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Biodegradation of Light Fuel Oils in Water and Soil as Determined by the Manometric Respirometric Method
2009
Karhu, M. | Kaakinen, J. | Kuokkanen, T. | Rämö, J.
In this biological oxygen demand (BOD) study, the manometric respirometric BOD OxiTop® method was used to monitor the biodegradation of two summer grade (SFO 1 and 2) and two winter grade light fuel oils (WFO 1 and 2) in OECD 301 F conditions, in groundwater, and in two different Finnish forest soils (mineral-poor and mineral-rich). The biodegradation measurements in the OECD 301 F conditions were carried out in two nutrient solutions for 28 days. In both solutions WFO 1 reached the highest biodegradation degree, 32% in the solution OECD 301 F, and 70% in a solution containing additional ammonium chloride. In groundwater conditions all the biodegradation degrees of fuel oils remained below 2% within the 28-day period. SFO 1 reached the highest 30 day biodegradability (4%) in mineral-poor soil, 18% in mineral-rich soil. In a 189-day measurement in a mineral-rich soil, the biodegradation degree for the SFO 1 was 94%. The manometric respirometric method proved to be a very suitable and practicable measurement method for the purpose of biodegradation studies of highly volatile light fuel oils, because in this method samples are treated to a lesser degree than in conventional methods, and dilutions are not needed. Results also indicated a considerable effect of conditions on the biodegradability in both water and soil environments. The results of these biodegradation studies could be used when planning in situ treatment methods based on natural biodegradation. In situ treatment methods are eco-efficient, and are especially suitable for sparsely populated sites.
Mostrar más [+] Menos [-]Age-Dependent Bioaccumulation of Organochlorine Compounds in Fish and their Selective Biotransformation in Top Predators from Lake Maggiore (Italy)
2009
Volta, Pietro | Tremolada, Paolo | Neri, Maria Chiara | Giussani, Gianluigi | Galassi, Silvana
Fish and piscivorous bird eggs collected in 2003 from Lake Maggiore (Italy), were analysed for PCB and DDT contamination. Lake Maggiore has been severely polluted by DDT through production of the pesticide within its catchment. Although agricultural application of DDT was banned in Italy in the 1978, industrial production continued until 1996, with enough contamination of water and soil for serious bioaccumulation in the lake biota. PCB and DDT concentrations in a whitefish (Coregonus macrophthalmus Nusslin 1882) were seen to be dependent on season and fish age, but not on sex. The average increase of the lipid-normalised concentration of DDTs and PCBs was two-fold across season and also across age, resulting in an overall increase of four fold. The seasonal variation was related to the eco-physiological cycle of the fish and to the contamination dynamic of the lake, while the effect of the fish age was explained on the base of biomagnification-related mechanisms. A fugacity model was applied to predict the age-dependent bioaccumulation potential of PCBs, whose concentrations were rather stable in recent years in the lake. Predicted values for compounds with negligible biotransformation were in good agreement with experimental data (calculated vs. experimental mean difference of 14%), and a relationship between the increase of experimental age-dependent concentration and K ow was observed. The good correspondence between the predicted and the measured values for most PCB congeners confirmed the general inability of fishes to biotransform these compounds. On the contrary, the importance of biotransformation processes was recognised in birds; eggs of a fish eating bird (Podiceps cristatus) from the same area selectively bioaccumulated p,p'-DDE. For PCBs, congener 149 appears to be completely metabolized by the bird species, and congeners 95, 101, 132, 151 and 174 were reduced as well. The role of the meta-para free position on at least one phenyl ring of PCB congeners in biotransformation processes was confirmed.
Mostrar más [+] Menos [-]Rapid Test Methods for the Field Screening of Heavy Metals in Soil Samples
2009
Jozic, Marija | Peer, Thomas | Malissa, Hans
In the present work, rapid test methods for field screening of soil for Cu, Ni, and Pb content are presented. They are based on commercially obtainable Microquant tests (Merck, Germany), which are originally developed for water analysis. The same type of color reaction was also used for the determination of heavy metals in soil extracts: Reagents to form colored metal complexes are cuprizone for Cu, dimethylglyoxime for Ni, and dithizone for Pb. The experimental conditions for the colorimetric determination of these metals in the soil extracts were studied and additionally modified. An aqua regia solution (HCl/HNO₃, 3:1) was used for the rapid extraction of metals from soil. To establish accuracy, results obtained with the proposed test methods were compared with those obtained with the standard laboratory method using microwave digestion and flame atomic absorption spectrometry (FAAS). Real soil samples containing metals at background levels generally yielded approximately 50% of the total content obtained with the standard FAAS method. High recovery values of spiked samples confirm that the colorimetric methods are unaffected by soil matrix effects.
Mostrar más [+] Menos [-]Electrocoagulation Studies on Treatment of Biodigester Effluent using Aluminum Electrodes
2009
Ponselvan, F Infant Anto | Kumar, Mayank | Malviya, Jodha Ram | Srivastava, Vimal Chandra | Mall, Indra Deo
In the present paper, electrocoagulation (EC) has been employed for the reduction of chemical oxygen demand (COD) reduction of a distillery wastewater (biodigester effluent) in a batch EC reactor using aluminum electrode. The individual and interactive effects of the four main independent parameters have been studied on the COD removal efficiency using a central composite experimental design. The parameters studied are current density (j): 44.65-223.25 A/m²; initial pH (pH ₀): 2-8; inter-electrode distance (g): 1-3 cm; and electrolysis time (t): 30-150 min. Pareto analysis of variance of the results showed a high coefficient of determination value (R ² = 0.9693) and satisfactory prediction for second-order regression model. Maximum COD removal efficiency of 52.23% was obtained with j = 120 A/m², pH ₀ = 6.0, g = 1 cm, and t = 150 min.
Mostrar más [+] Menos [-]Ozone Level Assessment on the Boukornine National Park (Tunisia) using Plant Biomonitoring: Influence of Altitudinal Parameter and Meteorological Conditions
2009
Mechergui, R. | Ben Mansoura, A. | Laffray, X. | Albouchi, A. | Akrimi, N. | Garrec, J. P.
The variations of tropospheric ozone levels was assessed for the first time in the Boukornine National Park (N.E. Tunisia) by detection of leaf injury development on Nicotiana tabacum “Bel-W3” exposed to environmental conditions during summer 2004. Two cultivars of tobacco (Nicotiana tabacum), Bel-W3 (sensitive) and Bel-B (resistant to ozone), were used for this biomonitoring study. These cultivars were dispersed in 24 different biostations, according to a square grid mesh, every 2 weeks. Four successive cultures were utilized to follow the ozone levels inside the park during the summer exposure period. Levels of ozone may vary in time and space depending on the local environmental and meteorological conditions. The results showed a positive correlation between ozone concentration and foliar injury index (FII; r = 0.958; p < 0.05). A significant positive correlation was observed between the FII of Bel-W3 tobacco plant and AOT40 (accumulated over the threshold of 40 ppb). The altitude appeared to be the most important variable explaining the variation of ozone pollution with the highest correlation coefficient (r = 0.964; p < 0.0001). The altitude was followed by topography for the prediction of ozone concentration levels. Maximal temperature was also an important factor in addition to the others in determining the FII and was negatively correlated with the FII (r = −0.979; p < 0.05). Average ambient ozone levels were positively linked to plant leaf damage. The ozone profile characterizing the study area was primarily influenced by wind direction and speed in relation to intercontinental transport, in addition to the local influence of motor vehicles traffic flow in the Tunis region.
Mostrar más [+] Menos [-]Evaluation of Coal Fly Ash-Based Synthetic Aggregates as a Soil Ameliorant for the Low Productive Acidic Red Soil
2009
Jayasinghe, G. Y. | Tokashiki, Y. | Kitou, M.
A potential new way of producing coal fly ash-based granular synthetic aggregates (CSA) using waste coal fly ash (CFA), paper waste, lime, and gypsum and their utilization as a soil ameliorant to improve crop production in low productive acidic red soil in Okinawa, Japan were studied. The red soil was amended with CSA at three different mixing ratios (i.e., CSA/soil—1:1, 1:5, and 1:10) for the cultivation of Brassica rapa var. Pervidis commonly known as Komatsuna, and the physico-chemical parameters of CSA-soil mixtures and plant growth were analyzed. Incorporation of CSA to the red soil improved the physical and chemical properties of the soil such as water holding capacity, hydraulic conductivity, bulk density, pH, exchangeable cation concentration, cation exchange capacity, particle size distribution, soil pH, electrical conductivity, and carbon content. CSA amendment at ratios of 1:1, 1:5, and 1:10 decreased bulk density by 29.39%, 14.28% and 11.11%, respectively, compared to the original red soil. The acidic pH of the red soil (5.12) was increased to 7.13 and 6.37 by CSA/soil ratios of 1:5 and 1:10, respectively. CSA amendment in soil at 1:5 ratio increased water holding capacity, saturated hydraulic conductivity, electrical conductivity, cation exchange capacity, carbon, potassium (K), magnesium (Mg), and calcium (Ca) content by 0.06 kg kg⁻¹, ten times, 15.95 mS m⁻¹, 1.76 cmolc kg⁻¹, 6.07 g kg⁻¹, 0.42 g kg⁻¹, 0.24 g kg⁻¹, and 3.38 g kg⁻¹, respectively, in comparison to the original red soil. Heavy metal contents of the CSA-soil mixtures were below the maximum pollutant concentrations suggested by the US Environmental Protection Agency. Moreover, Na, K, Mg, Ca, copper (Cu), and zinc (Zn) contents in the CSA-soil mixtures increased in comparison with the original red soil. CSA amendment in soil at the ratio of 1:5 and 1:10 resulted in an increase in plant height and plant fresh weight by three and 12 times, respectively, and there was increase in N, K, Mg, Ca, Cu, and Zn contents of the shoots. The results suggest that utilization of eccentric CSA as soil amendment agent can be regarded as an effective waste management practice.
Mostrar más [+] Menos [-]Chemical Composition Change in TSP Due to Dust Storm at Gosan, Korea: Do the Concentrations of Anthropogenic Species Increase Due to Dust Storm
2009
Kim, Na Kyung | Park, Hye-Jin | Kim, Yong Pyo
Aerosol composition change between dust storm and non-dust storm periods in spring is studied using the total suspended particle data measured at Gosan, a background area in Korea. The concentrations of eight inorganic ions and 12 elements were analyzed for the TSP samples collected from March 1992 to May 2006. Two-step statistical analyses were carried out for the data: F test and t test. The concentrations of anthropogenic ionic species showed increasing trend since 2003. The absolute concentrations of most anthropogenic species such as sulfate or nitrate increased (from 7.33 to 9.25 µg m⁻³ and from 2.04 to 4.84 µg m⁻³, respectively) during the dust storm period. However, the enrichment factors or normalized concentrations based on Al of most anthropogenic species decreased during dust storm period (factor of 0.1-0.5). It suggests that, in general, relative importance of anthropogenic species during dust storm would be not high.
Mostrar más [+] Menos [-]The Emergent Science of Engineering a Sustainable Urban Environment
2009
Goudie, Douglas
Engineering is taking a lead role in sustainability implementation, despite problems linking institutional decision-makers with such things as water purification and cleansing wetlands. An emerging science may help speed an all-system approach to implementing sustainable urban planning. The many innovative approaches to engineering and planning will lead to cities and suburbs where water, urban travel, energy chains and food provision infrastructures are bound together by ESD values, flow-on principles and a workable process of sustainability achievement. JCU Townsville is developing such a process of Sustainability Implementation Planning (SIP) and Engineering, aspiring to become a tropics sustainability exemplar. This article reports on a 90-strong workshop: Paths to Sustainability held in August 2008, with strong regional leadership support. An integrated intellectual frame and ‘futures oriented' blueprint is provided to achieve the myriad cultural, social, economic, energy, water, food, engineering and environmental needs to ‘go sustainable' in an urban setting, where most of us live. The workshop results show SIP water management begins with local raindrops, local capture, local ground penetration, use and reuse, entering local nutrient flows to local urban food gardens and then used as a source to grow aquatic protein and fuel oils. Energy engineering becomes a local mix of renewables and innovative storage, appropriate building design, transport systems and industry; including embodied and life-cycle energy analysis and careful considerations in all built structure and use. Urban planning, people movement, housing location and travel mode will increasingly be judged by energy costs, as will food production.
Mostrar más [+] Menos [-]The Role of Mucus in Mytella falcata (Orbigny 1842) Gills from Polluted Environments
2009
David, José Augusto de Oliveira | Fontanetti, Carmem S.
Bivalve mussels can concentrate pollutants which, in high amounts, can cause cellular, physiological and behavioral changes. The gill mucus is essential for many metabolic and behavioral procedures on marine mussels including the response to environmental pollution. The present work analyzed the mucous cell number in Mytella falcata gill filaments from three sites of Santos estuary (Brazil) with different levels of sediment contamination named as sites A, B, and C. Site A is located at a low impacted region of the estuary, and sites B and C are under influence of port activities, domestic sewage, and industries like a still mill located in front of site C (the most contaminated area with high amounts of polycyclic aromatic hydrocarbons). An increase in mucous cell number was detected in animals from sites B and C, when compared to site A; this increase occurred preferentially in the frontal zone and was related to sediment contamination. Mucous cell analysis can be used as an efficient biomarker. It is suggested that mucus produced in lateral and abfrontal zones is responsible for eliminating pollutants previously absorbed and mucus produced in frontal zone is responsible for pollutant arrest and elimination as pseudofeces.
Mostrar más [+] Menos [-]Environmental Behaviour of Metolachlor and Diuron in a Tropical Soil in the Central Region of Brazil
2009
Dores, Eliana F. G. C. | Spadotto, Cláudio A. | Weber, Oscarlina L. S. | Carbo, Leandro | Vecchiato, Antonio B. | Pinto, Alicio A.
The environmental behaviour of metolachlor and diuron was studied in the Central-western region of Brazil, by means of a field study where six experimental plots were installed. The soil was classified as a Latosol, and the soil horizons were characterized. Sorption of metolachlor and diuron was evaluated in laboratory batch experiments. Metolachlor and diuron were applied to the experimental plots on uncultivated soil in October 2003. From this date to March 2004, the following processes were studied: leaching, runoff and dissipation in top soil. K oc of metolachlor varied from 179 to 264 mL g⁻¹ in the soil horizons. K oc of diuron in the Ap horizon was 917 mL g⁻¹, decreasing significantly in the deeper horizons. Field dissipation half-lives of metolachlor and diuron were 18 and 15 days, respectively. In percolated water, metolachlor was detected in concentrations ranging from 0.02 to 2.84 μg L⁻¹. In runoff water and sediment, metolachlor was detected in decreasing concentrations throughout the period of study. Losses of 0.02% and 0.54% of the applied amount by leaching and runoff, respectively, were observed confirming the high mobility of this herbicide in the environment. In percolated water, diuron was detected with low frequency but in relatively high concentrations (up to 6.29 μg L⁻¹). In runoff water and soil, diuron was detected in decreasing concentrations until 70 days after application, totalizing 13.9% during the whole sampling period. These results show the importance of practices to reduce runoff avoiding surface water contamination by these pesticides, particularly diuron.
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