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Phytoremediation of a sulphonated azo dye Green HE4B by Glandularia pulchella (Sweet) Tronc. (Moss Verbena)
2011
Kabra, Akhil N. | Khandare, Rahul V. | Kurade, Mayur B. | Govindwar, Sanjay P.
PURPOSE: The dyes and dye stuffs present in effluents released from textile dyeing industries are potentially mutagenic and carcinogenic. Phytoremediation technology can be used for remediating sites contaminated with such textile dyeing effluents. The purpose of the work was to explore the potential of Glandularia pulchella (Sweet) Tronc. to decolorize different textile dyes, textile dyeing effluent, and synthetic mixture of dyes. METHODS: Enzymatic analysis of the plant roots was performed before and after decolorization of dye Green HE4B. Analysis of the metabolites of Green HE4B degradation was done using UV–Vis spectroscopy, high-performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR), and gas chromatography–mass spectroscopy (GC-MS). The ability of the plant to decolorize and detoxify a textile dyeing effluent and a synthetic mixture of dyes was studied by a determination of the American Dye Manufacturer’s Institute (ADMI), biological oxygen demand (BOD), and chemical oxygen demand (COD). Phytotoxicity studies were performed. RESULT: Induction of the activities of lignin peroxidase, laccase, tyrosinase, and 2,6-dichlorophenol indophenol reductase was obtained, suggesting their involvement in the dye degradation. UV–Vis spectroscopy, HPLC, and FTIR analysis confirmed the degradation of the dye. Three metabolites of the dye degradation were identified, namely, 1-(4-methylphenyl)-2-{7-[(Z)-phenyldiazenyl] naphthalen-2-yl} diazene; 7,8-diamino-2-(phenyldiazenyl) naphthalen-1-ol; and (Z)-1,1′-naphthalene-2,7-diylbis (phenyldiazene) using GC-MS. ADMI, BOD, and COD values were reduced. The non-toxic nature of the metabolites of Green HE4B degradation was revealed by phytotoxicity studies. CONCLUSION: This study explored the phytoremediation ability of G. pulchella (Sweet) Tronc. in degrading Green HE4B into non-toxic metabolites.
Показать больше [+] Меньше [-]Heavy metal contamination and risk assessment in water, paddy soil, and rice around an electroplating plant
2011
Liu, Jie | Zhang, Xue-Hong | Tran, Henry | Wang, Dun-Qiu | Zhu, Yi-Nian
PURPOSE: The objective of this paper is to assess the impact of long-term electroplating industrial activities on heavy metal contamination in agricultural soils and potential health risks for local residents. METHODS: Water, soil, and rice samples were collected from sites upstream (control) and downstream of the electroplating wastewater outlet. The concentrations of heavy metals were determined by an atomic absorption spectrophotometer. Fractionation and risk assessment code (RAC) were used to evaluate the environmental risks of heavy metals in soils. The health risk index (HRI) and hazard index (HI) were calculated to assess potential health risks to local populations through rice consumption. RESULTS: Hazardous levels of Cu, Cr, and Ni were observed in water and paddy soils at sites near the plant. According to the RAC analysis, the soils showed a high risk for Ni and a medium risk for Cu and Cr at certain sites. The rice samples were primarily contaminated with Ni, followed by Cr and Cu. HRI values >1 were not found for any heavy metal. However, HI values for adults and children were 2.075 and 1.808, respectively. CONCLUSION: Water, paddy soil, and rice from the studied area have been contaminated by Cu, Cr, and Ni. The contamination of these elements is related to the electroplating wastewater. Although no single metal poses health risks for local residents through rice consumption, the combination of several metals may threaten the health of local residents. Cu and Ni are the key components contributing to the potential health risks.
Показать больше [+] Меньше [-]Study of the uncertainty in NO₂ chemiluminescence measurements due to the NO-O₃ reaction in sampling lines
2011
Miñarro, Marta Doval | Ferradás, Enrique González | Rico, Jonathan Barberá | Alonso, Fernando Díaz | Martínez, Francisco J Marzal | Trigueros, Cristina Romero
Introduction The change in light intensity that takes place when an ambient air sample is drawn into the detection chamber of a chemiluminescence monitor generates changes in the concentrations of several species, such as NO₂, NO and O₃. Although this phenomenon has been known for several decades, there is still no commonly accepted approach on when or how to correct for it in NO₂ and O₃ readings. Discussion In this work, we have assessed the expanded uncertainty of two chemiluminescence NO x analysers commercially available according to EN 14211:2005, with the aim of establishing the maximum allowable standard uncertainty due to the reaction between NO and O₃ in the sampling system. Conclusion Although this maximum allowable uncertainty cannot be a universal value--as it will depend on the performance of each analyser--our results have led us to propose the conservative value of 2%. We have also proposed a methodology for improving data quality which could be easily implemented by those responsible for air quality data validation.
Показать больше [+] Меньше [-]Polychlorinated biphenyls in farmed and wild Onchorhynchus kisutch and Onchorhynchus mykiss from the Chilean Patagonia
2011
Montory, Monica | Habit, Evelyn | Bahamonde, Paulina | Fernández, Pilar | Grimalt, Joan O. | Saez, Katia | Rudolph, Ignacio | Barra, Ricardo
Purpose This paper analyses the presence of polychlorinated biphenyls (PCBs) in escaped: farmed and wild salmons in southern Chile, analysing their concentrations and congener profiles in two species (Oncorhynchus kisutch and Oncorhynchus mykiss). Methods Muscle samples from both farmed and escaped fish of two species, O. mykiss (rainbow trout) and O. kisutch (coho salmon), were analysed for PCBs (42 congeners). To differentiate between the wild salmon and the salmon that have escaped from fish farms, the astaxanthin content in the muscular tissue was analysed with a high-performance liquid chromatography -diode array detector method. PCBs were measured by gas chromatography with an electron capture detector. Results The levels of astaxanthin can be used to differentiate between farmed, escaped and wild-borne salmons with statistically different concentrations. When comparing the total PCB concentrations for both trout and salmon samples, it can be determined that a separate analysis for farmed, escaped and wild-borne fish more accurately describes the real differences in the concentrations; these differences are hidden when separate analyses are not performed. The congener profiles are similar in both trout and coho salmon, where the tri-, tetra- and penta-CB congeners are the most abundant. Conclusion This study is the first report of PCBs in wild-borne, farmed and escaped salmons for the Southern Hemisphere, considering that Chile is actually one of the principal world producers of salmon.
Показать больше [+] Меньше [-]Incorporation of in silico biodegradability screening in early drug development--a feasible approach
2011
Steger-Hartmann, Thomas | Lange, Reinhard | Heuck, Klaus
Introduction The concentration of a pharmaceutical found in the environment is determined by the amount used by the patient, the excretion and metabolism pattern, and eventually by its persistence. Biological degradation or persistence of a pharmaceutical is experimentally tested rather late in the development of a pharmaceutical, often shortly before submission of the dossier to regulatory authorities. Materials and methods To investigate whether the aspect of persistence of a compound could be assessed early during drug development, we investigated whether biodegradation of pharmaceuticals could be predicted with the help of in silico tools. To assess the value of in silico prediction, we collected results for the OECD 301 degradation test (“ready biodegradability”) of 42 drugs or drug synthesis intermediates and compared them to the prediction of the in silico tool BIOWIN. Results and discussion Of these compounds, 38 were predictable with BIOWIN, which is a module of the Estimation Programs Interface (EPI) Suite™ provided by the US EPA. The program failed to predict the two drugs which proved to be readily biodegradable in the degradation tests. On the other hand, BIOWIN predicted two compounds to be readily biodegradable which, however, proved to be persistent in the test setting. Conclusion The comparison of experimental data with the predicted one resulted in a specificity of 94% and a sensitivity of 0%. The results of this study do not indicate that application of the biodegradation prediction tool BIOWIN is a feasible approach to assess the ready biodegradability during early drug development.
Показать больше [+] Меньше [-]PAH desorption from sediments with different contents of organic carbon from wastewater receiving rivers
2011
Qi, Weixiao | Liu, Huijuan | Qu, Jiuhui | Ren, Huimin | Xu, Wei
Background and aim Many rivers have to receive treated or untreated wastewater as the main water sources in the world, especially in the countries facing with water shortage. For instance, the Haihe and Huaihe River Basin, which are among areas facing crises for water resources in China, receive 33,400 million tons of wastewater per year. As the sediment has large capacity for sorbing hydrophobic organic pollutants such as polycyclic aromatic hydrocarbons (PAHs), it can act as a natural repository for the contaminants. This means pollutants can release into water phase again under some conditions, such as resuspension, sediment dredging, etc. The objective of this research was to study the trends of PAH release from sediments in rivers receiving much wastewater, such as Yongding New River (YD), Northsewer (NS), and Southsewer (SS) from Haihe River Basin. These rivers received most of the wastewater from Tianjin, China and merge into Bohai Bay finally. Methods Sediments (namely YD, NS, and SS) were collected from Yongding New River, Northsewer, and Southsewer, respectively. The physical and chemical properties of the sediments, including particle size distribution, total organic carbon (TOC) and black carbon (BC) contents, elemental compositions, organic functional groups analyzed from Fourier transformed infrared (FTIR), and nuclear magnetic resonance (NMR) spectra, were characterized. PAH desorption from the sediments was measured with the Tenax shaken slurry desorption method. Results The NS sediment had a greatly higher TOC and BC contents, while lower BC-to-TOC ratio than YD and SS sediments. NMR and FTIR analysis showed that aliphatic carbons were more abundant in NS sediment than SS sediment. The desorption experiments showed that PAHs desorbed more rapidly from YD and NS sediments than from SS sediment. PAH fraction desorbed after each interval during the experiment except 0.8 day was significantly correlated with PAH properties among all the three sediments. Discussion The higher BC-to-TOC ratio in SS sediment corresponded to slower desorption rate and less desorption extent of PAHs from SS sediment among the three sediments. This probably could be explained by the extremely strong sorption ability of BC. It also proved that the sequestration of PAHs in sediment was not simply the result of higher organic carbon content. Conclusions Considering the physical and chemical characterization of the sediments and PAH desorption properties comprehensively, BC-to-TOC ratio was a more important factor controlling the behavior of PAHs in sediments than absolute TOC or BC content.
Показать больше [+] Меньше [-]The effect of continuous exposure of copper on the properties and extracellular polymeric substances (EPS) of bulking activated sludge
2011
Li, Jia | Liu, Xiang | Liu, Yan | Ramsay, Juliana | Yao, Chenchao | Dai, Ruihua
INTRODUCTION: This study investigated the effect of copper on chemical oxygen demand (COD) removal efficiency and on the properties (mainly settling and dewatering) and the composition of extracellular polymeric substances (EPS) when 20 mg/L Cu(II) was continuously dosed to a sequencing batch reactor (SBR) inoculated with activated sludge. MATERIALS AND METHODS: The results showed that the continuous addition of 20 mg/L Cu(II) seriously inhibited the removal of sodium benzoate (provided as a model organic pollutant) by activated sludge in a SBR. RESULTS AND DISCUSSION: After 40 days of acclimation, the removal efficiency presented a slight but unsteady recovery and the settling and dewatering properties improved, indicating that sludge bulking had been inhibited. Additionally, the proportion of loosely bound EPS in the total EPS increased with time and the relative composition of the total organics was polysaccharide > humic substances > protein > DNA. CONCLUSION: The effects of copper on the composition of EPS and the settling and dewatering properties of bulking activated sludge were also discussed for the first time in this paper.
Показать больше [+] Меньше [-]Influence of sintering temperature on the characteristics of shale brick containing oil well-derived drilling waste
2011
Li, Xiang-Guo | Lv, Yang | Ma, Bao-Guo | Jian, Shou-Wei | Tan, Hong-Bo
INTRODUCTION: The influence of sintering temperature on the physico-mechanical characteristics (such as water absorption, apparent porosity, bulk density, weight loss on ignition, firing shrinkage, and compressive strength), leachability, and microstructure of shale brick containing oil well-derived drilling waste (DW) was investigated. METHODS: The experiments were conducted at a temperature ranging from 950°C to 1,050°C with 30% DW addition. RESULTS: The results indicate that increasing the sintering temperature decreases the water absorption and apparent porosity and increases the shrinkage, density, and compressive strength of sintered specimens. Moreover, the physico-mechanical properties of samples sintered at 1,050°C meet the requirements of the MU20 according to GB/T 5101-2003 (in China). The heavy metal concentrations of the leachate are much lower than the current regulatory limits according to GB16889-2008. CONCLUSION: The results from XRD and SEM show that increasing sintering temperature results in an increase of the high temperature liquid phase, which may have a significant effect on the densification process of the samples.
Показать больше [+] Меньше [-]Remediation of polycyclic aromatic hydrocarbon (PAH) contaminated soil through composting with fresh organic wastes
2011
Zhang, Yuan | Zhu, Yong-Guan | Houot, Sabine | Qiao, Min | Nunan, Naoise | Garnier, Patricia
INTRODUCTION: Composting may enhance bioremediation of PAH-contaminated soils by providing organic substrates that stimulate the growth of potential microbial degraders. However, the influence of added organic matter (OM) together with the microbial activities on the dissipation of PAHs has not yet been fully assessed. MATERIALS AND METHODS: An in-vessel composting-bioremediation experiment of a contaminated soil amended with fresh wastes was carried out. Four different experimental conditions were tested in triplicate during 60 days using laboratory-scale reactors: treatment S (100% soil), W (100% wastes), SW (soil/waste mixture), and SWB (soil/waste mixture with inoculation of degrading microorganisms). RESULTS AND DISCUSSION: A dry mass loss of 35 ± 5% was observed in treatments with organic wastes during composting in all the treatments except treatment S. The dissipation of the 16 USEPA-listed PAHs was largely enhanced from no significant change to 50.5 ± 14.8% (for SW)/63.7 ± 10.0% (for SWB). More obvious dissipation was observed when fresh wastes were added at the beginning of composting to the contaminated soil, without significant difference between the inoculated and non-inoculated treatments. Phospholipid fatty acid (PLFA) profiling showed that fungi and G-bacteria dominated at the beginning of experiment and were probably involved in PAH dissipation. Subsequently, greater relative abundances of G + bacteria were observed as PAH dissipation slowed down. CONCLUSIONS: The results suggest that improving the composting process with optimal organic compositions may be a feasible remediation strategy in PAH-contaminated soils through stimulation of active microbial populations.
Показать больше [+] Меньше [-]Water-quality issues in the Niger Delta of Nigeria: a look at heavy metal levels and some physicochemical properties
2011
Nduka, John Kanayochukwu | Orisakwe, Orish Ebere
Introduction Water contamination is a notable environmental problem of the Niger Delta, Nigeria. The present work is an improved attempt at a scientific discourse of water-quality issues in the Niger Delta of Nigeria with respect to heavy metal levels in surface water in view of the hitherto dearth of scientific data. Materials and methods We have looked at the Fe, Mn, Cu, Cd, Cr, Pb, Ni, Zn (quantified by atomic absorption spectrophotometry) profiles and some physicochemical properties (pH and salinity) of some surface water used by the local population in the mid Niger Delta. Surface water samples were collected from these surface waters in the dry and rainy seasons. Results Akiplai wellhead stream and Etebde River had the highest level of iron. In Delta State, high levels of cadmium were found in Ijala creek, Ubeji creek, Jeddo River, and Ekpan River, respectively. High lead levels were seen in Jeddo River, Ekurede-Itsekiri Creek, and Ughelli River. In River State, Tombia River had the highest levels of chromium, lead, and nickel. Ijala creek, Eja-Etan, Ifie-Kporo, Ubeji Creek, Jeddo, Ekpan Rivers, and Ekurede-Itsekiri Creek, all in Delta State, presented highest salinity levels. Orash River, Ughewhe stream, and Egbo stream have a lowest pH of 5.22, 5.32, and 5.53, respectively, while Ifie-Kporo River have a highest pH of 8.18. Conclusion Most of the metal levels were above US EPA Maximum Contaminant Level MCL indicative of water pollution which may be of public health importance, and we, therefore, recommend water-quality monitoring.
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