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Rapid Quantification of Escherichia coli in Potable Water by Fluorescence In Situ Hybridization Performed in Liquid (liq-FISH) and a Microfluidic System Texto completo
2019
Yamaguchi, Nobuyasu | Goto, Satoko
Specific and sensitive detection of fecal microbes in potable water is essential for ensuring the safety of water supplies. To this end, because conventional culture-based methods typically require at least 24 h to detect fecal bacteria, rapid and simple microbiological detection methods are considered necessary. Fluorescence in situ hybridization (FISH) is a useful culture-independent technique for selectively and rapidly detecting target bacteria using fluorescently labeled probes that hybridize with intracellular ribosomal RNA. However, typical FISH assays are relatively complicated to perform, making FISH unsuitable for routine tests. In this study, we developed an “in liquid-fluorescence in situ hybridization” assay (liq-FISH) to enumerate Escherichia coli cells, indicator of fecal contamination, rapidly. The assay performs the entire in situ hybridization procedure in liquid and requires only two simple steps—addition of fixative followed by the addition of fluorescent probe. Important processes in FISH, fixation and hybridization, were optimized, and then specificity of the optimized liq-FISH procedure was confirmed by E. coli and other eight gammaproteobacterial species. The findings showed that only E. coli cells fluoresced under a fluorescence microscope; however, filtration process is required to observe and count hybridized cells by fluorescence microscopy. For simple and semi-automated counting following liq-FISH, our developed microscope-based microfluidic counting system was applied. Hybridized cells were injected into a microfluidic device, which permitted the detection and enumeration of E. coli cells flowing through the microchannel (width: 100 μm, depth: 15 μm). The obtained results were compared with those obtained by conventional fluorescence microscopy, and results showed the similarity (r = 0.908). E. coli cells could be counted within 5 h (filtration for concentration of low numbers of E. coli cells (if necessary): 0.5 h, fixation of cells: 2 h, in situ hybridization: 2 h, counting: 0.5 h), and this method would be useful for rapidly quantifying E. coli cells in potable water.
Mostrar más [+] Menos [-]Target and non-target botanical pesticides effect of Trichodesma indicum (Linn) R. Br. and their chemical derivatives against the dengue vector, Aedes aegypti L Texto completo
2019
Chellappandian, Muthiah | Senthil-Nathan, Sengottayan | Vasantha-Srinivasan, Prabhakaran | Karthi, Sengodan | Thanigaivel, Annamalai | Kalaivani, Kandaswamy | Sivanesh, Haridoss | Stanley-Raja, Vethamonickam | Chanthini, Kanagaraj Muthu-Pandian | Shyam-Sundar, Narayanan
The effects of crude ethanol derived leaf extract Trichodesma indicum (Linn) (Ex-Ti) and their chief derivatives were accessed on the survival and development of the dengue mosquito Ae. aegypti also their non-toxic activity against mosquito predator. T. indicum is recognized to be the vital weed plant and a promising herb in the traditional ayurvedic medicine. In this study, the GC-MS chromatogram of Ex-Ti showed higher peak area percentage for cis-10-Heptadecenoic acid (21.83%) followed by cycloheptadecanone (14.32%). The Ex-Ti displayed predominant mortality in larvae with 96.45 and 93.31% at the prominent dosage (200 ppm) against III and IV instar. Correspondingly, sub-lethal dosage against the enzymatic profile of III and IV instar showed downregulation of α,β-carboxylesterase and SOD protein profiles at the maximum concentration of 100 ppm. However, enzyme level of GST as well as CYP450 increased significantly dependent on sub-lethal concentration. Likewise, fecundity and hatchability of egg rate of dengue mosquito decreased to the sub-lethal concentration of Ex-Ti. Repellent assay illustrates that Ex-Ti concentration had greater protection time up to 210 min at 100 ppm. Also, activity of Ex-Ti on adult mosquito displayed 100% mortality at the maximum dosage of 600, 500 and 400 ppm within the period of 50, 60 and 70 min, respectively. Photomicrography screening showed that lethal dosage of Ex-Ti (100 ppm) produced severe morphological changes with dysregulation in their body parts as matched to the control. Effects of Ex-Ti on the Toxorhynchites splendens IV instar larvae showed less mortality (43.47%) even at the maximum dosage of 1500 ppm as matched to the chemical pesticide Temephos. Overall, the present research adds a toxicological valuation on the Ex-Ti and their active constituents as a larvicidal, repellent and adulticidal agents against the global burdening dengue mosquito.
Mostrar más [+] Menos [-]Inequality of female health and its relation with urbanization level in China: geographic variation perspective Texto completo
2019
Yang, Hao | Pu, Haixia | Wang, Shaobing | Ni, Runxiang | Li, Bin
Urbanization development plays a vital role in the health of modern residents; however, there have been very limited researches to specifically and comprehensively explore the relationship between urbanization level evaluating indicators (ULEIs) and female health outcomes. The mortality rate of breast cancer (BC), cervical cancer (CC), and ovarian cancer (OC) and classified urbanization factor are collected at provincial level. Stepwise regression model (SRM) and geographically weighted regression model (GWRM) are conducted to obtain spatial relationship between the mortality rate of those cancer and ULEI. Our results show that there is remarkable difference of mortality rate of BC, CC, and OC in different provinces as well as higher BC, CC, and OC distributed in northern regions. The increase of value added of primary industry (VAPI), taxi, and coal consumption has detrimental effect on BC and CC. Fuel oil consumption (FOC) ultimately results in increase of mortality rate of BC and OC, and urban fixed asset investment (UFAI) poses a risk to increase the mortality rate of OC. Contrarily, natural gas consumption (NGC) appear to mitigate mortality rate of BC. In particular, our findings demonstrate that there exist spatial differences for VAPI, FOC, NGC, taxi, and coal consumption influencing BC, CC, and OC. It is suggested that policy makers should take account of regional discrepancy and implement a sustainable urbanization development considering female health.
Mostrar más [+] Menos [-]Methods for monitoring construction off-road vehicle emissions: a critical review for identifying deficiencies and directions Texto completo
2019
Sepasgozar, Samad M. E. | Li, Heng | Shirowzhan, Sara | Tam, Vivian W. Y.
The paper reviews the existing applications of sensing technologies for measuring construction off-road vehicle emissions (COVE) such as earthmoving equipment. The current literature presented different measurement methods and reported the results of utilisation of new technologies for measuring COVE. However, previous papers used different technology applications covering only a part of the monitoring process with its own limitations. Since technologies are advancing and offering novel solutions, there is an urgent need to identify the gaps, re-evaluate the current methods, and develop a critical agenda for automating the entire process of collecting emissions data from construction sites, and monitoring the emission contributors across cities. This paper systematically identifies relevant papers through a search of three key databases—Web of Science, Engineering Valley and Scopus—covering the publications in the last decade from 2008 to 2017. An innovative robust research method was designed to select and analyse the relevant papers. The identified papers were stored in a data set, and a thematic algorithm employed to find the clusters of papers which might be potentially relevant. The selected papers were used for further micro-thematic analysis to find key relevant papers on COVE, and the gap in the literature. A sample of relevant papers was found relevant to COVE and critically reviewed by coding and content analysis. This paper critically reviews the selected papers and also shows that there is a considerable gap in the applications of new technologies for measuring in-use COVE in real time based on real activities toward automated methods. This review enables practitioners and scholars to gain a concrete understanding of the gap in measuring COVE and to provide a significant agenda for future technology applications.
Mostrar más [+] Menos [-]Removal of Silver Nanoparticles from Water Environment: Experimental, Mathematical Formulation, and Cost Analysis Texto completo
2019
Syafiuddin, Achmad | Salmiati, Salmiati | Hadibarata, Tony | Salim, Mohd Razman | Kueh, Ahmad Beng Hong | Suhartono, Suhartono
This paper deals with the comprehensive analysis for the removal of silver nanoparticles (AgNPs) from water environment. A new activated carbon derived from an agricultural waste, water lily mango seed shells, was proposed as a low-cost adsorbent to remove AgNPs. In addition, a new simple kinetic model was mathematically formulated and then tested using primary and secondary experimental AgNP adsorption data on different adsorbents. Moreover, cost analysis for the activated carbon production and removal of AgNPs was also estimated. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and inductively coupled plasma mass spectroscopy (ICPMS) analyses were employed for the characterization. The proposed model evaluation was carried out using six statistical indicators, which are the coefficient of determination (R²), root mean squared error (RMSE), percentage of error in maximum estimated value (Eₘₐₓ), percentage of error in minimum estimated value (Eₘᵢₙ), mean absolute percent error (MAPE), and mean absolute deviation (MAD). This study found that the proposed activated carbon performed a rapid removal with a maximum percentage of up to 97%. It was also interesting to note that the proposed model outperformed existing kinetic models having the same number of parameters. Cost analysis carried out in this study exhibited that the activated carbon was highly economical compared with other water treatment technologies reported elsewhere.
Mostrar más [+] Menos [-]Sulfur and Nitrogen Gases in the Vapor Streams from Ore Cyanidation Wastes at a Sharply Continental Climate, Western Siberia, Russia Texto completo
2019
Yurkevich, Nataliya | Bortnikova, Svetlana | Abrosimova, Natalya | Makas, Alexei | Olenchenko, Vladimir | Yurkevich, Nikolay | Edelev, Alexey | Saeva, Olga | Shevko, Artem
The article presents the results of the study of the vapor streams from sulfide-containing tailings after gold mining by cyanidation (Ursk waste heaps, Kemerovo region, Russia). The gas survey of sulfur dioxide, dimethyl sulfide, dimethyl sulfoxide, carbon disulfide, and N-containing substances concentrations was carried out using a portable device GANK-4 on a series of profiles covering the waste heaps and the surrounding area with simultaneous measurement of temperatures in the air and soil. The concentration maps-schemes of the studied gases in the surface layer were constructed. The high positive correlation of gases between themselves is established, which indicates similar mechanisms of their formation. The electrical resistivity tomography determined the internal structure of the waste heap. Active “breathing” zones were identified in which the maximum fluctuations in the concentrations of sulfur, selenium, and nitrogen-containing compounds in the near-surface air layer were recorded. Such zones are marked with lower resistances in comparison with other areas on the geo-electric profiles. There is an inverse correlation between the resistivity of the tailings and its temperature and a direct correlation between the concentration of gas in the air and the temperature of the soil. High concentrations of CS₂, the volatile gas compound of the second hazard class, were found in the concentrations that exceed 6–8 times the daily average norm. Further investigation of the mine tailings seasonal transformation with the production of toxic gases deserves special attention due to high environmental risks and poor knowledge of this problem. The oxidation of ore cyanidation wastes in summer and methylation in winter due to seasonal temperature fluctuation lead to production of gases of great concern including toxic СS₂.
Mostrar más [+] Menos [-]Effects of Liming and Urochloa brizantha Management on Leaching Potential of Picloram Texto completo
2019
Passos, Ana Beatriz R. J. | Souza, Matheus F. | Saraiva, Douglas T. | da Silva, Antônio Alberto | Queiroz, Maria Eliana L. R. | Carvalho, Felipe P. | Silva, Daniel Valadão
In pastures, the application of limestone is often performed after removal of the animals for proper development and establishment of regrowth. Together with this practice, the use of picloram in high concentrations for dicotyledonous weeds is common. Therefore, the evaluation of the behavior of this herbicide in these conditions is critical. The objective of this study was to determine the leaching of the picloram, in the soil with different pH and cultivated with Urochloa brizantha (signalgrass) trimmed or not. The experiment was plotted in a subdivided plot with four repetitions, where the plots were constituted by factors pH (5.3 and 6.4) and Urochloa brizantha managements (trimmed and no trimmed). The subplots were composed by depths (0 to 50 cm). The picloram was applied to the top of the columns after 65 days after emergency. A rain of intensity of 60 mm was simulated 12 h after the herbicide application. Picloram concentration was quantified by the high-performance liquid chromatography. Besides that, a control treatment was added without the presence of the signalgrass, for each substrate. The picloram was not detected in the percolated water through the columns. Picloram leached to deeper layers in the soil with pH 6.4, independently of the signalgrass management. The signalgrass reduced the leaching of the picloram, and those no-trimmed demonstrate a higher capacity to retain the herbicide in superficial layers. The liming of the soil increases the pH and reduces the amount of organic matter in the soil, which favors the leaching of picloram to the layer of 30–35 cm. Trimming of Urochloa brizantha reduces the capacity of this forage to reduce the leaching of picloram.
Mostrar más [+] Menos [-]Electrodialytic Arsenic Removal from Bulk and Pre-treated Soil Texto completo
2019
Ferreira, Ana Rita | Couto, Nazaré | Ribeiro, Alexandra B. | Ottosen, Lisbeth M.
Arsenic (As) is a well-known highly toxic and carcinogenic element. A combination of electrodialytic remediation (EDR) after soil washing with flocculant addition targeting remediation of a soil polluted with As from wood preservation industry is the focus of this paper. The fine fraction (< 0.063 mm) from the washed soil after dry sieving was also considered. The EDR experiments were carried out in a 2-compartment cell applying 0.01 mA/cm² during 14, 7 and 3 days. The suspended soil slurry was placed in cathode compartment separated by anion exchange membrane (AEM) of the anolyte where the pH was kept at 10. The soil was highly polluted with As, and the EDR was able to remove between 50 and 80% corresponding to 400–478 mg As/kg of soil. The major part of the As was removed within the first 3 days (63%), and approx. 10% more of As was released doubling the time of the experiment: 72% in 7 days and 80% in 14 days. The pre-treated soil showed higher As initial concentration, but did not show a clear advantage in terms of removal rate as the original soil (not washed or sieved) showed 80% of As removal comparing with 61% and 50% for washed and fine fraction, respectively (although the absolute removed concentration was similar). The sequential extraction results confirmed that As was bound into more mobile fractions in original soil, and the higher removal was mainly due to its larger exchangeable and reducible fractions compared to the oxidizable and residual fraction in pre-treated soil.
Mostrar más [+] Menos [-]Bioethanol Mill Wastewater Purification by Combination of Coagulation-Flocculation and Microbial Treatment of Trametes versicolor INACC F200 Texto completo
2019
Sari, Ajeng Arum | Hadibarata, Tony | Hanifah, Ummu | Randy, Ahmad | Amriani, Feni | Lotulung, Puspa Dewi N. | Yasin, Hasbi | Saefumillah, Asep | Shauqī, Ilyās
Black liquor is generated from the pretreatment process of biomass-based bioethanol production and due its environmental impact, should be treated effectively before discharged to the water body. Chemical treatment using coagulation-flocculation method was commonly used for wastewater treatment. In the case of black liquor, chemical treatment is often insufficient and further treatment was needed to degrade lignin in order to reduce its black coloration. This present study investigated the two-step treatment to decolorize black liquor using chemical coagulation-flocculation and biological treatment using white-rot fungus Trametes versicolor INACC F200. The biological treatment was optimized by applying a response surface methodology (RSM) of the utilization of CuSO₄ concentration, Tween 80 concentration, and agitation. Furthermore, lignin degradation was also confirmed using FTIR and LC-MS. Initial chemical treatment using ferrous sulfate and polyacrylamide as coagulant-flocculant with a ratio of 3:3, resulted in black liquor decolorization at 80.9% and reduced the COD up to 90.77%. A full quadratic stepwise model was utilized with CuSO₄ inducer, Tween 80 mediator, and agitation speed as the independent variables. Optimum decolorization of 96.188% was predicted when using 2 mM CuSO₄, 2% Tween 80, and an agitation speed of 150 rpm. The highest enzyme activity during the decolorization process was lignin peroxidase (LiP). FT-IR and LC-MS profile showed that lignin-associated bond was eliminated and the molecular weight of lignin was decreased after the treatment. This study concludes the effective decolorization and delignification of black liquor by the two-step chemical and biological treatment.
Mostrar más [+] Menos [-]Heavy metal distribution, translocation, and human health risk assessment in the soil-rice system around Dongting Lake area, China Texto completo
2019
Tang, Lin | Deng, Sihan | Tan, Di | Long, Jiumei | Lei, Ming
Heavy metals including copper (Cu), zinc (Zn), cadmium (Cd), chromium (Cr), lead (Pb), and arsenic (As) were investigated in 89 pairs of rice plant and paddy soils around Dongting Lake area, China. Rice plants and soils were collected with GPS device, and heavy metal contents in different rice plant tissues and soils were measured. The aim of the present study was to assess the heavy metal pollution and translocation in the whole soil-rice system, including the consequent human health risk for residents. According to the indices of average geoaccumulation (Igₑₒ) of the studied elements, paddy soils in study area were moderately polluted by Cd, lowly polluted by Pb, and not polluted by Cu, Zn, Cr, and As. Considering the much higher concentrations of studied elements in roots than in other tissues of rice plants, a great mass of these elements was assumed to be confined in the roots. The low translocation factors from root to shoot (Tfᵣₒₒₜ₋ₛₕₒₒₜ) of all the studied heavy metals (0.04–0.74) underpinned this. The high translocation factors from soil to root (Tfₛₒᵢₗ₋ᵣₒₒₜ) of Cd (9.12), As (4.38), and Zn (2.05) indicated the high bioavailability of these heavy metals for rice plant. The health risk assessment using target hazard quotients (THQs) model indicated that Cd (5.17 for adults and 4.49 for children respectively) and As (3.61 for adults and 3.14 for children respectively) could cause human health risk both for adults and children. Further, given the rate of individual THQ values exceeding one, Cu might also be considered as a potential human health dangerous element in the study area. It was worth noting that as one of the main pollutants, Pb did not show human health risk through rice grain consumption due to its low Tf values in soil-rice system. However, the risk identification of As using comparisons of measured concentrations with risk screening value in Chinese paddy soil standard (GB15618-2018) was not consistent with the human health risk assessment result. This might indicate that site-specific risk screening values of As in China is in demand.
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