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  • Rhizoremediation of a dioxin-like PCB polluted soil by alfalfa: dynamic characterization at temporal and spatial scale
    Chemosphere (IF 4.208) Pub Date : 2017-09-19
    Chen Tu, Luyao Ma, Pengpeng Guo, Fang Song, Ying Teng, Haibo Zhang, Yongming Luo
    更新日期:2017-09-20
  • Reduced ultraviolet light transmission increases insecticide longevity in protected culture raspberry production
    Chemosphere (IF 4.208) Pub Date : 2017-09-19
    Heather Leach, John C. Wise, Rufus Isaacs

    High tunnels are large protective structures used for season extension of many crops, including raspberries. These structures are often covered in plastic films to reduce and diffuse ultraviolet light transmission for pest and disease control, but this may also affect the photodegradation and efficacy of pesticides applied under these tunnels. We compared the residue levels of ten insecticides under three tunnel plastics with varying levels of UV transmission and open field conditions. Raspberry plants placed in research-scale tunnels were treated with insecticides and residues on fruit and foliage were monitored for one or two weeks in early 2015 and early and late 2016. Plastics that reduce UV transmission resulted in 50% greater residues of some insecticides compared to transparent plastics, and 60% compared to uncovered tunnels. This increased persistence of residues was evident within 1 day and remained consistently higher for up to 14 days. This pattern was demonstrated for multiple insecticides, including bifenthrin, esfenvalerate, imidacloprid, thiamethoxam, and spinosad. In contrast, the insecticide malathion degraded rapidly regardless of the plastic treatment, indicating less sensitivity to photodegradation. Bioassays using insecticide-treated leaves that were under UV-blocking plastic revealed higher mortality of the invasive fruit pest, Drosophila suzukii, compared to leaves that were uncovered. This indicates that the activity of pesticides under high tunnels covered in UV-reducing plastics may be prolonged, allowing for fewer insecticide applications and longer intervals between sprays. This information can be used to help optimize pest control in protected culture berry production.

    更新日期:2017-09-19
  • Effects of monochloramine and hydrogen peroxide on the bacterial community shifts in biologically treated wastewater
    Chemosphere (IF 4.208) Pub Date : 2017-09-19
    Yi Yang, Dan Cheng, Yingnan Li, Ling Yu, Karina Yew-Hoong Gin, Jiaping Paul Chen, Martin Reinhard

    Amending feed water with biocide is one of the strategy conventionally used to control biofouling in membrane-based water treatment systems. In this study, the impacts of two biocides, monochloramine (MCA) and hydrogen peroxide (H2O2), on the bacterial community in wastewater samples were investigated at equivalent biocidal efficiency levels. Viable bacterial numbers were determined before and after treatment for 10 min and 60 min using both culture-dependent heterotrophic plate count (HPC) and culture-independent propidium monoazide (PMA)-droplet digital PCR (ddPCR). Shifts of the live bacterial diversity were studied using high-throughput sequencing of 16S rRNA genes and followed by bioinformatics analysis. At the genus level, MCA treatment increased the relative abundance of Mycobacterium, Pseudomonas, Sphingomonas, Clostridium, Streptococcus, Undibacterium, Chryseobacterium and Cloacibacterium, while decreasing Arcobacter, Nitrospira and Sphingobium. H2O2 treatment increased the relative abundance of Anaerolinea and Filimonas, and diminished Denitratisoma and Thauera. The findings of this study suggest a combination of different types of biocide may be the most efficient strategy for biofouling mitigation and increasing membrane treatment efficiency.

    更新日期:2017-09-19
  • Oxidative degradation of benzene rings using iron sulfide activated by hydrogen peroxide/ozone
    Chemosphere (IF 4.208) Pub Date : 2017-09-19
    Junko Hara

    Mineral pyrites—metal sulfides abundant in the earth's crust—exhibit oxidative ability when exposed to water. This oxidizing ability makes mineral pyrites suitable for the natural and enhanced remediation of environmentally hazardous materials. Herein, we evaluate the benzene ring degradation ability of iron bisulfide activated by H2O2 and O3 and elucidate the corresponding reaction pathways. A set of control experiments was conducted to optimize the reaction conditions, i.e., the FeS2/H2O ratio under aerobic conditions and the H2O2 and/or O3 dosages. Benzene ring was successfully decomposed to CO2 via organic acids even by the simplest FeS2/H2O combination. This process was accelerated by the addition of both O3 and H2O2. The extent of degradation to CO2 increased in the presence of O3, while oxalic acid generation increased in the presence of H2O2. The reaction proceeded via the radicals generated on FeS2/H2O, which is enhanced by O3, and a Fenton-like reaction using the iron obtained from FeS2 dissolution.

    更新日期:2017-09-19
  • Water quality parameters, biomarkers and metal bioaccumulation in native fish captured in the ilha river, southern brazil
    Chemosphere (IF 4.208) Pub Date : 2017-09-19
    Thaís Dalzochio, Leonardo Airton Ressel Simões, Mateus Santos de Souza, Gabriela Zimmermann Prado Rodrigues, Ismael Evandro Petry, Natália Bordin Andriguetti, Gláucia Joselaine Herbert Silva, Günther Gehlen, Luciano Basso da Silva

    The Ilha River is one of the main tributaries of the Sinos River, southern Brazil, and it is located in an area characterized by low population density and presence of agricultural activities. Thus, this study aimed to assess the water quality of two sites of the Ilha River (source and mouth, S1 and S2 respectively) in five sampling periods using water physicochemical and microbiological analyses, biomarkers, such as condition factor, micronucleus test, gill histopathological analysis, and metal bioaccumulation in the native fish Bryconamericus iheringii. Mean values of BOD5, thermotolerant coliforms, aluminum, iron and lead exceeded the limits established by the Brazilian legislation for surface waters at both sampling sites. Significant higher micronucleus, nuclear abnormalities and mucous cells frequencies were found at S2 in, at least, one sampling period, whereas fish from S1 presented significant lower condition factor, higher frequencies of lamellar alterations and higher concentrations of chromium and nickel in muscle. Additionally, concentrations of cadmium, chromium and lead in fish muscle exceeded the limits considered for safe human consumption at both sites in at least one sampling period. Data from our study evidenced the mouth of the Ilha River suffers from point genotoxic effects, whereas the source is also contaminated by metals, despite being located in an area under minor anthropic activities.

    更新日期:2017-09-19
  • Determination of triazine herbicides and their metabolites in multiple medicinal parts of traditional Chinese medicines using streamlined pretreatment and UFLC-ESI-MS/MS
    Chemosphere (IF 4.208) Pub Date : 2017-09-18
    Congmin Liu, Xiaowen Dou, Lei Zhang, Qian Li, Jia'an Qin, Yaping Duan, Meihua Yang
    更新日期:2017-09-19
  • Cleavage of the main carbon chain backbone of high molecular weight polyacrylamide by aerobic and anaerobic biological treatment
    Chemosphere (IF 4.208) Pub Date : 2017-09-18
    Wenzhe Song, Yu Zhang, Yingxin Gao, Dong Chen, Min Yang
    更新日期:2017-09-19
  • River catchment responses to anthropogenic acidification in relationship with sewage effluent: An ecotoxicology screening application
    Chemosphere (IF 4.208) Pub Date : 2017-09-18
    P.J. Oberholster, A.-M. Botha, L. Hill, W.F. Strydom
    更新日期:2017-09-19
  • Characterization of PCDD/Fs and dioxin-like PCBs emitted from two woodchip boilers in Taiwan
    Chemosphere (IF 4.208) Pub Date : 2017-09-18
    Shih Ting Bai, Shu Hao Chang, Jing Min Duh, Fu Hsiang Sung, Jhen Sheng Su, Moo Been Chang

    This study investigates the formation and removal of PCDD/Fs and dl-PCBs in two woodchips boilers during different operating periods. Results indicate that combustion condition affects PCDD/F and dl-PCB formation within the woodchip combustion process. PCDD/F and dl-PCB concentrations during the start-up period are much higher than those measured during normal operation and shut-down periods due to unstable combustion. PCDD/F and dl-PCB concentrations at APCDs inlet of Plant A are significantly higher than that of Plant B due to the lower combustion temperature (500-850 oC) compared with Plant B (850-925 oC). Major PCDD/F congeners at APCDs inlet of both plants during normal operation are O8CDD, 1,2,3,4,6,7,8-H7CDD and 1,2,3,4,6,7,8-H7CDF, while major dl-PCBs are TeCB-77, PeCB-118 and PeCB-126. The removal efficiencies of PCDD/F and PCBs achieved with the APCDs of Plant A are 95.6% and 88.6%, respectively, while those of Plant B are 99.3% and 94.9%. Possibly, the AC concentration of Plant A exceeds the optimal AC concentration and, PCDD/Fs and dl-PCBs might be formed because the AC injected can supply additional reaction area and carbon source. Also, this may be due to different operating temperatures of APCDs, which affects removal efficiency of PCDD/F and dl-PCB congeners. The emission factors (PCDD/Fs+dl-PCBs) of Plants A and B are calculated as 17.86 and 1.25 μg I-TEQ/ton, respectively. Concentrations of PCDD/Fs in the BF ash of Plants A and B during normal operation are measured as 98.57 and 38.06 ng I-TEQ/g, which are significantly higher than the standard limit (1.0 ng I-TEQ/g) promulgated by Taiwan EPA.

    更新日期:2017-09-18
  • Unusual arsenic metabolism in Giant Pandas
    Chemosphere (IF 4.208) Pub Date : 2017-09-18
    Simone Braeuer, Eveline Dungl, Wiebke Hoffmann, Desheng Li, Chengdong Wang, Hemin Zhang, Walter Goessler
    更新日期:2017-09-18
  • Excretion pattern and dynamics of glutathione detoxification of microcystins in Sprague Dawley rat
    Chemosphere (IF 4.208) Pub Date : 2017-09-18
    Wei Li, Jun He, Jun Chen, Ping Xie

    The excretion route and dynamics of the glutathione (GSH) conjugate of microcystin-RR (MCRR), MCRR-GSH, were quantitatively studied in Sprague Dawley rat exposed with MCRR-GSH via liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS). In the MCRR-GSH-treated rat, the average MCRR-Cysteine (MCRR-Cys)/MCRR-GSH ratio reached as high as 105.3, which indicated that the intermediate conjugate MCRR-GSH was rapidly converted to the product compound MCRR-Cys. Besides, MCRR was consistently detected in MCRR-GSH-treated rat, which suggested that MCRR can be dissociated from the MCRR-GSH conjugate and the reversibility of the MC-GSH conjugate. Results of total MC contents analysis in excrement showed that the total MC contents in urine were significantly higher than those in feces. The ratio of the total MC content in urine to feces was as high as 129.3, which demonstrates that the urine is the main route of excretion after MCRR-GSH-treatment. In urine, the MCRR-Cys concentration was 27.8-fold, 19.4-fold higher than MCRR-GSH and MCRR, respectively. Our results, for the first time, quantitatively found that MCRR-GSH was rapidly converted to MCRR-Cys after exposed to rat, and was excreted mainly through urine in the form of the MCRR-Cys conjugate. This study suggests that the GSH detoxification pathway of MCs could help to explain the greater sensitivity of mammals to MCs.

    更新日期:2017-09-18
  • Measurement of urinary Benzo[a]pyrene tetrols and their relationship to other polycyclic aromatic hydrocarbon metabolites and cotinine in humans
    Chemosphere (IF 4.208) Pub Date : 2017-09-18
    Donald C. Hilton, Debra A. Trinidad, Kendra Hubbard, Zheng Li, Andreas Sjödin

    Biomonitoring of exposure to polycyclic aromatic hydrocarbons (PAHs) typically uses measurement of metabolites of PAHs with four or less aromatic rings, such as 1-hydroxypyrene, even though interest may be in exposure to larger and carcinogenic PAHs, such as benzo[a]pyrene (B[a]P). An improved procedure for measuring two tetrol metabolites of B[a]P has been developed. Using 2 mL urine, the method includes enzymatic deconjugation of the tetrol conjugates, liquid-liquid extraction, activated carbon solid phase extraction (SPE) and Strata-X SPE, and gas chromatography–electron capture negative ionization–tandem mass spectrometric determination. Limits of detection were 0.026 pg/mL (benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol, BPT I-1) and 0.090 pg/mL (benzo[a]pyrene-r-7,t-8,c-9,c-10-tetrahydrotetrol, BPT II-1). We quantified BPT I-1 and BPT II-1 in urine from a volunteer who consumed one meal containing high levels of PAHs (barbequed chicken). We also measured urinary concentrations of BPT I-1 and BPT II-1 in smokers and nonsmokers, and compared these concentrations with those of monohydroxy PAHs (OH-PAHs) and cotinine. Urinary elimination of BPT I-1 and BPT II-1 as a function of time after dietary exposure was similar to that observed previously for OH-PAHs. While the median BPT I-1 concentration in smokers’ urine (0.069 pg/mL) significantly differs from nonsmokers (0.043 pg/mL), BPT I-1 is only weakly correlated with cotinine. The urinary concentration of BPT I-1 shows a weaker relationship to tobacco smoke than metabolites of smaller PAHs, suggesting that other routes of exposure such as for example dietary routes may be of larger quantitative importance.

    更新日期:2017-09-18
  • Bacterial inactivation and regrowth in ozonated activated sludges
    Chemosphere (IF 4.208) Pub Date : 2017-09-17
    C. Fall, B.C. Silva-Hernández
    更新日期:2017-09-18
  • Growth and Cd uptake by rice (Oryza sativa) in acidic and Cd-contaminated paddy soils amended with steel slag
    Chemosphere (IF 4.208) Pub Date : 2017-09-17
    Huaidong He, Nora F.Y. Tam, Aijun Yao, Rongliang Qiu, Wai Chin Li, Zhihong Ye

    Contamination of rice (Oryza sativa) by Cd is of great concern. Steel slag could be used to amend Cd-contaminated soils and make them safe for cereal production. This work was conducted to study the effects of steel slag on Cd uptake and growth of rice plants in acidic and Cd-contaminated paddy soils and to determine the possible mechanisms behind these effects. Pot (rhizobag) experiments were conducted using rice plants grown on two acidic and Cd-contaminated paddy soils with or without steel slag amendment. Steel slag amendment significantly increased grain yield by 36–45% and root catalase activity, and decreased Cd concentrations in brown rice by 66–77% compared with the control, in both soils. Steel slag amendment also markedly decreased extractable soil Cd, Cd concentrations in pore-water and Cd translocation from roots to above-ground parts. It also significantly increased soil pH, extractable Si and Ca in soils and Ca concentrations in roots. Significant positive correlations were found between extractable soil Cd and Cd concentrations in rice tissues, but it was negatively correlated with soil pH and extractable Si. Calcium in root tissues significantly and negatively correlated with Cd translocation factors from roots to straw. Overall, steel slag amendment not only significantly promoted rice growth but decreased Cd accumulation in brown rice. These benefits appear to be related to improvements in soil conditions (e.g. increasing pH, extractable Si and Ca), a reduction in extractable soil Cd, and suppression of Cd translocation from roots to above-ground parts.

    更新日期:2017-09-18
  • Liver volatolomics to reveal poultry exposure to γ-hexabromocyclododecane (HBCD)
    Chemosphere (IF 4.208) Pub Date : 2017-09-17
    Jérémy Ratel, Christelle Planche, Frédéric Mercier, Patrick Blinet, Nathalie Kondjoyan, Philippe Marchand, Agnès Fournier, Angélique Travel, Catherine Jondreville, Erwan Engel
    更新日期:2017-09-18
  • Hydrochars and phosphate enhancing the transport of nanoparticle silica in saturated sands
    Chemosphere (IF 4.208) Pub Date : 2017-09-17
    Cheng Liu, Nan Xu, Gang Feng, Dongmei Zhou, Xueying Cheng, Zuling Li
    更新日期:2017-09-18
  • Influence of human activities and organic matters on occurrence of polybrominated diphenyl ethers in marine sediment core: A case study in the Southern Yellow Sea, China
    Chemosphere (IF 4.208) Pub Date : 2017-09-17
    Guoguang Wang, Lijuan Feng, Jingshuai Qi, Xianguo Li

    The Southern Yellow Sea (SYS) is an important reservoir of anthropogenic organic contaminants, such as polybrominated diphenyl ethers (PBDEs). To reconstruct the historical records of PBDEs and examine their relationships with the human activities and organic matters, a210Pb-dated sediment core was collected from the central mud area in the SYS. The concentrations of tri-to hepta-BDEs (∑7PBDEs) and BDE-209 ranged from 9.8 to 99.8 pg g−1 d.w. and from 12.1 to 855.4 pg g−1 d.w., respectively, both displaying the increasing trends from the bottom to the surface. More importantly, there was a faster increase for PBDEs since the 1990s, especially for BDE-209, which responded well with the rapid economic growth, and the increases of urbanization and industrialization in the local areas of the SYS. The analogously vertical patterns and significant relationships between PBDEs and total organic carbon (TOC) implied the TOC-dependent deposition of PBDEs in the core. Furthermore, multiple biomarker-based proxies of terrestrial organic matter (TOM) and marine organic matter (MOM) were introduced to systematically investigate the different effects of TOM and MOM on PBDE deposition in the SYS. The similarly down-core profiles and significant correlations were found between PBDEs and the MOM proxies (sum of rassicasterol, dinosterol and C37 alkenones (∑A + B + D) and marine TOC) as well as the branched and isoprenoid tetraether (BIT), but not for TOM proxies (∑C27+C29+C31n-alkanes, terrestrial and marine biomarker ratio (TMBR) and terrestrial TOC), indicating that MOM was an important factor driving PBDE deposition in the sediment core from the SYS.

    更新日期:2017-09-18
  • Alterations in growth performance and stress responses in juvenile rockfish, Sebastes schlegelii, exposed to dietary chromium with varying levels of dietary ascorbic acid supplementation
    Chemosphere (IF 4.208) Pub Date : 2017-09-17
    Jun-Hwan Kim, Hee-Ju Park, Ju-Chan Kang

    Juvenile rockfish Sebastes schlegelii (mean length 10.8±1.4 cm, and mean weight 31.7±3.6 g) were exposed for 4 weeks to different levels of dietary chromium (Cr6+) at 0, 120, and 240 mg/L and ascorbic acid (AsA) at 100, 200, and 400 mg/L. Growth performance of S. schlegelii was significantly decreased due to dietary Cr exposure, whereas lysozyme activity was notably increased. Exposure to dietary Cr resulted in substantial accumulation of Cr in the blood. Levels of two stress indicators, plasma cortisol and heat shock protein 70, of S. schlegelii were increased due to dietary Cr exposure. The results indicated that dietary Cr exposure affected growth performance, lysozyme activity, and stress responses of S. schlegelii, and high levels of AsA supplementation significantly attenuated dietary Cr-induced toxicity.

    更新日期:2017-09-18
  • 更新日期:2017-09-18
  • Metabolic signatures of bisphenol A and genistein in Atlantic salmon liver cells
    Chemosphere (IF 4.208) Pub Date : 2017-09-17
    Pål A. Olsvik, Kaja H. Skjærven, Liv Søfteland

    Screening has revealed that aquafeeds with high inclusion of plant material may contain small amounts of endocrine disrupting agricultural pesticides. In this work, bisphenol A (BPA) and genistein (GEN) were selected as model endocrine disrupting toxicants with impact on DNA methylation in fish. Atlantic salmon hepatocytes were exposed in vitro to four concentrations of BPA and GEN (0.1, 1.0, 10 and 100 μM) for 48 h. Toxicity endpoints included cytotoxicity, global DNA methylation, targeted transcriptomics and metabolomic screening (100 μM). GEN was not cytotoxic in concentrations up to 100 μM, whereas one out of two cell viability assays indicated a cytotoxic response to 100 μM BPA. Compared to the control, significant global DNA hypomethylation was observed at 1.0 μM BPA. Both compounds upregulated cyp1a1 transcription at 100 μM, while estrogenic markers esr1 and vtg1 responded strongest at 10 μM Dnmt3aa transcription was downregulated by both compounds at 100 μM. Metabolomic screening showed that BPA and GEN resulted in significant changes in numerous biochemical pathways consistent with alterations in carbohydrate metabolism, indicating perturbation in glucose homeostasis and energy generation, and glutamate metabolism. Pathway analysis showed that while the superpathway of methionine degradation was among the most strongly affected pathways by BPA, GEN induced changes to uridine and pyrimidine biosynthesis. In conclusion, this mechanistic study proposes metabolites associated with glucose and glutamate metabolism, glucuronidation detoxification, as well as transcriptional markers cyp1a1, vtg1, esr1, ar, dnmt3aa, cdkn1b and insig1 as markers for BPA and GEN exposure in fish liver cells.

    更新日期:2017-09-18
  • Genotoxic potential of the binary mixture of cyanotoxins microcystin-LR and cylindrospermopsin
    Chemosphere (IF 4.208) Pub Date : 2017-09-17
    Klara Hercog, Sara Maisanaba, Metka Filipič, Ángeles Jos, Ana M. Cameán, Bojana Žegura
    更新日期:2017-09-18
  • Microplate freeze-dried cyanobacterial bioassay for fresh-waters environmental monitoring
    Chemosphere (IF 4.208) Pub Date : 2017-09-15
    Keila Martín-Betancor, Marie-José Durand, Gérald Thouand, Francisco Leganés, Francisca Fernández-Piñas, Ismael Rodea-Palomares
    更新日期:2017-09-15
  • Volatilization and oxidative artifacts of PM bound PAHs at low volume sampling (2): Evaluation and comparison of mitigation strategies effects
    Chemosphere (IF 4.208) Pub Date : 2017-09-15
    Catia Balducci, Angelo Cecinato, Valerio Paolini, Ettore Guerriero, Mattia Perilli, Paola Romagnoli, Carmela Tortorella, Renato Michele Nacci, Aldo Giove, Antonio Febo
    更新日期:2017-09-15
  • Antagonistic effect of humic acid and naphthalene on biochar colloid transport in saturated porous media
    Chemosphere (IF 4.208) Pub Date : 2017-09-15
    Wen Yang, Yang Wang, Jianying Shang, Kesi Liu, Prabhakar Sharma, Juan Liu, Baoguo Li
    更新日期:2017-09-15
  • Antibiotics in the agricultural soils from the Yangtze River Delta, China
    Chemosphere (IF 4.208) Pub Date : 2017-09-15
    Jianteng Sun, Qingtao Zeng, Daniel C.W. Tsang, Lizhong Zhu, Xiangdong Li
    更新日期:2017-09-15
  • Optimization of the precursor removal of dichloroacetonitrile (DCAN), an emerging nitrogenous disinfection by-product, in an up-flow BAC filter
    Chemosphere (IF 4.208) Pub Date : 2017-09-15
    Shuai Wang, Tao Lin, Wei Chen, Han Chen

    The process parameters of the up-flow biological activated carbon filter (UBACF) were optimized in a pilot-scale trial for controlling the precursor of dichloroacetonitrile (DCAN), an emerging nitrogenous disinfection by-product. The experiments were performed using a central composite design (CCD) with the response surface methodology (RSM). The results showed that the removal efficiencies of formation potentials (FP) of DCAN increased from 28.9% to 64.4% with the optimized ozone dose, expansion rate of BAC and backwashing cycle, being scheduled to 1.52 mg/L, 27% and 9.5 d, respectively. Excitation and emission matrix (EEM) spectra indicated that the fluorescence peaks of aromatic protein (AP) and soluble microbial products-like (SMPs)-like region were weakened significantly in the effluent of improved process (IP) with optimization, which were main precursors of DCAN. The bacterial community before and after the optimization of UBACF was determined using the high-throughput sequencing technology. The class and genus of microorganism demonstrated that the IP had a more diverse microbial community and more even distribution of species in BAC filter. It was favor of the growth of Alphaproteobacteria, Bacilli and Betaproteobacteria attached to the BAC particles, which could biodegrade effectively the precursors of DCAN.

    更新日期:2017-09-15
  • Evaluation of thirteen haloacetic acids and ten trihalomethanes formation by peracetic acid and chlorine drinking water disinfection
    Chemosphere (IF 4.208) Pub Date : 2017-09-15
    Runmiao Xue, Honglan Shi, Yinfa Ma, John Yang, Bin Hua, Enos C. Inniss, Craig D. Adams, Todd Eichholz

    Free chlorine is a commonly used disinfectant in drinking water treatment. However, disinfection by-products (DBPs) are formed during water disinfection. Haloacetic acids (HAAs) and trihalomethanes (THMs) are two major groups of DBPs. Iodo-HAAs and iodo-THMs (I-HAAs and I-THMs) are formed during the disinfection of the water containing high levels of iodide and are much more toxic than their chlorinated and brominated analogs. Peracetic acid (PAA) is a strong antimicrobial disinfectant that is expected to reduce the formation of HAAs and THMs during disinfection. In this study, the formations of thirteen HAAs and ten THMs, including the iodinated forms, have been investigated during PAA disinfection and chlorination as the comparison. The DBP formations under different iodide concentrations, pHs, and contact times were systematically investigated. Two types of commercial PAAs containing different concentrations of PAA and hydrogen peroxide (H2O2) were studied. A solid-phase microextraction gas chromatography-mass spectrometry method was upgraded for THM analysis including I-THMs. HAAs were analyzed by following a recently developed high performance ion chromatography-tandem mass spectrometry method. Results show that the ratio of PAA and H2O2 concentration significantly affect the formation of I-THMs and I-HAAs. During PAA disinfection with lower PAA than H2O2, no detectable levels of THMs and HAAs were observed. During PAA disinfection with higher PAA than H2O2, low levels of monoiodoacetic acid, diiodoacetic acid, and iodoform were formed, and these levels were enhanced with the increase of iodide concentration. No significant quantities of choro- or bromo-THMs and HAAs were formed during PAA disinfection treatment.

    更新日期:2017-09-15
  • Seasonal Variations in The Atmospheric Concentrations of Polychlorinated Biphenyls in Kuwait
    Chemosphere (IF 4.208) Pub Date : 2017-09-15
    Bondi Gevao, Massimiliano Porcelli, Smitha Rajagopalan, Divya Krishnan, Karell Martinez-Guijarro, Hassan Alshemmari, Majed Bahloul, Jamal Zafar

    The spatial and temporal variations in the atmospheric concentrations of PCBs were concomitantly measured at several sites over a twelve-month period in Kuwait to examine seasonal variability and urban-rural concentration gradients using two sampling methods. The annual mean (and range) of ∑PCB concentrations measured using high volume samplers was 10.8 (1.2 – 32) pg m-3at the remote site and 39.4 (1.1 – 128) pg m-3at the urban site. The median concentrations of ΣPCBs at the urban location (30.3 pg m-3) was significantly higher (p < 0.001) that that measured at the remote location (8.6 pg m-3) consistent with the view that urban centers are an important net source of these compounds to the environment. Passive sampler derived concentrations across the country showed a uniform distribution except at a few locations in the vicinity of suspected sources where elevated concentrations were measured. As with active sampling data, the concentrations measured using passive samplers were higher in urban areas (range, 4 – 78 pg/m3) compared to remote sites (range, 2.2-17 pg/m3). The concentrations measured at some urban sites correlated extremely well with mean temperature during the deployment period whereas temperature correlations with measured concentrations were negative at remote and semi-rural sites suggesting that air-surface exchange maybe a key driving mechanism of the current levels of PCBs in Kuwait.

    更新日期:2017-09-15
  • Melamine-based dendrimer amine-modified magnetic nanoparticles as an efficient Pb(II) adsorbent for wastewater treatment: Adsorption optimization by response surface methodology
    Chemosphere (IF 4.208) Pub Date : 2017-09-14
    Fatemeh Jiryaei Sharahi, Afsaneh Shahbazi

    Magnetic Fe3O4 nanoparticles with an average diameter of 64 nm was synthesized solvothermically and subsequently modified with melamine-based dendrimer amine (MDA–Fe3O4) via grafting method. The synthesized materials were characterized using DLS, SEM, XRD, FTIR, VSM, TGA and elemental analysis techniques. The MDA–Fe3O4 was employed for the efficient removal of Pb(II) ions from an aqueous solution. The adsorption efficiency was investigated in relation to the independent variables of Pb(II) concentration (80–250 mg L−1), pH of the solution (3–7), adsorbent dosage (0.1–0.5 g L−1) and temperature (10–40 °C) via a central composite design (CCD) using response surface methodology (RSM). The significance of independent variables and their interactions was tested using ANOVA at a 95% confidence limit (α = 0.05). A second-order quadratic model was established to predict the adsorption efficiency. Under the optimum condition (initial Pb(II) concentration = 110 mg L−1, MDA-Fe3O4 dosage = 0.49 g L−1, pH = 5 and temperature = 30 °C) a removal percentage of 85.6% was obtained. The isotherm data fitted well to the Freundlich model within the concentration range of the experimental study. A maximum adsorption capacity of 333.3 mg g−1 was predicted by the Langmuir model. The adsorption rate of Pb(II) ions onto MDA–Fe3O4 was in good agreement with the pseudo-second-order model (R2 = 0.999; k2 = 4.7 × 10−4 g mg−1min−1). Thermodynamically, adsorption was spontaneous and endothermic. The MDA–Fe3O4 was successfully regenerated using 0.3 M HCl with little loss of adsorption capacity (≈7%) for five successive adsorption cycles.

    更新日期:2017-09-15
  • A bioconcentration factors and Plant–Water partition coefficients of munitions compounds in barley
    Chemosphere (IF 4.208) Pub Date : 2017-09-14
    Tifany L. Torralba–Sanchez, Dave T.F. Kuo, Herbert E. Allen, Dominic M. Di Toro
    更新日期:2017-09-15
  • Source profiles and contributions of biofuel combustion for PM2.5, PM10 and their compositions, in a city influenced by biofuel stoves
    Chemosphere (IF 4.208) Pub Date : 2017-09-14
    Ying-Ze Tian, Jia-Bao Chen, Lin-Lin Zhang, Xin Du, Jin-Jin Wei, Hui Fan, Jiao Xu, Hai-Ting Wang, Liao Guan, Guo-Liang Shi, Yin-Chang Feng
    更新日期:2017-09-15
  • Survey of ecological environmental conditions and influential factors for public parks in Shanghai
    Chemosphere (IF 4.208) Pub Date : 2017-09-14
    Lina Wang, Jiang Chang, Xinran Zheng, Jing Liu, Mingzhou Yu, LiLi Liu, Yi Yang, Huige Zhang
    更新日期:2017-09-15
  • Global assessment of calcium channel blockers in the environment: Review and analysis of occurrence, ecotoxicology and hazards in aquatic systems
    Chemosphere (IF 4.208) Pub Date : 2017-09-14
    Gavin N. Saari, W. Casan Scott, Bryan W. Brooks

    As an urban water cycle is increasingly realized, aquatic systems are influenced by sewage and wastewater effluent discharges of variable quality. Such urbanization results in exposures of non-target aquatic organisms to medicines and other contaminants. In the present study, we performed a unique global hazard assessment of calcium channel blockers (CCB) in multiple environmental matrices. Effluent and freshwater observations were primarily from North America (62% and 76%, respectively) and Europe (21% and 10%, respectively) with limited-to-no information from rapidly urbanizing regions of developing countries in Asia-Pacific, South America, and Africa. Only 9% and 18% of occurrence data were from influent sewage and marine systems, though developing countries routinely discharge poorly treated wastewater to heavily populated coastal regions. Probabilistic environmental exposure distribution (EED) 5th and 95th percentiles for all CCBs were 1.5 and 309.1 ng/L in influent, 5.0 and 448.7 ng/L for effluent, 1.3 and 202.3 ng/L in freshwater, and 0.17 and 12.9 ng/L in saltwater, respectively. Unfortunately, global hazards and risks of CCBs to non-target organisms remain poorly understood, particularly for sublethal exposures. Thus, therapeutic hazard values (THV) were calculated and employed during probabilistic hazard assessments with EEDs when sufficient data was available. Amlodipine and verapamil in effluents and freshwater systems exceeded THVs 28% of the time, highlighting the need to understand ecological consequences of these CCBs. This global scanning approach demonstrated the utility of global assessments to identify specific CCBs, chemical mixtures with common mechanisms of action, and geographic locations for which environmental assessment efforts appear warranted.

    更新日期:2017-09-15
  • Atmospheric deposition of mercury and cadmium impacts on topsoil in a typical coal mine city, Lianyuan, China
    Chemosphere (IF 4.208) Pub Date : 2017-09-14
    Jie Liang, Chunting Feng, Guangming Zeng, Minzhou Zhong, Xiang Gao, Xiaodong Li, Xinyue He, Xin Li, Yilong Fang, Dan Mo
    更新日期:2017-09-14
  • A case study of air quality - Pesticides and odorous phytochemicals on Kauai, Hawaii, USA
    Chemosphere (IF 4.208) Pub Date : 2017-09-14
    Jun Wang, Robert Boesch, Qing X. Li
    更新日期:2017-09-14
  • Evaluation of the sorption mechanism of ionic liquids onto multi-walled carbon nanotubes
    Chemosphere (IF 4.208) Pub Date : 2017-09-14
    Jerzy Wojsławski, Anna Białk-Bielińska, Monika Paszkiewicz, Michał Toński, Piotr Stepnowski, Joanna Dołżonek

    The knowledge of the sorption mechanism of different chemicals onto third generation carbon sorbents such as carbon nanotubes (CNTs) is needed in order to project systems for the effective removal of pollutants from the environment. This paper reports evaluation of the sorption mechanism of selected ionic liquids (ILs), being considered as potential pollutant in environment, onto various CNTs. CNTs characterized by the smallest diameter and the biggest surface area showed the highest sorption capacity to isolate ILs from an aqueous solution. CNTs with a bigger diameter, a functionalized surface and particularly a helical shape showed a lower sorption capacity. The sorption mechanism has been defined as complex, including van der Waals, π-π and electrostatic interactions with dominating π-π interactions. Due to the relatively high sorption coefficient (355.98 ± 20.69–6397.10 ± 355.42 L kg−1 depending on the IL) the study showed that MWCNTs can potentially be used to effectively isolate ILs from an aqueous solution. Moreover, proved in this study, the fast sorption kinetic, and uncomplicated regeneration process, leading to an even higher sorption capacity means that CNTs are promising material which could find potential applications in the treatment of water contaminated by ILs.

    更新日期:2017-09-14
  • The use of toxicokinetics and exposure studies to show that carprofen in cattle tissue could lead to secondary toxicity and death in wild vultures
    Chemosphere (IF 4.208) Pub Date : 2017-09-14
    V. Naidoo, M.A. Taggart, N. Duncan, K. Wolter, J. Chipangura, R.E. Green, T.H. Galligan
    更新日期:2017-09-14
  • Mixed sulfate-reducing bacteria-enriched microbial fuel cells for the treatment of wastewater containing copper
    Chemosphere (IF 4.208) Pub Date : 2017-09-13
    Waheed Miran, Jiseon Jang, Mohsin Nawaz, Asif Shahzad, Sang Eun Jeong, Che Ok Jeon, Dae Sung Lee
    更新日期:2017-09-14
  • Echophysiological responses to excess iron in lowland and upland rice cultivars
    Chemosphere (IF 4.208) Pub Date : 2017-09-13
    Caroline Müller, Solange Ferreira da Silveira Silveira, Danilo de Menezes Daloso, Giselle Camargo Mendes, Andrew Merchant, Kacilda Naomi Kuki, Marco Antonio Oliva, Marcelo Ehlers Loureiro, Andréa Miyasaka Almeida

    Iron (Fe) is an essential nutrient for plants but under high concentrations, such as that found naturally in clay and waterlogged soils, its toxic effect can limit production. This study aimed to investigate the stress tolerance responses exhibited by different rice cultivars. Both lowland and upland cultivars were grown under excess Fe and hypoxic conditions. Lowland cultivars showed higher Fe accumulation in roots compared with upland cultivars suggesting the use of different strategies to tolerate excess Fe. The upland Canastra cultivar displayed a mechanism to limit iron translocation from roots to the shoots, minimizing leaf oxidative stress induced by excess Fe. Conversely, the cultivar Curinga invested in the increase of R1/A, as an alternative drain of electrons. However, the higher iron accumulation in the leaves, was not necessarily related to high toxicity. Nutrient uptake and/or utilization mechanisms in rice plants are in accordance with their needs, which may be defined in relation to crop environments. Alterations in the biochemical parameters of photosynthesis suggest that photosynthesis in rice under excess Fe is primarily limited by biochemical processes rather than by diffusional limitations, particularly in the upland cultivars. The electron transport rate, carboxylation efficiency and electron excess dissipation by photorespiration demonstrate to be good indicators of iron tolerance. Altogether, these chemical and molecular patterns suggests that rice plants grown under excess Fe exhibit gene expression reprogramming in response to the Fe excess per se and in response to changes in photosynthesis and nutrient levels to maintain growth under stress.

    更新日期:2017-09-14
  • Intake of DDT and its metabolites through food items among reproductive age women in Bangladesh
    Chemosphere (IF 4.208) Pub Date : 2017-09-13
    Rehnuma Haque, Tsukasa Inaoka, Miho Fujimura, Risa Kakimoto, Daisuke Ueno
    更新日期:2017-09-14
  • Metal-free carbon materials-catalyzed sulfate radical-based advanced oxidation processes: A review on heterogeneous catalysts and applications
    Chemosphere (IF 4.208) Pub Date : 2017-09-13
    Qingxia Zhao, Qiming Mao, Yaoyu Zhou, Jianhong Wei, Xiaocheng Liu, Junying Yang, Lin Luo, Jiachao Zhang, Hong Chen, Hongbo Chen, Lin Tang
    更新日期:2017-09-14
  • Changes in activation energy and kinetics of heat-activated persulfate oxidation of phenol in response to changes in pH and temperature
    Chemosphere (IF 4.208) Pub Date : 2017-09-13
    Jie Ma, Haiyan Li, Liping Chi, Hongkun Chen, Changzhao Chen

    Persulfate (peroxydisulfate, S2O82−) is the newest oxidant used for the in situ chemical oxidation (ISCO) remediation of soil and groundwater. The present study investigated impacts of solution pH, temperature, and persulfate concentration on the reaction rate constant (k1), activation energy (Ea), and reaction order of the heat-activated persulfate process. Phenol was chosen as the model organic contaminant. As temperature increased from 30 °C to 70 °C, k1 exhibited a significant increase from 0.003 h−1∼0.962 h−1 (pH 1.3–13.9) to 1.184 h−1∼9.91 h−1 (pH 1.3–13.9), which corroborated with the activation of persulfate using heat. As pH increased from 1.3 to 13.9, k1 exhibited a 4.3-fold increase at 70 °C and a 320-fold increase at 30 °C, thereby suggesting that: 1) the phenol oxidation rate increased under alkaline conditions, and 2) the enhancement of reaction rate due to alkaline activation was more pronounced at a lower temperature. Increasing pH significantly reduced Ea from 139.7 ± 1.3 kJ/mol at pH 1.3 to 52.0 ± 3.3 kJ/mol at pH 13.9. In contrast to changing pH, increasing persulfate concentration from 20 to 320 mM significantly increased k1 but did not affect Ea. Changes in Ea suggest that persulfate oxidation of phenol experienced different reaction pathways or elementary reaction sequences as the pH changed from 1.3 to 13.9. In addition, the k1 and Ea data also suggest that a minimal pH threshold of ∼11 was required for the effective alkaline activation of persulfate.

    更新日期:2017-09-14
  • Mercury accumulation plant Cyrtomium macrophyllum and its potential for phytoremediation of mercury polluted sites
    Chemosphere (IF 4.208) Pub Date : 2017-09-13
    Yu Xun, Liu Feng, Youdan Li, Haochen Dong

    Cyrtomium macrophyllum naturally grown in 225.73 mg kg−1 of soil mercury in mining area was found to be a potential mercury accumulator plant with the translocation factor of 2.62 and the high mercury concentration of 36.44 mg kg−1 accumulated in its aerial parts. Pot experiments indicated that Cyrtomium macrophyllum could even grow in 500 mg kg−1 of soil mercury with observed inhibition on growth but no obvious toxic effects, and showed excellent mercury accumulation and translocation abilities with both translocation and bioconcentration factors greater than 1 when exposed to 200 mg kg−1 and lower soil mercury, indicating that it could be considered as a great mercury accumulating species. Furthermore, the leaf tissue of Cyrtomium macrophyllum showed high resistance to mercury stress because of both the increased superoxide dismutase activity and the accumulation of glutathione and proline induced by mercury stress, which favorited mercury translocation from the roots to the aerial parts, revealing the possible reason for Cyrtomium macrophyllum to tolerate high concentration of soil mercury. In sum, due to its excellent mercury accumulation and translocation abilities as well as its high resistance to mercury stress, the use of Cyrtomium macrophyllum should be a promising approach to remediating mercury polluted soils.

    更新日期:2017-09-14
  • Energetic costs and biochemical biomarkers associated with esfenvalerate exposure in Sericostoma vittatum
    Chemosphere (IF 4.208) Pub Date : 2017-09-13
    Andreia C.M. Rodrigues, Carlos Gravato, Carla Quintaneiro, Maria D. Bordalo, Carlos Barata, Amadeu M.V.M. Soares, João L.T. Pestana
    更新日期:2017-09-14
  • Zerovalent iron in conjunction with surfactants to remediate sediments contaminated by polychlorinated biphenyls and nickel
    Chemosphere (IF 4.208) Pub Date : 2017-09-13
    Yingxin Wu, Yu Wang, Xiongfei Huang, Siyuan Chen, Xi Zhong, Zhuobiao Ni, Xinde Cai, Xiaowen Liu, Marie-Odile Simonnot, Rongliang Qiu
    更新日期:2017-09-14
  • Polybrominated diphenyl ethers and indicator polychlorinated biphenyls in human milk from China under the Stockholm Convention
    Chemosphere (IF 4.208) Pub Date : 2017-09-13
    Lei Zhang, Shuaixing Yin, Yunfeng Zhao, Zhixiong Shi, Jingguang Li, Yongning Wu

    Seven congeners of polybrominated diphenyl ethers (PBDEs) (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153,BDE-154 and BDE-183) and six indicator polychlorinated biphenyls (PCBs) (PCB-28, PCB-52, PCB-101, PCB-138, PCB-153 and PCB-180) were measured in 32 regional pooled human milk samples originating from 1760 volunteering primiparous mothers to evaluate the current human body burden of general population and the temporal trend in China. Individual human milk samples were collected following a WHO-designed procedure. This work is one of parts of the evaluation of effectiveness of Stockholm Convention performance. The concentration of ∑7PBDEs ranged from 0.3 ng g−1 lipid to 4.0 ng g−1 lipid with a mean of 1.5 ng g−1 lipid. The concentration of ∑6PCBs ranged from 2.3 ng g−1 lipid to 19.0 ng g−1 lipid with a mean of 6.6 ng g−1 lipid. By comparing with background determination in 2007, there was no significance for ∑7PBDEs. However, BDE-47, BDE-99, and BDE-100 significantly decreased with an average of 45%, 48%, and 46%, respectively, from 2007 to 2011, and an increase of BDE-183 was founded in most regions. For ∑6PCBs, there was a significant decline with an average reduction of 41% from 2007 to 2011. These results indicate the effectiveness of reduction and elimination of POPs in China. Future national human milk biomonitoring is worthy to be done to further evaluate the time trend and effectiveness of the Convention performance.

    更新日期:2017-09-14
  • Identification, assessment and prioritization of ecotoxicological risks on the scale of a territory: application to WWTP discharges in a geographical area located in northeast Lyon, France
    Chemosphere (IF 4.208) Pub Date : 2017-09-13
    Alain Brus, Yves Perrodin

    The ecotoxicological risk assessment methodologies developed up to now mainly focus on local pollution and do not incorporate an evaluation and prioritization of the different risk situations present in the same territory. This article presents the different phases of formulating an innovative methodology developed to fill this gap, and its application to all the 18 WasteWater Treatment Plants (WWTP) of a geographical area located northeast of Lyon, France. The aim was also take into account emerging pollutants that are very often “forgotten” in ecotoxicological risk assessments. The results of the study show the extreme diversity of the ecotoxicity of the pollutants present in discharges, with “minimum” PNEC values in the region of a millionth of a microgram (10-6 μg/l) and “maximum” PNEC values in the region of several tens of micrograms. They also show very considerable diversity of the flows of the receiving watercourses in the territory concerned (from several m3/s to 600m3/s). The Risk Quotients (RQ) resulting from these 2 datasets, calculated for each WWTP and for each of the 10 pollutants most implicated in ecotoxicological risks (Diclofenac, Amoxicillin, Trimethoprim, Roxithromycin, 17β-estradiol, 17α-Ethynylestradiol, Estrone, Nonylphenol, Octylphenol, Nickel, et NH4+), vary from 0.000002 to 187.7 when using the median concentration values of these pollutants, and from 0.000007 to 3750 when using their maximum concentration values. Globally, they show that: (1) the risks are higher for small streams that receive WWTP discharges of average size, (2) the risks are low to very low for discharges into watercourses with high flow rates.

    更新日期:2017-09-13
  • An interspecies correlation model to predict acute dermal toxicity of plant protection products to terrestrial life stages of amphibians using fish acute toxicity and bioconcentration data
    Chemosphere (IF 4.208) Pub Date : 2017-09-12
    Lennart Weltje, Philipp Janz, Peter Sowig

    This paper presents a model to predict acute dermal toxicity of plant protection products (PPPs) to terrestrial amphibian life stages from (regulatory) fish data. By combining existing concepts, including interspecies correlation estimation (ICE), allometric relations, lethal body burden (LBB) and bioconcentration modelling, an equation was derived that predicts the amphibian median lethal dermal dose (LD50) from standard acute toxicity values (96-h LC50) for fish and bioconcentration factors (BCF) in fish. Where possible, fish BCF values were corrected to 5% lipid, and to parent compound. Then, BCF values were adjusted to an exposure duration of 96 hours, in case steady state took longer to be achieved. The derived correlation equation is based on 32 LD50 values from acute dermal toxicity experiments with 15 different species of anuran amphibians, comprising 15 different PPPs. The developed ICE model can be used in a screening approach to estimate the acute risk to amphibian terrestrial life stages from dermal exposures to PPPs with organic active substances. This has the potential to reduce unnecessary testing of vertebrates.

    更新日期:2017-09-13
  • Current-use flame retardants: Maternal exposure and neurodevelopment in children of the CHAMACOS cohort
    Chemosphere (IF 4.208) Pub Date : 2017-09-12
    Rosemary Castorina, Asa Bradman, Heather M. Stapleton, Craig Butt, Dylan Avery, Kim G. Harley, Robert B. Gunier, Nina Holland, Brenda Eskenazi

    Flame retardants are commonly used in consumer products found in U.S. households. Restrictions on the use of polybrominated diphenyl ether flame retardants have resulted in increased use of replacement chemicals, including Firemaster 550® (FM 550®) and organophosphate flame retardants (PFRs): tris(1,3- dichloro-2-propyl) phosphate (TDCIPP); tris(chloropropyl) phosphate (TCIPP); tris(2-chloroethyl) phosphate (TCEP); and triphenyl phosphate (TPHP). Animal research suggests that PFRs may affect neurodevelopment through noncholinergic mechanisms similar to some organophosphate (OP) pesticides. Despite the widespread presence of these compounds in home environments, and their structural similarity to neurotoxic OP pesticides, understanding of human exposure and health effects of PFRs is limited. We measured four urinary PFR metabolites from pregnant women in the CHAMACOS birth cohort study (n = 310) and assessed neurodevelopment of their children at age 7. Metabolites of TDCIPP (BDCIPP: bis(1,3-dichloro-2-propyl) phosphate) and TPHP (DPHP: diphenyl phosphate) were detected in >75% of urine samples, and isopropylphenyl phenyl phosphate (ip-PPP), a metabolite of one component of FM 550®, was detected in 72% of urine samples. We observed decreases of 2.9 points (95% Confidence Interval (CI): −6.3, 0.5) and 3.9 points (95% CI: −7.3,-0.5) in Full-Scale intelligence quotient and Working Memory, respectively, for each ten-fold increase in DPHP in adjusted regression models (n = 248). Decreases in Full-Scale IQ and Working Memory were greater in models of the molar sum of the PFR metabolites compared to the DPHP models. This is the first study to examine PFR and FM 550® exposures and potential neurodevelopmental outcomes in pregnant women and children. Additional research is warranted.

    更新日期:2017-09-13
  • A novel A-B process for enhanced biological nutrient removal in municipal wastewater reclamation
    Chemosphere (IF 4.208) Pub Date : 2017-09-12
    Guangjing Xu, Han Wang, Jun Gu, Nan Shen, Zheng Qiu, Yan Zhou, Yu Liu

    This study developed an innovative A-B process for enhanced nutrients removal in municipal wastewater reclamation, in which a micro-aerated moving bed biofilm reactor served as A-stage and a step-feed sequencing batch reactor (SBR) as B-stage. In the A-stage, 55% of COD and 15% of ammonia nitrogen was removed, while more than 88% of the total nitrogen was removed via nitritation and denitritation, together with 93% of phosphorous removal at the B-stage where ammonia oxidizing bacteria activity was significantly higher than nitrite oxidizing bacteria activity. Meanwhile substantial phenotype of polyphosphate accumulating organisms (PAOs) was also observed in the B-stage SBR. Fluorescence in situ hybridization revealed that Accumulibacter was the dominant PAOs with undetectable Competibacter. Compared to the conventional activated sludge process, the proposed A-B process could offer a more cost-effective alternative for enhanced biological nutrients removal from municipal wastewater with less energy consumption.

    更新日期:2017-09-13
  • Effective removal of trace thallium from surface water by nanosized manganese dioxide enhanced quartz sand filtration
    Chemosphere (IF 4.208) Pub Date : 2017-09-12
    Xiaoliu Huangfu, Chengxue Ma, Jun Ma, Qiang He, Chun Yang, Jian Zhou, Jin Jiang, Yaan Wang

    Thallium (Tl) has drawn wide concern due to its high toxicity even at extremely low concentrations, as well as its tendency for significant accumulation in the human body and other organisms. The need to develop effective strategies for trace Tl removal from drinking water is urgent. In this study, the removal of trace Tl (0.5 μg L−1) by conventional quartz sand filtration enhanced by nanosized manganese dioxide (nMnO2) has been investigated using typical surface water obtained from northeast China. The results indicate that nMnO2 enhanced quartz sand filtration could remove trace Tl(I) and Tl(III) efficiently through the adsorption of Tl onto nMnO2 added to a water matrix and onto nMnO2 attached on quartz sand surfaces. Tl(III)-HA complexes might be responsible for higher residual Tl(III) in the effluent compared to residual Tl(I). Competitive Ca2+ cations inhibit Tl removal to a certain extent because the Ca2+ ions will occupy the Tl adsorption site on nMnO2. Moreover, high concentrations of HA (10 mgTOC L−1), which notably complexes with and dissolves nMnO2 (more than 78%), resulted in higher residual Tl(I) and Tl(III). Tl(III)-HA complexes might also enhance Tl(III) penetration to a certain extent. Additionally, a higher pH level could enhance the removal of trace Tl from surface water. Finally, a slight increase of residual Tl was observed after backwash, followed by the reduction of the Tl concentration in the effluent to a “steady” state again. The knowledge obtained here may provide a potential strategy for drinking water treatment plants threatened by trace Tl.

    更新日期:2017-09-13
  • Characterisation of artisanal mine waste on Buru Island, Indonesia and toxicity to the brittle star Amphipholis squamata
    Chemosphere (IF 4.208) Pub Date : 2017-09-12
    Amanda J. Reichelt-Brushett, Bernard Thomas, Pelli L. Howe, Yusthinus Male, Malcolm W. Clark

    Artisanal small-scale gold mining (ASGM) using mercury (Hg) amalgamation commenced on Buru Island, Indonesia, in 2012, but was halted in 2015 due to concerns of widespread Hg contamination. Much of the Hg used in the mining process is lost to trommel waste which is disposed of in settlement ponds that drain into adjacent waterways and into Kayeli Bay. Several thousand unmanaged trommel sites and associated tailing ponds exist on Buru Island. This study shows that waste from the Marloso trommel at the Gogrea site contained 203 mg/kg total Hg (THg), with a negligible proportion present as bioavailable methyl Hg (MeHg) and a low total organic carbon content. There are currently very few tools available for ecotoxicological risk assessment of mine tailings for tropical marine ecosystems, and we support the development of Tailings Toxicity Tests (TTTs) and describe laboratory toxicity test methods using the cosmopolitan benthic echinoderm Amphipholis squamata. Undiluted trommel waste caused 100% mortality of A. squamata within 48 h, and a 96-h LC50 of 6.7% w/w trommel waste (4 mg/kg THg) was estimated. Sub-lethal effects on the water vascular system of the brittle star were assessed by quantification of the Ability to Right Itself (ARI), and a 48-h EC50 of 7.3% w/w trommel waste (14.4 mg/kg THg) was estimated. The results show that trommel waste produced on Buru Island is highly contaminated with THg and is acutely toxic, raising serious concern for receiving ecosystems where Hg methylation to more toxic and bioavailable forms is likely.

    更新日期:2017-09-13
  • Achieving enhanced denitrification via hydrocyclone treatment on mixed liquor recirculation in the anoxic/aerobic process
    Chemosphere (IF 4.208) Pub Date : 2017-09-12
    Yi Liu, Hualin Wang, Yinxiang Xu, Qingsong Tu, Xiurong Chen
    更新日期:2017-09-13
  • Investigating sources and sinks of N2O expression from freshwater microbial communities in urban watershed sediments
    Chemosphere (IF 4.208) Pub Date : 2017-09-11
    Christopher Weisener, Jumin Lee, Subba Rao Chaganti, Thomas Reid, Nick Falk, Ken Drouillard
    更新日期:2017-09-13
  • Ammonium-based fertilizers enhance Cd accumulation in Carpobrotus rossii grown in two soils differing in pH
    Chemosphere (IF 4.208) Pub Date : 2017-09-11
    Miaomiao Cheng, Anan Wang, Caixian Tang

    Nitrogen fertilization has been shown to improve Cd uptake by plants but there is little information on the effects of N forms. This study examined the effects of N form on Cd bioavailability and phytoextraction in two soils differing in pH. Plants of halophytic species Carpobrotus rossii were grown in an acidic Sodosol [pH (CaCl2) 4.9] and a neutral Vertosol (pH 7.2) spiked with 20 mg kg−1 Cd as CdCl2. Three N forms, KNO3, (NH4)2SO4 and (NH2)2CO at a rate of 24 mg N kg−1 were applied at weekly intervals, together with nitrification inhibitor dicyanodiamide (DCD). Cadmium availability was measured, and Cd speciation in the rhizosphere analysed using synchrotron-based X-ray absorption spectroscopy. The uptake, translocation and accumulation of Cd in plants were also assessed. The reduced N forms (NH4+ and urea), compared to NO3−-N, decreased rhizosphere pH by 0.25 units in Sodosol and 0.72 units in Vertosol, but decreased Cd-phosphate (by 23%) only in the Vertosol. Moreover, the reduced N forms increased the extractable Cd concentration in the rhizosphere of the Vertosol by 92% and of the Sodosol by 14%. They increased root Cd concentration by 70% and Cd uptake per unit root length by 40% in the Vertosol, and increased the translocation of Cd from the roots to the shoots by 76% in the Sodosol. The results suggest that the supply of NH4+-based N favors Cd phytoextraction in C. rossii.

    更新日期:2017-09-13
  • Migration and distribution of sodium ions and organic matters during electro-dewatering of waste activated sludge at different dosages of sodium sulfate
    Chemosphere (IF 4.208) Pub Date : 2017-09-09
    Jun Xiao, Xu Wu, Wenbo Yu, Sha Liang, Jiangwei Yu, Yueyuan Gu, Huali Deng, Jiukun Hu, Keke Xiao, Jiakuan Yang
    更新日期:2017-09-13
  • A new V-doped Bi2(O,S)3 oxysulfide catalyst for highly efficient catalytic reduction of 2-nitroaniline and organic dyes
    Chemosphere (IF 4.208) Pub Date : 2017-09-08
    Angaw Kelemework Abay, Dong-Hau Kuo, Xiaoyun Chen, Albert Daniel Saragih
    更新日期:2017-09-13
  • Novel (5-nitrofurfuryl)-substituted esters of phosphonoglycine – Their synthesis and phyto- and ecotoxicological properties
    Chemosphere (IF 4.208) Pub Date : 2017-09-08
    Jarosław Lewkowski, Marta Morawska, Rafał Karpowicz, Piotr Rychter, Diana Rogacz, Kamila Lewicka
    更新日期:2017-09-13
  • The enhancement of atrazine sorption and microbial transformation in biochars amended black soils
    Chemosphere (IF 4.208) Pub Date : 2017-09-08
    Fan Yang, Wei Zhang, Jinmei Li, Shuyao Wang, Yue Tao, Yifan Wang, Ying Zhang
    更新日期:2017-09-13
  • Nano-sized emission from commercially available paints used for indoor surfaces during drying
    Chemosphere (IF 4.208) Pub Date : 2017-09-08
    Rikke Bramming Jørgensen, Ingrid Grav Hveding, Karoline Solheim

    Consumers worry about the presence of nano-particles in paints and the risk of exposure. As a result, the paint industry now omits marketing paints as containing nanoparticles. The industry claims that no nanoparticles are released into the indoor environment; this, however, has yet to be documented. In this study, the emission of nano-sized emission from four indoor paints was investigated. The emission was studied for both base and full-pigmented versions of the paints, which consisted of three water-borne acrylic paints and one solvent-borne alkyd paint. All experiments were performed twice in a 6.783 m3 stainless-steel test chamber under standardized conditions (22.98°C, 50.08% RH, air exchange rate 0.48 h-1). Emissions during the paint-drying period were measured using a TSI Fast Mobility Particle Sizer (FMPS) measuring the number concentration of nano-particles and the size distribution in the range 5.6–560 nm.The results from the solvent-borne paint showed the highest concentration, with a mean concentration of 3.2·105 particles/cm3 and a maximum of 1.4·106 particles/cm3. This paint also had the smallest particle size distribution, with 9.31 nm particles as the most dominant particle size. The results from this study showed that the exposure to nanoparticles for the residents evaluated over a 7 or 28 day period was low and that interior paints are probably not very important when it comes to identifying products that release nano-particles into indoor environments.

    更新日期:2017-09-13
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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