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Influence of surface properties of RO membrane on membrane fouling for treating textile secondary effluent Full text
2017
Reverse osmosis (RO) is a promising technology for treating and reusing textile secondary effluent (SE). To better understand the effect of membrane surface properties on membrane fouling, the performances of three commercial polyamide thin-film composite RO membranes (BW30-4040, CPA2-4040, and RE-4040-FEN) with different roughness and hydrophilicity were investigated for treating textile SE. The RO membranes were characterized by ATR-FTIR, SEM, AFM, and contact angle, respectively. The results showed that the flux increased with an increase in the surface hydrophilicity of membrane. CPA2-4040 had the highest hydrophilic surface and thus the largest initial flux. There was a strong correlation between the membrane fouling and the surface roughness; the fouling increased with an increase in the surface roughness. The roughest surface of CPA2-4040 led to the most significantly flux decline. However, the fouling reversibility was not related directly to surface roughness. BW30-4040 with the secondary roughness and the most hydrophobic surface had the highest fouling reversibility. This was mainly due to the primary hydrophilicity of textile SE in nature. Fluorescence excitation-emission matrix (EEM) showed that hydrophilic neutral protein-like matters and soluble microbial products (SMP) were the main foulants, thus stronger affinity with hydrophilic surface of membrane. Graphical abstract ᅟ
Show more [+] Less [-]Quantitative study on nitrogen deposition and canopy retention in Mediterranean evergreen forests Full text
2017
To assess the impact of nitrogen (N) pollutants on forest ecosystems, the role of the interactions in the canopy needs to be understood. A great number of studies have addressed this issue in heavily N-polluted regions in north and central Europe. Much less information is available for the Iberian Peninsula, and yet this region is home to mountain forests and alpine grasslands that may be at risk due to excessive N deposition. To establish the basis for ecology-based policies, there is a need to better understand the forest response to this atmospheric impact. To fill this gap, in this study, we measured N deposition (as bulk, wet, and throughfall fluxes of dissolved inorganic nitrogen) and air N gas concentrations from 2011 to 2013 at four Spanish holm oak (Quercus ilex) forests located in different pollution environments. One site was in an area of intensive agriculture, two sites were influenced by big cities (Madrid and Barcelona, respectively), and one site was in a rural mountain environment 40 km north of Barcelona. Wet deposition ranged between 0.54 and 3.8 kg N ha⁻¹ year⁻¹ for ammonium (NH₄⁺)-N and between 0.65 and 2.1 kg N ha⁻¹ year⁻¹ for nitrate (NO₃⁻)-N, with the lowest deposition at the Madrid site for both components. Dry deposition was evaluated with three different approaches: (1) a canopy budget model based in throughfall measurements, (2) a branch washing method, and (3) inferential calculations. Taking the average dry deposition from these methods, dry deposition represented 51–67% (reduced N) and 72–75% (oxidized N) of total N deposition. Canopies retained both NH₄⁺-N and NO₃-N, with a higher retention at the agricultural and rural sites (50–60%) than at sites located close to big cities (20–35%, though more uncertainty was found for the site near Madrid), thereby highlighting the role of the forest canopy in processing N pollutant emissions.
Show more [+] Less [-]Adsorption of 1,2-dichlorobenzene and 1,2,4-trichlorobenzene in nano- and microsized crystals of MIL-101(Cr): static and dynamic gravimetric studies Full text
2017
This work aims to highlight the promising adsorption capacity and kinetic of (poly)chlorobenzene pollutants in the hybrid MIL-101(Cr) type material for technological uses in industrial waste exhaust decontamination. The influence of the MIL-101(Cr) crystal size (nano- and microcrystals) on the adsorption behavior was studied in static and dynamic modes. For this purpose, crystals of MIL-101(Cr) in nano- and micrometric sizes were synthesized and fully characterized. Their sorption properties regarding 1,2-dichlorobenzene were examined using gravimetric method in dynamic (p/p° = 0.5) and static (p/p° = 1) modes at room temperature. 1,2,4-trichlorobenzene adsorption was only performed under static mode because of its too low vapor pressure. 1,2-dichlorobenzene and 1,2,4-trichlorobenzene were used to mimic 2,3-dichlorodibenzo-p-dioxin and 1,2,3,4-tetrachlorodibenzo-p-dioxin, respectively, and more largely dioxin compounds. Adsorptions of these probes were successfully carried out in nano- and microcrystals of MIL-101(Cr). Indeed, in static mode (p/p° = 1) and at room temperature, nanocrystals adsorb 2266 molecules of 1,2-dichlorobenzene and 2093 molecules of 1,2,4-trichlorobenzene per unit cell, whereas microcrystals adsorb 1871 molecules of 1,2-dichlorobenzene and 1631 molecules of 1,2,4-trichlorobenzene per unit cell. In dynamic mode, the 1,2-dichlorobenzene adsorbed amounts are substantially similar to those obtained in static mode. However, the adsorption kinetics are different because of a different scheme of diffusivity of the adsorbate between the two modes. To the best of our knowledge, these adsorption capacities of MIL-101(Cr) as adsorbent for polychlorobenzenes trapping have never been referenced. MIL-101(Cr) appears as a promising material for technological uses in industrial waste exhaust decontamination.
Show more [+] Less [-]Fullerol C60(OH)24 nanoparticles and mycotoxigenic fungi: a preliminary investigation into modulation of mycotoxin production Full text
2017
Increased use of fullerols in various fields and expected increase of their environmental spread impose the necessity for testing fullerol nanoparticles (FNP) effects on microbiota. There is little information available on the interaction of mycotoxigenic fungi and FNP, despite FNP having a great potential of modifying mycotoxin production. Namely, FNP exhibit both ROS-quenching and ROS-producing properties, while oxidative stress stimulates mycotoxin synthesis in the fungi. In order to shed some light on the extent of interaction between FNP and mycotoxigenic fungi, the effects of fullerol C₆₀(OH)₂₄ nanoparticles (10, 100, 1000 ng/mL) on mycelial growth, aflatoxin production and oxidative stress modulation in an aflatoxigenic strain of Aspergillus flavus (NRRL 3251) during 168 h of incubation in a liquid culture medium were examined. FNP slightly reduced mycelial biomass weight, but significantly decreased aflatoxin concentration in media. Lipid peroxide content, superoxide dismutase, catalase and glutathione peroxidase activities suggest that FNP treatments hormetically reduced oxidative stress within fungal cells in turn suppressing aflatoxin production. These findings contribute to the assessment of environmental risk and application potential of fullerols.
Show more [+] Less [-]Effects of small hydropower plants on mercury concentrations in fish Full text
2017
Although the impacts of large dams on freshwater biota are relatively well known, the effects of small hydropower plants (SHP) are not well investigated. In this work, we studied if mercury (Hg) concentrations in fish rise in two tropical SHP reservoirs, and whether similar effects take place during impoundment. Total Hg concentrations in several fish species were determined at two SHP in the Upper Guaporé River basin floodplain, Brazil. In total, 185 specimens were analysed for Hg content in dorsal muscle and none of them reported levels above the safety limit (500 μg kg⁻¹) for fish consumption recommended by the World Health Organisation (WHO). The highest levels of Hg (231 and 447 μg kg⁻¹) were found in carnivorous species in both reservoirs. Mercury increased as a function of standard length in most of the fish populations in the reservoirs, and higher Hg concentrations were found in fish at the reservoir compared with fish downstream. The high dissolved oxygen concentrations and high transparency of the water column (i.e. oligotrophic reservoir) together with the absence of thermal stratification may explain low Hg methylation and low MeHg levels found in fish after flooding. Overall, according to limnological characteristics of water, we may hypothesise that reservoir conditions are not favourable to high net Hg methylation.
Show more [+] Less [-]Particle size distribution and gas–particle partitioning of polychlorinated biphenyls in the atmosphere in Beijing, China Full text
2017
Zhu, Qingqing | Zheng, Minghui | Liu, Guorui | Zhang, Xian | Dong, Shujun | Gao, Lirong | Liang, Yong
Size-fractionated samples of urban particulate matter (PM; ≤1.0, 1.0–2.5, 2.5–10, and >10 μm) and gaseous samples were simultaneously obtained to study the distribution of polychlorinated biphenyls (PCBs) in the atmosphere in Beijing, China. Most recent investigations focused on the analysis of gaseous PCBs, and much less attention has been paid to the occurrence of PCBs among different PM fractions. In the present study, the gas–particle partitioning and size-specific distribution of PCBs in atmosphere were investigated. The total concentrations (gas + particle phase fractions) of Σ₁₂ dioxin-like PCBs, Σ₇ indicator PCBs, and ΣPCBs were 1.68, 42.1, and 345 pg/m³, respectively. PCBs were predominantly in the gas phase (86.8–99.0 % of the total concentrations). The gas–particle partition coefficients (K ₚ) of PCBs were found to be a significant linear correlated with the subcooled liquid vapor pressures (P L ⁰) (R ² = 0.83, P < 0.01). The slope (m ᵣ) implied that the gas–particle partitioning of PCBs was affected both by the mechanisms of adsorption and absorption. In addition, the concentrations of PCBs increased as the particle size decreased (>10, 2.5–10, 1.0–2.5, and ≤1.0 μm), with most of the PCBs contained in the fraction of ≤1.0 μm (53.4 % of the total particulate concentrations). Tetra-CBs were the main homolog in the air samples in the gas phase and PM fractions, followed by tri-CBs. This work will contribute to the knowledge of PCBs among different PM fractions and fill the gap of the size distribution of particle-bound dioxin-like PCBs in the air.
Show more [+] Less [-]Antimicrobial activity and acute toxicity of ozonated lomefloxacin solution Full text
2017
de Oliveira, Amanda Marchi Duarte | Maniero, Milena Guedes | Rodrigues-Silva, Caio | Guimarães, José Roberto
Lomefloxacin (LOM) is a synthetic antimicrobial from the fluoroquinolone family (FQ) used as a veterinary and human drug. Once in the environment, LOM may pose a risk to aquatic and terrestrial microorganisms due to its antimicrobial activity. This study evaluated the effect of ozonation of LOM (500 μg L⁻¹), the residual antimicrobial activity against Escherichia coli and acute toxicity against Vibrio fischeri. In addition, degradation products were investigated by UHPLC-MS/MS and proposed. Ozonation was carried out varying the applied ozone dose from 0 to 54.0 mg L⁻¹ O₃ and pH values of 3, 7, and 11. Ozonation was most efficient at pH 11 and led to 92.8% abatement of LOM in a 9-min reaction time (54.0 mg L⁻¹ O₃ applied ozone dose). Ozonation at pH 3 was able to degrade 80.4% of LOM. At pH 7, 74.3% of LOM was degraded. Although the LOM concentration and the antimicrobial activity of the solution dropped as ozone dose increased (antimicrobial activity reduction of 95% at pH 11), toxicity to V. fischeri increased for pH 7 and 11 (i.e., 65% at pH 7 and 75% at pH 11). The reduction in antimicrobial activity may be related to the oxidation of piperazinyl and the quinolone moiety. The formation of intermediates depended on the oxidant (hydroxyl radicals or/and molecular O₃) that acted the most in the process.
Show more [+] Less [-]Reactive Black 5 dye degradation using filters of smuggled cigarette modified with Fe3+ Full text
2017
Glugoski, Letícia Polli | de Jesus Cubas, Paloma | Fujiwara, Sérgio Toshio
This study presents an attempt to solve two serious environmental problems: the generation of toxic effluents and solid waste disposal. The work proposes recycling cigarette filters with the purpose of degrading reactive dyes, which are used in the textile industry. Filters of smuggled cigarettes were recycled through Fe³⁺ immobilization on their surface. The material obtained was characterized through Fourier transform infrared spectroscopy (FTIR), atomic absorption spectroscopy (AAS), scanning electron microscopy–energy-dispersive spectroscopy (SEM-EDS), and ultraviolet–visible spectroscopy (UV–vis). The factorial design revealed that the most suitable conditions for the degradation of Reactive Black 5 dye were obtained by using 1 g of material at pH 3.0 in a 100 mg L⁻¹ hydrogen peroxide solution. The material showed excellent performance in the Reactive Black 5 dye degradation process; in 60 min, 99.09 % dye was removed. At pH 7.0, the dye degradation was 72.67 %, indicating that the material prepared can be used at pH values greater than 3.0 without the occurrence of hydrated Fe³⁺ oxide precipitation. Furthermore, the material showed no loss of catalytic activity after three degradation studies.
Show more [+] Less [-]Catchment land use-dependent effects of barrage fishponds on the functioning of headwater streams Full text
2017
Four, Brian | Arce, Evelyne | Danger, Michaël | Gaillard, Juliette | Thomas, Marielle | Banas, Damien
Catchment land use-dependent effects of barrage fishponds on the functioning of headwater streams Full text
2017
Four, Brian | Arce, Evelyne | Danger, Michaël | Gaillard, Juliette | Thomas, Marielle | Banas, Damien
Extensive fish production systems in continental areas are often created by damming headwater streams. However, these lentic systems favour autochthonous organic matter production. As headwater stream functioning is essentially based on allochthonous organic matter (OM) supply, the presence of barrage fishponds on headwater streams might change the main food source for benthic communities. The goal of this study was thus to identify the effects of barrage fishponds on the functioning of headwater streams. To this end, we compared leaf litter breakdown (a key ecosystem function in headwater streams), their associated invertebrate communities and fungal biomass at sites upstream and downstream of five barrage fishponds in two dominant land use systems (three in forested catchments and two in agricultural catchments). We observed significant structural and functional differences between headwater stream ecosystems in agricultural catchments and those in forested catchments. Leaf litter decay was more rapid in forest streams, with a moderate, but not significant, increase in breakdown rate downstream from the barrage fishponds. In agricultural catchments, the trend was opposite with a 2-fold lower leaf litter breakdown rate at downstream sites compared to upstream sites. Breakdown rates observed at all sites were closely correlated with fungal biomass and shredder biomass. No effect of barrage fishponds were observed in this study concerning invertebrate community structure or functional feeding groups especially in agricultural landscapes. In forest streams, we observed a decrease in organic pollution (OP)-intolerant taxa at downstream sites that was correlated with an increase in OP-tolerant taxa. These results highlighted that the influence of barrage fishponds on headwater stream functioning is complex and land use dependent. It is therefore necessary to clearly understand the various mechanisms (competition for food resources, complementarities between autochthonous and allochthonous OM) that control ecosystem functioning in different contexts in order to optimize barrage fishpond management.
Show more [+] Less [-]Catchment land use-dependent effects of barrage fishponds on the functioning of headwater streams Full text
2017
Four, Brian | Arce, Evelyne | Danger, Michaël | Gaillard, Juliette | Thomas, Marielle | Banas, Damien | Département Ecologie des Forêts, Prairies et milieux Aquatiques (DEPT EFPA) ; Institut National de la Recherche Agronomique (INRA) | Unité de Recherches Animal et Fonctionnalités des Produits Animaux (URAFPA) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL) | Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC) ; Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS) ; Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo) ; Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS) | Agence de l'Eau Rhin-Meuse | Zone Atelier Moselle
International audience | Extensive fish production systems in continental areas are often created by damming headwater streams. However, these lentic systems favour autochthonous organic matter production. As headwater stream functioning is essentially based on allochthonous organic matter (OM) supply, the presence of barrage fishponds on headwater streams might change the main food source for benthic communities. The goal of this study was thus to identify the effects of barrage fishponds on the functioning of headwater streams. To this end, we compared leaf litter breakdown (a key ecosystem function in headwater streams), their associated invertebrate communities and fungal biomass at sites upstream and downstream of five barrage fishponds in two dominant land use systems (three in forested catchments and two in agricultural catchments). We observed significant structural and functional differences between headwater stream ecosystems in agricultural catchments and those in forested catchments. Leaf litter decay was more rapid in forest streams, with a moderate, but not significant, increase in breakdown rate downstream from the barrage fishponds. In agricultural catchments, the trend was opposite with a 2-fold lower leaf litter breakdown rate at downstream sites compared to upstream sites. Breakdown rates observed at all sites were closely correlated with fungal biomass and shredder biomass. No effect of barrage fishponds were observed in this study concerning invertebrate community structure or functional feeding groups especially in agricultural landscapes. In forest streams, we observed a decrease in organic pollution (OP)-intolerant taxa at downstream sites that was correlated with an increase in OP-tolerant taxa. These results highlighted that the influence of barrage fishponds on headwater stream functioning is complex and land use dependent. It is therefore necessary to clearly understand the various mechanisms (competition for food resources, complementarities between autochthonous and allochthonous OM) that control ecosystem functioning in different contexts in order to optimize barrage fishpond management.
Show more [+] Less [-]The key role of biogenic manganese oxides in enhanced removal of highly recalcitrant 1,2,4-triazole from bio-treated chemical industrial wastewater Full text
2017
Wu, Ruiqin | Wu, Haobo | Jiang, Xinbai | Shen, Jinyou | Faheem, Muhammad | Sun, Xiuyun | Li, Jiansheng | Han, Weiqing | Wang, Lianjun | Liu, Xiaodong
The secondary effluent from biological treatment process in chemical industrial plant often contains refractory organic matter, which deserves to be further treated in order to meet the increasingly stringent environmental regulations. In this study, the key role of biogenic manganese oxides (BioMnOx) in enhanced removal of highly recalcitrant 1,2,4-triazole from bio-treated chemical industrial wastewater was investigated. BioMnOx production by acclimated manganese-oxidizing bacterium (MOB) consortium was confirmed through scanning electronic microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) analysis. Pseudomonas and Bacillus were found to be the most predominant species in acclimated MOB consortium. Mn²⁺ could be oxidized optimally at neutral pH and initial Mn²⁺ concentration below 33 mg L⁻¹. However, 1,2,4-triazole removal by BioMnOx produced occurred optimally at slightly acidic pH. High dosage of both Mn²⁺ and 1,2,4-triazole resulted in decreased 1,2,4-triazole removal. In a biological aerated filter (BAF) coupled with manganese oxidation, 1,2,4-triazole and total organic carbon removal could be significantly enhanced compared to the control system without the participation of manganese oxidation, confirming the key role of BioMnOx in the removal of highly recalcitrant 1,2,4-triazole. This study demonstrated that the biosystem coupled with manganese oxidation had a potential for the removal of various recalcitrant contaminants from bio-treated chemical industrial wastewater.
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