Chemical characteristics and source apportionment of PM<Subscript>2.5</Subscript> using PCA/APCS,UNMIX, and PMF at an urban site of Delhi,India

The present study investigated the comprehensive chemical composition [organic carbon (OC), elemental carbon (EC), water-soluble inorganic ionic components (WSICs), and major & trace elements] of particulate matter (PM_2.5) and scrutinized their emission sources for urban region of Delhi. The 135 PM_2.5 samples were collected from January 2013 to December 2014 and analyzed for chemical constituents for source apportionment study. The average concentration of PM_2.5 was recorded as 121.9 ± 93.2 μg m^?3 (range 25.1–429.8 μg m^?3), whereas the total concentration of trace elements (Na, Ca, Mg, Al, S, Cl, K, Cr, Si, Ti, As, Br, Pb, Fe, Zn, and Mn) was accounted for ～17% of PM_2.5. Strong seasonal variation was observed in PM_2.5 mass concentration and its chemical composition with maxima during winter and minima during monsoon seasons. The chemical composition of the PM_2.5 was reconstructed using IMPROVE equation, which was observed to be in good agreement with the gravimetric mass. Source apportionment of PM_2.5 was carried out using the following three different receptor models: principal component analysis with absolute principal component scores (PCA/APCS), which identified five major sources; UNMIX which identified four major sources; and positive matrix factorization (PMF), which explored seven major sources. The applied models were able to identify the major sources contributing to the PM_2.5 and re-confirmed that secondary aerosols (SAs), soil/road dust (SD), vehicular emissions (VEs), biomass burning (BB), fossil fuel combustion (FFC), and industrial emission (IE) were dominant contributors to PM_2.5 in Delhi. The influences of local and regional sources were also explored using 5-day backward air mass trajectory analysis, cluster analysis, and potential source contribution function (PSCF). Cluster and PSCF results indicated that local as well as long-transported PM_2.5 from the north-west India and Pakistan were mostly pertinent.     

Experimental investigation of performance and emissions of a VCR diesel engine fuelled with <Emphasis Type="Italic">n</Emphasis>-butanol diesel blends under varying engine parameters

The continuous rise in the cost of fossil fuels as well as in environmental pollution has attracted research in the area of clean alternative fuels for improving the performance and emissions of internal combustion (IC) engines. In the present work, n-butanol is treated as a bio-fuel and investigations have been made to evaluate the feasibility of replacing diesel with a suitable n-butanol-diesel blend. In the current research, an experimental investigation was carried out on a variable compression ratio CI engine with n-butanol-diesel blends (10–25% by volume) to determine the optimum blending ratio and optimum operating parameters of the engine for reduced emissions. The best results of performance and emissions were observed for 20% n-butanol-diesel blend (B20) at a higher compression ratio as compared to diesel while keeping the other parameters unchanged. The observed deterioration in engine performance was within tolerable limits. The reductions in smoke, nitrogen oxides (NO _x ), and carbon monoxide (CO) were observed up to 56.52, 17.19, and 30.43%, respectively, for B20 in comparison to diesel at rated power. However, carbon dioxide (CO₂) and hydrocarbons (HC) were found to be higher by 17.58 and 15.78%, respectively, for B20. It is concluded that n-butanol-diesel blend would be a potential fuel to control emissions from diesel engines.

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Microplastic pollution,a threat to marine ecosystem and human health: a short review

Human populations are using oceans as their household dustbins, and microplastic is one of the components which are not only polluting shorelines but also freshwater bodies globally. Microplastics are generally referred to particles with a size lower than 5 mm. These microplastics are tiny plastic granules and used as scrubbers in cosmetics, hand cleansers, air-blasting. These contaminants are omnipresent within almost all marine environments at present. The durability of plastics makes it highly resistant to degradation and through indiscriminate disposal they enter in the aquatic environment. Today, it is an issue of increasing scientific concern because these microparticles due to their small size are easily accessible to a wide range of aquatic organisms and ultimately transferred along food web. The chronic biological effects in marine organisms results due to accumulation of microplastics in their cells and tissues. The potential hazardous effects on humans by alternate ingestion of microparticles can cause alteration in chromosomes which lead to infertility, obesity, and cancer. Because of the recent threat of microplastics to marine biota as well as on human health, it is important to control excessive use of plastic additives and to introduce certain legislations and policies to regulate the sources of plastic litter. By setup various plastic recycling process or promoting plastic awareness programmes through different social and information media, we will be able to clean our sea dustbin in future.     

Chemical properties of soils in relation to forest composition in moist temperate valley slopes of Garhwal Himalaya, India

The present study was undertaken in moist temperate forest of Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim of the present study was to assess the chemical properties of soils in relation to the forest structure and composition. Twelve forest types according to the altitude, slope aspect, and species composition were selected for the study. Chemical properties of the soil, i.e., total nitrogen (N), available phosphorus (P), available potassium (K), organic carbon (C), soil organic matter (SOM), pH and C:N ratios were analyzed for three different depths viz., (i) ??Upper?? (0?C10?cm), (ii) ??Middle?? (11?C30?cm), and (iii) ??Lower?? (31?C60?cm) in all the selected forest types. Phytosociological and diversity parameters viz. total basal cover (Gha^?1), stem density (Nha^?1), tree species richness (SR), Simpson concentration of dominance and Shannon?CWiener diversity index ( $ \overline{\rm H} $ ) were also calculated for each forest type. Values of N, P, K, C, SOM, C:N ratio and pH ranged from 0.17 to 0.45?%, 2.73 to 20.17?ppm, 40.67 to 261.17?ppm, 2.29 to 4.31?%, 3.95 to 7.43?%, 8.12 to 14.49 and 5.47 to 6.67, respectively. N showed a positive relationship with C and K. P was positively correlated with C and negatively correlated with altitude. P was higher in the soil of lower horizons of all the forest types. K was found to be positively correlated with altitude, C and N. pH of all the forest types was slightly acidic. C was comparatively higher in mixed broad-leaved forest types. No relationship between altitude and C was observed, which may be due to different composition of forest types along the altitudinal gradient and their differential decomposition rates. C content decreased with the depth of the soil. C showed positive correlation with N, P, and K. N showed a positive correlation with Gha^?1. K showed a negative correlation with SR and $ \overline{\rm H} $ . P showed no relationship with the phytosociological parameters. This study also provides the comparisons between the results of chemical analysis of the present study with numerous other previous studies in the temperate Himalayan region of the Uttarakhand. The values of soil chemical properties of the present study in most of the forest types are on the higher end than the values previously recorded for the other similar forests of the region. The possible reason being luxuriant vegetation and undisturbed nature of these forest types, which is evident from higher values of diversity and other phytosociological parameters.     

Overcoming growing water scarcity: Exploring potential improvements in water productivity in India

Improvements in water productivity (WP) are often suggested as one of the alternative strategies for overcoming growing water scarcity in India. This paper explores the potential improvements in WP of food grains at district level, which currently varies between 0.11 and 1.01 kilogram per cubic metre (kg/m³), in the 403 districts that account for 98% of the total production of food grains. The paper first finds the maximum yield function conditional on consumptive water use (CWU) and then explores the potential improvements in WP by: (a) bridging the gap between actual and maximum yield while keeping CWU constant; and (b) changing the maximum yield by adjusting the CWU using supplementary or deficit irrigation. Deficit irrigation in some areas may decrease yield but can increase production if land availability is not a constraint. A large potential exists for bridging the yield gap in irrigated areas with CWU between 300 and 475 mm. Of the 222 districts that fall under this category, a 50% reduction in yield gap alone could increase production by 100 million tonnes (Mt) without increasing CWU. Supplementary irrigation can increase yield and WP in rain‐fed and irrigated areas of 266 and 16 districts with CWU is below 300 mm. Deficit irrigation in irrigated areas of 185 districts with CWU above 475 mm could increase yield, WP and production. Decreasing CWU in irrigated areas with CWU between 425 and 475 mm reduces yield slightly, but if availability of land is not a constraint then the benefits due to water saving and production increases could exceed the cost.     

Assessment of noise pollution during Deepawali festival in a small township of Haridwar City of Uttarakhand,India

In the present study, noise levels were measured in two different areas within Haridwar City viz., residential and commercial area, on festive day and non-festive day (after) of Deepawali in November 2007. The results show that there is an enhanced pressure of noise during the festival of light. The average noise level on festive day shows a rise of 29.6 and 18.1% when compared to non-festive day, respectively, for residential and commercial area.     

Role of physiographic factors in distribution of <Emphasis Type="Italic">Abies pindrow</Emphasis> (<Emphasis Type="Italic">Silver Fir</Emphasis>) along an altitudinal gradient in Himalayan temperate forests

We have made an attempt to understand the significance of physiographic factors viz., altitude, aspect, slope and soil characteristics in determining the structure, composition, growth behavior and distribution of Himalayan Silver Fir (Abies pindrow Spach.) through a comparative analysis of two temperate forests. The occurrence of highest density (370 and 225 ind/ha), importance value index (213.10 and 190.60) and total basal cover (TBC; 95.72 and 51.15 m²/ha) values along with the availability of higher organic carbon (6.53 and 4.47%), nitrogen (N; 0.73 and 0.44%) and potassium (K; 621 and 319 ppm) contents in the soils just beneath the hilltops (2,650–2,800 and 2,550–2,650 m asl), on steeper slopes (45°–50° and 42°–45°) and North-East aspects have revealed better growth of A. pindrow on both the sites. Stem density positively correlated with TBC (0.771), Shannon–Wiener diversity index (H′; 0.879), OC (0.601), N (0.758) and K (0.752), whereas TBC has shown significant positive relationship with H′ (0.894), K (0.793) and N (0.716). Similarly, H′ has also shown significant positive correlation with slope (0.721), K (0.855) and N (0.791). Interestingly, positive correlation of altitude with stem density (0.557) and of slope with TBC (0.608) was noticed in the distribution of A. pindrow individuals.     

Development of an analytical method for analysis of flubendiamide, des-iodo flubendiamide and study of their residue persistence in tomato and soil

Flubendiamide is a new insecticide that has been found to give excellent control of lepidopterous pests of tomato. This study has been undertaken to develop an improved method for analysis of flubendiamide and its metabolite des-iodo flubendiamide and determine residue retention in tomato and soil. The analytical method developed involved extraction of flubendiamide and its metabolite des-iodo flubendiamide with acetonitrile, liquid-liquid partitioning into hexane-ethyl acetate mixture (6:4, v v?1) and cleanup with activated neutral alumina. Finally the residues were dissolved in gradient high pressure liquid chromatography (HPLC) grade acetonitrile for analysis by HPLC. The mobile phase, acetonitrile-water at 60:40 (v v?1) proportion and the wavelength of 235 nm gave maximum peak resolution. Using the above method and HPLC parameters described, nearly 100 % recovery of both insecticides were obtained. There was no matrix interference and the limit of quantification (LOQ) of the method was 0.01 mg kg?1. Initial residue deposits of flubendiamide on field-treated tomato from treatments @ 48 and 96 g active ingredient hectare?1 were 0.83 and 1.68 mg kg?1, respectively. The residues of flubendiamide dissipated at the half-life of 3.9 and 4.4 days from treatments @ 48 and 96 g a.i. ha?1, respectively and persisted for 15 days from both the treatments. Des-iodo flubendiamide was not detected in tomato fruits at any time during the study period. Residues of flubendiamide and des-iodo flubendiamide in soil from treatment @ 48 and 96 g a.i. ha?1 were below detectable level (BDL, < 0.01 mg kg?1) after 20 days. Flubendiamide completely dissipated from tomato within 20 days when the 480 SC formulation was applied at doses recommended for protection against lepidopterous pests.     

Green Synthesis of Silver Nanoparticle Capped with <Emphasis Type="Italic">Allium cepa</Emphasis> and Their Catalytic Reduction of Textile Dyes: An Ecofriendly Approach

Today, environment pollution control is a matter of concern, everybody is willing to make a product that should be ecofriendly. Nowadays, water resources are full of untreated waste materials, discharge of hazardous and toxic dyes coming from textile and other chemical industries. These environmental hazards are difficult to remove by commercial water treatment plans, thus we need something that would present an efficient means for removal of these hazards. In this research paper, we have synthesize silver nanoparticle in a green way by using aqueous extract of Allium cepa (onion), and further these silver nanoparticle were tested for the catalytic degradation of various dyes by UV/Visible spectroscopy and silver nanoparticle showed reduction in dyes intensity after a particular period of incubation time. SEM and TEM, Particle size and Zeta potential analysis was done to analyze the surface morphology, particle size range and stability of the silver nanoparticle. Greenly synthesized silver nanoparticle was found to be spherical in shape, having particle size value ranged from 50 to 100 nm with a zeta potential value of ?29 mV. An EDX spectroscopy method was used to confirm the presence of silver nanoparticle in the synthesized material. An X-ray crystallography was done to ensure the crystallinity of the silver nanoparticle. Further an ATR-FTIR was performed to confirm the capping of the silver nanoparticle with the phenolic group of the onion. All these study emphasized that silver nanoparticle capped with onion (AgNPs@Ac) is the excellent catalyst for the reduction of hazardous and toxic dyes as well as they serve best purpose of the eco-friendly approach.     

Fabrication of Biodegradable Superabsorbent Using RSM Design for Controlled Release of KNO<Subscript>3</Subscript>

Present study envisaged the sequential experimental design approach for the development of biodegradable Gelatin-Tapoica/polyacrylamide superabsorbent. Percentage water uptake efficacy of candidate sample was optimized using Response Surface Methodology (RSM) design under microwave irradiation. Different process variables such as potassium persulphate and ammonium persulphate (KPS:APS) ratio, pH, reaction time concentration of acrylamide and N,N-methylene-bis-acrylamide (MBA) were investigated as a function of percentage swelling using sequential experimental design. Maximum liquid efficacy of 1550% was obtained at KPS:APS?=?1.0:0.5; acrylamide?=?7.67?×?10^?1 mol L^?1; MBA?=?1.76?×?10^?2 mol L^?1; pH 10 and time?=?110 s. The 3D crosslinked network formed was characterized using Fourier Transformation Infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopic (SEM) techniques and thermal stability was ensured by Thermal gravimetric Analysis/Differential Thermal Analysis/Differential Thermal Gravimetric (TGA/DTA/DTG) studies. Superabsorbent synthesized could increase the moisture content in different type of soils and was found to enhance the water-holding capability of the soil upto 60 days in clayey, 40 days in sandy and 51 days in mixture of two soils under controlled conditions. Further, candidate polymer was investigated for the in-vitro controlled release of the KNO₃ with diffusion exponent ‘n’ was found to be 0.4326 indicating Fickian type diffusion. Also, initial diffusion coefficient (D_I?=?3.49?×?10^?5 m² h^?1) was found to be greater than the lateral diffusion coefficient (D_L?=?3.76?×?10^?6 m² h^?1) indicated rapid release of KNO₃ during initial hours with slow release afterwards. The ecofriendly nature of the synthesized polymer was also tested by conducting biodegradation studies and it was found to degrade upto 94% and 88.1% within 70 days with degradation rate of 1.34 and 1.26% per day using composting method and vermicomposting method respectively. So, the synthesized candidate polymer was found to be boon for agriculture-horticulture sector with wide applicability.