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Principles, Developments and Design Criteria of In Situ Chemical Oxidation 全文
2013
Baciocchi, Renato
This paper provides a short overview of the main oxidation processes more commonly applied for the remediation of contaminated sites, with specific reference to their application for the in situ remediation of contaminated sites, i.e. In Situ Chemical Oxidation (ISCO). A review of the main patents issued on this topic shows the relevant contribution to the development of this technology in the last 20 years, especially in the USA. The still limited deployment of ISCO in other geographical areas may be improved by the increased acceptance of the technology that may come from the development of proper application guidelines based on accepted design criteria. The latter ones are also discussed in this paper with reference to the application of Fenton's treatment. © 2013 Springer Science+Business Media Dordrecht.
显示更多 [+] 显示较少 [-]Biodegradation and Kinetics of Phenanthrene and Pyrene in the Presence of Nonionic Surfactants by Arthrobacter Strain Sphe3 全文
2013
Aryal, Mahendra | Liakopoulou-Kyriakides, Maria
Surfactant-enhanced solubilization and subsequent biodegradation of phenanthrene and pyrene from aqueous solutions by Arthrobacter strain Sphe3 was investigated. The results show that growth of Arthrobacter strain Sphe3 was increased upon increase in concentration of Tween 20 and Tween 80. Inhibition of bacterial growth was observed with increasing Triton X-100 concentrations, whereas sodium dodecyl sulfate (SDS) totally inhibited this bacterial growth. Phenanthrene and pyrene solubilization was enhanced in the presence of surfactants and found to be linearly proportional to their concentrations, above the critical micelle concentration (CMC). In addition, Tween 20 and Tween 80 enhanced the biodegradation of phenanthrene and pyrene. The high correlation coefficient (R ²) values obtained at all the concentrations studied, suggest that biodegradation kinetics of both phenanthrene and pyrene in the presence of Tween 20 and Tween 80 follow first-order kinetic equation model. Experimental results suggest that Tween 20 and Tween 80 may have great potential for applications in bioremediation of these polycyclic aromatic hydrocarbon (PAH) compounds using Arthrobacter strain Sphe3.
显示更多 [+] 显示较少 [-]Evaluation of Pretreatment Using UASB and SGBR Reactors for Pulp and Paper Plants Wastewater Treatment 全文
2013
Turkdogan, F Ilter | Park, Jaeyoung | Evans, Eric A. | Ellis, Timothy G.
Static granular bed reactor (SGBR) and upflow anaerobic sludge blanket (UASB) reactor were demonstrated at mesophilic condition for the treatment of pulp and paper mill wastewater. The hydraulic retention times (HRTs) were varied from 4 to 24 h following 29-day start-up period. The overall chemical oxygen demand (COD) removal efficiency of the SGBR was higher than the UASB during this study. At 4 h HRT, the COD removal was greater than 70 % for the SGBR and 60 % for the UASB. Biomass yield and volatile fatty acids concentration of SGBR were slightly less than UASB at organic loading rates ranging from 1.2 to 5.1 kg/m³/day. The results indicated that the SGBR system can be considered a viable alternative system for anaerobic treatment for pulp and paper wastewater.
显示更多 [+] 显示较少 [-]Photodegradation of Volatile Organic Compounds in the Water-Soluble Fraction of Kuwait Crude Oil in Seawater: Effect of Environmental Factors 全文
2013
Saeed, Talat | Ali, Lulwa N. | Al-Bloushi, Amal | Al-Hashash, Huda | Al-Bahloul, Majed | Al-Khabbaz, Ahmad | Ali, Sadika G.
Volatile organic compounds (VOCs) are ubiquitous in marine areas in many parts of the world. Effect of environmental factors (light intensity, temperature, oxygen levels, and presence of sensitizer) on photodegradation of VOCs present in water-soluble fraction of Kuwait crude oil was investigated in laboratory conditions. The results showed that all factors investigated had significant effects on photo degradation rates. Higher temperatures produced faster degradation rates. At 15 °C, most of the volatile optimally degraded when light intensity was set at 750 W/m². Oxygen level of 7 ppm and presence of sensitizer was also required. Oxygen level of 4 ppm and light intensity of 500 W/m² and presence of a sensitizer produced optimal degradation rates for most of the compounds at 30 °C. At 40 °C, deoxygenated water-soluble fraction and light intensity of 500 W/m² produced the fastest degradation for many of the volatile compounds. Linear regression indicated that for most of the compounds temperature had the greatest effect on degradation rates.
显示更多 [+] 显示较少 [-]Mapping Atmospheric Corrosion on Modern Materials in the Greater Athens Area 全文
2013
Kambezidis, Harry D. | Kalliampakos, George
In this study, we investigate the corrosion effects on modern materials at various sheltered and unsheltered locations in the Greater Athens Area (GAA) due to atmospheric pollution, since materials deterioration could emerge severe economic costs in the near future. The preselected materials are weathering steel, copper, bronze, zinc, and aluminum, which are mainly used in modern constructions in the GAA. The method applied in this study leads in the production of corrosion maps for GAA in the period 2000–2009 by using sophisticated geoanalytical methods together with dose–response functions for the selected materials. The corrosion effects are significant for weathering steel, moderate for copper and bronze and weak for zinc and aluminum. Also, a corrosion trend analysis is performed, which can be a very helpful tool for future protection of such materials from atmospheric pollution. The results show increasing corrosion trends for weathering steel and copper in the eastern regions of GAA, probably caused by the recent operation of the Athens International Airport at Spata, while no corrosion trends were observed to the other materials. The method applied in this work provides comprehensive results for the estimation of the impact of atmospheric corrosion on various construction materials.
显示更多 [+] 显示较少 [-]Composition and Integrity of PAHs, Nitro-PAHs, Hopanes, and Steranes in Diesel Exhaust Particulate Matter 全文
2013
Huang, Lei | Bohac, Stanislav V. | Chernyak, Sergei M. | Batterman, Stuart A.
Diesel exhaust particulate matter contains many semivolatile organic compounds (SVOCs) of environmental and health significance. This study investigates the composition, emission rates, and measurement integrity of 25 SVOCs, including polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and diesel biomarkers hopanes and steranes. Diesel engine particulate matter (PM), generated using an engine test bench, three engine conditions, and ultralow sulfur diesel (ULSD), was collected on borosilicate glass fiber filters. Under high engine load, the PM emission rate was 0.102 g/kWh, and emission rates of ΣPAHs (10 compounds), ΣNPAHs (6 compounds), Σhopanes (2 compounds), and Σsteranes (2 compounds) were 2.52, 0.351, 0.02-2 and 1 μg/kWh, respectively. Storage losses were evaluated for three cases: conditioning filters in clean air at 25 C and 33 % relative humidity (RH) for 24 h, storing filter samples (without extraction) wrapped in aluminum foil at 4 C for up to 1 month, and storing filter extracts in glass vials capped with Teflon crimp seals at 4 C for up to 6 months. After conditioning filters for 24 h, 30 % of the more volatile PAHs were lost, but lower volatility NPAHs, hopanes and steranes showed negligible changes. Storing wrapped filters and extracts at 4 C for up to 1 month did not lead to significant losses, but storing extracts for 5 months led to significant losses of PAHs and NPAHs; hopanes and steranes demonstrated greater integrity. These results suggest that even relatively brief filter conditioning periods, needed for gravimetric measurements of PM mass, and extended storage of filter extracts, can lead to underestimates of SVOC concentrations. Thus, SVOC sampling and analysis protocols should utilize stringent criteria and performance checks to identify and limit possible biases occurring during filter and extract processing. © 2013 Springer Science+Business Media Dordrecht.
显示更多 [+] 显示较少 [-]Submarine Groundwater Discharge as a Source of Mercury in the Bay of Puck, the Southern Baltic Sea 全文
2013
Szymczycha, Beata | Miotk, Michał | Pempkowiak, Janusz
Both groundwater flow and mercury concentrations in pore water and seawater were quantified in the groundwater seeping site of the Bay of Puck, southern Baltic Sea. Total dissolved mercury (HgTD) in pore water ranged from 0.51 to 4.90 ng l⁻¹. Seawater samples were characterized by elevated HgTD concentrations, ranging from 4.41 to 6.37 ng l⁻¹, while HgTD concentrations in groundwater samples ranged from 0.51 to 1.15 ng l⁻¹. High HgTD concentrations in pore water of the uppermost sediment layers were attributed to seawater intrusion into the sediment. The relationship between HgTD concentrations and salinity of pore water was non-conservative, indicating removal of dissolved mercury upon mixing seawater with groundwater. The mechanism of dissolved mercury removal was further elucidated by examining its relationships with both dissolved organic matter, dissolved manganese (Mn II), and redox potential. The flux of HgTD to the Bay of Puck was estimated to be 18.9 ± 6.3 g year⁻¹. The submarine groundwater discharge-derived mercury load is substantially smaller than atmospheric deposition and riverine discharge to the Bay of Puck. Thus, groundwater is a factor that dilutes the mercury concentrations in pore water and, as a result, dilutes the mercury concentrations in the water column.
显示更多 [+] 显示较少 [-]Biotreatment of Melanoidin-Containing Distillery Spent Wash Effluent by Free and Immobilized Aspergillus oryzae MTCC 7691 全文
2013
Chavan, M. N. | Dandi, N. D. | Kulkarni, M. V. | Chaudhari, A. B.
A total of three fungal isolates from samples collected at spent wash disposal area were screened for their ability to degrade melanoidin. Distillery molasses spent wash was decolorized, and its chemical oxygen demand (COD) was reduced in immobilized fungal bioreactor (IFB) in the absence of carbon and nitrogen source using fungal mycelia of Aspergillus oryzae MTCC 7691. Fungal mycelia immobilized on baggase packed in a glass column under a batch-wise mode (1) effected removal of 75.71 +/- 0.12 % color, 51.0 +/- 0.13 % biological oxygen demand (BOD), 86.19 +/- 2.56 % COD, and 49.0 +/- 0.12 % phenolic pigments of distillery spent wash up to 25 days at 30 degrees C, while free fungal mycelia resulted in removal of 63.1 +/- 0.16 % color, 27.74 +/- 0.14 % BOD, 76.21 +/- 1.62 % COD, and 37.32 +/- 0.17 % phenolic pigments of distillery spent wash using shake flask, (2) manganese peroxidase (MnP) activity was highest (1.55 +/- 0.01 U ml(-1) min(-1)) in immobilized fungi, followed by lignin peroxidase (0.65 +/- 0.01 U ml(-1) min(-1)) and laccase activity (0.9 +/- 0.01 CU ml (1) min (1)), (3) accumulative MnP activity was highly correlated with (r=0.9216) spent wash decolorization and (r=0.7282) reduction of phenolic pigments, suggesting the presence of MnP activities in bioremediation of spent wash and (4) degradation of spent wash was confirmed by high-performance thin layer chromatography and gas chromatography-mass spectrometry analysis. Measurement of chlorophyll a content of Chlorella species cultivated on treated spent wash effluent obtained from immobilized fungal bioreactor was 5.16 +/- 0.71 mu g ml(-1) compared with 1.306 +/- 0.017 +/-mu g ml(-1) obtained with untreated spent wash. Thus, this work may provide a reasonable alternative for cost-effective bioremediation of distillery spent wash using immobilized A. oryzae on baggase fibers.
显示更多 [+] 显示较少 [-]Occurrence and Removal of Antiviral Drugs in Environment: A Review 全文
2013
Jain, Swati | Kumar, Pardeep | Vyas, Raj K. | Pandit, Prabhat | Dalai, Ajay K.
Antiviral drugs have been recently recognized as one of the emerging contaminants in the environment. These are discharged after therapeutic use through human excretion. Effluent containing high concentration of antiviral drugs discharged from production facilities is also a cause of concern to nearby aquatic bodies. There is an increased interest in their removal because they are highly bioactive. Some antiviral drugs are resistant to conventional methods of degradation, and there is a risk of development of antiviral resistance in humans and animals if exposed repeatedly for long periods. To date, the potential human, animal, and ecological risks associated with the discharge of these antiviral compounds to the environment are not well documented. This study presents a brief summary on occurrence, ecotoxicological risks, and physicochemical properties of antiviral drugs in the environment. The needs regarding removal, disposal, and treatment of antiviral drugs are also addressed.
显示更多 [+] 显示较少 [-]Individual and Mixture Toxicity of Commercial Formulations Containing Glyphosate, Metsulfuron-Methyl, Bispyribac-Sodium, and Picloram on Rhinella arenarum Tadpoles 全文
2013
Lajmanovich, Rafael C. | Junges, Celina M. | Attademo, Andrés M. | Peltzer, Paola M. | Cabagna-Zenklusen, Mariana C. | Basso, Agustín
We investigated the effects of four commercial formulations of herbicides (glyphosate [GLY], metsulfuron-methyl [MET], bispyribac-sodium [BIS], and picloram [PIC]) individually, and in three 50:50 mixtures (GLY–MET, GLY–BIS, GLY–PIC) on the common toad Rhinella arenarum (Anura: Bufonidae) tadpoles. Enzymatic parameters such as, glutathione S-transferase (GST), butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) activities, as well as erythrocyte nuclear abnormalities (ENA) were studied. Interactions between herbicides in mixtures were evaluated and classified as additive, synergistic, or antagonistic. Toxicity results (48-h LC₅₀) showed that PIC was the most toxic herbicide, followed by BIS, GLY, and MET, while GLY–PIC was the most toxic mixture, followed by GLY–BIS, and GLY–MET. All commercial herbicide formulations and their mixtures significantly inhibited BChE activity in exposed tadpoles. The AChE activity was also inhibited by all herbicides and their mixtures, except by GLY–BIS. The inhibition of GST activity was only significant for GLY, MET, PIC, and GLY–MET. A significant increase in the frequency of ENA was found for tadpoles exposed either to commercial herbicide formulations or to mixtures, except for GLY. All the mixtures showed synergism for BChE activity while for AChE only the GLY–MET and GLY–PIC mixtures acted synergistically. GLY–MET showed synergism for GST, whereas for ENA, the mixture GLY–BIS was antagonistic. This study with R. arenarum tadpoles demonstrates that the interactions between three of the most intensively used herbicides in soybean crops results in synergistic effects on mortality and neurotoxicity and synergistic or additive effects in genotoxicity.
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