Efficient degradation of organic pollutants using peroxydisulfate activated by magnetic carbon nanotube.

The magnetic composite of Fe3O4 and carbon nanotube (MCNT) was fabricated in a facile one-pot solvothermal method and employed to activate peroxydisulfate (PDS) for degradation of Rhodamine B (RhB) and other pollutants. The effects of operational factors including MCNT dosage and PDS dosage were studied, and high removal efficiencies of 84.2-99.5% were achieved for these pollutants with 0.3 g/L MCNT and 4 mM PDS. The effects of environmental factors including initial pH, inorganic cations, inorganic anions, humic acid and water matrix were also studied. Reusability test showed that the removal efficiency declined in four consecutive runs, which was attributed to the adsorbed oxidation products on the catalyst surface. Based on quenching experiments, solvent exchange (H2O to D2O), inductively coupled plasma and open circuit potential tests, it was concluded that radicals of ·OH/SO4·- and the non-radical electron-transfer pathway were involved in the MCNT/PDS system, and the contributions of O2·-, 1O2, high-valent iron-oxo species and homogenous activation were insignificant. Moreover, the orbital-weighted Fukui functions of RhB were calculated by density functional theory, and its plausible degradation pathway was proposed based on the calculation results. Finally, toxicity evaluation of the degradation products was performed in the quantitative structure-activity relationship approach.

The CD68+ macrophages to CD8+ T-cell ratio is associated with clinical outcomes in hepatitis B virus (HBV)-related hepatocellular carcinoma.

BACKGROUND: Tumor microenvironment plays an essential role during the progression of hepatocellular carcinoma (HCC). Tumor infiltrating immune cells (TILs) was an important component of tumor microenvironment. However, whether TIL features are correlated with the prognosis of HCC patients remains unclear. METHODS: Cancer tissue and paired paracancerous tissues from 220 stage II∼III HBV-related HCC patients were collected. TILs were analyzed using a tyramide signal amplification system combined with immunohistochemistry. Kaplan-Meier survival analysis was conducted to investigate the associations between the prognosis and the infiltrating pattern of TILs. RESULTS: The patients were classified into three distinct subgroups (Clusters (C)1-3) with different overall survival (OS) and disease-free survival (DFS) according to the distribution pattern of TILs. The CD68/CD8 ratio in the cancer SA was correlated with the prognosis. Patients with a higher CD68/CD8 ratio exhibited poorer OS and DFS than those with a lower ratio. The CD68/CD8 ratio in the cancer SA was an independent factor for OS prediction but not DFS. CONCLUSION: CD68+ macrophages and CD8+ T-cells are essential immunological determinants for HBV-related HCC prognosis, and the CD68/CD8 ratio in cancer SA is a novel, prognostic factor for OS prediction in HBV-related HCC patients.

Aggregation behavior of aqu/nC60 produced via extended mixing: Influence of sunlight and agitation intensity.

Aggregation of C60, as an important process governing its mobility and toxicity, has been quantitatively investigated. However, effects of sunlight and agitation intensity on the aggregation behavior of aqu/nC60 produced via extended mixing, have not been clarified. Therefore, in the present study, the aggregation behavior of aqu/nC60 produced at 500 and 800 rpm in the absence and presence of sunlight was investigated. Aggregation with increasing concentrations could be accelerated, while changes of Zave and zeta potential were not obvious. Critical coagulation concentrations (CCCs) of aqu/nC60 obtained at 800 rpm in the absence/presence of sunlight and that at 500 rpm under sunlight were 330, 205 and 170 mM NaCl, and 10.0, 2.6 and 3.1 mM CaCl2, respectively. These CCCs indicated that the aqu/nC60 prepared by the extended mixing were more stable than those produced by other methods. Salt-induced aggregation occurred more easily for aqu/nC60 formed under sunlight than that formed in the dark. Extra surface oxidation induced by high agitation intensity remarkably increased the stability of aqu/nC60 in NaCl solutions. In contrast, in CaCl2 solutions, aqu/nC60 formed at high agitation intensity had similar stability or even inadequate stability to that obtained at low agitation intensity due to the charge neutralization and cross-link bridging.

Parental exposure to heavy fuel oil induces developmental toxicity in offspring of the sea urchin Strongylocentrotus intermedius.

The present study investigated the toxic effects of parental (maternal/paternal) exposure to heavy fuel oil (HFO) on the adult reproductive state, gamete quality and development of the offspring of the sea urchin Strongylocentrotus intermedius. Adult sea urchins were exposed to effluents from HFO-oiled gravel columns for 7 days to simulate an oil-contaminated gravel shore, and then gametes of adult sea urchins were used to produce embryos to determine developmental toxicity. For adult sea urchins, no significant difference in the somatic size and weight was found between the various oil loadings tested, while the gonad weight and gonad index were significantly decreased at higher oil loadings. The spawning ability of adults and fecundity of females significantly decreased. For gametes, no effect was observed on the egg size and fertilization success in any of the groups. However, a significant increase in the percentage of anomalies in the offspring was observed and then quantified by an integrative toxicity index (ITI) at 24 and 48 h post fertilization. The offspring from exposed parents showed higher ITI values with more malformed embryos. The results confirmed that parental exposure to HFO can cause adverse effects on the offspring and consequently affect the recruitment and population maintenance of sea urchins.

Accurate Measurements of Wall Shear Stress on a Plate with Elliptic Leading Edge.

A micro-floating element wall shear stress sensor with backside connections has been developed for accurate measurements of wall shear stress under the turbulent boundary layer. The micro-sensor was designed and fabricated on a 10.16 cm SOI (Silicon on Insulator) wafer by MEMS (Micro-Electro-Mechanical System) processing technology. Then, it was calibrated by a wind tunnel setup over a range of 0 Pa to 65 Pa. The measurements of wall shear stress on a smooth plate were carried out in a 0.6 m × 0.6 m transonic wind tunnel. Flow speed ranges from 0.4 Ma to 0.8 Ma, with a corresponding Reynold number of 1.05 × 106~1.55 × 106 at the micro-sensor location. Wall shear stress measured by the micro-sensor has a range of about 34 Pa to 93 Pa, which is consistent with theoretical values. For comparisons, a Preston tube was also used to measure wall shear stress at the same time. The results show that wall shear stress obtained by three methods (the micro-sensor, a Preston tube, and theoretical results) are well agreed with each other.

Toxicity of Water-Accommodated Fractions (WAF), Chemically Enhanced WAF (CEWAF) of Oman Crude Oil and Dispersant to Early-Life Stages of Zebrafish (Danio rerio).

This study focused on comparing the lethal and sublethal toxicity of water-accommodated fractions (WAF) and chemically enhanced WAF (CEWAF) of crude oil to zebrafish (Danio rerio) on early life stages (ELS). Results showed that the addition of GM-2 dispersant caused an increase in the levels of total petroleum hydrocarbons (TPHs) and total priority polycyclic aromatic hydrocarbons (ΣPAHs). Based on ΣPAHs, the LC20 estimates for WAF and CEWAF were 4.88 µg L-1 and 1.19 µg L-1, respectively, indicating that CEWAF was approximately four times more toxic. CEWAF exposure caused markedly lower hatching rates and higher malformation frequencies than WAF. Meanwhile, the general morphology score (GMS) values in CEWAF were about fourfold lower than that in WAF, indicating that CEWAF exposure induced more significant developmental delay. The results suggested that chemical dispersant enhanced the toxicity of crude oil to zebrafish on ELS and its application could increase the exposure of fishes to crude oil.

Circulating Hepatocellular Cells are a Bad Prognostic Factor for HCC Patients.

BACKGROUND/AIMS: Circulating hepatocellular carcinoma cells (CHCCs) may be detected by reverse transcription-polymerase chain reaction (RT-PCR). We investigated the relationship between CHCCs and hepatoma patients' survival period after different managements. METHODOLOGY: Peripheral blood (5 ml) samples were obtained from 93 patients with hepatocellular carcinoma (HCC), and from 33 control subjects (9 with liver cirrhosis after hepatitis B, 14 with chronic hepatitis B, 10 with healthy people) between January 1st, 2009 and December 31, 2012. To detect CHCCs in peripheral blood, alpha-fetoprotein (AFP) messenger RNA (mRNA) was amplified from total RNA extracted from whole blood by RT-PCR. RESULTS: AFPmRNA was detected in 49 blood samples from the HCC patients (49/93, 53.0%). In contrast, there were no clinical control subjects whose samples showed detectable AFPmRNA. The presence of AFPmRNA in blood seemed to be correlated with the tumor stage (by TNM classification) of HCC, the serum AFP value, and the presence of intrahepatic metastasis, portal vein thrombosis, tumor diameter and/or distant metastasis. CONCLUSIONS: The presence of AFP mRNA in peripheral blood may be an indicator of CHCCs, which might predict hematogenous spreading metastasis in patients with HCC and may be as a bad prognostic factor for HCC patients.

Efficient removal of organic pollutants by activation of peroxydisulfate with the magnetic CoFe2O4/carbon nanotube composite.

A magnetic composite of CoFe2O4 and carbon nanotube (CNT) was prepared using the solvothermal approach and then employed for the activation of peroxydisulfate (PDS) to degrade reactive black 5 (RB5) and other organic pollutants. Characterization results of the composite catalyst revealed the successful loading of spherical CoFe2O4 particles on CNTs, possessing abundant porosity as well as magnetic separation capability. Under the degradation conditions of 0.2 g/L CoFe2O4-CNT dosage and 4 mM PDS dosage, the removal efficiencies of 10 mg/L RB5 and other pollutants were in the range of 94.5 to ~ 100%. The effects of pH, co-existing ions/humic acid, and water matrices as well as the reusability of the catalyst were also investigated in detail. Furthermore, the degradation mechanism and pathway were proposed based on quenching experiments, LC-MS analysis, and density functional theory (DFT) calculations, and the toxicity of the degradation products was evaluated in the quantitative structure-activity relationship approach.

Clinical Significance of HHLA2 as a Novel Therapeutic Target for Colorectal Cancer.

BACKGROUND: Colorectal cancer (CRC) is a high-indence malignance of the digestive system with a high mortality rate in the world. AIM: The results are desired to provide an important theoretical basis for discovering new therapeutic targets for CRC. OBJECTIVE: The expression of human endogenous retrovirus-H-long terminal repeat association protein 2 (HHLA2) in human CRC was detected to explore its correlationship with clinicopathological features and prognosis of patients and its potential in treating CRC. METHODS: Western blot was employed to detect HHLA2 expression in fresh tissues obtained from 6 CRC patients' excisions, including cancer, paracancer, and normal issues. Immunohistochemical staining was employed to determine HHLA2 expression in paraffin-embedded specimens of 139 patients with colorectal cancer, and its relationship with the clinicopathological profiles and survival was analyzed. Small interfering RNA (siRNA) targeting HHLA2 was used to transfect CRC cells to silent HHLA2. MTT, plate colony formation, cell scratch, and Transwell assay were conducted to observe the proliferation, migration, and invasion of CRC cells. RESULTS: HHLA2 protein was expressed in human colorectal cancer tissues, paracancer tissues and normal tissues, which was significantly upregulated in cancer tissues (P<0.01). HHLA2 expression level in CRC tissues showed a close correlationship with the invasion depth of the tumor (P=0.000), metastasis of regional lymph nodes (P=0.018), clinical stage (P=0.010), and patient survival (P=0.011). Correlation with gender (P=0.873), age (P=0.864), location of the tumor (P=0.768), degree of tumor differentiation (P=0.569) and distant metastasis (P=0.494) exhibited no significance. The survival time of CRC patients with high and low HHLA2 expression groups was 43.231 months and 55.649 months, respectively, with a statistical difference between the two groups (P=0.001). Silencing HHLA2 inhibited proliferation, migration and invasion of CRC cells significantly. CONCLUSION: HHLA2 is overexpressed in CRC tissues which is associated with poor prognosis of patients. HHLA2 might be recognized as a new candidate for adjuvant diagnosis and prognosis of CRC, as well as a promised new target for immunotherapy of CRC.

Thyroid disrupting effects and the developmental toxicity of hexafluoropropylene oxide oligomer acids in zebrafish during early development.

As perfluorooctanoic acid (PFOA) alternatives, hexafluoropropylene oxide dimeric acid (HFPO-DA) and hexafluoropropylene oxide trimeric acid (HFPO-TA) have been increasingly used and caused considerable water pollution. However, their toxicities to aquatic organisms are still not well known. Therefore, in this study, zebrafish embryos were exposed to PFOA (0, 1.5, 3 and 6 mg/L), HFPO-DA (0, 3, 6 and 12 mg/L) and HFPO-TA (0, 1, 2 and 4 mg/L) to comparatively investigate their thyroid disrupting effects and the developmental toxicity. Results demonstrated that waterborne exposure to PFOA and its two alternatives decreased T4 contents, the heart rate and swirl-escape rate of zebrafish embryos/larvae. The transcription levels of genes related to thyroid hormone regulation (crh), biosynthesis (tpo and tg), function (trα and trß), transport (transthyretin, ttr), and metabolism (dio1, dio2 and ugt1ab), were differently altered after the exposures, which induced the thyroid disrupting effects and decreased the heart rate. In addition, the transcription levels of some genes related to the nervous system development were also significantly affected, which was associated with the thyroid disrupting effects and consequently affected the locomotor activity of zebrafish. Therefore, HFPO-DA and HFPO-TA could not be safe alternatives to PFOA. Further studies to uncover the underlying mechanisms of these adverse effects are warranted.

Metabolic disturbance of short- and medium-chain chlorinated paraffins to zebrafish larva.

Chlorinated paraffins (CPs) are widely produced chemicals. Short-chain CPs (SCCPs) and medium-chain CPs (MCCPs) were listed as Persistent Organic Pollutants (POPs) and candidate POPs under the Stockholm Convention, respectively. The present study explored the developmental toxicity and metabolic disruption caused by SCCPs and MCCPs in zebrafish (Danio rerio) larvae. CPs exposure at environmentally relevant levels caused no obvious phenotypic changes with zebrafish larvae except that the body length shortening was observed after exposure to CPs at 1-200 µg/L for 7 day post fertilization. A further metabolomic approach was conducted to explore the early biological responses of developmental toxicity induced by CPs at low dose (1, 5, and 10 µg/L). The results of metabolic disorder, pathway analysis and chronic values indicated that, compared with SCCPs, MCCPs exhibited more risks to zebrafish larvae at low doses. Lipid metabolism was markedly affected in SCCPs exposure group, whereas MCCPs primarily disturbed lipid metabolism, amino acid, and nucleotide metabolisms. Compare with SCCPs, the relatively higher lipid solubility, protein affinity and metabolic rate of MCCPs can probably explain why MCCP-mediated metabolic disruption was significantly higher than that of SCCP. Notably, SCCPs and MCCPs have the same potential to cause cancer, but no evidence indicates the mutagenicity. In summary, our study provides insight into the potential adverse outcome for SCCP and MCCP at low doses.

Combined effects of PFOS and PFOA on zebrafish (Danio rerio) embryos.

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are two kinds of emerging contaminants most studied in recent years. However, there is limited information about their combined toxicity to aquatic organisms. In the present study, the single and combined toxicity of PFOA and PFOS to zebrafish (Danio rerio) embryos were investigated. PFOS was more toxic than PFOA for the single toxicity. In four mixtures, PFOS and PFOA showed complex interactive effects that changed from additive to synergistic effect, then to antagonistic effect, and at last turnover to synergic effect again, with increased molar ratios of PFOS. Neither the concentration-addition model nor the independent-action model could predict the combined effects when strong interactive effects existed. Although the interactive effects of PFOS and PFOA affected their combined toxicity, the trend of mixture toxicity still showed an increase with increasing molar ratios of PFOS in the mixture.

Polystyrene microplastics alleviate adverse effects of benzo[a]pyrene on tissues and cells of the marine mussel, Mytilus galloprovincialis.

As two major ubiquitous pollutants, microplastics (MPs) and polycyclic aromatic hydrocarbons (PAHs) coexist in the marine environment. However, the role of MPs in altering the toxicity of PAHs to marine organisms is poorly understood. We therefore investigated the accumulation and toxicity of benzo[a]pyrene (B[a]P, 0.4 nM), in the marine mussel Mytilus galloprovincialis over a 4-day of exposure with or without the presence of 10 µm polystyrene microplastics (PS MPs) (10 particles/mL). The presence of PS MPs significantly decreased B[a]P accumulation in soft tissues of M. galloprovincialis by approximately 6.7%. Single exposure of PS MPs or B[a]P decreased the mean epithelial thickness (MET) of digestive tubules and enhanced reactive oxygen species (ROS) levels in haemolymph, while upon co-exposure the adverse impacts were alleviated. Real-time q-PCR results showed that most selected genes involved in stress response (FKBP, HSP90), immune (MyD88a, NF-κB) and detoxification (CYP4Y1) were induced for both single exposure and co-exposure. The co-presence of PS MPs down-regulated the mRNA expression of NF-κB in gills compared with of B[a]P alone. The uptake and toxicity reductions of B[a]P might result from the decrease of its bioavailable concentrations caused by the adsorption of B[a]P by PS MPs and the strong affinity of B[a]P to PS MPs. Adverse outcomes for the co-existence of marine emerging pollutants under long-term conditions remain to be further validated.

Different Life-Stage Exposure to Hexafluoropropylene Oxide Trimer Acid Induces Reproductive Toxicity in Adult Zebrafish (Danio rerio).

As a novel alternative to perfluorooctanoic acid (PFOA), hexafluoropropylene oxide trimer acid (HFPO-TA) has been widely used and has caused ubiquitous water pollution. However, its adverse effects on aquatic organisms are still not well known. In the present study, zebrafish at different life stages were exposed to 0, 5, 50, and 100 µg/L of HFPO-TA for 21 days to investigate reproductive toxicity in zebrafish. The results showed that HFPO-TA exposure significantly inhibited growth and induced reproductive toxicity in zebrafish, including a decrease of the condition factor, gonadosomatic index, and the average number of eggs. Histological section observation revealed that percentages of mature oocytes and spermatozoa were reduced, while those of primary oocytes and spermatocytes increased. In addition, exposure to HFPO-TA at three stages induced a significant decrease in the hatching rate, while the heart rate and normal growth rate of F1 offspring were only significantly inhibited for the exposure from fertilization to 21 days postfertilization (dpf). Compared with the exposure from 42 to 63 dpf, the reproductive toxicity induced by HFPO-TA was more significant for the exposure from fertilization to 21 dpf and from 21 to 42 dpf. Expression of the genes for cytochrome P450 A1A, vitellogenin 1, estrogen receptor alpha, and estrogen receptor 2b was significantly up-regulated in most cases after exposure to HFPO-TA, suggesting that HFPO-TA exhibited an estrogen effect similar to PFOA. Therefore, HFPO-TA might disturb the balance of sex steroid hormones and consequently induce reproductive toxicity in zebrafish. Taken together, the results demonstrate that exposure to HFPO-TA at different life stages could induce reproductive toxicity in zebrafish. However, the underlying mechanisms deserve further investigation. Environ Toxicol Chem 2023;42:2490-2500. © 2023 SETAC.

Toxicity of polyfluorinated and perfluorinated compounds to lettuce (Lactuca sativa) and green algae (Pseudokirchneriella subcapitata).

Recently, polyfluorinated and perfluorinated compounds (PFCs) have been detected in most surface waters around the world. Because some PFCs are persistent and tend to accumulate in surface waters, their potential adverse effects to aquatic organisms have received increasing attention. Nevertheless, currently available toxicity information is limited. The aim of this study was to evaluate the toxicity effects of seven PFCs on root elongation of lettuce (Lactuca sativa) and photosynthesis of green algae (Pseudokirchneriella subcapitata). It was found that the toxicity profiles of both species tested were similar and had good relations with the fluorinated carbon-chain length of the PFCs investigated. One of the compounds tested, perfluorobutanoic acid, was found to be more toxic than expected in the algae test, which may be related with acidification of the test solution. It was concluded that because short-chained PFCs are becoming the predominant PFC pollutants in surface waters, their long-term toxicity and mixture toxicity with other PFCs should be studied in greater detail.

Magnetic graphene oxide for methylene blue removal: adsorption performance and comparison of regeneration methods.

A series of Fe3O4-graphene oxide (GO) composite materials (MGOs) with abundant surface area, rich oxygen-containing functional groups, and magnetic properties were prepared in a facile coprecipitation method and then employed for the adsorptive removal of methylene blue (MB) from water. The kinetic data were better fitted in the pseudo-second-order model than in the pseudo-first-order model, and the intraparticle diffusion model revealed the two-step diffusion process including diffusion in the boundary layer and in the porous structures. The maximum adsorption amounts of MB were calculated to be 37.5-108 mg/g at 25 °C and pH 9 using the Langmuir isotherm model. Thermodynamic study showed that the adsorption process was spontaneous, with ΔH° of 23.0-49.6 kJ/mol and ΔS° of 131-249 J∙mol-1∙K-1. The adsorption amount of MB increased with pH in the range of 4-10. Inorganic ions including Na+ and Ca2+ suppressed the adsorption of MB, and the more pronounced impact of Ca2+ was ascribed to its higher valence state. The cetyltrimethylammonium bromide (CTAB) surfactant showed a stronger inhibitory effect than Ca2+. The adsorption mechanism was proposed to be a combination of electrostatic interactions, hydrophobic adsorption, and electron donor-acceptor interactions. Two methods were used for the regeneration of spent MGO, and the results showed that the peroxomonosulfate (PMS) oxidation method was more favorable than the acid washing method, considering the better regeneration ability and lower amount of washing water used. Finally, the reaction mechanism of PMS oxidation was analyzed based on quenching tests and in situ open circuit potential measurements, which proved that OH and 1O2 played dominant roles and that the fine adsorption ability of MGO promoted the reaction between them and MB.

Fabrication of Co3O4-Bi2O3-Ti catalytic membrane for efficient degradation of organic pollutants in water by peroxymonosulfate activation.

In this study, a functionalized Co3O4-Bi2O3-Ti catalytic membrane (CBO-Ti-M) was prepared and applied for removing organic pollutants via activating peroxymonosulfate (PMS) in the dead-end filtration mode. Characterizations including scanning electron microcopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) showed that the Co3O4-Bi2O3 catalyst was successfully supported on the Ti membrane. The CBO-Ti-M /PMS system could efficiently remove various organic pollutants such as sulfamethoxazole, methyl orange, bisphenol A and methylene blue, achieving removal efficiencies of 98.0%-99.5%. The effects of PMS concentration, flow rate and solution environment on degradation efficiency were investigated in detail. Furthermore, quenching experiments, electron spin resonance (ESR) and in-situ open circuit potential (OCP) tests collectively demonstrated that singlet oxygen as well as the non-radical electron transfer pathway mainly contributed in the reaction mechanism. The synergistic effect of Co and Bi was illustrated according to XPS results, and the possible degradation pathway of MB was proposed based on LC-MS analysis. Reusability test showed that pollutant removal efficiency with the CBO-Ti-M /PMS system remained stable in four runs and limited metal leaching was observed.

Efficient degradation of organic dyes using peroxymonosulfate activated by magnetic graphene oxide.

Magnetic graphene oxide (MGO) was prepared and used as a catalyst to activate peroxymonosulfate (PMS) for degradation of Coomassie brilliant blue G250 (CBB). The effects of operation conditions including MGO dosage, PMS dosage and initial concentration of CBB were studied. CBB removal could reach 99.5% under optimum conditions, and high removals of 98.4-99.9% were also achieved for other organic dyes with varied structures, verifying the high efficiency and wide applicability of the MGO/PMS catalytic system. The effects of environmental factors including solution pH, inorganic ions and water matrices were also investigated. Reusability test showed that CBB removals maintained above 90% in five consecutive runs, indicating the acceptable recyclability of MGO. Based on quenching experiments, solvent exchange (H2O to D2O) and in situ open circuit potential (OCP) test, it was found that ˙OH, SO4˙- and high-valent iron species were responsible for the efficient degradation of CBB in the MGO/PMS system, while the contributions of O2˙-, 1O2 and the non-radical electron-transfer pathway were limited. Furthermore, the plausible degradation pathway of CBB was proposed based on density functional theory (DFT) calculations and liquid chromatography-mass spectrometry (LC-MS) results, and toxicity variation in the degradation process was evaluated by computerized structure-activity relationships (SARs) using green algae, daphnia, and fish as indicator species.

Blue TiO2 nanotube electrocatalytic membrane electrode for efficient electrochemical degradation of organic pollutants.

In this study, a Ti3+-doped TiO2 porous membrane (Blue TiO2/Ti) was fabricated and employed for electrochemical degradation of organic pollutants in the single-pass flow-through mode. Characterizations including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microcopy (SEM) and energy dispersive spectroscopy (EDS) verified that Ti3+-doped anatase TiO2 with nanotube structures was successfully prepared. Electrochemical analysis including linear sweep voltammetry (LSV), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and electrochemical active surface area (ESA) revealed higher oxygen evolution potential (OEP, 2.23 V vs. Ag/AgCl), larger redox peak current, lower impedance and larger ESA (69 cm2/cm2) of Blue TiO2/Ti compared to the Ti and TiO2/Ti membranes. The effects of current density, flow rate and solution environment on the removal of methylene blue (MB) were investigated. The removal rates of various organic pollutants including sulfamethoxazole (SMX), methyl orange (MO), bisphenol A (BPA) and MB could reach 92.2%-99.5%. The quenching experiment proved that hydroxyl radicals (•OH) played the major role in the Blue TiO2/Ti based electrochemical system. Furthermore, the degradation pathways of two typical pollutants (SMX and MB) were proposed by analyzing the oxidation products with liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS), with the assistance of orbital-weighted Fukui index (fw0 and fw-) obtained through Density Functional Theory (DFT) calculations. Moreover, toxicity indexes of the oxidation products were obtained and compared to the parent SMX and MB using Toxicity Estimation Software Tool (TEST) software. Finally, the long-term operation performance of the Blue TiO2/Ti membrane was evaluated.

Legacy and emerging persistent organic pollutants in the marginal seas of China: Occurrence and phase partitioning.

Emerging per-and polyfluoroalkyl substances (PFASs) and traditional organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs) in the marginal seas of China were analyzed to study the occurrence, transport and phase partitioning. The influence of organic carbon (OC) and element carbon (EC) on particulate emerging pollutants in seawater was studied for the first time. The concentrations of PFASs, OCPs and PAHs in the seawater (dissolved phase plus particulate phase) ranged from 1.4 to 8.6, 0.76 to 4.3 and 8.4 to 130 ng L-1, respectively. Pollutants in the northern East China Sea were generally higher than that in the southern East China Sea and South China Sea, which may be attribute to river discharges and land sources in the Yangtze River Delta. The Yellow Sea Coastal Current and Yangtze River Dilute Water drove the transport of contaminants from north to south marginal seas. Positive correlations between EC and PAHs were found, which can be explained by co-emission of them during combustion. Moreover, positive correlations between OC, EC and Log Kd for BkF, BeP, HCB, 6:2 FTSA were found, which demonstrated that OC and EC promoted the partitioning of these high oleophilic compounds to suspended particle.