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Toxicity evaluation of textile effluents and role of native soil bacterium in biodegradation of a textile dye Полный текст
2018
Khan, Sana | Malik, Abdul
Water pollution caused by the discharge of hazardous textile effluents is a serious environmental problem worldwide. In order to assess the pollution level of the textile effluents, various physico-chemical parameters were analyzed in the textile wastewater and agricultural soil irrigated with the wastewater (contaminated soil) using atomic absorption spectrophotometer and gas chromatography-mass spectrometry (GC-MS) analysis that demonstrated the presence of several toxic heavy metals (Ni, Cu, Cr, Pb, Cd, and Zn) and a large number of organic compounds. Further, in order to get a comprehensive idea about the toxicity exerted by the textile effluent, mung bean seed germination test was performed that indicated the reduction in percent seed germination and radicle-plumule growth. The culturable microbial populations were also enumerated and found to be significantly lower in the wastewater and contaminated soil than the ground water irrigated soil, thus indicating the biotic homogenization of indigenous microflora. Therefore, the study was aimed to develop a cost effective and ecofriendly method of textile waste treatment using native soil bacterium, identified as Arthrobacter soli BS5 by 16S rDNA sequencing that showed remarkable ability to degrade a textile dye reactive black 5 with maximum degradation of 98% at 37 °C and pH in the range of 5–9 after 120 h of incubation.
Показать больше [+] Меньше [-]Biology, taxonomy, and IPM strategies of Bactrocera tau Walker and complex species (Diptera; Tephritidae) in Asia: a comprehensive review Полный текст
2018
Jaleel, Waqar | Lu, Lihua | He, Yurong
Bactrocera flies are the serious pests of fruit, vegetables, and nuts over the world. Bactrocera tau Walker is an economically important pest of agricultural crops. In Asia, approximately 30–40% losses of agricultural products are caused by B. tau infestation every year. In Asia, the B. tau contains a complex of sibling species that called the tau complex. However, the basic studies of B. tau and complex species are very important for integrated management. A comprehensive review of the B. tau and complex species has not been provided elsewhere. So, considering the importance of B. tau and complex species, this study provides the published information on ecology, nomenclature, identification tools, geographical distribution, potential invasion, and IPM tactics of B. tau and complex species, which would be more informative for publication facilitating related to integrated pest management (IPM) strategies of B. tau and complex species. In IPM of B. tau and complex species, the phytochemical and biological controls have not been applied successfully in Asia; there is an urgent need to study and applications of these two mentioned control techniques against the B. tau and complex species in Asia.
Показать больше [+] Меньше [-]Applicability of radon emanometry in lithologically discontinuous sites contaminated by organic chemicals Полный текст
2018
De Miguel, Eduardo | Barrio-Parra, Fernando | Elío, Javier | Izquierdo-Díaz, Miguel | García-González, Jerónimo Emilio | Mazadiego, Luis Felipe | Medina, Rafael
Applicability of radon emanometry in lithologically discontinuous sites contaminated by organic chemicals Полный текст
2018
De Miguel, Eduardo | Barrio-Parra, Fernando | Elío, Javier | Izquierdo-Díaz, Miguel | García-González, Jerónimo Emilio | Mazadiego, Luis Felipe | Medina, Rafael
The applicability of radon (²²²Rn) measurements to delineate non-aqueous phase liquids (NAPL) contamination in subsoil is discussed at a site with lithological discontinuities through a blind test. Three alpha spectroscopy monitors were used to measure radon in soil air in a 25,000-m² area, following a regular sampling design with a 20-m² grid. Repeatability and reproducibility of the results were assessed by means of duplicate measurements in six sampling positions. Furthermore, three points not affected by oil spills were sampled to estimate radon background concentration in soil air. Data histograms, Q-Q plots, variograms, and cluster analysis allowed to recognize two data populations, associated with the possible path of a fault and a lithological discontinuity. Even though the concentration of radon in soil air was dominated by this discontinuity, the characterization of the background emanation in each lithological unit allowed to distinguish areas potentially affected by NAPL, thus justifying the application of radon emanometry as a screening technique for the delineation of NAPL plumes in sites with lithological discontinuities.
Показать больше [+] Меньше [-]Applicability of radon emanometry in lithologically discontinuous sites contaminated by organic chemicals Полный текст
2018
Miguel García, Eduardo de | Barrio Parra, Fernando | Elio Medina, Javier de | Izquierdo Díaz, Miguel | García González, Jeronimo Emilio | Mazadiego Martínez, Luis Felipe | Medina Ferro, Rafael
The applicability of radon (222Rn) measurements to delineate non-aqueous phase liquids (NAPL) contamination in subsoil is discussed at a site with lithological discontinuities through a blind test. Three alpha spectroscopy monitors were used to measure radon in soil air in a 25,000-m2 area, following a regular sampling design with a 20-m2 grid. Repeatability and reproducibility of the results were assessed by means of duplicate measurements in six sampling positions. Furthermore, three points not affected by oil spills were sampled to estimate radon background concentration in soil air. Data histograms, Q-Q plots, variograms, and cluster analysis allowed to recognize two data populations, associated with the possible path of a fault and a lithological discontinuity. Even though the concentration of radon in soil air was dominated by this discontinuity, the characterization of the background emanation in each lithological unit allowed to distinguish areas potentially affected by NAPL, thus justifying the application of radon emanometry as a screening technique for the delineation of NAPL plumes in sites with lithological discontinuities.
Показать больше [+] Меньше [-]Annual variation patterns of the effluent water quality from a green roof and the overall impacts of its structure Полный текст
2018
Chai, Hongxiang | Tang, Yue | Su, Xiaojie | Wang, Weijie | Lu, Hao | Shao, Zhiyu | He, Qiang
To explore the optimal combination of vegetation type, substrate type, and substrate thickness in a green roof and the interannual variation patterns of the runoff quality, eight green roof units were constructed in Shenzhen, China. Runoff quality of the eight units was monitored for 3 years (24 rainfall events). The rainfall event mean concentrations (EMC) were used to evaluate runoff quality as well as annual pollutant load. An orthogonal L₈(2⁴) experiment was designed to verify the significance of different factors. An optimal level of significant factors was selected to determine the optimal design of green roof. The optimal vegetation was Ophiopogon japonicus. The optimal substrate was modified perlite, while optimal substrate thickness was 200 mm. A three-year interannual variation analysis was performed on the optimal green roof. It was found that the interannual variation of each runoff quality index is different. The concentrations of SS, COD, and NH₄⁺-N in the runoff decreased with years. The concentration of NO₃⁻-N increased over time, while TP remained stable. The concentration of TN had certain volatility with no significant interannual variation. Overall, the runoff quality of the green roof improves over time. The optimal green roof’s runoff quality in the third year including 11 rainfall events was monitored. Results showed that the effluent quality from the green roof was lower than that of precipitation. The average concentrations of SS, COD, NH₄⁺-N, TN, and TP decreased respectively by 37.85%, 28.89%, 30.25%, 14.52%, and 12.93%, but NO₃⁻-N increased by 69.91% comparing to the traditional roof.
Показать больше [+] Меньше [-]Potato tubers contamination with nitrate under the influence of nitrogen fertilizers and spray with molybdenum and salicylic acid Полный текст
2018
Elrys, AhmedS. | Abdo, AhmedI. E. | Desoky, El-SayedM.
A field trial was conducted through 2015 and 2016 growing seasons to study the effect of nitrogen fertilizer sources and foliar spray with molybdenum (Mo), salicylic acid (SA) and their combination on tubers yield, some chemical constituents, nutrients uptake, nitrate accumulation and nitrate reductase activity in potato tubers. N source was added at a rate of 350 kg N ha⁻¹in five equal doses as two different forms, the first is urea and the second is ammonium sulfate plus calcium nitrate equally. SA was sprayed with three rates of 0, 75 and 150 mg l⁻¹. Also, Mo as ammonium molybdate was sprayed using three rates 0, 50 and 100 mg l⁻¹Mo. Both treatments of SA and Mo were applied separately as well as with each other, at three successive times 30, 50 and 70 days after planting of potato plants. Results indicated that the addition of 350 kg N ha⁻¹ as ammonium sulfate and calcium nitrate equally caused a significant elevation (P > 0.05) in fresh weight, chlorophyll b, carotenoids, chlorophyll a, nitrate reductase activity, dry weight and NPK uptake by potato tubers compared with the same amount of nitrogen in the form of urea only. All the aforementioned characteristics were improved with increasing concentration of Mo and/or SA. The highest accumulation of nitrate was recorded under the addition of 350 kg N ha⁻¹ as urea alone. The highest average of all the aforementioned characteristics was observed at the treatment of 350 kg N ha⁻¹ as ammonium sulfate and calcium nitrate equally plus spraying with 100 mg l⁻¹Mo and 150 mg l⁻¹ SA. In contrast, this treatment gave the lowest accumulation of nitrates in potato tubers.
Показать больше [+] Меньше [-]Study of marine bacteria inactivation by photochemical processes: disinfection kinetics and growth modeling after treatment Полный текст
2018
Moreno-Andrés, Javier | Acevedo-Merino, Asunción | Nebot, Enrique
The importance of seawater treatment in order to avoid microbiological pollution related to aquaculture or ballast water management has increased during the last few years. Bacterial indicators used for the evaluation of different disinfection treatments are usually related with both waste and drinking water, these standards are not usual microorganisms found in seawater. Thus, it is thought necessary to study the behavior of different marine-specific organisms in regard to improve the disinfection processes in seawater. In this study, three different bacteria have been selected among major groups of bacterial community from marine waters: two water-associated, Roseobacter sp. and Pseudomonas litoralis, and one sediment-associated, Kocuria rhizophila. A kinetic inactivation model together with a post-treatment growth tendency has been obtained after the application of UV-C and UV/H₂O₂ processes. According to the first kinetic rate constant, different responses were obtained for the different bacterial groups. Once the treatment was applied, modeling of growth curves revealed high recover within the first 3 days after treatment, even when UV/H₂O₂ was applied. This study introduces a sensitivity index, in which results show different levels of resistance for both treatments, being Roseobacter sp. the most sensitive bacteria, followed by P. litoralis and K. rhizophila.
Показать больше [+] Меньше [-]Assessment of GHG mitigation and CDM technology in urban transport sector of Chandigarh, India Полный текст
2018
Bhargava, Nitin | Gurjar, BholaRam | Mor, Suman | Ravindra, Khaiwal
The increase in number of vehicles in metropolitan cities has resulted in increase of greenhouse gas (GHG) emissions in urban environment. In this study, emission load of GHGs (CO, N₂O, CO₂) from Chandigarh road transport sector has been estimated using Vehicular Air Pollution Inventory (VAPI) model, which uses emission factors prevalent in Indian cities. Contribution of 2-wheelers (2-w), 3-wheelers (3-w), cars, buses, and heavy commercial vehicles (HCVs) to CO, N₂O, CO₂, and total GHG emissions was calculated. Potential for GHG mitigation through clean development mechanism (CDM) in transport sector of Chandigarh under two scenarios, i.e., business as usual (BAU) and best estimate scenario (BES) using VAPI model, has been explored. A major contribution of GHG load (~ 50%) in Chandigarh was from four-wheelers until 2011; however, it shows a declining trend after 2011 until 2020. The estimated GHG emission from motor vehicles in Chandigarh has increased more than two times from 1065 Gg in 2005 to 2486 Gg by 2011 and is expected to increase to 4014 Gg by 2020 under BAU scenario. Under BES scenario, 30% of private transport has been transformed to public transport; GHG load was possibly reduced by 520 Gg. An increase of 173 Gg in GHGs load is projected from additional scenario (ADS) in Chandigarh city if all the diesel buses are transformed to CNG buses by 2020. Current study also offers potential for other cities to plan better GHG reduction strategies in transport sector to reduce their climate change impacts.
Показать больше [+] Меньше [-]Leaching of metals from asphalt pavement incorporating municipal solid waste incineration fly ash Полный текст
2018
Yang, Jin-Zhong | Yang, Yufei | Li, Ying | Chen, Lin | Zhang, Jing | Die, Qingqi | Fang, Yanyan | Pan, Yueyi | Huang, Qifei
Rising municipal solid waste incineration (MSWI) makes it imperative to recycle the fly ash (FA). FA can be solidified by asphalt and then applied in the asphalt road. However, little information on the metal leaching and associated with risks from asphalt solidified forms for FA is available. In the present study, metal leaching characteristics and long-term leaching potential from the asphalt-based FA matrices was determined based on the national standard method and simulating the actual using of the solidified forms in highways, respectively. The immobilization effect of asphalt on MSWI FA is well. Leaching velocity was in the order of magnitude of 10~10⁻⁶ cm h⁻¹ during the entire leaching period. At the early age, leaching velocity of metals is high, especially Zn, Cd, and Ba. Cumulative leaching concentration of metals and leaching time has positive correlation. Only considering the leaching of simulating acid, leaching of metals in asphalt-based matrices is very slow, and the leaching toxicity of metals is lower than the Chinese National Standard.
Показать больше [+] Меньше [-]Plasma-activated water: antibacterial activity and artifacts? Полный текст
2018
Chen, Tung-Po | Liang, Junfeng | Su, Tsan-Liang
Broad biological activities of “plasma-activated water” (PAW) have drawn great attentions recently. Treatment of water using gas discharge plasma led to acidic solutions with excellent and broad antibacterial activity. Because PAW caused severe membrane damages in bacteria and diffused freely in extracellular matrix, PAW also demonstrated good anti-biofilm activity. However, further studies revealed that trace amounts of metal ions (mainly copper and zinc) in PAW brought by plasma treatment played key roles in bacteria inactivation. The contribution of metal ions to the antibacterial activity varied among PAWs from different working gases. However, solution acidification caused by reactive species in plasma was essential. The experimental results demonstrated that potential artifacts in reported biological activities of PAWs should be considered.
Показать больше [+] Меньше [-]Coupling loss characteristics of runoff-sediment-adsorbed and dissolved nitrogen and phosphorus on bare loess slope Полный текст
2018
Wu, Lei | Qiao, Shanshan | Peng, Mengling | Ma, Xiaoyi
Soil and nutrient loss is a common natural phenomenon but it exhibits unclear understanding especially on bare loess soil with variable rainfall intensity and slope gradient, which makes it difficult to design control measures for agricultural diffuse pollution. We employ 30 artificial simulated rainfalls (six rainfall intensities and five slope gradients) to quantify the coupling loss correlation of runoff-sediment-adsorbed and dissolved nitrogen and phosphorus on bare loess slope. Here, we show that effects of rainfall intensity on runoff yield was stronger than slope gradient with prolongation of rainfall duration, and the effect of slope gradient on runoff yield reduced gradually with increased rainfall intensity. But the magnitude of initial sediment yield increased significantly from an average value of 6.98 g at 5° to 36.08 g at 25° with increased slope gradient. The main factor of sediment yield would be changed alternately with the dual increase of slope gradient and rainfall intensity. Dissolved total nitrogen (TN) and dissolved total phosphorus (TP) concentrations both showed significant fluctuations with rainfall intensity and slope gradient, and dissolved TP concentration was far less than dissolved TN. Under the double influences of rainfall intensity and slope gradient, adsorbed TN concentration accounted for 7–82% of TN loss concentration with an average of 58.6% which was the main loss form of soil nitrogen, adsorbed TP concentration accounted for 91.8–98.7% of TP loss concentration with an average of 96.6% which was also the predominant loss pathway of soil phosphorus. Nitrate nitrogen (NO₃⁻-N) accounted for 14.59–73.92% of dissolved TN loss, and ammonia nitrogen (NH₄⁺-N) accounted for 1.48–18.03%. NO₃⁻-N was the main loss pattern of TN in runoff. Correlation between dissolved TN, runoff yield, and rainfall intensity was obvious, and a significant correlation was also found between adsorbed TP, sediment yield, and slope gradient. Our results provide the underlying insights needed to guide the control of nitrogen and phosphorus loss on loess hills.
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