Studies on Adsorptive Desulfurization by Activated Carbon

Sulfur removal using adsorption requires a proper process parametric study to determine its optimal performance characteristics. In this study, response surface methodology was employed for sulfur removal from model oil (dibenzothiophene; DBT dissolved in iso‐octane) using commercial activated carbon (CAC) as an adsorbent. Experiments were carried out as per central composite design with four input parameters such as initial concentration (C₀: 100–900 mg/L), adsorbent dosage (m: 2–22 g/L), time of adsorption (t: 15–735 min), and temperature (T: 10–50°C). Regression analysis showed good fit of the experimental data to the second‐order polynomial model with coefficient of determination R²‐value of 0.9390 and Fisher F‐value of 16.5. The highest removal of sulfur by CAC was obtained with m = 20 g/L, t = 6 h, and T = 30°C.     

Time vs. Money: A Quantitative Evaluation of Monitoring Frequency vs. Monitoring Duration

The National Research Council has estimated that over 126,000 contaminated groundwater sites are unlikely to achieve low ug/L clean‐up goals in the foreseeable future. At these sites, cost‐effective, long‐term monitoring schemes are needed in order to understand the long‐term changes in contaminant concentrations. Current monitoring optimization schemes rely on site‐specific evaluations to optimize groundwater monitoring frequency. However, when using linear regression to estimate the long‐term zero‐order or first‐order contaminant attenuation rate, the effect of monitoring frequency and monitoring duration on the accuracy and confidence for the estimated attenuation rate is not site‐specific. For a fixed number of monitoring events, doubling the time between monitoring events (e.g., changing from quarterly monitoring to semi‐annual monitoring) will double the accuracy of estimated attenuation rate. For a fixed monitoring frequency (e.g., semi‐annual monitoring), increasing the number of monitoring events by 60% will double the accuracy of the estimated attenuation rate. Combining these two factors, doubling the time between monitoring events (e.g., quarterly monitoring to semi‐annual monitoring) while decreasing the total number of monitoring events by 38% will result in no change in the accuracy of the estimated attenuation rate. However, the time required to collect this dataset will increase by 25%. Understanding that the trade‐off between monitoring frequency and monitoring duration is not site‐specific should simplify the process of optimizing groundwater monitoring frequency at contaminated groundwater sites.     

Vascular plants distribution in relation to topography and environmental variables in alpine zone of Kedarnath Wild Life Sanctuary,West Himalaya

The present study was carried out in Tungnath alpine meadows of Kedarnath Wild Life Sanctuary, Western Himalaya from subalpine to upper alpine zone. A total of four summits were selected along an altitudinal gradient and sampled for detailed vegetation analysis using multi summit approach as per Global observation research initiative in alpine environments(GLORIA). Species richness, diversity, and evenness among four summits as well as the interaction between environmental variables with plant communities were assessed. Monthly mean soil temperature was calculated using data retrieved from geo-precision temperature logger in order to identify the trend of soil temperature among different season and altitudinal gradient and its implications to plant communities. Soil samples were analyzed fromeach summit by collecting randomized composite soil samples. The indirect non-metric multidimensional scaling(NMDS) and direct canonical correspondence analysis(CCA) tools of ordination techniques to determine the linkage between plant species from various sample summits and biotic/abiotic environmental gradients were used in the present study. The results of the study demonstrated increase in species richness as soil temperature increases, the ecotone representing summits were found most warm summits followed by highest species richness. Annual soil temperature increased by 1.43°C at timberline ecotone. Whereas, at upper alpine zone the soil temperature increased by 0.810 C from year 2015 to 2016. S?rensen's similarity index was found to be increased between subalpine and upper alpine zone with increase in the presence of subalpine plant species at upper alpine zone. Both the ordination tools separate the subalpine summit and their respective vegetation from summits representingtimberline ecotone and upper alpine zone. Soil p H, altitude, soil cation exchange capacity were found as the key abiotic drivers for distribution of plant species.     

Estimating boundary currents from satellite altimetry: A case study for the east coast of India

We present a methodology to derive surface geostrophic current from a newly released altimetric sea-level data set. TOPEX/Poseidon data were first completely reprocessed from Geophysical Data Records using new algorithms accommodating marginal seas and coastal conditions. The methodology applied to the reprocessed data essentially consists of a smoothing of the raw along-track coastal altimetric data at scales at which the geostrophic equilibrium holds. This was reduced to a computational procedure using a set of objective criteria. We have applied the method to the East India Coastal Current (EICC) at the western boundary of the Bay of Bengal. This paper first examines the quality of the new data set, which compares well with tide-gauge data; the current we derived is consistent with independent estimates. Our methodology reveals the full spectrum of the along-shore current, ranging from intra-seasonal to inter-annual time scales, from the deep ocean to the shelf-break area where the EICC exists. The algorithm can be applied to any coastal region where an order of the Rossby radius can be defined, and it therefore opens up bright prospects for mapping the variability of other boundary-current systems in the world ocean from altimetry.     

Community responses to mountain tourism: A case in Bhyundar Valley, Indian Himalaya

Tourism industry has become an important part of Indian economy, and tourism development has been, however, concentrated to a few areas. Accumulation of tourism activities has reached the critical stage in most of the tourism centers, which pose serious threats to the natural environment. The Bhyundar Valley of Nanda Devi Biosphere Reserve （NDBR） in Uttarakhand State of the Indian Himalaya is a burning example of such problems. Land use/cover changes, deforestation and accumulation of garbage are some of the negative impacts of unregulated tourism in the valley. Unsustainable activities of tourists and villagers in the valley make such problems very severe. To deal with the ongoing problems and ensure community involvement in tourism management and environmental conservation, the Biosphere Reserve Authority introduced ecotourism in the form of Eco Development Committees （EDCs） in the Bhyundar Valley. Study reveals that many problems associated with tourism have been minimized to some extent with the help of EDCs but few are still prevailing in valley. However, the existing attempts to conserve the valley from the negative effects of tourism are inadequate and modifications are needed in the current initiatives.     

Anomalous absorption in thioformaldehyde

Absorption against the Cosmic Microwave Background (CMB), called the anomalous absorption, is an unusual phenomenon. The transition 1₁₁–1₁₀ at 4.829 GHz of formaldehyde (H₂CO) was the first one showing the anomalous absorption. The c-C₃H₂ is the second molecule showing anomalous absorption through its transition 2₂₀–2₁₁ at 21.590 GHz. Structure of thioformaldehyde (H₂CS) is very similar to that of the H₂CO. Therefore, we have investigated about the physical conditions under which the transition 1₁₁– 1₁₀ at 1.0465 GHz of H₂CS would be found in anomalous absorption in cool cosmic objects. As in case of H₂CO, the anomalous absorption of 1₁₁–1₁₀ of H₂CS is found sensitive to the relative collisional rates and it requires that the collisional rate for the transition 1₁₁–2₁₁ must be smaller than that for the transition 1₁₀–2₁₂.     

Chemical composition of rain water and influence of airmass trajectories at a rural site in an ecological sensitive area of Western Ghats (India)

Samples of rain water were collected during monsoon season (June to September) of 2006 and 2007 at Hudegadde, a rural site located in an ecological sensitive area of Western Ghats. The collected samples were analyzed for pH, conductivity and major ions. At this site, rainwater pH varied from 4.20 to 7.39 with 5.65 as volume weighed mean. The observed mean was slightly lower than the average pH reported at most of the Indian continental sites. Monthly variation showed that average pH of rain water was the lowest during September (end of monsoon) and the highest during July (peak of monsoon). Overall, marine sources had dominating influence at this site. However, significant influence of anthropogenic and crustal sources from local as well as inter-continental regions was also noticed. As compared to NO₃⁻, higher concentration of SO₄²⁻ was noticed which might be due to contribution from industrial activities responsible for SO₂ emission. At this site, influence of five types of airmass trajectories was noticed i.e. i) C.I.O. (Central part of Indian Ocean)-when air masses blown from Maldives and nearby region of central Indian ocean. These airmasses had higher concentrations of nss Ca²⁺ which did not show any adverse impact on the pH; ii) N.W.I.O.(North-West Indian Ocean)-when airmasses travelled from oceanic region close to north-east Africa. These airmassses had higher concentrations of nss sulphate and nitrate and gave rise to acid rain; iii) S.W.I.O. (South -West Indian Ocean)- when airmasses came from southern part of Indian ocean (close to Mauritius). During these airmasses, rain water samples had almost equal ratio of nss SO₄²⁻ and nss Ca²⁺ similar to N.W.I.O but very low NO₃⁻ ; iv) Gulf-when airmasses were observed coming from Gulf region. Although these airmasses contributed only 2% of the total number of samples but carried high amount of nss SO₄²⁻ which gave rise to acid rain. The second lowest pH was observed during these airmasses which might be due to very high nssSO₄²⁻/nssCa²⁺ ratios; v) N.W.I.O. + S.W.I.C. (North-West Indian Ocean+South-West Indian Continental)- when airmasses originated from north-west Indian Ocean travelling towards south continental part of India and then arriving to the site. During these airmasses, samples showed typical influence of urban activities having high concentrations of nss SO₄²⁻ and NO₃⁻ leading to the lowest pH of rain water.     

Traditional agrodiversity management: A case study of central himalayan village ecosystem

Environmental, biological, socio-cultural and economic status variation existing in the Central Himalaya have led to the evolution of diverse and unique traditional agroecosystems, crop species and livestock, which facilitate the traditional mountain farming societies to sustain themselves. Indigenous agroecosystems are highly site specific and differ from place to place, as they have evolved along divergent lines. For maintenance of traditional agrodiversity management the farmers of the Central Himalaya have evolved various types of crop rotations in consonance with the varied environmental conditions and agronomic requirements. In irrigated flat lands two crops are harvested in a year with negligible fallow period but in rainfed conditions if a cropping sequence is presumed to be starting after winter fallow phase then four major cropping seasons can be identified namely first kharif season (first crop season), first rabi season (second crop season), second kharif season (third crop season) and second rabi season (fourth crop season). Highest crop diversity is present in kharif season in comparison to rabi season. Traditionally the fields are left fallow after harvest of the second kharif season crop. Important characteristics of agrodiversity management are the use of bullocks for draught power, human energy as labour, crop residues as animal feed and animal waste mixed with forest litter as organic input to restore soil fertility levels. Women provide most of the human labour except for ploughing and threshing grain. The present study deals with assessment of traditional agrodiversity management such as (i) crop diversity, (ii) realized yield under the traditional practices and (iii) assess the differences of realized yields under sole and mixed cropping systems. It indicated that crop rotation is an important feature of the Central Himalayan village ecosystem which helps to continue the diversity of species grown, as are the distribution of crops in the growing period and the management of soil fertility. The cropping diversity existing and the sequences practiced by the traditional farmers seems to have achieved high degree of specialization and thus even when the yield/biomass variations are about 60%, the farmers continue to practice these sequences as they need to maintain diversity and synergistic relationships of crops in addition to manage the food and labour requirements for crop husbandry. Crop yields are generally higher in irrigated systems than rainfed systems and in sole cropping as compared with mixed cropping. However, gross biological and economic yields are higher in mixed cropping than sole cropping systems.     

Heavy metals accumulation and ecophysiological effect on <Emphasis Type="Italic">Typha angustifolia</Emphasis> L. and <Emphasis Type="Italic">Cyperus esculentus</Emphasis> L. growing in distillery and tannery effluent polluted natural wetland site,Unnao, India

Distillery and tanneries are major source of heavy metals pollution in natural wetland sites in India. Present study deals with the heavy metals accumulation potential of Typha angustifolia and Cyperus esculentus growing in distillery and tannery effluent polluted wetland sites. The metal accumulation pattern in both macrophytes showed direct correlation with the metal content in sediments. Both macrophytes were observed root accumulator for Fe, Cr, Pb, Cu, and Cd. The metal accumulation in T. angustifolia was found higher than C. esculentus, and accumulation pattern was Fe > Mn > Cr > Zn > Pb > Cu > Ni > Cd. Simultaneously, chlorophyll, protein, cysteine, and ascorbic acid were also induced in T. angustifolia than C. esculentus. In addition, formation of multinucleolus in shoot of T. angustifolia was found an evidence of extra protein synthesis for tolerance under stress conditions. Hence, C. esculentus was observed potential but less tolerance for metals than T. angustifolia. Therefore, these wetland plants could be used for phytoremediation of heavy metals from wastewater.