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The study of mechanisms of biological activity of copper oxide nanoparticle CuO in the test for seedling roots of Triticum vulgare Full text
2017
Korotkova, Anastasia Mickhailovna | Lebedev, Svyatoslav Valeryevich | Gavrish, Irina Aleksandrovna
The rapid development of nanotechnology raises questions assessment of their impact on living objects. In the present study, we evaluated the impact of nanoparticle (NP) CuO at concentrations ranging from 0.8 to 63.5 g/l in the test on wheat seedlings Triticum vulgare during 1–72 h. In the viability test (WST-test), cells were isolated from the roots of seedlings T. vulgare, 12 h not observed increase reductase activity after 24 h decreased rate of not more than 19% compared with the control. The number of dead cells in seedlings of T. vulgaris after exposure with CuO nanoparticles to the test with Evans blue increased by 5–15% compared to control. We observed that a significant increase in copper revenues leaves 4.5–8.9 times more in relation to the control and the roots—in 5–9.7 times. During the determined amount of active oxygen species, a significant proportional increase in the total pool of reactive oxygen species (ROS) in roots increased to 27.6% after exposure to NP CuO compared with the control. It is shown that in the introduction in medium, the NP CuO in the doses ranging from 3.2 to 63.5 g/l leads to DNA fragmentation and increases the fragments less than 3000 bp on 51.4–62.8%. The totality of our results influences nanoforms of copper oxide on the amount of ROS, and the viability of the genomic component of the cells shows different mechanisms of damage in the activation of a metabolic reaction, to determine the concentration of nano-CuO.
Show more [+] Less [-]Assessment of metal contamination in the Hun River, China, and evaluation of the fish Zacco platypus and the snail Radix swinhoei as potential biomonitors Full text
2017
Wu, Xing | Wang, Shaofeng | Chen, Hongxing | Kong, Bill | Chen, Hongwei | Gao, Mi | Bi, Ran | Klerks, Paul L. | Wang, He | Luo, Yongju | Xie, Lingtian
The Hun River is a major tributary of the Liao River in the northeast area of China and provides drinking water for 23 million local residents. This study was designed to assess the severity of metal contamination in the Hun River and the potential use of indigenous organisms (the fish Zacco platypus and the snail Radix swinhoei) as biomonitors of metal contamination. Water, sediment, and the native fish and snails were collected at four sampling sites that differed in their physicochemical characteristics and their contamination levels. The samples were analyzed for Cd, Cr, Cu, Ni, Pb, and Zn by ICP-MS. The results showed that although the overall potential ecological risks of the metals were low at our sampling sites, Cd posed a noteworthy ecological risk. Strong correlations were obtained between Cd concentrations in the organisms and in the environment. The results indicated that Z. platypus and R. swinhoei can be useful biomonitoring species for assessing Cd contamination. Biomonitoring with the snail may be most effective when focused on the gonad/digestive tissue (because of the high metal accumulation there), but further work is needed to confirm this.
Show more [+] Less [-]Advanced oxidative processes and membrane separation for micropollutant removal from biotreated domestic wastewater Full text
2017
Silva, Larissa L. S. | Sales, Julio C. S. | Campos, Juacyara C. | Bila, Daniele M. | Fonseca, Fabiana V.
The presence of micropollutants in sewage is already widely known, as well as the effects caused by natural and synthetic hormones. Thus, it is necessary to apply treatments to remove them from water systems, such as advanced oxidation processes (AOPs) and membrane separation processes, which can oxidize and remove high concentrations of organic compounds. This work investigated the removal of 17β-estradiol (E2), 17α-ethinylestradiol (EE2), and estriol (E3) from biotreated sewage. Reverse osmosis processes were conducted at three recoveries (50, 60, and 70 %). For E2 and EE2, the removals were affected by the recovery. The best results for RO were as follows: the E2 compound removal was 89 % for 60 % recovery and the EE2 compound removal was 57 % for 50 % recovery. The RO recovery did not impact the E3 removal. It was concluded that the interaction between the evaluated estrogens, and the membrane was the major factor for the hormone separation. The AOP treatment using H₂O₂/UV was carried out in two sampling campaigns. First, we evaluated the variation of UV doses (24.48, 73.44, 122.4, and 244.8 kJ m⁻²) with 18.8 mg L⁻¹ of H₂O₂ in the reaction. EE2 showed considerable removals (around 70 %). In order to optimize the results, an experimental design was applied. The best result was obtained with higher UV dose (122.4 kJ m⁻²) and lower H₂O₂ concentration (4 mg L⁻¹), achieving removal of 91 % for E3 and 100 % for E2 and EE2.
Show more [+] Less [-]Archaeometric researches on the provenance of Mediterranean Archaic Phoenician and Punic pottery Full text
2017
Amadori, M. L. | Del Vais, C. | Fermo, P. | Pallante, P.
The aim of this study is to setup a first chemical database that could represent the starting point for a reliable classification method to discriminate between Archaic Phoenician and Punic pottery on the base of their chemical data. This database up to now can discriminate between several different areas of production and provenance and can be applied also to unknown ceramic samples of comparable age and production areas. More than 100 ceramic fragments were involved in this research, coming from various archaeological sites having a crucial importance in the context of the Phoenician and Punic settlement in central and western Mediterranean: Carthage (Tunisia), Toscanos (South Andalusia, Spain), Sulci, Monte Sirai, Othoca, Tharros (Sardinia, Italy) and Pithecusa (Campania, Italy). Since long-time archaeologists hypothesised that Mediterranean Archaic Phoenician and Punic pottery had mainly a local or just a regional diffusion, with the exception of some particular class like transport amphorae. To verify the pottery provenance, statistical analyses were carried out to define the existence of different ceramic compositional groups characterised by a local origin or imported from other sites. The existing literature data are now supplemented by new archaeometric investigations both on Archaic Phoenician ceramics and clayey raw materials from Sardinia. Therefore, diffractometric analyses, optical microscopy observations and X-ray fluorescence analyses were performed to identify the mineralogical and chemical composition of Othoca ceramics and clayey raw material. The obtained results were then compared with own literature data concerning Phoenician and Punic pottery in order to find features related to the different ceramic productions and their provenance. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were also performed on the chemical compositional data in order to discriminate ceramic groups. A very complex situation was found: imported ceramics coming from Carthage, with a large-scale distribution, were found together with a predominant local production pottery. The archaeometric results demonstrate that historical and typological approach has to be supported by scientific analyses to better understand local or Mediterranean exchanges.
Show more [+] Less [-]Cultivation of freshwater microalgae in biodiesel wash water Full text
2017
Sassi, Patrícia Giulianna Petraglia | Calixto, Clediana Dantas | da Silva Santana, Jordana Kaline | Sassi, Roberto | Costa Sassi, Cristiane Francisca | Abrahão, Raphael
Biodiesel wash water is a contaminating industrial effluent that must be treated prior to disposal. The use of this effluent as a low-cost alternative cultivation medium for microalgae could represent a viable supplementary treatment. We cultivated 11 microalgae species with potential use for biodiesel production to assess their growth capacities in biodiesel industrial washing waters. Only Monoraphidium contortum, Ankistrodesmus sp., Chlorococcum sp., and one unidentified Chlorophyceae species grew effectively in that effluent. M. contortum showed the highest growth capacity and had the second highest fatty acid content (267.9 mg g⁻¹ of DW), predominantly producing palmitic (20.9%), 7,10,13-hexadecatrienoic (14%), oleic (16.2%), linoleic (10.5%), and linolenic acids (23.2%). In the second phase of the experiment, the microalgae were cultivated in biodiesel wash water at 75% of its initial concentration as well as in WC (control) medium. After 21 days of cultivation, 25.8 and 7.2% of the effluent nitrate and phosphate were removed, respectively, and the chemical oxygen demand was diminished by 31.2%. These results suggest the possibility of cultivating biodiesel producing microalgae in industrial wash water effluents.
Show more [+] Less [-]Effects of modified biochar on rhizosphere microecology of rice (Oryza sativa L.) grown in As-contaminated soil Full text
2017
Liu, Shusi | Lü, Yixin | Yang, Chen | Liu, Chuanping | Ma, Lin | Dang, Zhi
Biochar was carbon-rich and generated by high-temperature pyrolysis of biomass under oxygen-limited conditions. Due to the limitations of surface functional groups and the weakness of surface activity in the field of environmental remediation, the raw biochar frequently was chemically modified to improve its properties with a new performance. In this study, a kind of high-efficiency and low-cost amino biochar modified by nano zero-valent iron (ABC/NZVI) was synthesized and applied to paddy soil contaminated with arsenic (As). Dynamic changes of soil properties, arsenic speciations and rhizosphere microbial communities have been investigated over the whole growth period of rice plants. Pot experiments revealed that the ABC/NZVI could decrease the arsenic concentration in rice straw by 47.9% and increase the content of nitrogen in rice straw by 47.2%. Proportion of Geobacter in soil with ABC/NZVI treatment increased by 175% in tillering period; while Nitrososphaera decreased by 61 and 20% in tillering and maturity, respectively, compared to that of control. ABC/NZVI promotes arsenic immobilization in rhizosphere soil and precipitation on root surface and reduces arsenic accumulation in rice. At the same time, ABC/NZVI would inhibit Nitrososphaera which is related to ammonia oxidation process, and it would have a promising potential as soil amendment to reduce nitrogen loss probably.
Show more [+] Less [-]Factorial design application in photocatalytic wastewater degradation from TNT industry—red water Full text
2017
Guz, Ricardo | de Moura, Cristiane | da Cunha, Mário Antônio Alves | Rodrigues, Marcio Barreto
In trinitrotoluene (TNT) purification process, realized in industries, there are two washes carried out at the end of the procedure. The first is performed with vaporized water, from which the first effluent, called yellow water, is originated. Then, a second wash is performed using sodium sulfite, generating the red water effluent. The objective of this work was to get the best conditions for photocatalytic degradation of the second effluent, red water, in order to reduce toxicity and adjust legal parameters according to regulatory agencies for dumping these effluents into waterways. It has used a statistical evaluation for factor interaction (pH, concentration) that affects heterogeneous photocatalysis with titanium dioxide (TiO₂). Thus, the treatment applied in the factorial experimental design consisted of using a volume equal to 500 mL of the effluent to 0.1 % by batch treatment, which has changed TiO₂ pH and concentration, according to the design, with 20 min time for evaluation, where it was used as response to the reduction of UV–Vis absorption. According to the design responses, it has obtained optimum values for the parameters evaluated: pH = 6.5 and concentration of 100 mg/L of TiO₂ were shown to be efficient when applied to red water effluent, obtaining approximately 91 % of discoloration.
Show more [+] Less [-]Effect of substituted hydroxyl groups in the changes of solution turbidity in the oxidation of aromatic contaminants Full text
2017
Villota, N | JM, Lomas | LM, Camarero
This paper deals with the changes of turbidity that are generated in aqueous solutions of phenol when they are oxidized by using different Fenton technologies. Results revealed that if the Fenton reaction was promoted with UV light, the turbidity that was generated in the water doubled. Alternatively, the use of ultrasonic waves produced an increase in turbidity which initially proceeded slowly, reaching intensities eight times higher than in the conventional Fenton treatment. As well, the turbidity showed a high dependence on pH. It is therefore essential to control acidity throughout the reaction. The maximum turbidity was generated when operating at pH = 2.0, and it slowly decreased with increasing to a value of pH = 3.0, at which the turbidity was the lowest. This result was a consequence of the presence of ferric ions in solution. At pH values greater than 3.5, the turbidity increased almost linearly until at pH = 5.0 reached its maximum intensity. In this range, ferrous ions may generate an additional contribution of radicals that promote the degradation of the phenol species that produce turbidity. Turbidity was enhanced at ratios R = 4.0 mol H₂O₂/mol C₆H₆O. This value corresponds to the stoichiometric ratio that leads to the production of turbidity-precursor species. Therefore, muconic acid would be a species that generate high turbidity in solution according to its isomerism. Also, the results revealed that the turbidity is not a parameter to which species contribute additively since interactions may occur among species that would enhance their individual contributions to it. Analyzing the oxidation of phenol degradation intermediates, the results showed that meta-substituted compounds (resorcinol) generate high turbidity in the wastewater. The presence of polar molecules, such as muconic acid, would provide the structural features that are necessary for resorcinol to act as a clip between two carboxylic groups, thus establishing directional hydrogen bonds that would generate an adduct in the 2:2 ratio. In addition, some similarity is observed between the turbidity and the presence of dihydroxybenzoquinone. This molecule has a structure that could establish hydrogen bond links with the carboxylic groups in 1:2 ratio. Such supramolecular structures would possess high molecular weight and robustness that would hinder the passage of light through the water, generating high turbidity.
Show more [+] Less [-]Photocatalytic processes assisted by artificial solar light for soil washing effluent treatment Full text
2017
Satyro, Suéllen | Race, Marco | Marotta, Raffaele | Dezotti, Márcia | Guida, Marco | Clarizia, Laura
Contaminated soil has become a growing issue in recent years. The most common technique used to remove contaminants (such as metals) from the soil is the soil washing process. However, this process produces a final effluent containing chelating agents (i.e., ethylenediaminedisuccinic acid, also known as EDDS) and extracted metals (i.e., Cu, Fe, and Zn) at concentrations higher than discharge limits allowed by the Italian and Brazilian environmental law. Therefore, it is necessary to develop further treatments before its proper disposal or reuse. In the present study, soil washing tests were carried out through two sequential paths. Moreover, different artificial sunlight-driven photocatalytic treatments were used to remove Cu, Zn, Fe, and EDDS from soil washing effluents. Metal concentrations after the additional treatment were within the Brazilian and Italian regulatory limits for discharging in public sewers. The combined TiO₂-photocatalytic processes applied were enough to decontaminate the effluents, allowing their reuse in soil washing treatment. Ecotoxicological assessment using different living organisms was carried out to assess the impact of the proposed two-step photocatalytic process on the effluent ecotoxicity. Graphical Abstract ᅟ
Show more [+] Less [-]Coated mesh photocatalytic reactor for air treatment applications: comparative study of support materials Full text
2017
Passalia, Claudio | Nocetti, Emanuel | Alfano, Orlando | Brandi, Rodolfo
An experimental comparative study of different meshes as support materials for photocatalytic applications in gas phase is presented. The photocatalytic oxidation of dichloromethane in air was addressed employing different coated meshes in a laboratory-scale, continuous reactor. Two fiberglass meshes and a stainless steel mesh were studied regarding the catalyst load, adherence, and catalytic activity. Titanium dioxide photocatalyst was immobilized on the meshes by dip-coating cycles. Results indicate the feasibility of the dichloromethane elimination in the three cases. When the number of coating cycles was doubled, the achieved conversion levels were increased twofold for stainless steel and threefold for the fiberglass meshes. One of the fiberglass meshes (FG2) showed the highest reactivity per mass of catalyst and per catalytic surface area.
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