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Effect of biochar amendment on yield and photosynthesis of peanut on two types of soils
2015
Xu, Cheng-Yuan | Hosseini-Bai, Shahla | Hao, Yanbin | Rachaputi, Rao C. N. | Wang, Hailong | Xu, Zhihong | Wallace, Helen
Biochar has significant potential to improve crop performance. This study examined the effect of biochar application on the photosynthesis and yield of peanut crop grown on two soil types. The commercial peanut cultivar Middleton was grown on red ferrosol and redoxi-hydrosol (Queensland, Australia) amended with a peanut shell biochar gradient (0, 0.375, 0.750, 1.50, 3.00 and 6.00 %, w/w, equivalent up to 85 t ha⁻¹) in a glasshouse pot experiment. Biomass and pod yield, photosynthesis-[CO₂] response parameters, leaf characteristics and soil properties (carbon, nitrogen (N) and nutrients) were quantified. Biochar significantly improved peanut biomass and pod yield up to 2- and 3-folds respectively in red ferrosol and redoxi-hydrosol. A modest (but significant) biochar-induced improvement of the maximum electron transport rate and saturating photosynthetic rate was observed for red ferrosol. This response was correlated to increased leaf N and accompanied with improved soil available N and biological N fixation. Biochar application also improved the availability of other soil nutrients, which appeared critical in improving peanut performance, especially on infertile redoxi-hydrosol. Our study suggests that application of peanut shell derived biochar has strong potential to improve peanut yield on red ferrosol and redoxi-hydrosol. Biochar soil amendment can affect leaf N status and photosynthesis, but the effect varied with soil type.
Afficher plus [+] Moins [-]The effects of cyfluthrin on some biomarkers in the liver and kidney of Wistar rats
2015
Yılmaz, Mehmet | Rencuzogullari, Eyyup | Canli, Mustafa
Pesticides can cause oxidative stress resulting to deleterious effects in animal metabolisms. Cyfluthrin is a synthetic pyrethroid used worldwide to protect crops and to eliminate pests. Thus, the aim of this study was to investigate the effects of the cyfluthrin on the level of malondialdehyde (MDA) and activities of catalase (CAT), glutathione peroxidase (GPx), and acetylcholinesterase (AChE) in the liver and kidney of Wistar Albino Sprague Dawley rats (Rattus norvegicus var. albinos) following intraperitoneal treatment of cyfluthrin (1.2, 12, and 120 mg/kg b.w./day) for 21 days. Comparisons were made with two control solutions named as serum physiologic and solvent in which cyfluthrin was dissolved. CAT activity in the liver and kidney of rats did not change after the lowest cyfluthrin treatment, while its activity significantly decreased at the higher doses. In general, cyfluthrin significantly decreased the activity of GPx in the liver and kidney at all doses, while MDA levels in the liver increased at all doses. Cyfluthrin significantly decreased AChE activity in the liver of rats at all doses, while this was true at the highest dose for the kidney. This study showed that the studied biomarkers were effective in determining the toxic effects of cyfluthrin. Thus, they should be used to monitor pesticide-affected areas before untargeted animals, including humans who suffer from the use of pesticides.
Afficher plus [+] Moins [-]Uptake and speciation of vanadium in the rhizosphere soils of rape (Brassica juncea L.)
2015
Tian, Li-Yan | Yang, Jin-Yan | Huang, Jen-How
The response of rape (Brassica juncea L.) to different vanadium (V) speciation in rhizosphere soils was investigated in pot experiments using an agricultural soil containing 147 mg V kg⁻¹ supplemented with 0–500 mg V kg⁻¹ of pentavalent V [V(V)] and a mining soil containing 774 mg V kg⁻¹. Tetravalent V [V(IV)] accounted for 76.1 and 85.9 % of total V in the untreated agricultural soil and mining soil, respectively. The proportion of both V(V) and water-extractable V increased with increasing concentrations of V(V) in the agricultural soil. The growth of rape substantially reduced the concentrations of V(V) but not V(IV) in the rhizosphere soil, suggesting that V(V) was actively involved in the soil–rape interaction of V. Both soil V(V) and water-extractable V were negatively related to the total rape biomass, but were positively correlated with the concentration of root V. No such relationships were found for total V and soil V(IV). Together, these results indicate that soil V(V) and water-extractable V might better reflect the toxicity of V in soils than total V and soil V(IV). Rape accumulated V in the sequence: roots > > stem > leaf > seed. As indicated by the remarkably low root bioconcentration factor of V(V) (0.41–7.24 %), rape had a lower ability to accumulate V than other plants reported in the literature (14.6–298 %). Only a small fraction of V in rape roots was translocated to the aboveground organs (the translocation factor was 3.57–46.9 %). No V was detectable in seeds in the soils at 147 and 197 mg V kg⁻¹, and no seed was produced in the soils at higher V concentrations. Thus, the risk of V intake by humans via the consumption of rapeseed-based foods under normal conditions is considered to be lower than that of other plants.
Afficher plus [+] Moins [-]Uncertainty assessment of water quality modeling for a small-scale urban catchment using the GLUE methodology: a case study in Shanghai, China
2015
Zhang, Wei | Li, Tian | Dai, Meihong
There is often great uncertainty in water quality modeling for urban drainage systems because water quality variation in systems is complex and affected by many factors. The stormwater management model (SWMM) was applied to a small-scale urban catchment with a simple and well-maintained stormwater drainage system without illicit connections. This was done to assess uncertainty in build-up and wash-off modeling of pollutants within the generalized likelihood uncertainty estimation (GLUE) methodology, based on a well-calibrated water quantity model. The results indicated great uncertainty of water quality modeling within the GLUE methodology. Comparison of uncertainties in various pollutant build-up and wash-off models that were available in SWMM indicated that those uncertainties varied slightly. This may be a consequence of the specific characteristics of rainfall events and experimental sites used in the study. The uncertainty analysis of water quality parameters in SWMM is conducive to effectively evaluating model reliability, and provides an experience base for similar research and applications.
Afficher plus [+] Moins [-]Study of the succession of microbial communities for sulfur cycle response to ecological factors change in sediment of sewage system
2015
Liu, Yanchen | Dong, Qian | Wu, Chen | Zhou, Xiaohong | Shi, Hanchang
The biological reaction process of sulfur in biofilms and sediments causes serious problems of corrosion and odor in sewage systems. This study aims to reveal the distribution and shift of microbial diversity that survives inside the sediment in response to surrounding changes in sewage systems. The successions of microbial community were compared via denaturing gradient gel electrophoresis and by constructing phylogenetic trees via maximum likelihood method. The results indicated that the shift of microbial diversity is not significant along the vertical layer inside the sediment. The influences of sediment accumulation time on the shift in microbial diversity are evident, particularly with the switch of the accumulation stage. Implementing a control strategy for oxygen injection and nitrate addition evidently inhibits and stimulates some dominant sulfate-reducing bacterial strains in the sediment. The diversity in the total bacteria is positively related with ORP, dissolved oxygen, and sulfide concentration.
Afficher plus [+] Moins [-]Comparison of bioavailable vanadium in alfalfa rhizosphere soil extracted by an improved BCR procedure and EDTA, HCl, and NaNO3 single extractions in a pot experiment with V–Cd treatments
2015
Yang, Jie | Teng, Yanguo | Zuo, Rui | Song, Liuting
The BCR sequential extraction procedure was compared with EDTA, HCl, and NaNO₃ single extractions for evaluating vanadium bioavailability in alfalfa rhizosphere soil. The amounts of vanadium extracted by these methods were in the following order: BCR (bioavailable V) > EDTA ≈ HCl > NaNO₃. Both correlation analysis and stepwise regression were adopted to illustrate the extractable vanadium between different reagents. The correlation coefficients between extracted vanadium and the vanadium contents in alfalfa roots were R NₐNO₃ = 0.948, R HCₗ = 0.902, R EDTA = 0.816, and R bᵢₒₐᵥₐᵢₗₐbₗₑ V = 0.819. The stepwise multiple regression equation of the NaNO₃ extraction was the most significant at a 95 % confidence interval. The influence of pH, total organic carbon, and cadmium content of soil to vanadium bioavailability were not definite. In summary, both the BCR sequential extraction and the single extraction methods were valid approaches for predicting vanadium bioavailability in alfalfa rhizosphere soil, especially the single extractions.
Afficher plus [+] Moins [-]Screening of 18 species for digestate phytodepuration
2015
Pavan, Francesca | Breschigliaro, Simone | Borin, Maurizio
This experiment assesses the aptitude of 18 species in treating the digestate liquid fraction (DLF) in a floating wetland treatment system. The pilot system was created in NE Italy in 2010 and consists of a surface-flow system with 180 floating elements (Tech-IA®) vegetated with ten halophytes and eight other wetland species. The species were transplanted in July 2011 in basins filled with different proportions of DLF/water (DLF/w); periodic increasing of the DLF/w ratio was imposed after transplanting, reaching the worst conditions for plants in summer 2012 (highest EC value 7.3 mS cm/L and NH₄-N content 225 mg/L). It emerged that only Cynodon dactylon, Typha latifolia, Elytrigia atherica, Halimione portulacoides, Salicornia fruticosa, Artemisia caerulescens, Spartina maritima and Puccinellia palustris were able to survive under the system conditions. Halophytes showed higher dry matter production than other plants. The best root development (up to 40-cm depth) was recorded for Calamagrostis epigejos, Phragmites australis, T. latifolia and Juncus maritimus. The highest nitrogen (10–15 g/m²) and phosphorus (1–4 g/m²) uptakes were obtained with P. palustris, Iris pseudacorus and Aster tripolium. In conclusion, two halophytes, P. palustris and E. atherica, present the highest potential to be used to treat DLF in floating wetlands.
Afficher plus [+] Moins [-]Coal fly ash as a resource for rare earth elements
2015
Franus, Wojciech | Wiatros-Motyka, Małgorzata M. | Wdowin, Magdalena
Rare earth elements (REE) have been recognised as critical raw materials, crucial for many clean technologies. As the gap between their global demand and supply increases, the search for their alternative resources becomes more and more important, especially for the countries which depend highly on their import. Coal fly ash (CFA), which when not utilised is considered waste, has been regarded as the possible source of many elements, including REE. Due to the increase in the energy demand, CFA production is expected to grow, making research into the use of this material a necessity. As Poland is the second biggest coal consumer in the European Union, the authors have studied different coal fly ashes from ten Polish power plants for their rare earth element content. All the fly ashes have a broadly similar distribution of rear earth elements, with light REE being dominant. Most of the samples have REE content relatively high and according to Seredin and Dai (Int J Coal Geol 94: 67–93, 2012) classification can be considered promising REE raw materials.
Afficher plus [+] Moins [-]Biosorption and bioaccumulation of thallium by thallium-tolerant fungal isolates
2015
Sun, Jialong | Zou, Xiao | Xiao, Tangfu | Jia, Yanlong | Ning, Zengping | Sun, Min | Liu, Yizhang | Jiang, Tao
Little is known about the biosorption and bioaccumulation capacity of thallium (Tl) by microorganisms that occur in Tl-polluted soil. The present study focused on characterizing the biosorption and bioaccumulation of Tl by Tl-tolerant fungi isolated from Tl-polluted soils. Preliminary data showed a positive correlation between the biomass and the biosorbed Tl content. The Tl-tolerant strains were capable of bioaccumulating Tl, up to 7189 mg kg⁻¹ dry weight. The subcellular distribution of Tl showed obvious compartmentalization: cytoplasm ≫ cell wall > organelle. The majority of Tl (up to 79 %) was found in the cytoplasm, suggesting that intracellular compartmentalization appeared to be responsible for detoxification. These findings further suggest the applicability of the fungal isolates for cleanup of Tl in Tl-polluted water and soil.
Afficher plus [+] Moins [-]Antibiotic-resistant genes and antibiotic-resistant bacteria in the effluent of urban residential areas, hospitals, and a municipal wastewater treatment plant system
2015
Li, Jianan | Cheng, Weixiao | Xu, Like | Strong, P. J. | Chen, Hong
In this study, we determined the abundance of 8 antibiotics (3 tetracyclines, 4 sulfonamides, and 1 trimethoprim), 12 antibiotic-resistant genes (10 tet, 2 sul), 4 antibiotic-resistant bacteria (tetracycline, sulfamethoxazole, and combined resistance), and class 1 integron integrase gene (intI1) in the effluent of residential areas, hospitals, and municipal wastewater treatment plant (WWTP) systems. The concentrations of total/individual targets (antibiotics, genes, and bacteria) varied remarkably among different samples, but the hospital samples generally had a lower abundance than the residential area samples. The WWTP demonstrated removal efficiencies of 50.8 % tetracyclines, 66.8 % sulfonamides, 0.5 logs to 2.5 logs tet genes, and less than 1 log of sul and intI1 genes, as well as 0.5 log to 1 log removal for target bacteria. Except for the total tetracycline concentration and the proportion of tetracycline-resistant bacteria (R² = 0.330, P < 0.05), there was no significant correlation between antibiotics and the corresponding resistant bacteria (P > 0.05). In contrast, various relationships were identified between antibiotics and antibiotic resistance genes (P < 0.05). Tet (A) and tet (B) displayed noticeable relationships with both tetracycline and combined antibiotic-resistant bacteria (P < 0.01).
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