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Cell cycle stage specific application of municipal landfill leachates to assess the genotoxicity in root meristem cells of barley (Hordeum vulgare) Full text
2014
Srivastava, Anjil Kumar | Kumar, Ravi Ranjan | Singh, Ashok Kumar
Municipal solid wastes (MSW) are unavoidable sources of environmental pollution. Improper disposal of municipal waste results in the leaching of toxic metals and organic chemicals, which can contaminate the surface and ground water leading to serious health hazard. In this study, the toxic effects of the leachate prepared from municipal solid waste samples were examined in root meristem cells of barley (Hordeum vulgare L.) at various stages of cell cycle, i.e., G₁, S, and G₂. Seeds of barley were exposed to 2.5, 5, and 10 % of leachates in soil and aqueous media in 48 h at different cell cycle stages. The physicochemical data of the present study revealed that municipal solid waste leachate contains high amount of heavy metals, which significantly affected growth and physiological activities of barley. Significant inhibition in hypocotyl length, germination, and mitotic index were observed at all concentration of leachate treatment. Induction of chromosomal aberrations (CA’s) and micronuclei (MN) formation were also observed with different concentrations of leachate treatment at 7, 17, and 27 h of presoaking durations, which falls in G₁, S, and G₂phase of the cell cycle, respectively. Also, exposure of leachate at S phase of the cell cycle had significant effects in barley through chromosomal aberration and micronuclei formation.
Show more [+] Less [-]Reduction of Fusarium rot and maintenance of fruit quality in melon using eco-friendly hot water treatment Full text
2014
Sui, Yuan | Droby, Samir | Zhang, Danfeng | Wang, Wenjie | Liu, Yongsheng
Significant losses in harvested fruit can be directly attributable to decay fungi and quality deterioration. Hot water treatment (HWT) has been demonstrated to be an effective and economic environment-friendly approach for managing postharvest decay and maintaining fruit quality. In this study, the effects of HWT (45 °C for 10, 15, 20, and 25 min) on in vitro growth of Fusarium oxysporum, in vivo Fusarium rot, and natural decay of melon were investigated. HWT inhibited spore germination and germ tube elongation of F. oxysporum. Protein impairment and ATP consumption triggered by HWT contributed to the inhibitory effect. Results of in vivo studies showed that HWT effectively controlled Fusarium rot and natural decay of melon. Correspondingly, HWT induced a significant increase in content of total phenolic compounds and lignin of melon. These findings indicate that the effects of HWT on Fusarium rot may be associated with the direct fungal inhibition and the elicitation of defense responses in fruit. Importantly, HWT used in this study had beneficial effects on fruit quality as well. HWT may represent an effective non-chemical approach for management of postharvest Fusarium rot.
Show more [+] Less [-]The double-edged sword of humic substances: contrasting their effect on respiratory stress in eastern rainbow fish exposed to low pH Full text
2014
Holland, Aleicia | Duivenvoorden, Leo J. | Kinnear, Susan H. W.
High amounts of humic substances (HS) are commonly found in natural acidic waterways and have been suggested to offer some protection against low pH. This study investigated the ability of HS to decrease respiratory stress in eastern rainbowfish (Melanotaenia splendida splendida) exposed to decreases in pH (range of 7–3.5) in soft and hard water. Repeated measures ANOVA revealed a significant difference in respiration (time taken for ten operculum movements) between pH and HS treatments, with a significant interaction between pH and HS present in 5/6 trials. Respiratory stress was shown to increase with increasing acidity, but significantly decreased in treatments with HS (10 and 20 mg/L) compared to those without. The fish exposed to pH treatments without HS also displayed increased hyperactivity, larger operculum movements and increased mucous production. Increased morbidity was shown in HS treatments at pH 3.5 (soft water) and at pH 4 (hard water) compared to treatment without HS. This indicates that HS is helpful in ameliorating the effects of decreased pH on respiration at sublethal pH levels; however, as pH decreases further, it seems that HS increases the toxicity (morbidity) of the low pH.
Show more [+] Less [-]Temporal and spatial variation of arsenic species in the Dahuofang reservoir in northeast China Full text
2014
Qin, Yanwen | Ma, Yingqun | Zheng, Binghui | Zhang, Lei | Zhao, Yanmin
Overlying water, pore water, and sediment samples were collected from the Dahuofang reservoir in November 2011 and April 2012, respectively. Total arsenic and arsenic species including arsenite, arsenate, monomethylarsonic, and dimethylarsinic were analyzed by ICP-MS and HPLC–ICP-MS. The results indicated that the environments of the Dahuofang reservoir were in reduced conditions, arsenite was the predominant species in pore water and sediments in the reservoir. Arsenic concentrations in overlying water were very low in all the samples but showed different trend during the different time. In November, arsenic concentrations in the reservoir inlet were higher than that in the other sites, whereas arsenic showed accumulation from the upstream to downstream of the reservoir in samples collected in April. In pore water, arsenic concentrations were about 23 and 37 times higher than those in overlying water in November and April, respectively, and relatively high levels of arsenite were also detected in the pore water. In surface sediments, total arsenic and arsenic species content in the reservoir inlet showed the following decreasing order: R1 > R10 > R4. The results also showed that moderate ecological risks exist in pore water and sediments in the Dahuofang reservoir.
Show more [+] Less [-]Spatial variability of sediment ecotoxicity in a large storm water detention basin Full text
2014
Merchan, Carolina Gonzalez | Perrodin, Yves | Barraud, Sylvie | Sébastian, Christel | Becouze-Lareure, Céline | Bazin, Christine | Kouyi, Gislain Lipeme
Detention basins are valuable facilities for urban storm water management, from both the standpoint of flood control and the trapping of pollutants. Studies performed on storm water have shown that suspended solids often constitute the main vector of pollutants (heavy metals, polycyclic aromatic hydrocarbon (PAH), etc.). In order to characterise the ecotoxicity of urban sediments from storm water detention basins, the sediments accumulated over a 6-year period were sampled at five different points through the surface of a large detention basin localised in the east of Lyon, France. A specific ecotoxicological test battery was implemented on the solid phase (raw sediment) and the liquid phase (interstitial water of sediments). The results of the study validated the method formulated for the ecotoxicological characterization of urban sediments. They show that the ecotoxicological effect of the sediments over the basin is heterogeneous and greater in areas often flooded. They also show the relationship between, on one hand, the physical and chemical characteristics of the sediments and, on the other hand, their ecotoxicity. Lastly, they contribute to a better understanding of the dynamics of the pollution close to the bottom of detention basins, which can be useful for improving their design. The results of this research raise particularly the issue of using oil separators on the surface of detention basins.
Show more [+] Less [-]Habitat use by giant panda in relation to man-made forest in Wanglang Nature Reserve of China Full text
2014
Kang, Dongwei | Wang, Xiaorong | Yang, Hongwei | Duan, Lijuan | Li, Junqing
To evaluate the effectiveness of human restoration in species conservation, in this study, we undertook a field survey of giant panda (Ailuropoda melanoleuca) habitat and man-made forest habitat in Wanglang Nature Reserve of China. Our results revealed that giant panda did not use the man-made forest in this area so far, and that there were significant differences between the giant panda habitat and the man-made forest habitat. Compared with giant panda habitat, the man-made forest habitat was characterized by lower shrub coverage, thinner trees and lower bamboo density. To improve the effectiveness of human restoration, the habitat requirement of giant panda should be fully consider in the whole process of habitat restoration.
Show more [+] Less [-]Effects of ammonia on methane oxidation in landfill cover materials Full text
2014
Long, Yu-Yang | Liao, Yan | Miao, Jing-Yu | Shen, Dong-Sheng
The effects of ammonia (NH₃) on CH₄attenuation in landfill cover materials consisting of landfill cover soil (LCS) and aged municipal solid waste (AMSW), at different CH₄concentrations, were investigated. The CH₄oxidation capacities of LCS and AMSW were found to be significantly affected by the CH₄concentration. The maximum oxidation rates for LCS and AMSW were obtained at CH₄concentrations of 5 % and 20 %(v/v), respectively, within 20 days. CH₄biological oxidation in AMSW was significantly inhibited by NH₃at low CH₄concentrations (5 %, v/v) but highly stimulated at high levels (20 % and 50 %, v/v). Oxidation in LCS was stimulated by NH₃at all CH₄concentrations due to the higher conversion of the nitrogen in NH₃in AMSW than in LCS. NH₃increases CH₄oxidation in landfill cover materials.
Show more [+] Less [-]Agro-industrial wastes as effective amendments for ecotoxicity reduction and soil health improvement in aided phytostabilization Full text
2014
Galende, María A. | Becerril, José M. | Gómez-Sagasti, María T. | Barrutia, Oihana | Garbisu, Carlos | Hernández, Antonio
Aided phytostabilization is a technology that uses metal tolerant plants and organic and/or inorganic amendments to reduce soil metal bioavailability, while improving soil health. Our objective was to determine the effects of the application of amendments [sheep manure (SHEEP), poultry litter (POULTRY), cow slurry (COW), and paper mill sludge mixed with poultry litter (PAPER)], together with the growth of a metallicolous Festuca rubra L. population, on (i) chemical and microbial indicators of soil health and (ii) soil ecotoxicity, during the aided phytostabilization of a Zn/Pb contaminated mine soil. Amendment application led to an increase in soil pH, organic matter content, and inorganic salts, resulting in a decrease in Pb and Zn CaCl₂-extractable concentrations in soil, which, in turn, contributed to lower ecotoxicity and a stimulation of plant growth and soil microbial communities. The factor most affecting the metal extractability was probably soil pH. POULTRY was the best amendment in terms of increasing plant growth, chlorophylls content, and soil microbial biomass and activity, but resulted in higher levels of phytoavailable Pb and Zn. SHEEP and PAPER were more effective at reducing metal CaCl₂-extractability and, consequently, led to lower values of metal accumulation in plant tissues, thereby reducing the risk of metals entering into the food chain. When combined with the application of organic amendments, the metallicolous F. rubra population studied here appears an excellent candidate for aided phytostabilization. Our results indicate that the application of organic amendments is essential for the short-term recovery of highly contaminated metalliferous soils during aided phytostabilization.
Show more [+] Less [-]Semivolatile PAH and n-alkane gas/particle partitioning using the dual model: up-to-date coefficients and comparison with experimental data Full text
2014
Sangiorgi, G. | Ferrero, L. | Perrone, M. G. | Papa, E. | Bolzacchini, E.
The gas/particle partitioning coefficient K ₚ , of a semivolatile compound is a key parameter for its atmospheric fate. The most complete method of predicting K ₚ for polycyclic aromatic hydrocarbons (PAHs) is offered by the dual model, as it describes both the adsorption on soot and absorption into organic matter processes. However, experimental and model data exist almost exclusively for PAHs. In order to bridge this gap, experimental data on the phase partitioning of both PAHs and n-alkanes were collected at an urban and a remote site. Moreover, all the necessary parameters (e.g., octanol–air and soot–air partitioning coefficients) for the dual model have been collected and updated or (if missing) estimated for the first time. The results point out that both absorption and adsorption seem to contribute to the partitioning of PAHs and n-alkanes. However, it seems that the dual model always underestimates the particle sorption not only for PAHs but also for n-alkanes.
Show more [+] Less [-]Occurrences and inventories of heavy metals and brominated flame retardants in wastes from printed circuit board production Full text
2014
Zhou, Xiaoyu | Guo, Jie | Zhang, Wei | Zhou, Peng | Deng, Jingjing | Lin, Kuangfei
Pollutants including heavy metals and brominated flame retardant were detected in 10 types of production wastes from a typical printed circuit board manufacturing plant, and their inventories were estimated. Rinsing water from etching process had the highest concentrations of copper (665.51 mg/L), lead (1.02 mg/L), nickel (3.60 mg/L), chromium (0.97 mg/L), and tin (1.79 mg/L). Powdered solid waste (SW) from the cut lamination process contained the highest tetrabromobisphenol-A (TBBPA) levels (49.86 mg/kg). Polybrominated diphenyl ethers (PBDEs) were absent in this plant, in agreement with the international regulations of PBDE phase out. The pollutant inventories in the wastes exhibited in the order of copper > > zinc > tin ≈ nickel > lead > chromium > > TBBPA. The potential environmental impact of pollutants in SW during production and disposal were further investigated. A high partitioning of pollutant concentration between the total suspended particle and SW (−0.10 < log KTS < 2.12) was observed for most pollutants, indicating the emission pathway from SW to the airborne atmosphere in the workshop. Although SW met the toxicity characteristic leaching procedure, drilling powder with the smallest particle diameter still showed high leachabilities of lead and tin which may lead to a negative environmental impact during disposal.
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