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Surface Modification of Sporopollenin with Calixarene Derivative : Characterization and Application for Metal Removal Полный текст
2012
Gubbuk, Ilkay Hilal | Gürfidan, Leyla | Erdemir, Serkan | Yılmaz, Mustafa
In this study, p-tert-butylcalix[4]-aza-crown (CAC) immobilized sporopollenin (Sp) was used as a sorbent for the removal of Cu(II), Pb(II) and Zn(II) from aqueous media. Sporopollenin was firstly functionalized with 3-chloropropyltrimethoxysilane (CPTS) in order to obtain chloro-sporopollenin (Sp-Cl). The Sp-Cl was reacted subsequently with CAC yielding CAC-bonded sporopollenin (Sp-Cl-CAC). The new sorbent was characterized by infrared spectroscopy (FTIR), thermal analysis (TG/DTG) and scanning electron microscopy (SEM). The sorption properties of modified sorbent (Sp-Cl-CAC) are also investigated. The optimum pH values for the separation of metal ions from aqueous solution onto Sp-Cl-CAC were 5.0 for Pb(II) and Cu(II) and 5.5 for Zn(II). The maximum sorption capacities for Cu(II), Pb(II) and Zn(II) were 0.07 (4.44 mg g), 0.07 (4.58 mg g) and 0.14 (29.00 mg g) mmol g, respectively. Sorption thermodynamic parameters of such as free energy ( ∆G), enthalpy ( ∆H), and entropy ( ∆S) were evaluated.
Показать больше [+] Меньше [-]Effectiveness of Conventional and Low-Cost Wastewater Treatments in the Removal of Pharmaceutically Active Compounds Полный текст
2012
Camacho-Muñoz, D. | Martin, J. | Santos, J. L. | Aparicio, I. | Alonso, E.
In the present work, the effectiveness of conventional wastewater treatments (activated sludge and oxidation ditches) and low-cost wastewater treatments (trickling filter beds, anaerobic lagooning and constructed wetlands) in the removal of pharmaceutically active compounds has been studied. To evaluate the efficiency of removal, 16 pharmaceutically active compounds belonging to seven therapeutic groups (anti-inflammatory drugs, antibiotics, antiepileptic drugs, β-blockers, nervous stimulants, estrogens and lipid regulators) have been monitored during 1-year period in influent and effluent wastewater from 11 wastewater treatment plants of Spain. Mean removal rates of pharmaceutically active compounds achieved in conventional wastewater treatments were slightly higher than those achieved in low-cost treatments, being 64% and 55%, respectively. Ibuprofen, naproxen, salicylic acid and caffeine were the pharmaceutical compounds most efficiently removed, regardless the wastewater treatment applied, with removal rates up to 99%. Anaerobic lagooning was the less effective treatment for the removal of the most persistent compounds: carbamazepine and propranolol.
Показать больше [+] Меньше [-]Initial Effects of a New Highway Section on Soil and Groundwater Полный текст
2012
Earon, Robert | Olofsson, Bo | Renman, Gunno
The environmental impacts of 16 different contaminants originating from the E18 Highway (17,510 annual average daily traffic) were studied over the initial months of the highway’s operational life. Investigative methods used included electrical resistivity surveying, water chemistry analyses, soil analyses, distribution modeling, and transportation modeling of contaminants. The study conclusively showed a year-round infiltration due to melting of the snowpack from road salt, and a strong preferential, anthropogenic pathway due to increased hydraulic conductivities of road construction materials relative to in situ soils. The resistivity surveys produced values well below the expected values for the highway materials, indicating increased ionic content within the unsaturated zone. Time lapse resistivity modeling showed a clear downwards spreading of contamination from the roadway to subsurface distances greater than 5 m. Elevated concentrations of nearly every studied contaminant relative to baseline values were observed, with many metal concentrations within the snow pack averaging values in excess of the Swedish Environmental Protection Agency’s groundwater limitations. Distribution modeling demonstrated a potential offset of peak values from the road surface due to plowing and splash transport processes, and indicated different distribution behavior during winter months than during summer months. One-dimensional transport modeling demonstrated the importance of adsorption and other retentive factors to the migration of contaminants to groundwater and provided an estimate for potential long-term contaminant concentrations.
Показать больше [+] Меньше [-]An Exploratory Study of Particulate PAHs in Low-Polluted Urban and Rural Areas of Southwest Spain: Concentrations, Source Assignment, Seasonal Variation and Correlations with Other Air Pollutants Полный текст
2012
Bernalte, Elena | Marín Sánchez, Carmen | Pinilla Gil, Eduardo | Cereceda Balic, Francisco | Vidal Cortez, Víctor
A set of 72 PM₁₀ samples from low-polluted urban and rural locations belonging to the regional air monitoring network of Extremadura (Spain) were collected in a 1 year sampling period. Sample pre-treatment and analytical determination by gas chromatography–ion trap mass spectrometry were optimised and validated for the analysis of the priority 16 US Environmental Protection Agency polycyclic aromatic hydrocarbons (PAHs). The influence of meteorological conditions (temperature, relative humidity and solar radiation) and other atmospheric pollutants (O₃, NO₂, SO₂, PM₁₀) has been covered in detail and Pearson correlation test were used for this purpose. Spatial distribution of particulate PAHs was evaluated and the comparison with other European sites was also established. Possible emission sources were identified and assigned by using molecular diagnostic criteria.
Показать больше [+] Меньше [-]Sediment Pollution, Transport, and Abatement Measures in the City Canals of Delft, the Netherlands Полный текст
2012
Kelderman, P.
This paper presents an overview of a long-term study on sediment pollution in the city canals of Delft, the Netherlands. This pollution was most evident for the inner city canal system, with copper, lead, zinc, and polycyclic aromatic hydrocarbons (PAHs) as main pollutants. Sediments of the outer city canals generally had a much better quality. Pollution levels, mutual correlations, and spatial variations were investigated for the various sediment parameters. Also, heavy metal binding forms onto Delft sediments were assessed with the help of sequential extraction techniques; results were found to be in line with expected preferential physicochemical binding processes. Input of sediments into the Delft inner city canals was shown to be largely driven by busy shipping traffic on the main canal surrounding the inner city. Mass balances for the inner city were used to quantify internal and external pollution sources; 65–85 % of the heavy metal pollution can be attributed to sources outside the Delft area. As shown by factor and cluster analyses, it is highly probable that these external sources derive from the river Rhine. A gradual improvement of the sediment quality has set in; it is expected that, due to further pollution abatement measures, this improvement will continue over the years to come. With respect to the ship-induced sediment input into the inner city canals, it was estimated that a reduction of ship velocities to <1.5 m/s will bring down the sediment input mentioned above to about 85 %.
Показать больше [+] Меньше [-]Arsenic(V) Adsorption from Aqueous Solution on Magnetic Fe₀.₂(Co ₂₀Ni ₈₀) ₀.₈ Alloy Porous Microfibers Полный текст
2012
Liu, Ruijiang | Lu, Yi | Shen, Xiangqian | Liang, Qingrong | Wang, Qiuju
The magnetic, nanocrystalline Fe₀.₂(Co₂₀Ni₈₀)₀.₈ alloy porous microfibers were prepared by the citrate gel thermal decomposition and reduction process. The morphology, chemical composition, microstructure, and magnetic properties of the microfibers were investigated by X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray, Brunauere–Emmette–Teller, and vibration sample magnetometer. The as-prepared magnetic, nanocrystalline Fe₀.₂(Co₂₀Ni₈₀)₀.₈ porous microfibers consisting of about 48 nm grains are characterized by diameters of 1–4 μm, specific surface area of 17.73 m²/g, and specific magnetization of 196.7 Am²/kg. The arsenic(V) absorption on these magnetic Fe₀.₂(Co₂₀Ni₈₀)₀.₈ porous microfibers at room temperature was determined by the ICP-AES measurement of arsenic(V) in aqueous solution. The results show that the pseudo-first-order kinetic model is consistent with the arsenic(V) adsorption process and a good correlation coefficient (R ² = 0.9862). By comparing among the Langmuir, Freundlich, Temkin, and Redlich–Peterson models for adsorption isotherms of arsenic(V) onto the magnetic Fe₀.₂(Co₂₀Ni₈₀)₀.₈ porous microfibers at room temperature, the Freundlich model and Redlich–Peterson model can be used to evaluate the arsenic(V) adsorption isotherm at room temperature. The arsenic(V) equilibrium absorbance of the magnetic Fe₀.₂(Co₂₀Ni₈₀)₀.₈ porous microfibers is up to 1.9 mg/g when the initial arsenic(V) concentration is 1.0 mg/L in aqueous solution.
Показать больше [+] Меньше [-]Soil Mobilisation of Al, Fe and Mn Due to Vicinal Intensive Hog Farming Operation Located in East Mediterranean Полный текст
2012
Michalopoulos, Charalampos | Liodakis, Stylianos
Concentrated Animal Feeding Operation activities lead to soil degradation in vicinity with the livestock breeding facilities, mainly due to ammonia emissions from the various stages of the process. In this research, the soil degradation effects of an intensive hog farming operation (IHFO) located at a Mediterranean limestone soil coastal area, have been investigated. Soil samples of the upper mineral soil were taken in various distances (10–1,500 m) and directions from the IHFO boundaries. Thirteen experimental cycles were carried out in the duration of 1.5 years starting in March 2009 until October 2010. The soil samples were analysed on total, exchangeable and water-soluble Al, Fe and Mn. Significantly higher concentrations of the exchangeable and water-soluble Al, Fe and Mn were observed on soil samples at increasing proximity downwind from the farm (south). Southern soil average concentrations of exchangeable Al³⁺, Fe³⁺ and Mn²⁺ ranged between 3.56 and 7.45 mmol Al³⁺ kg⁻¹ soil, 5.85 and 7.11 mmol Fe³⁺ kg⁻¹ soil and 2.36 and 5.03 mmol Mn²⁺ kg⁻¹ soil, respectively. Southern soil average concentrations of water-soluble Al, Fe and Mn forms ranged between 1.1 and 4.6 ppm Al, 0.5 and 0.8 ppm Fe and 0.4 and 1 ppm Mn, respectively.
Показать больше [+] Меньше [-]Arsenic Removal from Water by Iron-Modified Bamboo Charcoal Полный текст
2012
Liu, Xi | Ao, Hongyi | Xiong, Xiong | Xiao, Jinguang | Liu, Jiantong
The effectiveness of a novel and low-cost adsorbent, iron-modified bamboo charcoal (BC-Fe), for arsenic removal from aqueous systems was evaluated in this study. The BC-Fe was synthesized by loading iron onto bamboo charcoal via soaking in a ferric salt solution. The BC-Fe possessed a porous structure with a surface area of 277.895 m2/g. The adsorption characteristics of arsenic onto BC-Fe were further investigated at various pHs, contact times, arsenic concentrations, and adsorbent doses in batch tests. The corresponding optimum equilibrium pH ranges for As(III) and As(V) removal were 4–5 and 3–4, respectively. The equilibrium times for As(III) and As(V) adsorption were 30 and 35.5 h, respectively. The arsenic removal was strongly dependent on the initial adsorbate concentration and adsorbent dosage. The maximum arsenic removal capacities of BC-Fe under the experimental conditions were 7.237 and 19.771 mg/g for As(III) and As(V), respectively. The pseudo-second-order kinetic model and Freundlich isotherm explained the kinetic and equilibrium of both the As(III) and As(V) adsorbent processes, respectively. Based on these results, the BC-Fe developed in this study is a promising material for the treatment of arsenic-contaminated water.
Показать больше [+] Меньше [-]Potential of Aquatic Macrophytes as Bioindicators of Heavy Metal Pollution in Urban Stormwater Runoff Полный текст
2012
Ladislas, Séverine | El-Mufleh, Amelène | Gérente, Claire | Chazarenc, Florent | Andrès, Yves | Béchet, Béatrice
The concentrations of heavy metals in water, sediments, soil, roots, and shoots of five aquatic macrophytes species (Oenanthe sp., Juncus sp., Typha sp., Callitriche sp.1, and Callitriche sp.2) collected from a detention pond receiving stormwater runoff coming from a highway were measured to ascertain whether plants organs are characterized by differential accumulations and to evaluate the potential of the plant species as bioindicators of heavy metal pollution in urban stormwater runoff. Heavy metals considered for water and sediment analysis were Cd, Cr, Cu, Ni, Pb, Zn, and As. Heavy metals considered for plant and soil analysis were Cd, Ni, and Zn. The metal concentrations in water, sediments, plants, and corresponding soil showed that the studied site is contaminated by heavy metals, probably due to the road traffic. Results also showed that plant roots had higher metal content than aboveground tissues. The floating plants displayed higher metal accumulation than the three other rooted plants. Heavy metal concentrations measured in the organs of the rooted plants increased when metal concentrations measured in the soil increased. The highest metal bioconcentration factors (BCF) were obtained for cadmium and nickel accumulation by Typha sp. (BCF = 1.3 and 0.8, respectively) and zinc accumulation by Juncus sp. (BCF = 4.8). Our results underline the potential use of such plant species for heavy metal biomonitoring in water, sediments, and soil.
Показать больше [+] Меньше [-]Soil Degradation Due to Vicinal Intensive Hog Farming Operation Located in East Mediterranean Полный текст
2012
Liodakis, Stylianos | Michalopoulos, Charalampos | Efthymiou, Elpida | Katsigiannis, Georgios
One of the main environmental impacts of concentrated animal feeding operations is the soil degradation in vicinity with the livestock breeding facilities due to substances such as ammonia emitted from the various stages of the process. Owing to the high temperatures of the Mediterranean ecosystems, the evolution of gasses is more extensive and the soil degradation is consequently more severe than those obtained in northern Europe. In this research, the soil degradation effects of a large meat-producing, processing, and packaging unit have been investigated. The investigated intensive hog farming operation (IHFO) is located at a limestone soil coastal area with sea to the north and hills to the south. Soil samples of the upper mineral soil were taken in various distances and directions from the IHFO boundaries. Thirteen experimental cycles were carried out in the duration of 1.5 years starting in March 2009 until October 2010. The soil samples were analyzed on pH and electrical conductivity (EC) values as well as NH4 + and NO3 − concentrations. Significantly higher concentrations of the two nitrogen forms were observed on samples at increasing proximity downwind from the farm (south). Southern soil average NH4 + and NO3 − concentrations ranged between 0.4–118 μg NH4 +-N g−1 soil and 6.1–88.4 μg NO3 −-N g−1 soil, respectively. The variation of emitted gasses depositions was clearly reflected in the average pH and EC values. Average pH and EC values downwind from IHFO boundaries varied between 7.1–8.2 and 140–268 μS/cm, respectively.
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