Tetrabromobisphenol A In Soils Research Articles

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.

Composition, Release, and Transformation of Earthworm Tissue-Bound Residues of Tetrabromobisphenol A in Soil.

Earthworms accumulate organic pollutants to form earthworm tissue-bound residues (EBRs); however, the composition and fate of EBRs in soil remain largely unknown. Here, we investigated the fate of tetrabromobisphenol A (TBBPA)-derived EBRs in soil for 250 days using a 14C-radioactive isotope tracer and the geophagous earthworm Metaphire guillelmi. The EBRs of TBBPA in soil were rapidly transformed into nonextractable residues (NERs), mainly in the form of sequestered and ester-linked residues. After 250 days of incubation, 4.9% of the initially applied EBRs were mineralized and 69.3% were released to extractable residues containing TBBPA and its transformation products (TPs, generated mainly via debromination, O-methylation, and skeletal cleavage). Soil microbial activity and autolytic enzymes of earthworms jointly contributed to the release process. In their full-life period, the earthworms overall retained 24.1% TBBPA and its TPs in soil and thus prolonged the persistence of these pollutants. Our study explored, for the first time, the composition and fate of organic pollutant-derived EBRs in soil and indicated that the decomposition of earthworms may release pollutants and cause potential environmental risks of concern, which should be included in both environmental risk assessment and soil remediation using earthworms.

Persulfate activation with sodium alginate/sulfide coated iron nanoparticles for degradation of tetrabromobisphenol a in soil

The accumulation of tetrabromobisphenol A (TBBPA) in soil posed a serious threat to ecosystem and human health. Sodium alginate/sulfide coated iron nanoparticles (SA@S–Fe NPs) was synthesized by a two-step modification of Fe NPs prepared with tung tree leaves extracting solution, and utilized as a persulfate (PS) activator to degrade TBBPA in soil. Response surface methodology (RSM) optimization showed a theoretical maximum TBBPA degradation reaching 99.79% at the 34.28 °C, SA@S–Fe NPs and PS additions of 3.57 g kg−1 and 36.35 mM, respectively. The degradation mechanism of TBBPA suggested that the main reactive species produced in the SA@S–Fe NPs/PS system were •OH, SO4•−, and O2•−. Proposed mechanisms for the degradation of TBBPA in soil involved debromination, benzene rings split, hydroxylation, demethylation, and complete mineralization to CO2 and H2O. We also further studied the effect to soil physicochemical properties and morphology structure during TBBPA degradation in SA@S–Fe NPs/PS system, which showed that SOM, TN, C/N and TOC slightly reduced, the heavy metals Fe, Cu and Zn still existed in stable residue form, and the soil morphology showed a certain degree of aggregation. Therefore SA@S–Fe NPs/PS technology can effectively degrade soil TBBPA, maintain soil fertility, curb the migration of heavy metals, and environmental risks.

Degradation of TBBPA by nZVI activated persulfate in soil systems

Tetrabromobisphenol A (TBBPA) greatly impacts on ecosystems and human health due to its high environmental toxicity and persistence. Persulfate (PS) advanced oxidation technology to remove organic pollutants in soils has received intense attention. In this study, nanoscale zero-valent iron (nZVI) was synthesized through the borohydride reduction method to explore its activating potential towards PS to accelerate the degradation of TBBPA in soils. The degradation behaviors of TBBPA in soils were investigated by batch experiments. The degradation efficiency of TBBPA (5 mg kg−1) was 78.32% within 12 h under the following reaction conditions: 3 g kg−1 nZVI, 25 mM PS, and pH 5.5 at 25 °C. Notably, PS can be used effectively, and the pH changed slightly in the reaction system. Oxidative degradation of TBBPA is favored at higher temperatures and lower pH values, while it is inhibited when the amount of catalyst increases significantly. The coexisting heavy metal ions such as Zn(II) and Ni(II) inhibit TBBPA degradation, while Cu(II) accelerates the degradation. Radical scavenging and electron spin resonance (ESR) tests further confirmed the generation of SO4·−, ·OH, and O2·− in nZVI activated PS. The intermediates identified by gas chromatograph–mass spectrometry analysis indicated that TBBPA via debromination and the cleavage between the isopropyl group and one of the benzene rings complete degradation. These findings provide new insight into the mechanism of nZVI activation of PS and will promote its application in the degradation of refractory organic compounds.

Nanoscale zero-valent iron/cobalt@mesoporous hydrated silica core–shell particles as a highly active heterogeneous Fenton catalyst for the degradation of tetrabromobisphenol A

Degradation of TBBPA by NZVI/NZVC@mHS CSP/H 2 O 2 heterogeneous Fenton system. • Synthesis of NZVI/NZVC@mHS CSP materials by one-pot method. • The core–shell structure of the material reduced aggregation and increased the specific surface area. • The mesoporous network structure effectively prevented the leaching of Co (II). • NZVI/NZVC@mHS CSP efficiently degraded TBBPA as Fenton-like catalyst. While the bimetal heterogeneous Fenton system degraded organic pollutants, the leaching of heavy metals caused secondary pollution. To resolve this problem, nanoscale zero-valent iron/cobalt@mesoporous hydrated silica core–shell particles (NZVI/NZVC@mHS CSP) were synthesized as a novel Fenton-like catalyst for the rapid degradation of Tetrabromobisphenol A (TBBPA). The performance of NZVI/NZVC@mHS CSP in the degradation of TBBPA and the mechanism of their action were investigated through scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. NZVI/NZVC@mHS CSP exhibited a regular spherical shape with a surface area (115.44 m 2 ·g −1 ) that was 5 times more than that of the ordinary NZVI/NZVC (23.59 m 2 ·g −1 ). The core of NZVI/NZVC was covered with a hydrated silica shell that formed a mesoporous network that effectively prevented the leaching of cobalt ions from the core. The best catalytic performance of NZVI/NZVC@mHS CSP was obtained by optimizing the iron-to-cobalt ratio, H 2 O 2 concentration, and the dosage of the catalyst. The optimized NZVI/NZVC@mHS CSP exhibited the greatest mineralization activity (97.13%) for TBBPA removal than those in NZVI/NZVC bimetal (84.49%) and pure NZVI/NZVC@mHS CSP (59.37%). Thus, our results demonstrated that NZVI/NZVC@mHS CSP exhibited excellent reactivity in potential application as a highly active heterogeneous Fenton catalyst for degradation of TBBPA in soil and groundwater.

Spatial distribution, source identification, and anthropogenic effects of brominated flame retardants in nationwide soil collected from South Korea.

Soil samples were collected at 61 sites of the national monitoring network for persistent organic pollutants (POPs) in South Korea. The target compounds were brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), hexabromocyclododecanes (HBCDDs), and tetrabromobisphenol A (TBBPA). The mean concentrations of Σ27 PBDEs, Σ3 HBCDDs, and TBBPA in soil were 222, 17.2, and 4.4ng/g, respectively, but PBBs were not detected. Industrial sites had statistically higher BFR concentrations than suburban sites but no significant difference compared with urban sites. The commercial deca-BDE mixtures were the most likely source of PBDE contamination in the soil samples, with the minor influence of commercial penta-BDE and octa-BDE mixtures. The profiles of HBCDDs in most soil samples differed from those in the powder types of technical HBCDD mixtures, indicating that they are affected by the HBCDDs contained in commercial products and the conversion of HBCDD diastereoisomers (γ-HBCDD to α-HBCDD) in the environment. The concentrations of Σ27 PBDEs, Σ3 HBCDDs, and TBBPA were significantly correlated with population density, gross domestic product, and the number of companies (p<0.01), indicating a direct impact of anthropogenic activities. Significant correlations among BFRs were determined (0.63<r<0.74, p<0.01), suggesting that these pollutants had similar sources. Relatively good correlations (0.44<r<0.98, p<0.01) between BDE-209 and other light BDEs (except for BDE-71, -77,-126,-156, and-205) might result from the degradation of heavy BDEs under anaerobic and natural sunlight conditions. To the best of our knowledge, this study provides the most comprehensive soil monitoring data for various BFRs in South Korea. Furthermore, it is the first report on soil contamination by deca-BDE, HBCDDs, and TBBPA in South Korea.

The effects of prosperity indices and land use indicators of an urban conurbation on the occurrence of hexabromocyclododecanes and tetrabromobisphenol A in surface soil in South China

Hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) are legacy brominated flame retardants which are still produced and used in China. In this study, 187 surface soils from the Pearl River Delta (PRD) urban conurbation in China were collected, and the effects of urban conurbation development on the concentrations, distributions and human exposure risk of HBCDs and TBBPA were investigated. The concentration ranges of Σ3HBCD (sum of α-, β-, and γ-HBCD) and TBBPA in soil were below the limit of quantification (<LOQ) to 300 ng g−1 dry weight (dw) and < LOQ to 53.1 ng g−1 dw, respectively. Concentration levels of HBCDs and TBBPA in the PRD were affected both by distributions of land-use type and by the location of the city. Soils from residential areas contained the highest concentrations of Σ3HBCD (median: 1.75 ng g−1 dw) and TBBPA (1.92 ng g−1 dw) among all land-use types. In addition, soils from the central PRD had higher Σ3HBCD and TBBPA levels (0.46 and 0.90 ng g−1 dw) than those from the surrounding areas (0.17 and 0.07 ng g−1 dw). The concentrations of Σ3HBCD and TBBPA were highly correlated with urbanization level, population density, regional GDP and per capita income in all cities studied (p < 0.01), which indicates that the prosperity of the urban conurbation may play an important role in soil contamination of HBCDs and TBBPA in the PRD. Children living in residential areas had the highest estimated daily intakes of Σ3HBCD (7.09 pg kg−1 d−1) and TBBPA (7.76 pg kg−1 d−1), suggesting that people living in residential areas have a relatively higher exposure risk of HBCDs and TBBPA. This is a comprehensive study to report the effects of prosperity indices and land use indicators of an urban conurbation on the occurrence of HBCDs and TBBPA in soil in China.

Tetrabromobisphenol A alters soil microbial community via selective antibacterial activity

Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardant. Most studies regarding TBBPA have concentrated on its occurrence, distribution, toxicity and degradation in the environment. However, little is known about its ecological effects on soil microbial communities. In this study, we investigated the effect of TBBPA on soil microbial community. Overall, the data suggested that the growth and composition of soil microorganisms were correlated to the TBBPA concentration and exposure time. Phospholipid-derived fatty acid analysis (PLFAs) showed that significant microbial growth inhibitions were 46.1% and 46.9% in 40 mg/kg TBBPA-treated soils after 45-day incubation under aerobic and anaerobic conditions, respectively. Results of PLFAs and llumina sequencing indicated that TBBPA mainly inhibited Gram-positive bacteria, but not Gram-negative bacteria. The selective antibacterial activity of TBBPA toward Gram-positive bacteria was further confirmed in pure bacteria cultures. These data suggested that, in addition to their effect on microbial growth and composition, TBBPA may affect the microbial ecology. Additional research should be carried out to identify the ecological risk of TBBPA in soil.

Effects of the earthworm Metaphire guillelmi on the mineralization, metabolism, and bound-residue formation of tetrabromobisphenol A (TBBPA) in soil

Tetrabromobisphenol A (TBBPA) is one of the most widely used brominated flame retardants worldwide. The degradation and fate of this organic pollutant of soils is of great concern and can be strongly affected by geophagous earthworms through ingestion and burrowing activities. Using 14C-tracers, we studied the effects of the geophagous earthworm Metaphire guillelmi on the mineralization, metabolism, and bound-residue formation of TBBPA in a typical Chinese rice paddy soil during 30days of incubation in the laboratory. Earthworms significantly decreased both mineralization (from 3.9±0.3% of the initial amount to 2.6±0.2%) and dissipation (from 90.6±0.6% to 84.1±1.2%) of TBBPA in the soil, and stimulated the generation of O-methylation metabolites (TBBPA methyl ethers; from 1.4±0.4% to 15.4±0.6%). This resulted in a strong decrease in bound-residue formation of TBBPA and its metabolites in the soil (from 80.3±0.4% to 41.8±3.1%). Results from a first-order, two-compartment model that describes the fate of TBBPA in soil indicated that the TBBPA-derived bound residues were mainly attributed to the binding of metabolites to the soil matrix and not to the binding of TBBPA, and that earthworms reduced the kinetic rates of both polar metabolite generation and their bound-residue formation. Our results suggested that the geophagous earthworm Metaphire guillelmi strongly influenced the fate of TBBPA by altering the composition of metabolites and therefore bound-residue formation. The increased persistence of TBBPA and the formation of persistent O-methylation metabolites by M. guillelmi would increase the environmental risk of TBBPA.

Insights into tetrabromobisphenol A adsorption onto soils: Effects of soil components and environmental factors

Concerns regarding tetrabromobisphenol A (TBBPA), the most widely utilized brominated flame retardant in the world, are growing because of the wide application and endocrine-disrupting potential of this compound. To properly assess its environmental impacts, it is important to understand the mobility and fate of TBBPA in soil environments. In this study, the effects of soil components, dissolved organic carbon (DOC) and heavy metal cations on TBBPA adsorption onto two Chinese soils (red soil and black soil) were investigated using batch sorption experiments. The desorption behavior of TBBPA when the two soils are irrigated with eutrophicated river water was also investigated. The results showed that pH greatly affects the adsorptive behavior of TBBPA in soils. Iron oxide minerals and phyllosilicate minerals are both active surfaces for TBBPA sorption, in addition to soil organic matter (SOM). DOC (50mgOCL−1) exhibited a limited effect on TBBPA sorption only under neutral conditions. TBBPA sorption was only minimally affected by the heavy metals (Cu2+, Pb2+ and Cd2+) in the studied pH range. Eutrophicated river water significantly enhanced the desorption of TBBPA from red soil due to the change in soil solution pH. These findings indicate that mobility of TBBPA in soils is mainly associated with soil pH, organic matter and clay fractions: it will be retained by soils or sediments with high organic matter and clay fractions under acidic conditions but becomes mobile under alkaline conditions.

Degradation, Metabolism, and Bound-Residue Formation and Release of Tetrabromobisphenol A in Soil during Sequential Anoxic–Oxic Incubation

Tetrabromobisphenol A (TBBPA) is one of the most commonly used flame retardants and has become an environmental contaminant worldwide. We studied the fate of (14)C-labeled TBBPA in soil under static anoxic (195 days) and sequential anoxic (125 days)-oxic (70 days) conditions. During anoxic incubation, TBBPA dissipated with a half-life of 36 days, yielding four debromination metabolites: bisphenol A (BPA) and mono-, di-, and tribrominated BPA. At the end of anoxic incubation, all four brominated BPAs completely disappeared, leaving BPA (54% of initial TBBPA) as the sole detectable organic metabolite. TBBPA dissipation was accompanied by trace mineralization (<1.3%) and substantial bound-residue formation (35%), probably owing to chemical binding to soil organic matter. Subsequent oxic incubation was effective in degrading accumulated BPA (half-life 11 days) through mineralization (6%) and bound-residue formation (62%). However, 42% of the anoxically formed bound residues was released as TBBPA and lower brominated BPAs, which were then persistent during oxic incubation. Our results provide the first evidence for release of bound residues during alteration of the redox environment and indicate that sequential anoxic-oxic incubation approaches-considered effective in remediation of environments containing halogenated xenobiotics-do not completely remove xenobiotics from environmental matrices.

Adsorption of tetrabromobisphenol A on soils: Contribution of soil components and influence of soil properties

The adsorption of tetrabromobisphenol A (TBBPA) on several typical Chinese soils and soil mineral and organic components were comprehensively investigated in the present study. The adsorption isotherms were well described by the Freundlich equation and the corresponding adsorption capacity constant Kf ranged from 2.46 to 357.30L/kg and 16.52 to 136,731.98L/kg for the original soils and the soil components, respectively. Correlation analysis between the adsorption capacity and soil properties indicates that soil pH and soil organic carbon (SOC) content were the predominant factors determining TBBPA adsorption on the soils. At constant pH of 7.0, the soils with higher SOC content exhibited stronger adsorption affinity for TBBPA, suggesting the significant importance of SOC in the adsorption. The adsorption affinity of TBBPA became weaken for a given soil with increasing pH due to the enhanced electrostatic repulsion between the anionic TBBPA species and soil surface. Humins and black carbon of SOC played a predominant role in while soil minerals contributed slightly to the adsorption of TBBPA on the soils. The results of this study will provide a better understanding of the behaviors of TBBPA in soils.

Toxicity of three halogenated flame retardants to nitrifying bacteria, red clover ( Trifolium pratense), and a soil invertebrate ( Enchytraeus crypticus)

Halogenated flame retardants have a high sorption affinity to particles, making soils and sediments important sinks. Here, three of the most commonly used flame retardants have been tested for sub-lethal toxicity towards soil nitrifying bacteria, a terrestrial plant (seed emergence and growth of the red clover, Trifolium pratense), and a soil invertebrate (survival and reproduction of Enchytraeus crypticus). Tetrabromobisphenol A (TBBPA) was quite toxic to enchytraeids, with significant effects on reproduction detected already at the 10 mg kg −1 exposure level (EC 10 = 2.7 mg kg −1). In contrast, decabromodiphenyl ether (DeBDE) was not toxic at all, and short-chain chloroparaffins (CP 10–13) only affected soil nitrifying bacteria at the highest test concentration (EC 10 = 570 mg kg −1). Exposure concentrations were verified by chemical analysis for TBBPA and DeBDE, but not for CP 10–13, as a reliable method was not available. Based on the generated data, a PNEC for soil organisms can be estimated at 0.3 mg kg −1 for TBBPA and 57 mg kg −1 for short-chain chloroparaffins. No PNEC could be estimated for DeBDE. Measurements of TBBPA in soil are not available, but measured concentrations in Swedish sludge are all lower than the estimated threshold value for biological effects in soil.