Isotope dilution techniques (IDT) and sequential extraction procedures (SEPs) were compared to apprehend the differences between two techniques in determining metal exchangeability and vulnerability ...to pollute the urban groundwater. For this purpose, soil (n = 2), “soakaway” sediment deposited in the artificial infiltration facilities (AIF) (n = 4), and road dust (n = 2) were sampled from Tokyo metropolitan. Sorption coefficients of four metals (Cu, Zn, Cd and Pb) were assessed through isotopic exchangeability (E-value) and potential mobile pool i.e. addition of exchangeable, reducible and oxidizable fraction obtained by Community Bureau of Reference (BCR)-procedures. The E-value for the three samples were found smaller than the potential mobile pool but were higher than BCR-exchangeable fractions. The use of strong extractants are likely to play an active role in the disagreement between SEPs and IDT. IDT accounts for the isotopic exchangeability while BCR provides information of vulnerability of metals associated with different fractions that can leach under different environmental conditions. Sorption coefficients measured in soakaway sediment was found comparable to soil thus likely to retain metals. However, as variability in environmental conditions is likely to affect Kd, the soakaway sediment may become an active metal source in future rather than acting as the permanent sink. The study concludes that there is the possibility of errors while predicting metal vulnerability to groundwater with both techniques and thus a model compliance integrating the virtue of both techniques will be a way forward.
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•Better compliance amid isotope dilution and sequential extraction for high metal loading.•Isotopic exchangeability (E-value) was smaller than extracted potential mobile pool.•Coupling of IDT with BCR provide better estimate of leaching vulnerability for metals.•IDT accounts for actual exchangeability while SEPs provide leaching vulnerability.
In recent time, there have been significant advances in the reliability based design to take care of variability and uncertainty in the pile design. The principal objective of the study is to examine ...the applicability of Extreme Learning Machine (ELM) and Multivariate Adaptive Regression Spline (MARS) models for predicting the bearing capacity of a pile embedded in cohesionless soil and comparing their respective performances. The models are developed using numerical analysis and conventional equations. A comparative study is made between reliability indices obtained by First Order Second Moment Method (FOSM) and MARS and ELM based FOSM. The performance was evaluated using various performance parameters.
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•Wastewater treatments may not completely remove the SARS-CoV-2 RNA.•Activated sludge process exhibited better RNA removal efficacy than root-zone treatment.•ORF 1ab and S genes ...appeared more sensitive to treatment than N genes.•Temporal variability is observed in the removal efficacy of wastewater treatment plants.
In the initial pandemic phase, effluents from wastewater treatment facilities were reported mostly free from Severe Acute Respiratory Coronavirus 2 (SARS-CoV-2) RNA, and thus conventional wastewater treatments were generally considered effective. However, there is a lack of first-hand data on i) comparative efficacy of various treatment processes for SARS-CoV-2 RNA removal; and ii) temporal variations in the removal efficacy of a given treatment process in the backdrop of active COVID-19 cases. This work provides a comparative account of the removal efficacy of conventional activated sludge (CAS) and root zone treatments (RZT) based on weekly wastewater surveillance data, consisting of forty-four samples, during a two-month period. The average genome concentration was higher in the inlets of CAS-based wastewater treatment plant (WWTP) in the Sargasan ward (1.25 × 103 copies/ L), than that of RZT-based WWTP (7.07 × 102 copies/ L) in an academic institution campus of Gandhinagar, Gujarat, India. ORF 1ab and S genes appeared to be more sensitive to treatment i.e., significantly reduced (p < 0.05) than N genes (p > 0.05). CAS treatment exhibited better RNA removal efficacy (p = 0.014) than RZT (p = 0.032). Multivariate analyses suggested that the effective genome concentration should be calculated based on the presence/absence of multiple genes. The present study stresses that treated effluents are not always free from SARS-CoV-2 RNA, and the removal efficacy of a given WWTP is prone to exhibit temporal variability owing to variations in active COVID-19 cases in the vicinity and genetic material accumulation over the time. Disinfection seems less effective than the adsorption and coagulation processes for SARS-CoV-2 removal. Results stress the need for further research on mechanistic insight on SARS-CoV-2 removal through various treatment processes taking solid–liquid partitioning into account.
The Himalaya is one of the youngest and the loftiest mountain chains of the world; it is also referred to as the water tower of Asia. The Himalayan region harbors nearly 10,000 plant species ...constituting approximately 2.5% of the global angiosperm diversity of which over 4,000 are endemics. The present-day Himalayan flora consists of an admixture of immigrant taxa and diversified species over the last 40 million years. The interesting questions about the Himalayan flora discussed here are: how did the Himalaya achieve high endemic plant diversity starting with immigrant taxa and what were the main drivers of this diversity? This contribution aims to answer these questions and raise some more. We review and analyze existing information from diverse areas of earth and climate sciences, palaeobiology and phytogeography to evolve a bio-chronological record of plant species divergence and evolution in the Himalaya. From the analysis we infer the effects of major environmental upheavals on plant diversity in the region. The understanding developed in the following discussion is based on the idea that Himalaya experienced at least five phases of major geophysical upheavals, namely: (i) mega-collision between India and Eurasian plates, (ii) tectonic uplift in phases and progressive landform elevation, (iii) onset of southwest (SW) Indian monsoon, (iv) spurring of arid conditions in Central Asia, and (v) cyclic phases of cooling and warming in the Quaternary. The geophysical upheavals that were potentially disrupting for the ecosystem stability had a key role in providing impetus for biological diversification. The upheavals produced new geophysical environments, new ecological niches, imposed physical and physiological isolation barriers, acted as natural selection sieves and led to the formation of new species. This contribution aims to develop a comprehensive understanding of the plant biodiversity profile of the Himalaya in the context of complex, interconnected and dynamic relationship between earth system processes, climate and plant diversity.
Diesel engine modeling draws the greater attention due to its higher efficiency as compared to spark ignition (SI) engine. Still it is very challenging job to model diesel engine due to its complex ...combustion phenomena. The focus of the present study is to review the different available model used for modeling of CI engines. The modeling of CI engine is divided into single zone, multizone and multi-dimensional model. Which further subdivided in many submodel i.e. heat transfer, ignition delay period, droplet evaporation, intake and exhaust flow, chemical kinematics and soot formation model. A comparative study has also been carried out with experimental validation to show the compatibility with different modeling approach. Some optimum mathematical input parameter has been suggested by the analysis of different modeling approach to minimize the NOx emission and soot formation to make diesel engine more eco-friendly.
Multi-drug resistant microbes, pathogenic viruses, metals, and pharmaceuticals and personal care products (PPCPs) in water has become the crux of urban sustainability issues. However, vulnerability ...due to pollutant concurrences, source apportionment, and identification of better faecal indicators needs to be better understood. The present study focuses on the vulnerability of urban Guwahati, the largest city in Northeastern India, through analyzing the concurrence of PPCPs, enteric viruses, antibiotic resistant bacteria, metal, and faecal contamination in water. The study strives to identify a relevant marker of anthropogenic pollution for the Indian scenario. Samples from the Brahmaputra River (n = 4), tributary Bharalu River (an unlined urban drain; n = 3), and Ramsar recognized Lake (Dipor Bil; n = 1) indicate caffeine > acetaminophen > theophylline > carbamazepine > crotamiton for PPCPs and pepper mild mottle virus (PMMoV) > aichi > hepatitis A > norovirus GII > norovirus GI for enteric viruses. PMMoV was the better indicator of faecal pollution due to its prevalence, specificity and ease of detection. Antibiotic resistance was neither correlated with the prevalence of PPCPs nor E. coli. As, Co and Mn appear to be inducing antibiotic resistance in E. coli. While the risk quotient of the urban drain (Bharalu River) indicates one order higher magnitude than reported for other Indian rivers, the Lake exhibited the least pollution and better resilience. The concurrence of pollutants and multi-drug resistant E. coli, owing to the complete absence of wastewater treatment, puts the city in a highly vulnerable state. Pollution is being regulated only by the dilution capability of the Brahmaputra River, which needs to be further researched for seasonal variation.
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•Antibiotics resistance was not correlated with the prevalence of PPCPs and E. coli.•Risk quotient in the urban water was higher than reported for other Indian rivers.•PMMoV was a good faecal pollution indicator due to prevalence, specificity and detectability.•As, Co and Mn appear to be inducing antibiotic resistance in E.coli.•Wetland in the urban area exhibited the least pollution and better resilience for ARB.
Wastewater treatment plants (WWTPs) are being debated for being the hot spots for the development of antibiotic resistance in pathogenic microbial communities. We observed the prevalence of ...antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARG), and multidrug resistance (MDR) in two municipal WWTPs and one hospital WWTP in Western and Southern Sri Lanka, and compared the results with particular reference to Indian and the World scenario to trace the imprints of treatment on ARB and ARG. Result suggests that although wastewater treatment resulted in higher than 1.06 log Escherichia coli (E. coli) reduction at all WWTPs, yet the percent of E. coli resistant to most of the antibiotics increased from influent to effluent. Higher prevalence of ARB, ARG, and MDR were noted in hospital WWTP owing to the higher antibiotic concentrations used and excreted by the patients. With reference to India, the WWTPs in Sri Lanka showed more ARB and a consistent increase in its percentages after the treatment but were less resistant to Fluoroquinolone (FQ). E. coli strains isolated from each location of both countries showed multidrug resistance, which has increased after the treatment and was strongly correlated with FQ in every WWTP. Resistant genes for Fluoroquinolone (FQ) (aac-(6′)-1b-cr, qnrB, qnrS), β-lactams (ampC), and sulphonamides (sul1) were common in all the wastewaters except additional parC gene in the hospital effluent of Sri Lanka, implying much higher resistance for quinolones, especially for Ciprofloxacin. Multivariate statistical treatments suggest that effluent showed higher loadings and association for MDR/ARB, where pH change and more extensive interaction with metals during the treatment processes seem to have profound effects.
•Antibiotic resistance of E. coli was found increasing after treatment process.•The resistance genes aac-(6′)-1b-cr, qnrB, qnrS, ampC, sul1 were detected in WWTPs.•Cross-resistance within fluoroquinolones was stronger than non-fluoroquinolones.•Sri Lankan WWTPs exhibit more and consistent increase in resistance after the treatment than India.
Background: Himalayan Viola species (Banksha) are traditionally important herbs with versatile therapeutic benefits such as antitussive, analgesic, antipyretic, antimalarial, anti-inflammatory, and ...anticancerous ones. The current investigation was focused on exploring polyphenolic profiles, antioxidant, and antimicrobial potentials of wild viola species at 15 gradient locations (375–1829 m). Methods: Morphological, physiochemical, and proximate analyses were carried out as per WHO guidelines for plant drug standardization. Total polyphenolic and flavonoid content were carried out using gallic acid and rutin equivalent. UPLC-DAD was used to profile the targeted polyphenols (gallic acid, vanillic acid, syringic acid, p-coumaric acid, ferulic acid, rutin, quercetin, luteolin, caffeic acid, and epicatechin). Similarly, all samples were screened for antioxidant and antimicrobial activity. Statistical analysis was used to correlate polyphenolic and targeted activities to assess Viola species adaptation behavior patterns. Results: Viola canescens (V. canescens) and Viola pilosa (V. pilosa) were found abundantly at their respective sites. Among flowers and leaves, flowers of V. canescens and V. pilosa showed higher total polyphenolic and flavonoid content (51.4 ± 1.13 mg GAE/g and 65.05 ± 0.85 mg RE/g, and 33.26 ± 0.62 mg GAE/g and 36.10 ± 1.41 mg RE/g, respectively). Furthermore, UPLC-DAD showed the uppermost content of p-coumaric acid in flowers and ferulic acid in leaves, while rutin was significant in both the tissues. Conclusions: The adaptive behavior of Viola species showed variability in morphological characters with the altitudes, while targeted polyphenols and activities were significant at mid-altitudes. This research helps in the selection of right chemotype for agrotechnological interventions and the development of nutraceutical products.
► One step process for synthesizing pure and mixed phase TiO2 nanoparticles. ► The crystallite size of prepared TiO2 at different temperature is in the range of 19–68nm. ► The tensile strain has been ...observed below 600°C and converted into compressive strain at 700°C. ► Photoluminescence spectroscopy (PL) exhibits the change in PL intensity with phase change. ► Different trends have been observed in emission edges.
Pure and mixed phase TiO2 have been prepared by sol–gel method; calcinated at four different temperatures. The influence of calcination temperature on crystallite size, morphology, band gap and luminescence properties of resultant material have been investigated. Different trends were observed in the phase transformation, particle growth, shift in energy band gap and in luminescence with the change in tensile strain to compressive strain of the prepared TiO2 nanomaterial. X-ray diffraction (XRD) showed that prepared nanocrystals have pure anatase and anatase-rutile mixed structures. The prepared samples having crystallite size between 19nm to 68nm were observed at different calcination temperatures. Williamson-Hall plot results indicate the presence of tensile strain at 400, 500 and 600°C while compressive strain at 700°C. Scanning electron microscopy (SEM) shows that the particles are non-uniform. Ultraviolet-Visible spectroscopy (UV-Vis) is used to calculate the energy band gap of materials and it has been observed that the band gap decreases with increase in temperature. Fourier transform infrared spectroscopy (FTIR) describes local environment around TiO2 nanoparticles. Photoluminescence spectroscopy (PL) exhibits the change in PL intensity with phase change and different trends have been observed in emission edges.
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