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Heavy Metal Content of Soils and Plum Orchards in an Uncontaminated Area Texte intégral
2014
Bošković-Rakočević, Ljiljana | Milivojević, Jelena | Milošević, Tomo | Paunović, Gorica
Research was conducted to assess metal contamination of soils and fruits and evaluate potential human health risks. Heavy metal concentrations (Fe, Mn, Cu, Zn, Cd and Pb) in plum orchard soils were below maximum permissible concentration. Igₑₒshowed that soils were uncontaminated (Igₑₒ<0 for Fe and Mn) and uncontaminated to moderately contaminated (I gₑₒ for Cu, Zn, Pb and Cd ranged from 1.20–0.57, 1.32–0.98, 2.97–0.88 and 1.26–0.58, respectively). Fruit Zn, Cu, Mn, Pb and Cd concentrations were within maximum permissible concentration in foods in Serbia. Only Fe levels were above maximum permissible concentration at most locations. The soil-to-fruit transfer factor (TF) showed large differences between metals. TF for Cd and Pb was 0.0, for Mn 0.007–0.030 and for Zn 0.04–0.09, indicating no potential risk to human health, whereas TF for Fe and Cu was high, i.e. 0.30–1.51 and 0.33–1.69, respectively, suggesting that plum can accumulate Fe and Cu.
Afficher plus [+] Moins [-]Long-term Aerosol Characteristics over Eastern, Southeastern, and South Coalfield Regions in India Texte intégral
2014
Soni, Kirti | Kapoor, Sangeeta | Parmar, Kulwinder Singh
Natural and anthropogenic aerosols over coal mines regions in India play a significant role in influencing the regional radiation budget, causing climate implications to the overall hydrological cycle of India. In the reference of regional climate change and air quality, we discuss aerosol optical depth (AOD) variability and long-term trends (from Mar 2000–Dec 2012) over eastern, southeast, and south coalfield regions in India. The present work analyses the variations and trends in aerosol loading using Terra-MODIS (Moderate-Resolution Imaging Spectroradiometer) AOD₅₅₀data in the period 2000–2012. Overall, an increasing trend in AOD₅₅₀has been observed over all regions namely Raniganj (7.31 %) in eastern and Korba (5.0 %) in southeast, and Godavari Valley (32 %) in the south coalfield region in India. This increasing trend predominantly owes to a constant increase in the seasonal/monthly averaged AOD during the winter (Dec–Feb) and post-monsoon (Oct–Nov) seasons dominated by anthropogenic emissions. In contrast, a decreasing trend is observed during pre-monsoon (Mar–May) season over eastern coalfield region (−13 %), while at south coalfield region (44 %) and southeastern coalfield region (0.8 %), increasing trends are observed. Similarly, increasing trends is observed over all regions in monsoon (Jun–Sep) months. Furthermore, the values of Hurst exponent, fractal dimension, and predictability index for AODs are 0.5, 1.5, and 0, respectively suggesting that the AODs in all sites follow the Brownian time series motion (true random walk). High AOD values (0.59 ± 0.21) are observed over eastern region Raniganj.
Afficher plus [+] Moins [-]Analysis and Occurrence of Endocrine Disruptors in Brazilian Water by HPLC-Fluorescence Detection Texte intégral
2014
Melo, Suzyéth M. | Brito, Natilene M.
A method for simultaneous analysis of bisphenol A (BPA) and 17α-ethinylestradiol (EE2) in water supply was developed using solid-phase extraction and high-performance liquid chromatography with fluorescence detection. The linearity was evaluated between 2.5 and 200 μg L⁻¹(r> for the analytes. The limits of quantification were 1.5 and 2.1 ng L⁻¹for BPA and EE2, respectively. The extraction was made with C18 cartridges, and recoveries obtained varied between 70 and 102 % for the strengthening of 5 μg L⁻¹. After the validation, the method was applied in the determination of pollutants in surface water and water supply of Sao Luis, Brazil, where BPA was found in two of the eight samples analyzed, with concentrations of 1.11 and 3.61 μg L⁻¹.
Afficher plus [+] Moins [-]Hydrogenic Heavy Metals Contamination of Fluvisols in the Middle Cis-Urals Region, Russia Texte intégral
2014
Vodyanitskii, Yu. N. | Savichev, A. T.
In 1999, the Perm region ranked eighth among Russian regions in terms of technogenic load per unit of area (4.4 t/km²). The situation in the city of Perm is especially unfavorable in ecological terms due to aerial contamination and hydrogenic contamination, because of industrial wastes entering the small rivers that are tributaries of the Kama river. It was revealed that fluvisols of the city of Perm are contaminated by heavy metals of hydrogenic origin because of the unpurified sewage water entering them. The fluvisols of the city of Perm are contaminated by heavy metals of hydrogenic origin because of the unpurified sewage water entering them.Content of HMs in fine earth showed the deficit and excess compared with European Soil Clarke and Local Background. In relation to European Soil Clarkes elements can be divided into three groups: (1) scarce elements forming negative geochemical anomaly, (2) "normal" elements, which does not differ significantly from Clarke, (3) excess elements forming positive geochemical anomaly. Scarce elements include rubidium and arsenic. “Normal” elements are yttrium, gallium, zirconium and lead. Excess elements are nickel, copper, zinc, strontium and chromium. In the fluvisols, the Fe-rohrensteins are formed. Some elements are concentrated in the Fe-rohrensteins, and some others are not concentrated in them or are found in low concentrations. In Fe-rohrensteins the highly active group comprises As, Zn, Ni, Cu, Cr, and Pb; the moderately active one is represented by Sr, Nb, Ga, and Y; and the inert group contains Zr and Rb. The contents of some chemical elements in Fe-rohrensteins are much greater than those in the fine earth. The Pb and Zn contents in Fe-rohrensteins of the soil of small rivers basin are 440 and 890 mg/kg, respectively. In Fe-rohrensteins, the Pb and Zn contents are 42 % and 17 % of their concentrations in fine earth, respectively. Since some part of heavy metals is precipitated at the redox microbarriers around concretions (Fe-rohrensteins), it is removed from the biological cycle.
Afficher plus [+] Moins [-]Tree Response to Experimental Watershed Acidification Texte intégral
2014
Jensen, N. K. | Holzmueller, E. J. | Edwards, P. J. | Gundy, M Thomas-Van | DeWalle, D. R. | Williard, K. W. J.
Forest ecosystems in the Eastern USA are threatened by acid deposition rates that have increased dramatically since industrialization. We utilized two watersheds at the Fernow Experimental Forest in West Virginia to examine long-term effects of acidification on ecological processes. One watershed has been treated with ammonium sulfate (approximately twice the ambient deposition rate) since 1989 to simulate elevated acidic deposition, while the other served as a control. Prior to treatment, both watersheds were similar in age and species composition. Ten dominant overstory Prunus serotina and Liriodendron tulipifera trees were selected and cored from each watershed to measure bolewood concentrations of essential elements through time. In addition, changes in tree species basal area were analyzed utilizing 50 long-term growth plots. Results of this experiment show lower calcium and magnesium concentration and increased acidic cation concentration for both species in the treated watershed, indicating a negative treatment effect. Growth response, measured through relative growth rates of cored trees and changes in basal area from growth plots, was not as conclusive and appeared to differ by species. The resulting difference in species response indicates that acidification sensitivity is something that land managers should consider when managing forests affected by acidification.
Afficher plus [+] Moins [-]Photodegradation of Tri(Chloropropyl) Phosphate Solution by UV/O3 Texte intégral
2014
Ruan, Xin-Chao | Jin, Xiao | Yang, Ze-Yu | Zeng, Qing-Fu
A photodegradation technology based on the combination of ultraviolet radiation with ozone (UV/O₃) for degrading tri(chloropropyl) phosphate (TCPP) was developed in the present study. Parameters affecting the degradation of TCPP were optimized, and the developed technology was successfully applied to degrade TCPP in two real wastewater samples. The results showed that reaction time, ozone concentration, the initial acidity of reaction solution, and the initial concentration of TCPP in aqueous solution contributed to the degradation efficiency of TCPP. Under the optimized disposal conditions, 100 mg/L of TCPP aqueous solution with a pH value of 7 can be degraded effectively in 60 min with an ozone concentration of 66.2 mg/L. In detail, the yield rates of Cl⁻and PO₄³⁻was high up to 98.9 and 98.2 %, respectively; and total organic carbon (TOC) removal rate was high up to 94.3 %. Method application demonstrated that TCPP can be degraded effectively in pond water. However, only 83.2 and 61.9 % of Cl⁻and PO₄³⁻were produced, and the TOC removal rate was only 81.3 % after 60 min exposure in the effluent discharged from a wastewater treatment plant. Therefore, the presence of interferences may hinder the degradation of TCPP in real wastewater, but its potential application for real wastewater is promising in the future after appropriate domestication and evaluation.
Afficher plus [+] Moins [-]Degradation of Methyl Orange in Aqueous Solution by Microwave Irradiation in the Presence of Granular-Activated Carbon Texte intégral
2014
Xu, Dongyan | Cheng, Fei | Zhang, Yusong | Song, Zhonglai
The degradation of methyl orange (MO) in aqueous solution by microwave irradiation in the presence of granular-active carbon (GAC) was investigated. It was found that a synergistic rather than an additive effect of microwave irradiation and GAC contributes to the high-degradation efficiency. The ultraviolet and visible spectrum (UV–vis), infrared spectroscopy (IR), and scanning electron microscopy (SEM) measurements were conducted to trace the MO degradation process. It was demonstrated that the decrease in performance of GAC after repetitive use is largely attributed to the adsorption of some intermediate products on the surface of GAC. The regeneration of the spent GAC under microwave radiation was also investigated. The results show that the activity of spent GAC can be effectively recovered by microwave radiation and 74.1 % of its initial activity remains after six reaction cycles.
Afficher plus [+] Moins [-]Modeling the Odor Generation in WWTP: An Integrated Approach Review Texte intégral
2014
Carrera-Chapela, Fabio | Donoso-Bravo, Andres | Souto, José A. | Ruiz-Filippi, Gonzalo
Nuisance odors generation from waste and wastewater treatment plants are a cause of public discomfort and complaints. This situation impairs the air quality and represents a growing social and public health problem, especially in developing countries. Several modeling approaches have been developed and successfully implemented in the frame of a wastewater treatment plant for both the biological treatment and physicochemical processes. The mathematical modeling of the odor generation process is still considered a quite complex issue, mainly due to the fact that olfactory nuisance can be caused by many different chemical compounds and the perception of odors is influenced by subjective thresholds. Moreover, the impact of odor sources on air quality is highly conditioned by complex atmospheric dispersion processes. This review presents a critical state-of-art and assessment where information related to odor emissions impact studies as well as modeling applications are compiled and discussed.
Afficher plus [+] Moins [-]Estimation of Soil Base Cation Weathering Rates with the PROFILE Model to Determine Critical Loads of Acidity for Forested Ecosystems in Pennsylvania, USA: Pilot Application of a Potential National Methodology Texte intégral
2014
Phelan, Jennifer | Belyazid, Salim | Kurz, Daniel | Guthrie, Scott | Cajka, James | Sverdrup, Harald | Waite, Randall
Base cation weathering (BCw) rate is one of the most influential yet difficult to estimate parameters in the calculation of critical acid loads of nitrogen (N) and sulfur (S) deposition for terrestrial systems. Only the clay correlation–substrate method, a simple empirical model, has been used for estimating BCw rates for forest ecosystems in the conterminous USA and may not be suitable for application at all sites without calibration or revision. An alternate model, PROFILE, may offer an improved method to estimate BCw rates. It is a transferable, process-based model that simulates the weathering rates of groups of minerals. The objective of this study was to evaluate PROFILE using national datasets as a method to estimate BCw rates for forests in the USA, focusing on Pennsylvania (PA) as the first test state. The model paired with national datasets was successfully applied at 51 forested sites across PA. Weathering rates ranged from 119 to 9,245 eq ha⁻¹ year⁻¹ and were consistent with soil properties and regional geology. Comparisons of terrestrial critical acid loads with 2002 N and S deposition showed critical load exceedances at 53 % of the sites. This trial evaluation of PROFILE paired with national datasets in PA establishes that there are sufficient data to support the estimation of BCw rates and determination of critical acid loads for forests in the USA. However, the paired method should be applied in other locations to further evaluate the performance of the model in different regions of the country.
Afficher plus [+] Moins [-]Recovery of the Rare Metals from Various Waste Ashes with the Aid of Temperature and Ultrasound Irradiation Using Chelants Texte intégral
2014
Hasegawa, Hiroshi | Rahman, Ismail M. M. | Egawa, Yuji | Sawai, Hikaru | Begum, Zinnat A. | Maki, Teruya | Mizutani, Satoshi
The incineration fly ash (IFA), molten fly ash (MFA), thermal power plant fly ash (TPP-FA), and nonferrous metal processing plant ash (MMA) have been screened in terms of the following rare-termed metal contents: B, Ce, Co, Dy, Eu, Ga, Gd, Hf, In, Li, Lu, Mn, Nb, Nd, Ni, Pr, Rb, Sb, Se, Sm, Sr, Ta, Tb, Te, Ti, Tm, V, W, Y, and Yb. The pseudo-potential for recycling of the waste ashes, as compared to the cumulative concentration in the crust (mg kg⁻¹), was determined as follows: MMA > IFA > MFA > TPP-FA. The comparison with the crude ore contents indicates that the MMA is the best resource for reprocessing. The recovery of the target metals using aminopolycarboxylate chelants (APCs) has been attempted at varying experimental conditions and ultrasound-induced environment. A better APC-induced extraction yield can be achieved at 0.10 mol L⁻¹ concentration of chelant, or if the system temperature was maintained between 60 to 80 °C. Nevertheless, the mechanochemical reaction induced by the ultrasound irradiation has been, so far, the better option for rare metal dissolution with chelants as it can be conducted at a minimum chelant concentration (0.01 mol L⁻¹) and at room temperature (25 ± 0.5 °C).
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