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Alternative indicators for monitoring Cryptosporidium oocysts in reclaimed water Full text
2013
Agulló-Barceló, M. | Oliva, F. | Lucena, F.
With the widespread use of reclaimed water all over the world, there is a clear need to optimise its management in order to guarantee water safety. Model microorganisms (with either indicator or index function) are commonly used to assess risks related to the presence of enteric pathogens in water. Samples from five water reclamation plants located in Northeastern Spain were analysed to validate the use of three model microorganisms (Escherichia coli, somatic coliphages and spores of sulphite-reducing clostridia) as surrogates of Cryptosporidium total or infectious oocysts (TOO and IOO, respectively) in reclaimed water. Probability plots, simple and multiple linear regression and discriminant analyses were performed to assess their relationships. Results show that the detection of E. coli alone is not useful to model either the behaviour or concentrations of Cryptosporidium. However, discriminant analyses showed a high rate of correctly classified samples (91.9 %) when E. coli and somatic coliphages data were used together to predict the presence/absence of IOO. Spores of sulphite-reducing clostridia (SRC) showed parallel reduction patterns and high correlation values (r = 0.76) with reductions in TOO. Furthermore, simple regression analyses of SRC and TOO in reclaimed water showed high correlation values (r = 0.85). Therefore, at the treatment plants studied, SRC can be considered to have good indicator and index functions for TOO. From the point of view of health protection, the use of SRC together with E. coli (which is mandatory in the current Spanish regulations) would satisfy the need for improved reclaimed water management.
Show more [+] Less [-]Air dispersion of heavy metals in the vicinity of the As-Sb-Tl abounded mine and responsiveness of moss as a biomonitoring media in small-scale investigations Full text
2013
Bačeva, Katerina | Stafilov, Trajče | Šajn, Robert | Tănăselia, Claudiu
A systematic study was carried out to investigate air deposition and to explore the natural distribution and enrichment (contamination) with trace elements in the small area (cca. 13 km²) of an antimony-arsenic-thallium mineralization outcrop at an abandoned mine “Allchar.” The mine is located on the northwestern part of Kožuf Mount, Republic of Macedonia. The locality of Allchar is unique in its mineral composition; besides a very intriguing mineral, lorandite, there are 45 other minerals, some of which are rare. The distribution of 53 elements (with special attention to As, Sb, and Tl) were detected in 69 moss samples from eight various species collected from this area. Moss samples were analyzed following microwave digestion by inductively coupled plasma–mass spectrometry and inductively coupled plasma–atomic emission spectrometry. It was found that the atmospheric deposition for As in the moss samples on or around the Allchar mine is >6.5 times higher and for Tl is 19 times higher compared to values for the samples from the rest of the Allchar area. By the application of multivariate cluster and R-mode factor analyses (FA), five geochemical associations were determined. Cluster and R-mode FA were used to identify and characterize element associations, and five associations of elements were determined by the method of multivariate statistics. F1 (Co, Cr, Fe, Sc, Li, V, Ga, Y, Ni, Mn, Al, La-Lu, Cu, Ge, Be, Bi, and Hf); F2 (As, Tl, Sb, and Mg); F3 (Rb, Cs, and Mo); F4 (Sr, Ba, Hf, Zr, La-Lu, and Bi), and F5 (Cd, Zn, Ag, and Cu).
Show more [+] Less [-]Rape (Brassica chinensis L.) seed germination, seedling growth, and physiology in soil polluted with di-n-butyl phthalate and bis(2-ethylhexyl) phthalate Full text
2013
Ma, Tingting | Christie, Peter | Teng, Ying | Luo, Yongming
Phthalic acid esters (PAEs) pollution in agricultural soils caused by widely employed plastic products is becoming more and more widespread in China. PAEs polluted soil can lead to phytotoxicity in higher plants and potential health risks to human being. We evaluated the individual toxicity of di-n-butyl phthalate (DnBP) and bis(2-ethylhexyl) phthalate (DEHP), two representative PAEs, to sown rape (Brassica chinensis L.) seeds within 72 h (as germination stage) and seedlings after germination for 14 days by monitoring responses and trends of different biological parameters. No significant effects of six concentrations of PAE ranging from 0 (not treated/NT) to 500 mg kg(-1) on germination rate in soil were observed. However, root length, shoot length, and biomass (fresh weight) were inhibited by both pollutants (except root length and biomass under DEHP). Stimulatory effects of both target pollutants on malondialdehyde (MDA) content, superoxide dismutase (SODase) activity, ascorbate peroxidase (APXase) content, and polyphenoloxidase (PPOase) activity in shoots and roots (SODase activity in shoots excluded) were in the same trend with the promotion of proline (Pro) but differed with acetylcholinesterase activity (except in shoots under DnBP) for analyzed samples treated for 72 h and 14 days. Responses of representative storage compounds free amino acids (FAA) and total soluble sugar (TSS) under both PAEs were raised. Sensitivity of APXase and Pro in roots demonstrates their possibility in estimation of PAE phytotoxicity and the higher toxicity of DnBP, which has also been approved by the morphological photos of seedlings at day 14. Higher sensitivity of the roots was also observed. The recommended soil allowable concentration is 5 mg DnBP kg(-1) soil for the development of rape. We still need to know the phytotoxicity of DEHP at whole seedling stage for both the growing and development; on the other hand, soil criteria for PAE compounds are urgently required in China.
Show more [+] Less [-]Interaction of erythromycin ethylsuccinate and acetaminophen with protein fraction of extracellular polymeric substances (EPS) from various bacterial aggregates Full text
2013
Métivier, Romain | Bourven, Isabelle | Labanowski, Jérome | Guibaud, Gilles
Extracellular polymeric substances (EPS) are, along with microbial cells, the main components of the biological sludges used in wastewater treatment and natural biofilms. EPS play a major role in removing pollutants from water by means of sorption. The ability of soluble EPS (S-EPS) and bound EPS (B-EPS) derived from various bacterial aggregates (flocs, granules, biofilms) to bind at pH 7.0 ± 0.1 to two pharmaceutical substances, acetaminophen (ACE) and erythromycin ethylsuccinate (ERY), has been investigated using the fluorescence quenching method. Two intense fluorescence peaks, A (Ex/Em range, 200-250/275-380 nm) and B (Ex/Em range, 260-320/275-360 nm), corresponding respectively to the aromatic protein region and soluble microbial by-product-like region, were identified in a three-dimensional excitation-emission matrix of EPS samples. The fluorescence peak, which corresponds to humic-like substances, was also identified though at low intensity. The ability of EPS to bind ACE was found to exceed that for ERY. The aromatic protein fraction of EPS displays a slightly higher affinity for drugs than that shown by the soluble microbial by-product-like fraction. The S-EPS and B-EPS present the same affinity for ACE and ERY. The effective quenching constants (log K) derived from the Stern-Volmer Equation equaled at peak A (with S-EPS): 3.7 ± 0.2 to 4.0 ± 0.1 for ACE and 2.1 ± 0.3 to 2.7 ± 0.1 for ERY. With B-EPS, these values were 3.9 ± 0.1 to 4.0 ± 0.1 for ACE and 2.0 ± 0.2 to 2.6 ± 0.1 for ERY. Our results suggest that the weaker EPS affinity for ERY than for ACE serves to partially explain why only about 50-80 % of ERY is removed from wastewater at the treatment plant. Moreover, this work demonstrates that EPS from natural river biofilms are able to bind drugs, which in turn may limit the mobility of drugs in natural waters.
Show more [+] Less [-]Strengths and weaknesses of microarray approaches to detect Pseudo-nitzschia species in the field Full text
2013
Barra, Lucia | Ruggiero, Maria Valeria | Sarno, Diana | Montresor, Marina | Kooistra, Wiebe H. C. F.
The planktonic diatom genus Pseudo-nitzschia contains several genetically closely related species. Some of these can produce domoic acid, a potent neurotoxin. Thus, monitoring programs are needed to screen for the presence of these toxic species. Unfortunately, many are impossible to distinguish using light microscopy. Therefore, we assessed the applicability of microarray technology for detection of toxic and non-toxic Pseudo-nitzschia species in the Gulf of Naples (Mediterranean Sea). Here, 11 species have been detected, of which at least 5 are potentially toxic. A total of 49 genus- and species-specific DNA probes were designed in silico against the nuclear LSU and SSU rRNA of 19 species, and spotted on the microarray. The microarray was tested against total RNA of monoclonal cultures of eight species. Only three of the probes designed to be species-specific were indeed so within the limits of our experimental design. To assess the effectiveness of the microarray in detecting Pseudo-nitzschia species in environmental samples, we hybridized total RNA extracted from 11 seasonal plankton samples against microarray slides and compared the observed pattern with plankton counts in light microscopy and with expected hybridization patterns obtained with monoclonal cultures of the observed species. Presence of species in field samples generally resulted in signal patterns on the microarray as observed with RNA extracted from cultures of these species, but many a-specific signals appeared as well. Possible reasons for the numerous cross reactions are discussed. Calibration curves for Pseudo-nitzschia multistriata showed linear relationship between signal strength and cell number.
Show more [+] Less [-]Study of contaminant transport at an open-tipping waste disposal site Full text
2013
Ashraf, Muhammad Aqeel | Ismail Yusoff, | Yusof, Mohamad | Alias, Yatimah
Field and laboratory studies were conducted to estimate concentration of potential contaminants from landfill in the underlying groundwater, leachate, and surface water. Samples collected in the vicinity of the landfill were analyzed for physiochemical parameters, organic contaminants, and toxic heavy metals. Water quality results obtained were compared from published data and reports. The results indicate serious groundwater and surface water contamination in and around the waste disposal site. Analysis of the organic samples revealed that the site contains polychlorinated biphenyls and other organo-chlorine chemicals, principally chloro-benzenes. Although the amount of PCB concentration discovered was not extreme, their presence indicates a potentially serious environmental threat. Elevated concentrations of lead, copper, nickel, manganese, cadmium, and cobalt at the downgradient indicate that the contamination plume migrated further from the site, and the distribution of metals and metals containing wastes in the site is nonhomogeneous. These results clearly indicate that materials are poorly contained and are at risk of entering the environment. Therefore, full characterization of the dump contents and the integrity of the site are necessary to evaluate the scope of the problem and to identify suitable remediation options.
Show more [+] Less [-]Artificial and enhanced humification of soil organic matter using microwave irradiation Full text
2013
Kim, Min Chan | Kim, Han S.
Microwave (MW) irradiation, a less energy-intensive irradiation technique, was employed to promote the changes in physicochemical properties of soil organic matter (SOM). MW was irradiated to forest soils for 10 min. Then, the physical and chemical properties of the SOM were analyzed with UV absorbance spectroscopy, Fourier transform infrared spectroscopy, elemental analysis, and size exclusion chromatography. Also, the SOM was fractionated into biopolymer, fulvic acid, and humic acid, and each fraction was analyzed quantitatively. These analyses revealed that the SOM became more aromatic and nonpolar, highly condensed, and macromolecular organic substances that possess a higher amount of functional groups found in highly humified substances than the original SOM as a result of the MW irradiation. The humification-like alteration of SOM property was attributable to the thermal cracking and to the radical reaction, particularly when the MW was irradiated along with activated carbon under the aerobic condition. The results of this study suggest that the artificial and enhanced property changes of SOM can be accomplished by MW irradiation on an engineering time scale, which can contribute to the successful soil and groundwater remediation practice.
Show more [+] Less [-]Development and application of biotechnologies in the metal mining industry Full text
2013
Johnson, D Barrie
Metal mining faces a number of significant economic and environmental challenges in the twenty-first century for which established and emerging biotechnologies may, at least in part, provide the answers. Bioprocessing of mineral ores and concentrates is already used in variously engineered formats to extract base (e.g., copper, cobalt, and nickel) and precious (gold and silver) metals in mines throughout the world, though it remains a niche technology. However, current projections of an increasing future need to use low-grade primary metal ores, to reprocess mine wastes, and to develop in situ leaching technologies to extract metals from deep-buried ore bodies, all of which are economically more amenable to bioprocessing than conventional approaches (e.g., pyrometallurgy), would suggest that biomining will become more extensively utilized in the future. Recent research has also shown that bioleaching could be used to process a far wider range of metal ores (e.g., oxidized ores) than has previously been the case. Biotechnologies are also being developed to control mine-related pollution, including securing mine wastes (rocks and tailings) by using “ecological engineering” approaches, and also to remediate and recover metals from waste waters, such as acid mine drainage. This article reviews the current status of biotechnologies within the mining sector and considers how these may be developed and applied in future years.
Show more [+] Less [-]Polybrominated diphenyl ethers in surface sediments from principal watersheds of Shanghai, China: levels, distribution, influencing factors, and risk assessment Full text
2013
Wu, Ming-Hong | Tang, Liang | Xu, Gang | Ma, Jing | Liu, Ning | Wang, Liang | Lei, Jian-Qiu
Fourteen and 17 sediment samples were collected from three main rivers of Shanghai in July and November, respectively. Eight polybrominated diphenyl ether (PBDE) congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183, and BDE-209) were detected in these samples to clarify the pollution status in the metropolis. Instrumental analyses showed that the concentrations of ∑₈PBDEs ranged from 10.97 to 64.05 ng/g dry weight (dw), with an average value of 29.71 ng/g dw. BDE-209 was the predominant congener accounting for more than 97 % of total PBDEs, followed by BDE-47 and BDE-99. Remarkable spatial and seasonal distributions of PBDE concentrations were observed, suggesting that local sources, seasonal climates, and hydrologic conditions might be the influencing factors. Moderate correlations (r ² = 0.28–0.51, p < 0.05) were found between total organic carbon and PBDEs, which indicated that organic carbon content influenced the distributions of PBDEs in sediment of Shanghai at some extent. Hazard quotients revealed PBDEs posed no potential risk to benthic organisms in the study area at present.
Show more [+] Less [-]Investigation of uranium binding forms in selected German mineral waters Full text
2013
Osman, Alfatih A. A. | Geipel, Gerhard | Bernhard, Gert | Worch, Eckhard
Cryogenic time-resolved laser-induced fluorescence spectroscopy was successfully used to identify uranium binding forms in selected German mineral waters of extremely low uranium concentrations (<2.0 μg/L). The measurements were performed at a low temperature of 153 K. The spectroscopic data showed a prevalence of aquatic species Ca2UO2(CO3)3 in all investigated waters, while other uranyl-carbonate complexes, viz, UO2CO3(aq) and UO2(CO3)2 (2-), only existed as minor species. The pH value, alkalinity (CO3 (2-)), and the main water inorganic constituents, specifically the Ca(2+) concentration, showed a clear influence on uranium speciation. Speciation modeling was performed using the most recent thermodynamic data for aqueous complexes of uranium. The modeling results for the main uranium binding form in the investigated waters indicated a good agreement with the spectroscopy measurements.
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