High-performance Cu/Mn modified ceramsite as a persulfate activator to degrade oxytetracycline in batch Erlenmeyer flask and continuous-flow fixed-bed column systems: An exploration of its practicability and non-radical mechanisms.

Persulfate non-radical oxidation have excellent catalytic capability for degrading specific contaminants in complicated water environments. Nevertheless, the preparation of high-performance activators and their application in actual water treatment in continuous flow mode are still scarce and unsatisfactory. In this work, copper-, manganese-, and copper/manganese-doped ceramsites (Cu-C, Mn-C and Cu/Mn-C), successfully fabricated through a facile impregnation-calcination approach, were characterized and evaluated for their performance to activate potassium peroxydisulfate (PDS) and degrade oxytetracycline (OTC) under different pH, ceramsite dosages, and PDS dosages. Compared with Cu-C and Mn-C, Cu/Mn-C showed the highest OTC degradation rate (0.0264 min-1) via activating PDS with an OTC removal efficiency of 98.2% in 240 min at an initial OTC concentration of 40 mg/L. The removal efficiency of OTC by Cu/Mn-C only decreased to 92.8% after 5 cycles; the activating ability of the used Cu/Mn-C was almost completely recovered through 2 h of calcination at 500 °C. The results of electron paramagnetic resonance and radical quenching suggest that singlet oxygen (1O2) was unveiled to be the dominant reactive oxygen species (ROS) for contaminant degradation, originating from the regrouping of superoxide ions or reduction of active Cu/Mn sites. Synergies between Cu and Mn species to enhance ROS yield were the primary activating mechanisms. Six possible routes of OTC decomposition were inferred. Additionally, Cu/Mn-C behaved excellently in treating an actual wastewater using a continuous flow fixed-bed reactor. It is believed that this novel Cu/Mn-C/PDS system may create a fresh path to design effective and cheap metal-ceramsite hybrid activators for degrading recalcitrant contaminants in the actual application process.

Evaluation of Fe3O4-MnO2@RGO magnetic nanocomposite as an effective persulfate activator and metal adsorbent in aqueous solution.

A reduced graphene oxide (RGO) supported Fe3O4-MnO2 nanocomposite (Fe3O4-MnO2@RGO) was successfully prepared for catalytic degradation of oxytetracycline (20 mg/L) by potassium persulfate (PS) and adsorption removal of mixture of Pb2+, Cu2+, and Cd2+ ions (each 0.2 mM) in the synchronous scenario. The removal efficiencies of oxytetracycline, Pb2+, Cu2+, and Cd2+ ions were observed as high as 100%, 99.9%, 99.8%, and 99.8%, respectively, under the conditions of [PS]0 = 4 mM, pH0 = 7.0, Fe3O4-MnO2@RGO dosage = 0.8 g/L, reaction time = 90 min. The ternary composite exhibited higher oxytetracycline degradation/mineralization efficiency, greater metal adsorption capacity (Cd2+ 104.1 mg/g, Pb2+ 206.8 mg/g, Cu2+ 70.2 mg/g), and better PS utilization (62.6%) than its unary and binary counterparts including RGO, Fe3O4, Fe3O4@RGO, and Fe3O4-MnO2. More importantly, the ternary composite had good magnetic recoverability and excellent reusability. Notably, Fe, Mn, and RGO could play a synergistic role in the improvement of pollutant removal. Quenching results indicate that surface bounded SO4•- was the major contributor to oxytetracycline decomposition, and the -OH groups on the composite surface shouldered a significant role in PS activation. The results indicate that the magnetic Fe3O4-MnO2@RGO nanocomposite has a good potential for removing organic-metal co-contaminants in waterbody.

Advanced treatment of aged landfill leachate through the combination of aged-refuse bioreactor and three-dimensional electrode electro-Fenton process.

A combined process of the aged-refuse bioreactor (ARB)/three-dimensional electrode electro-Fenton (3D-EF) system was developed at lab-scale to treat aged landfill leachate. The optimum operating conditions were found to be 15 L/m3•d hydraulic loading rate for ARB; Fe2+ concentration 1.0 mM, initial pH 3.0, current density 30 mA/cm2 and electrode distance 6 cm for 3D-EF. Under these conditions, the total removal ratios of chemical oxygen demand, NH3-N, total phosphorus and colour were 96.2%, 94.3%, 99.2% and 93.6%, respectively. The microtoxicity of the leachate was substantially reduced after undergoing the hybrid treatment. The ARB process removed a considerable proportion of organic matter, while the 3D-EF system played an important role in removing the residue of recalcitrant substances and post-polish of final effluent. The combined process showed a promising potential for treatment of aged landfill leachate.

PIK3CA promotes proliferation and motility but is unassociated with lymph node metastasis or prognosis in esophageal squamous cell carcinoma.

The PIK3CA mutation has been extensively reported in the setting of cancers; however, the clinicopathological significance of PIK3CA expression has rarely been discussed in esophageal squamous cell carcinoma. In the present study, to confirm the significance of PIK3CA expression in association with metastasis and prognosis, which has been somewhat controversial in esophageal squamous cell carcinoma (ESCC), the relationship between clinicopathological features of ESCC and PIK3CA expression was analyzed using immunohistochemistry with a tissue microarray. Meanwhile, as additional verification and an ethnic control, another independent small cohort of Kazakh ESCC were analyzed by immunohistochemistry. To investigate the pilot role of PIK3CA in ESCC cells, ESCC cell lines ECa109 and EC9706 were transiently transfected with specific siRNA against PIK3CA. The silencing effect was detected by Western blot. Cell proliferation was examined using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay; apoptosis and the cell cycles were analyzed by flow cytometry. Furthermore, the migratory and invasive ability were evaluated by wound healing and transwell invasion assay, respectively. Expression of PIK3CA was significantly higher in ESCC than in paired normal controls and was ethnicity independent; no statistically significant difference was observed between PIK3CA expression and sex, age, depth of invasion, tumor differentiation, lymph node metastasis, or prognosis. Proliferation, migration, and invasion were all markedly reduced after knockout of PIK3CA. Moreover, the cell cycle was arrested at the S phase, and the apoptosis rate was significantly increased, suggesting that PIK3CA plays a key role in promoting the proliferation and motility of ESCC cells.

KIAA1377 is associated with lymph node metastasis in esophageal squamous cell carcinoma.

KIAA1377, of which there are few studies regarding cell biology and neurological diseases, has been found to be significantly amplified in esophageal squamous cell carcinoma (ESCC) with lymph node metastasis compared with ESCC without lymph node metastasis. This suggests that KIAA1377 may play a role in the lymph node metastasis of ESCC. There has, to the best of our knowledge, been no study performed to investigate the role of KIAA1377 in ESCC. In the present study, the expression of KIAA1377 was detected by immunohistochemistry, and its expression was statistically analyzed with clinicopathological parameters, using commercially obtained tissue arrays consisting of 86 cases of ESCC and 79 paired controls. KIAA1377 was knocked down ex vivo using transient transfection with specific small hairpin RNA (shRNA) vectors into ESCC TE-1 and EC9706 cell lines whose endogenous KIAA1377 level was highest. The variation of proliferation, migration and invasion were evaluated using methyl thiazolyl tetrazolium, wound healing and Transwell assay, respectively. It was found in vivo that KIAA1377 expression was significantly associated with lymph node metastasis and differentiation, and ex vivo that knockdown of KIAA1377 cannot significantly affect proliferation and mobility in the ESCC cell line TE-1. Overall, this is the first study suggesting that KIAA1377 may play a role in the lymph node micrometastasis of ESCC.

M2 isoform of pyruvate kinase (PKM2) is upregulated in Kazakh's ESCC and promotes proliferation and migration of ESCC cells.

The objectives of the present study are to explore role of pyruvate kinase isoenzyme type M2 (PKM2) in progression of Kazakh's esophageal squamous cell carcinoma (ESCC) in Xinjiang, China, and to clarify mechanism of PKM2 in malignant phenotype. PKM2 expression was examined using immunohistochemistry (IHC) in 101 matched pairs of ESCC and normal adjacent tissues (NATs) and using enzyme-linked immunosorbent assay (ELISA) in 35 serum samples of Kazakh's ESCC and 8 serum samples of healthy subjects. To investigate mechanism, small interfering RNA (siRNA)-PKM2 was transfected into ESCC cells. Cell migration and invasion were evaluated by wound healing and Transwell assays. Apoptosis and cell cycle were analyzed by flow cytometry (FCM). PKM2 expression was significantly higher in ESCC tissues (77.2 %, 78/101) compared with matched NAT (P = 0.003) and also higher in serum samples of Kazakh's ESCC patients (78.84 ng/mL) compared with healthy subjects (13.55 ng/mL) (P = 0.001). Patients with overexpression of PKM2 had a poor prognosis (P = 0.032). After knockdown of PKM2, cell proliferation, migration, and invasion were significantly reduced (P = 0.001), apoptosis increased (P = 0.001), and cell cycle was arrested at G1 phase. PKM2 overexpression was significantly correlated with the worse outcome of Kazakh's ESCC. Furthermore, PKM2 was involved in progression of ESCC by promoting proliferation and suppressing apoptosis, accelerating invasion, and influencing cell cycle. PKM2 could be a potential biomarker for molecular classification of ESCC.

Metadherin is required for the proliferation, migration, and invasion of esophageal squamous cell carcinoma and its meta-analysis.

Metadherin (MTDH) was found to be highly expressed in various squamous cell carcinomas (SCCs); however, meta-analysis evaluating the association of MTDH in SCC has not been performed. The purpose of this study was to explore the biological functions of MTDH in esophageal squamous cell carcinoma (ESCC) and to meta-analyze the association between MTDH and SCC. Immunohistochemistry was performed to examine MTDH expression using an ESCC tissue array consisting of 86 ESCC and 78 paired normal adjacent tissues (NATs). MTDH was significantly overexpressed in ESCC tissues compared with NATs and was significantly associated with lymph node metastasis, differentiation, and prognosis. Knockdown of MTDH using an MTDH-short hairpin RNA plasmid caused cell cycle arrest at the G0/G1 phase and induced apoptosis of EC9706 cells. Knockdown of MTDH suppressed the proliferation, invasion, and migration of ESCC cells. Furthermore, meta-analysis revealed that overexpression of MTDH was significantly associated with the lymph node metastasis, advanced clinical stage, and T classification of tissues in SCC, suggesting that MTDH might be used as a potential therapeutic target in the lymph node metastasis of ESCC.

Remediation of PAH-contaminated soil by the combination of tall fescue, arbuscular mycorrhizal fungus and epigeic earthworms.

A 120-day experiment was performed to investigate the effect of a multi-component bioremediation system consisting of tall fescue (Festuca arundinacea), arbuscular mycorrhizal fungus (AMF) (Glomus caledoniun L.), and epigeic earthworms (Eisenia foetida) for cleaning up polycyclic aromatic hydrocarbons (PAHs)-contaminated soil. Inoculation with AMF and/or earthworms increased plant yield and PAH accumulation in plants. However, PAH uptake by tall fescue accounted for a negligible portion of soil PAH removal. Mycorrhizal tall fescue significantly enhanced PAH dissipation, PAH degrader density and polyphenol oxidase activity in soil. The highest PAH dissipation (93.4%) was observed in the combination treatment: i.e., AMF+earthworms+tall fescue, in which the soil PAH concentration decreased from an initial value of 620 to 41 mg kg(-1) in 120 days. This concentration is below the threshold level required for Chinese soil PAH quality (45 mg kg(-1) dry weight) for residential use.

Under-expression of annexin A2 is associated with Kazakh's esophageal squamous cell carcinoma.

The aim of the study was to identify candidate biomarkers for esophageal squamous cell carcinoma (ESCC) in Kazakh ethnic in Xinjiang as well as to reveal the potential role of Annexin A2 in ESCC carcinogenesis and progression. Five paired of Kazakh's ESCC tissues (T) and matched adjacent morphologically normal tissues (N) were separated by two-dimensional electrophoresis (2-DE) and differential proteins were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Annexin A2 was identified as a down-regulated protein in Kazakh's ESCC and further validated by immunohistochemistry (IHC) in 77 Kazakh's ESCC formalin-fixed paraffin-embeded (FFPE) samples. The expression level of Annexin A2 protein significantly correlated with the degree of ESCC differentiation and depth of invasion. For clarification of the role of Annexin A2 in regulating cell phenotype, in vitro eukaryotic expression vectors harboring full length Annexin A2 (pCMV-XL5-Annexin A2) was tranfected into Eca109 cells, and transfection effects were evaluated by RT-PCR and Western blotting analysis, respectively. Functionally, there was a significant decrease in cell proliferation, migration, and invasion capability in Eca109 with transfected pCMV-XL5-Annexin A2 compared to the controls. Furthermore, up-regulating Annexin A2 can significantly cause cell cycle arrest at the G2 phase, but no apoptosis was induced. Together, our findings suggested that Annexin A2 was involved in malignant phenotype and was a potential biomark for molecular classification in ESCC.

MicroRNA-21 promotes cell growth and migration by targeting programmed cell death 4 gene in Kazakh's esophageal squamous cell carcinoma.

Esophageal cancer (EC) is the eighth most common cancer worldwide and the sixth most common cause of cancer death. There are two main types of EC--squamous cell carcinoma (ESCC) and adenocarcinoma (EAC). Although some advances in the exploration of its possible etiological mechanism were made recently including behaviors and environmental risk factors as well as gene alterations, the molecular mechanism underlying ESCC carcinogenesis and progression remains poorly understood. It has been reported that miR-21 was upregulated in most malignant cancers, the proposed mechanism of which was through suppressing expression of programmed cell death 4 (PDCD4). In present study, it is firstly reported that miR-21 was upregulated in Kazakh's ESCC and that miR-21 played a negative role in regulating PDCD4 using in situ hybridization (ISH) and luciferase reporter approach. Morever, in model of ESCC xenografted nude mice, miR-21 maybe used as an effective target in the treatment. The present results demonstrated that miR-21 may be a potential therapeutic target in management of ESCC.

Complete debromination of decabromodiphenyl ether using the integration of Dehalococcoides sp. strain CBDB1 and zero-valent iron.

This study investigated the effects of nano- and micro-scale zero-valent iron (nZVI and mZVI) particles on Dehalococcoides sp. strain CBDB1 participating in anaerobic reduction of polybrominated diphenyl ethers. nZVI (>0.25 g L(-)(1)) had an inhibitory effect upon this strain, whereas 1.0 g L(-1) mZVI showed no negative impact on bacterial growth. Strain CBDB1 could only utilize lower brominated congeners (<7 bromines) as electron acceptor. In the bio-ZVI system, decabromodiphenyl ether (BDE-209) was first reduced by ZVI to lower brominated congeners, which were then dehalogenated to diphenyl ether by CBDB1. Within 30 d, a BDE-209 debromination efficiency of 16% and 24% was obtained in the bio-nZVI (0.25 g L(-1)) and bio-mZVI (1.0 g L(-1)) systems with a corresponding diphenyl ether yield efficiency of 14% and 19%, respectively. The debromination efficiency increased significantly from 8% to 24% with an increase of mZVI dosage from 0.25 to 1.0 g L(-1) in the bio-mZVI system.

HMGA2 is down-regulated by microRNA let-7 and associated with epithelial-mesenchymal transition in oesophageal squamous cell carcinomas of Kazakhs.

AIMS: To investigate the expression of let-7 and its regulation of high-mobility group A2 protein (HMGA2), and to verify the relationship between let-7, HMGA2 and the process of epithelial-mesenchymal transition (EMT), in oesophageal squamous cell carcinomas (OSCC) of Kazakh patients. METHODS AND RESULTS: Expression of let-7 was significantly lower in Eca109 cells than in normal oesophageal squamous epithelium (P = 2.4 × 10(-7) ). Increased accumulation of let-7 after transfection of Eca109 cells with synthetic let-7 inhibited cell proliferation. Let-7 could repress expression of HMGA2 after co-transfection with let-7 and HMGA2 (P = 0.002). Moreover, let-7 expression was observed less frequently (P = 2.0 × 10(-8) ), and HMGA2 expression more frequently (P = 1.0 × 10(-10) ), in OSCC than in normal adjacent tissues; and let-7 expression was observed less frequently in OSCC from Kazakh patients than in those from Han and Uygur patients (P = 0.041). There was a reverse correlation between expression of let-7 and HMGA2 (P = 0.018). Expression of Snail was statistically higher in Kazakhs' OSCC (P = 0.029), and was correlated with depth of invasion (P = 0.021) and HMGA2 expression (P = 0.026). CONCLUSIONS: Expression of let-7 can suppress cell proliferation by acting directly on regulation of HMGA2 in OSCC. High expression of Snail and its correlation with HMGA2 expression and tumour invasion suggest that HMGA2 may be involved in EMT in the OSCC of Kazakh patients.

Study on an oxygen sensing rhenium(I) complex with enlarged sensing/active area: fabrication, photophysical parameters and molecular oxygen sensing performance.

In this paper, we synthesize a novel 1,10-phenanthroline-derived (Phen-derived) diamine ligand of benzo[f][1,10]phenanthroline-6,7-dicarbonitrile (Phen-CN) with enlarged conjugation planar and its corresponding Re(I) complex of Re(CO)3Cl(Phen-CN), hoping to achieve an optical sensor owing large sensing/active area. Its geometric and electronic structures are investigated, which suggests that the effective sensing/active area of Re(CO)3Cl(Phen-CN) is enlarged by the successful formation of conjugation planar. The promising photophysical parameters of Re(CO)3Cl(Phen-CN), including large sensing/active area and long excited state lifetime, make it a potential probe for oxygen detection. By doping Re(CO)3Cl(Phen-CN) into a polymer matrix of poly(vinylpyrrolidone), oxygen sensing performances of the resulted composite materials are investigated. Finally, a high sensitivity of 17.1 is realized, with short response/recovery time of 9s/32s.

Interaction of heavy metals and pyrene on their fates in soil and tall fescue (Festuca arundinacea).

90-Day growth chamber experiments were performed to investigate the interactive effect of pyrene and heavy metals (Cu, Cd, and Pb) on the growth of tall fescue and its uptake, accumulation, and dissipation of heavy metals and pyrene. Results show that plant growth and phytomass production were impacted by the interaction of heavy metals and pyrene. They were significantly decreased with heavy metal additions (100-2000 mg/kg), but they were only slightly declined with pyrene spiked up to 100 mg/kg. The addition of a moderate dosage of pyrene (100 mg/kg) lessened heavy metal toxicity to plants, resulting in enhanced plant growth and increased metal accumulation in plant tissues, thus improving heavy metal removal by plants. In contrast, heavy metals always reduced both plant growth and pyrene dissipation in soils. The chemical forms of Cu, Cd, and Pb in plant organs varied with metal species and pyrene addition. The dissipation and mineralization of pyrene tended to decline in both planted soil and unplanted soils with the presence of heavy metals, whereas they were enhanced with planting. The results demonstrate the complex interactive effects of organic pollutants and heavy metals on phytoremediation in soils. It can be concluded that, to a certain extent, tall fescue may be useful for phytoremediation of pyrene-heavy metal-contaminated sites. Further work is needed to enhance methods for phytoremediation of heavy metal-organics co-contaminated soil.

Remediation of polychlorinated biphenyl-contaminated soil by using a combination of ryegrass, arbuscular mycorrhizal fungi and earthworms.

In this work, a laboratory experiment was performed to investigate the influences of inoculation with the arbuscular mycorrhizal fungus (AMF) Glomus caledoniun L. and/or epigeic earthworms (Eisenia foetida) on phytoremediation of a PCB-contaminated soil by ryegrass grown for 180d. Planting ryegrass, ryegrass inoculated with earthworms, ryegrass inoculated with AMF, and ryegrass co-inoculated with AMF and earthworms decreased significantly initial soil PCB contents by 58.4%, 62.6%, 74.3%, and 79.5%, respectively. Inoculation with AMF and/or earthworms increased the yield of plants, and the accumulation of PCBs in ryegrass. However, PCB uptake by ryegrass accounted for a negligible portion of soil PCB removal. The number of soil PCB-degrading populations increased when ryegrass was inoculated with AMF and/or earthworms. The data show that fungal inoculation may significantly increase the remedial potential of ryegrass for soil contaminated with PCBs.

Surface modification of porous suspended ceramsite used for water treatment by activated carbon/Fe3O4 magnetic composites.

In this study, porous suspended ceramsite with a specific density close to that of water was prepared by high-temperature calcination using fly ash, feldspar, calcite, fired talc and kaolin as the raw materials. The ceramsite was modified by activated carbon/Fe3O4 magnetic composites. The optimum modification conditions determined by methylene blue adsorption experiment were: KOH/glucose ratio of 1.5:1, carbonization temperature of 400 degrees C, activation temperature of 850 degrees C, activation time of 1 h, and Fe3O4/KOH+glucose ratio of 1:10. The results demonstrated that the adsorption capacity of the modified ceramsite for methylene blue was significantly higher than that of the unmodified ones. The presence of the composites did not lead to significant decrease in the mechanical properties of the modified ceramsite. Moreover, the modified ceramsite showed good resistance towards acid and alkali. The modified ceramsite can be used as biocarrier and adsorbent for a wide range of contaminants in water and can subsequently be removed from the medium by a simple magnetic procedure.

[Investigation on role of p38α mitogen-activated protein kinases in human esophageal squamous cell carcinoma cell line Eca109].

OBJECTIVE: To investigate the role of p38α mitogen-activated protein kinases (MAPK) in human esophageal squamous cell carcinoma cell line Eca109. METHODS: Specific short hairpin (shRNA) vector as well as eukaryotic expression vector harbouring full length cDNA of human p38α MAPK were transfected into Eca109 cells. Cell proliferation after transfection was detected by MTT, cell cycle and apoptosis were assayed by flow cytometry. The variation of migration and invasion after transfection was determined using wound healing assay and Transwell assay, respectively. RESULTS: The proliferation of Eca109 cells after knock-down for 48 h (0.951 ± 0.086) was significantly increased (t = 3.20, P < 0.05) compared with control (0.811 ± 0.012), Sphase was increased but not significantly. Cell apoptosis rate after knock down for 48 h (17.400 ± 5.495) was significantly increased (t = 40.06, P < 0.01) compared with control(1.000 ± 0.721) . Migration after knock down for 72 h (0.034 ± 0.031) were enhanced pronouncedly (t = -5.79, P < 0.01) compared with control (0.278 ± 0.021) and invasive ability also increased; whereas the proliferation of Eca109 cells after over-expression for 48 h (0.472 ± 0.089) was inhibited significantly (t = -7.50, P < 0.01) compared with control(0.811 ± 0.012), cells arrested at G1 phase (t = 4.80, P < 0.01). Cell apoptosis rate (32.233 ± 1.457) were decreased significantly (t = 17.20, P < 0.01) compared with control (1.000 ± 0.721) mm, migration after overexpression for 72 h ((0.770 ± 0.054) mm) was suppressed pronouncedly compared with control groups of (0.278 ± 0.021) mm(t = 11.00, P < 0.01).Invasion after overexpression was inhibited. CONCLUSIONS: p38α MAPK plays an anti-oncogenic role in the pathogenesis of esophageal squamous cell carcinoma cell line Eca109.

Biodegradation of decabromodiphenyl ether (BDE-209) by a metal resistant strain, Bacillus cereus JP12.

A metal resistant bacterial strain, Bacillus cereus JP12, could use decabromodiphenyl ether (BDE-209) as the sole carbon and energy source for growth in mineral salt medium. Under the conditions of pH 6.0, 30°C, 150 rpm and an inoculum of OD600=0.6, more than 88% of the initial BDE-209 (1mg/L) was degraded after 12 days. The addition of appropriate surfactants and additional carbon sources could enhance the biodegradation efficiency of BDE-209. The presence of Cu(2+) (≤ 8 mg/L) and Zn(2+) (≤ 15 mg/L) provided a slight stimulating effect on BDE-209 removal. However, BDE-209 biodegradation efficiency was decreased when adding higher levels of metals due to reduced substrate availability caused by excess metal adsorption into the cell surface. Biosorption of heavy metals by JP12 led to release of light metals such as K(+) and Na(+). A BDE-209 biodegradation pathway was proposed on the basis of metabolite identification.

Effect of copper on in vivo fate of BDE-209 in pumpkin.

A 60-day growth chamber experiments were performed to investigate the effect of Cu stress on the uptake, translocation and metabolism of decabromodiphenyl ether (BDE-209) by pumpkin. A total of nine debrominated metabolites (de-PBDEs), two hydroxylated PBDEs (OH-PBDEs) and one methoxylated PBDEs (MeO-PBDEs) were detected in the tested plants. Concentrations of the total debrominated, hydroxylated or methoxylated metabolites generally followed the order of roots>stems>leaves, and de-PBDEs>OH-PBDEs>MeO-PBDEs. These results indicate that metabolism occurred preferentially in roots than in stems and leaves. The addition of moderate dosage of Cu (50mg/kg) resulted in increment in OH-PBDE concentrations in plant tissues, whereas higher concentrations of Cu could inhibit uptake and metabolism of BDE-209. No in vivo mineralization of BDE-209 was detected in the plants. These results provide valuable information about the behavior of BDE-209 in plant tissues under heavy metal exposure.

Treatment of petroleum refinery wastewater using a sequential anaerobic-aerobic moving-bed biofilm reactor system based on suspended ceramsite.

In this study, a novel suspended ceramsite was prepared, which has high strength, optimum density (close to water), and high porosity. The ceramsite was used to feed a moving-bed biofilm reactor (MBBR) system with an anaerobic-aerobic (A/O) arrangement to treat petroleum refinery wastewater for simultaneous removal of chemical oxygen demand (COD) and ammonium. The hydraulic retention time (HRT) of the anaerobic-aerobic MBBR system was varied from 72 to 18 h. The anaerobic-aerobic system had a strong tolerance to shock loading. Compared with the professional emission standard of China, the effluent concentrations of COD and NH3-N in the system could satisfy grade I at HRTs of 72 and 36 h, and grade II at HRT of 18 h. The average sludge yield of the anaerobic reactor was estimated to be 0.0575 g suspended solid/g CODremoved. This work demonstrated that the anaerobic-aerobic MBBR system using the suspended ceramsite as bio-carrier could be applied to achieving high wastewater treatment efficiency.