 for TBBPA removal in real water samples was achieved. The used Fe3O4@MON-NH2 can be easily regenerated and reused at least four times without significant reduction of the adsorption capacity. These results revealed the potential of Fe3O4@MON-NH2 for adsorption and removal of environmental pollutants from aqueous solution.

Room-temperature synthesis of microporous organic network for efficient adsorption and removal of tetrabromobisphenol A from aqueous solution

Development of energy-saving and rapid strategies to synthesize novel porous materials for efficient adsorption and removal of environmental pollutants is of great challenge and interest either in environmental science or in chemistry. Here we report a facile room temperature stirring method for rapid synthesis of microporous organic networks (MONs) with large surface area, excellent hydrophobicity, good thermal and solvent stabilities for efficient adsorption and removal of a typical brominated flame retardant tetrabromobisphenol A (TBBPA) from aqueous solution. The adsorption kinetics, isotherms and thermodynamics, effects of pH, ionic strength, humic acid, regeneration and reusability of MONs for TBBPA were studied in detail. The adsorption of TBBPA on MONs followed the pseudo-second-order kinetic and Langmuir adsorption models. Rely on the good π-π and hydrophobic interaction between MONs and TBBPA, a maximum adsorption capacity of 227.3 mg g−1 was realized, which is the largest adsorption capacity for TBBPA among all the reported sorbents up to date now. The large adsorption capacity, rapid adsorption kinetics, good stability and reusability make MONs a highly potential adsorbent for TBBPA removal from aqueous solution. This work may also promote the synthesis and application of MONs in pollutants’ removal.

Facile preparation of magnetic carbon nanotubes@ZIF-67 for rapid removal of tetrabromobisphenol A from water sample.

In this work, a novel magnetic carbon nanotube@zeolitic imidazolate framework-67 (MCNT@ZIF-67) composite was prepared facilely by a one-pot method using Fe3O4@SiO2 as the magnetic element, CNTs as the carbon matrix, and 2-methylimidazole (2-MIM) and cobaltous nitrate (Co(NO3)2·6H2O) as the organic and inorganic elements, respectively. The obtained MCNT@ZIF-67 composite was characterized by transmission electron microscopy (TEM), Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM). Static adsorption experiments demonstrated that the maximum adsorption capacity of MCNTs@ZIF-67 for tetrabromobisphenol A (TBBPA) is 83.23mgg-1, and the sorption isotherm was fitted well by the Freundlich adsorption model. Dynamic adsorption experiments illustrated that the adsorption of TBBPA on MCNTs@ZIF-67 can reach equilibrium in 20min, and the adsorption kinetics of TBBPA were fitted well by a pseudo-second-order kinetic model. The adsorption of TBBPA on MCNTs@ZIF-67 showed favorable selectivity. The pH and the NaCl and NH4Cl common salts did not affect the TBBPA adsorption. Then, the proposed magnetic composite was applied as the adsorbent for the rapid removal of TBBPA in water samples, and the removal ratio of MCNTs@ZIF-67 for TBBPA in different spiked water samples with different volumes was above 95% with RSD < 5%. Furthermore, as a new removal sorbent, the removal reproducibility of MCNTs@ZIF-67 for TBBPA was favorable and stable, with only a 6.0% decrease after 6cycles.

Adsorption characteristics of tetrabromobisphenol A onto sodium bisulfite reduced graphene oxide aerogels

Adsorbent 3-D sodium bisulfite reduced-graphene aerogels (S-rGA) were fabricated via the reduction of graphene oxide. It has high adsorption capacity and excellent reusability for the removal of tetrabromobisphenol A (TBBPA). S-rGA with its unique block and porous network structure was characterized using scanning Electron Microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis. The adsorption characteristics of S-rGA to TBBPA were investigated through batch experiments. In the study, the adsorption kinetics were well described by the pseudo-second-order model. The adsorption equilibrium well fit to the Langmuir model with maximum adsorption capacity of 128.37mg/g. Thermodynamic parameters suggested that the adsorption of TBBPA was exothermic and spontaneous. Fourier transformed infrared (FTIR) spectra indicated that ππ interaction might be consistent with the adsorption of TBBPA by S-rGA. Furthermore, reuse experiments indicated that S-rGA could be regenerated five times with only a slight loss in adsorption capacity. These results demonstrated that S-rGA is potentially an ideal adsorbents for enhancing the adsorption capacity of TBBPA in aqueous environments.

Effects of Cu2 + and humic acids on degradation and fate of TBBPA in pure culture of Pseudomonas sp. strain CDT

Soil contamination with tetrabromobisphenol A (TBBPA) has caused great concerns; however, the presence of heavy metals and soil organic matter on the biodegradation of TBBPA is still unclear. We isolated Pseudomonas sp. strain CDT, a TBBPA-degrading bacterium, from activated sludge and incubated it with 14C-labeled TBBPA for 87 days in the absence and presence of Cu2+ and humic acids (HA). TBBPA was degraded to organic-solvent extractable (59.4%±2.2%) and non-extractable (25.1%±1.3%) metabolites, mineralized to CO2 (4.8%±0.8%), and assimilated into cells (10.6%±0.9%) at the end of incubation. When Cu2+ was present, the transformation of extractable metabolites into non-extractable metabolites and mineralization were inhibited, possibly due to the toxicity of Cu2+ to cells. HA significantly inhibited both dissipation and mineralization of TBBPA and altered the fate of TBBPA in the culture by formation of HA-bound residues that amounted to 22.1%±3.7% of the transformed TBBPA. The inhibition from HA was attributed to adsorption of TBBPA and formation of bound residues with HA via reaction of reactive metabolites with HA molecules, which decreased bioavailability of TBBPA and metabolites in the culture. When Cu2+ and HA were both present, Cu2+ significantly promoted the HA inhibition on TBBPA dissipation but not on metabolite degradation. The results provide insights into individual and interactive effects of Cu2+ and soil organic matter on the biotransformation of TBBPA and indicate that soil organic matter plays an essential role in determining the fate of organic pollutants in soil and mitigating heavy metal toxicity.

Rapid Destruction of Tetrabromobisphenol A by Iron(III)-Tetraamidomacrocyclic Ligand/Layered Double Hydroxide Composite/H2O2 System.

Iron(III)-tetraamidomacrocyclic ligand (Fe(III)-TAML) activators have received widespread attentions for their abilities to activate hydrogen peroxide to oxidize many organic pollutants. In this study, Fe(III)-TAML/layered double hydroxide (LDH) composite was developed by intercalating Fe(III)-TAML into the interlayer of LDH. Electrostatic interaction and hydrogen bonding might account for the adsorption of Fe(III)-TAML on LDH. The newly synthesized Fe(III)-TAML/LDH composite showed superior reactivity as indicated by efficient decomposition of tetrabromobisphenol A (TBBPA) in the presence of hydrogen peroxide, which can be fully degraded within 20 s and the degradation rate increased up to 8 times compared to free Fe(III)-TAML. In addition, the toxicity of the system was significantly reduced after the reaction. The higher reactivity of Fe(III)-TAML/LDH system is attributed to the enhanced adsorption of TBBPA on LDH, which could increase the contact possibility between Fe(III)-TAML and TBBPA. On the basis of the analysis of reaction intermediates, β-scission at the middle carbon atom and C-Br bond cleavage in phenyl ring of TBBPA were involved in the degradation process. Furthermore, our results demonstrated that the Fe(III)-TAML/LDH composite can be reused several times, which could lower the overall cost for environmental implication and render Fe(III)-TAML/LDH as the potential environmentally friendly catalyst for future wastewater treatment under mild reaction conditions.