Vaneet Kumar

Distribution behavior of polycyclic aromatic hydrocarbons in roadside soil at traffic intercepts within developing cities

A study of polycyclic aromatic hydrocarbons pollution in roadside soil was conducted in developing city environment of northern India during autumn and winter season to ascertain the contamination levels and their distribution behavior in soil. The concentration of polycyclic aromatic hydrocarbons was determined at ten locations of Jalandhar city, Punjab in India at 1, 2 and 3 m distances from roadside in soil covering all the major traffic intercepts within city. The samples were extracted in acetone and dichloromethane (1:1) using soxhlet extraction. The extracts were then filtered on a silica gel micro column to remove impurities and elute was subjected to GC-FID. The total average concentration (city average) was found to be 4.04 ⧎g/g and 16.38 ⧎g/g during winter and autumn respectively. DiBenzo (ah) Anthracene and Benzo (a) Pyrene were the individual polycyclic aromatic hydrocarbons found in highest concentration at all the intercepts ranging between 0.008 to 28.4 ⧎g/g during winter and 0.01 to 252.55 ⧎g/g during autumn. Average concentration of non-carcinogenic and carcinogenic polycyclic aromatic hydrocarbons during winter and autumn was found to be 2.1 and 6.4 and 4.74 and 35.08 ⧎g/g respectively. The average ratio of non-carcinogenic and carcinogenic Polycyclic Aromatic Hydrocarbons was found to be 1:3 during winter, and 1:7.6 during autumn at most of the intercepts. Total carcinogenic polycyclic aromatic hydrocarbons concentration was found quite high (80 %) in comparison to non-carcinogenic polycyclic aromatic hydrocarbons (20 %) at most of the intercepts.

Optimal response surface design of Gum tragacanth-based poly[(acrylic acid)-co-acrylamide] IPN hydrogel for the controlled release of the antihypertensive drug losartan potassium

The present study proposes the development and optimization of a new interpenetrating polymer network (IPN), consisting of Gum tragacanth, poly(acrylic acid) (PAA), and poly(acrylamide) (PAAm), for the in situ controlled release of losartan potassium under different pH conditions at 37 °C. Solvent amount and monomer concentration were chosen as the process variables and percentage swelling was taken as the process response. ANOVA model fits were made for the data and gave the cubic model as the best fit, with a predicted R2 = 0.976. The maximum desirability was observed to be 19.63 mL solvent and 3.28 × 10−4 mol L−1 monomer concentration, at which the percentage swelling was found to be 266. Whereas, at 23.7 mL solvent and 6.7 × 10−4 mol L−1 monomer, the percentage swelling was found to be at the minimum (139%). The model was validated at the optimal points for developing devices with the maximum swelling capacity. Drug release through the synthesized matrix was found to show non-fickian behavior at pH 2.0, 7.0, and 9.2, with an increasing trend in gel characteristic constant (k). At each pH medium, the initial diffusion coefficient (DI) was found to be higher than the lateral diffusion coefficient (DL).

Adsorption of methyl violet from aqueous solution using gum xanthan/Fe3O4 based nanocomposite hydrogel

This research paper reports the utilization of gum xanthan-grafted-polyacrylic acid and Fe3O4 magnetic nanoparticles based nanocomposite hydrogel (NCH) for the highly effective adsorption of methyl violet (MV) from aqueous solution. Synthesized NCH was characterized using various techniques, such as FTIR, XRD, SEM-EDS, TEM and BET. Adsorption behavior of NCH was studied for the adsorption of MV and it was found to remove 99% dye from the solution. Adsorption process followed Langmuir isotherm model (qe=642mg/g) and pseudo-second-order kinetics model. Thermodynamic studies suggested that the adsorption process was endothermic and spontaneous. Moreover, the adsorbent was successfully utilized for successive five cycles of adsorption-desorption.

Synthesis, characterization and evaluation of Gum tragacanth and acrylic acid based hydrogel for sustained calcium chloride release – enhancement of water-holding capacity of soil

A novel cross-linked hydrogel has been synthesized through graft copolymerization of acrylic acid onto Gum tragacanth, in the presence of ascorbic acid–potassium persulphate as an initiator. Characterization of the synthesized hydrogel was carried out by thermogravimetric analysis (TGA), differential thermal analysis (DTA), differential thermogravimetric analysis (DTG) and scanning electron microscopy (SEM). The results indicated that 10% (w/w) swelled hydrogel could increase the moisture contents of the clay and sandy loam soil up to 5.35% and 4.49%, respectively. Furthermore, the synthesized material was used as a device for sustained release of calcium chloride for longer time. Such properties of synthesized hydrogel like swelling and water retaining capacity can be exploited in the field of agriculture.

Sources, distribution, and health effect of carcinogenic polycyclic aromatic hydrocarbons (PAHs) – current knowledge and future directions

Polycyclic aromatic hydrocarbons (PAHs) are chemical compounds containing two or more fused benzene rings in linear, angular or cluster arrangement, consisting of only carbon and hydrogen. Polycyclic aromatic carbons (PACs) include the unsubstituted hydrocarbons (PAHs) and substituted PAHs (e.g. nitro-PAH, oxygenated PAH). PAHs are the most stable form of hydrocarbons having low hydrogen-to-carbon ratio and usually occur in complex mixtures rather than single compounds. They are usually generated under inefficient combustion conditions (e.g. in incomplete supply of oxygen).This paper deals with type carcinogenic PAHs generated in the environment from various sources, environment distribution and health effect.This paper provides a review of current information on the concentrations, burdens and fate of PAHs in the atmosphere, with reference to the historical trends in PAH emissions. The major anthropogenic sources of PAHs and their effect on the concentrations of these compounds in air on a national–inter...

Biodegradation study of enzymatically catalyzed interpenetrating polymer network: Evaluation of agrochemical release and impact on soil fertility

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Studies on carcinogenic PAHs emission generated by vehicles and its correlation to fuel and engine types

Abstract The objective of this study was to find major PAHs produced in ambient air from the automobile exhaust as a function of fuels (diesel, petrol, and biodiesel) and engine type qualitatively and quantitatively. The recovery range was found between 30% and 70%. The study was carried out on two, three, and four wheelers. Biodiesel samples tested in the study were synthesized indigenously from different starting raw materials and analyzed for PAHs concentration in the exhaust on a Honda genset (EBK 2000AC Model). Biodiesel samples were blended with diesel in different ratio (25:75, 35:65 and 45:55) to investigate the exhaust behavior. Biodiesel was blended with Diesel the concentration of almost all PAHs reduces in comparison to pure Diesel exhaust. B(a)A and B(a) P was the common PAH found in higher concentration in almost all fuels. FTIR results indicate esterification of vegetable oil and NMR results indicate a complete conversion of oils into biodiesel.

Analysis of Polycyclic Aromatic Hydrocarbon, Toxic Equivalency Factor and Related Carcinogenic Potencies in Roadside Soil within a Developing City of Northern India

Preliminary analysis was performed to assess contamination levels in roadside soils, distribution behavior and human exposure with Polycyclic Aromatic Hydrocarbons (PAHs) during summer, winter, rainy, and autumn during 2013 in one of the developing cities of northern India. The concentration of PAHs was measured at ten different locations (at 1, 2, and 3 m) from roadside soil. Recovery range was 30% and 80% with lower value corresponding to the lower molecular weight PAHs compound. Identification and quantification of PAHs was done by GC-FID. Average PAHs concentration (city average) was found to be 16.53, 4.04, 17.49, and 7.82 μg g−1, during summer, winter, autumn, and the rainy seasons, respectively. Average concentration of low and high carcinogenic PAHs during summer, winter, autumn, and rainy was 5.1 and 31.29, 2.1 and 6.4, 4.74 and 35.08, 3.97 and 12.77μg g−1, respectively. The average ratio of low and high carcinogenic PAHs was found to be 1:6, 1:3, 1:7.6, and 1:3.21 during summer, winter, autumn, and the rainy seasons at most intercepts. Dib(ah)A and B(a)P were the two individual PAHs found in highest concentration during summer, winter, and the rainy seasons, whereas B(a)P and IP were individual PAHs found in highest concentration during autumn. It was also analyzed that high carcinogenic PAHs concentration was quite higher (around 85%) in comparison to low carcinogenic PAHs (around 15%) at most intercepts. This article also deals with the behavior of PAHs at places of average/high population and traffic density intercepts. Five-ringed PAHs were in highest concentration at all intercepts and seasons. Two-tailed T test was applied for authenticity of the data and results. Toxic equivalency factor of B(a)P and Dib(ah)A was maximum as compared to other PAHs.

Toxic equivalency factor and statically analysis of carcinogenic micro air pollutants in urban soil at the northern part of India

The objective of the present study was to ascertain contamination levels of soils with micro air pollutants (MAPs), toxic equivalency factor and statically analysis of carcinogenic MAPs, distribution behavior and human exposure during summer and winter round the year. The average MAP concentration were found to be 18.99 and 4.94, whereas concentration of 16 individual MAPs were found to vary between 0.03 and 199.23 μg/g and 0.009 and 29.4 μg/g, during summer and winter seasons, respectively. The average concentration of carcinogenic and low carcinogenic MAPs during summer and winter were found to be 5.2 and 31.20, 2.2 and 6.5, 4.75 respectively. The average ratio of low carcinogenic to carcinogenic MAPs was found to be 1:6 during summer and 1:3 during winter at most of the intercepts. It was also observed that five-ringed MAPs were in higher concentration than two-ringed MAPs in almost two seasons at most of the intercepts. Dib(a,h)A and B(a)P were the two individual polyaromatic hydrocarbons found in the highest concentration at almost all the intercepts in two seasons. It was also observed that the total potential carcinogenic MAP concentration was quite high (86%) in comparison to low carcinogenic MAPs (16%) at most of the intercepts within the city round the year.

Modification of gum ghatti via grafting with acrylamide and analysis of its flocculation, adsorption, and biodegradation properties

In this work, an environmentally friendly gum ghatti-crosslinked-polyacrylamide (Gg-cl-PAAM) hydrogel was synthesized from gum ghatti (Gg) and acrylamide (AAM) using a microwave-assisted grafting technique, and tested for use in water purification applications as an adsorbent and flocculent. The Gg-cl-PAAM was characterized using SEM, FTIR, and TGA, and displayed pH responsive swelling behavior, with maximum swelling (2117%) observed in solution with neutral pH. The flocculation characteristics of Gg-cl-PAAM were tested in clay solutions as a function of pH, temperature, and the polymer mass loading, showing that the best performance is obtained at neutral pH at 40°C. The adsorption capacities of Gg-cl-PAAM for the removal different dyes such as brilliant green (BG), rhodamine B (RhB), congo red (CR), and methyl orange (MO) were tested, revealing that the adsorption of all dyes followed the Langmuir isotherm model, with qm values of 523.62mgg-1 for BG, 421.60mgg-1 for RhB, 179.09mgg-1 for CR, and 173.69mgg-1 for MO. Finally, the environmentally friendly nature of Gg-cl-PAAM was examined using the soil-burial composting method, which demonstrated 93% degradation of the Gg-cl-PAAM hydrogel within 60days.