Biosorption kinetics of heavy metals by leaf biomass of Jatropha curcas in single and multi-metal system

Biosorption of Cu²⁺, Zn²⁺, and Cr⁶⁺ from aqueous solutions by leaf biomass of Jatropha curcas was investigated as a function of biomass concentration, initial metal ion concentration, contact time, and pH of the solution systematically. The aim of this study was to optimize biosorption process and find out a suitable kinetic model for the metal removal in single and multi-metal system. The experimental data were analyzed using two sorption kinetic models, viz., pseudo-first- and pseudo-second-order equations, to determine the best fit equation for the biosorption of metal ions Cu²⁺, Zn²⁺, and Cr⁶⁺ onto the leaf biomass of J. curcas in different metal systems. The experimental data fitted well the pseudo-second-order equation and provided the best correlation for the biosorption process. The findings of the present investigation revealed that J. curcas leaf biomass was an eco-friendly and cost-effective biosorbent for the removal of heavy metal ions from wastewater.     

Role of Bio-Energy Plantations for Carbon-Dioxide Mitigation with Special Reference to India

Fuelwood plays an important role in the rural economy of the developing countries of Asia and Africa. Optimizing energy fixation in forest trees through high density energy plantations (HDEP), gasification of wood, and conversion of forest tree biomass, are some of the potential areas whereby additional research and development input for efficient management of atmospheric carbon in our energy system can be incorporated. For example, the photosynthetic efficiency of forest trees is rarely above 0.5%, which on the basis of theoretical considerations can be increased by up to 6.6%. Thus there is an ample scope to improve the efficiency up to 1%, which amounts to doubling of the productivity of the forests. Recent policy changes and experiences with wood-based bio-energy programmes in several countries indicate that woodfuels may become increasingly attractive as industrial energy sources. Use of biodiesel and the formulation of a project for undertaking 13.4 million ha of Jatropha plantations in India highlight the seriousness with which the Government of India is promoting carbon neutral energy plantations. The cost of establishment of plantations primarily for fuel production and its conversion to energy are major deterrents in this pursuit. Some of the issues in developing countries, like low productivity on marginal lands, degraded forest lands, and unorganized units for biomass energy conversion, result in cost escalation as compared to other energy sources. This paper revisits the scope for raising energy plantations, a comparison of the direct and indirect mitigation potential uses of plantations as an adaptation strategy through reforestation and afforestation projects for climate change mitigation and socio-economic issues to make this venture feasible in developing countries.     

Cytotoxic effect of plant extract-based nanoparticles on cancerous cells: a review

Environmental Chemistry Letters - Cancer is one of the most fatal diseases causing deaths of millions of people worldwide. Since actual cancer treatments are rarely efficient and often toxic, there...     

Willow (Salix fragilis Linn.): A multipurpose tree species under pest attack in the cold desert of Lahaul valley, northwestern Himalaya, India

Salix fragilis is the most common willow species grown extensively under the indigenous agroforestry system in the cold desert of Lahaul valley located in the northwestern Himalayas, India. Presently, this tree is under severe pest attack, and other infections have made its survival in the area questionable. This deciduous multipurpose tree species provides vegetation cover to the barren landscape of Lahaul and is a significant contributor of fuel and fodder to the region. This study is a detailed profile of the plant in three villages within this region: Khoksar, Jahlma, and Hinsa. The willow provided 69.5%, 29%, and 42% of the total fuelwood requirements of Jahlma, Khoksar, and Hinsa respectively. A striking observation was that only 30.0 +/- 20.1% trees were healthy: 55.2 +/- 16.1% of the willows have dried up and 14.8 +/- 6.1% were in drying condition due to a combination of pest infestation and infection. To sustain this cultivation of willow under the existing agroforestry system in the region, we recommend that locally available wild species and other established varieties of willow growing in similar regions of the Himalayas be introduced on a trial basis.     

Predicting the distributional range shifts of Rhizocarpon geographicum (L.) DC. in Indian Himalayan Region under future climate scenarios

Environmental Science and Pollution Research - Himalaya, the highest mountain system in the world and house of important biodiversity hotspot, is sensitive to projected warming by climate change....     

Traditional agriculture in transition: a case of Har-ki Doon Valley (Govind Pashu Vihar Sanctuary and National Park) in Central Himalaya

Traditional crop diversity and landraces in agricultural land use in Himalaya have great significant for long-term sustainability of agroecosystems, together with conservation and management of the surrounding landscape. Traditional crop varieties and races, which evolved over time through trial and error, not only provide basic nutritional requirements, but also food security. Loss of crop biodiversity has taken place over recent years, principally and inadvertently related to changing lifestyle, growing demand for cash crops in regional markets and burgeoning apple farming, whose acreage has increased with a concomitant decline in area under traditional crops. For sustainable landscape development, on-farm conservation of traditional crop diversity is urgently needed. An empirical study was done to understand the causes and consequences of declines in crop biodiversity and production, effect of apple farming on traditional crops and changing lifestyles of traditional people.     

Landslides in the Garhwal Lesser Himalaya, UP, India

The Garhwal Lesser Himalaya is one of the most fascinating segments of the Himalayan arc and in many ways quite unique in its geomorphological features and geological setting. Although it has a mild and mature topography in comparison with the Central and Outer Himalayas, with its deeply dissected valleys it is more immature than other areas such as the Himachal and Kumaon Lesser Himalayas. Debris flows, rock falls and slow mass rock movements are frequent within this part of the Himalayas. The frequent landslides in the area are controlled by the trends of the rocks and slopes, the structural features and the rock lithologies. Correlating all these factors, this paper illustrates how the slopes on the ridges parallel to the Himalayan trend (i.e. WNW–ESE) are the most susceptible for the mass failure.     

Local level community forest management an effective tool in conserving forest biodiversity

Forest vegetation of a community managed forest (Van Panchayat) located between 1570–1700 m elevation was studied along four aspects. Quercus leucotrichophora was the dominant species on three of the four aspects. Across the aspects the total tree density ranged between 150 and 490 ind/ha, sapling density between 100 and 370 ind/ha, seedling density varied from 241 to 1090 ind/ha. The shrub density ranged from 166 to 690 ind/ha and herb density from 6000–17100 ind/ha. The total basal area of tree layer varied from 9.78 to 13.5 m²/ha showing that the forest is young. Species diversity value for tree layer varied from 0.14 to 1.69. Quercus leucotrichophora were regenerating well due to effective forest management by local communities. The higher proportion of seedlings of Quercus leucotrichophora indicating that the Van Panchayat are playing important role in conservation of oak forest of Himalaya.     

Distribution and Fractionation of Heavy Metals in Solid Waste from Selected Sites in the Industrial Belt of Delhi, India

Solid waste samples were collected from five small-scale industrial sites in the National Capital Territory (NCT) of Delhi. These industrial sites represent the regional spread of the industrial belt in the NCT of Delhi. Solid waste samples were digested using aqua-regia and HF in air tight teflon bombs for the quantitative analysis of heavy metals (Hg, Pb, Cd, Mn, Fe, Ni, Cu and Zn) by GBC model 902 atomic absorption spectrophotometer. Hg was analysed using hydrid generator attachment. Beside this sequential extraction was used to fractionate five heavy metals (Pb, Ni, Cd, Cu and Zn) into six operationally defined phases, viz. water soluble, exchangeable, carbonate-bound, Fe-Mn oxides, organic-bound and residual fractions to ascertain the relative mobility of these metals. The result obtained showed metal concentration to be in the range of Hg 0.42-2.3; Pb 23-530; Cd 014-224; Mn 494-19 964; Fe 35 684-233 119; Ni 192-1534; Cu 3065-10 144 and Zn 116-23 321 (all units in mg kg(-1)) in all the industrial areas studied. The fractionated toxic metals like Pb, Ni and Cd were observed to be in the range of 25-35, 15-50 and 40-50%, respectively, in mobile or bio-available fractions of solid waste. As this waste is often disposed-off by the roadsides, low lying areas, abandoned quarries or in landfill sites which are often not properly planned, thus posing potential risk to ground and surface water quality to millions of people living downstream.     

The impacts of tourism on the environment of Mussoorie, Garhwal Himalaya, India

Mussoorie, a hill resort in the Garhwal Himalaya reveals the changing trends and impacts of tourist activity on its environment. This study was carried out during 1993–1994 and it showed that while Mussoorie had a permanent residential population of 25400 during the winter months, in the peak tourist season of May and June the population exceeded 200000 per month. Because of this huge influx of tourists the demand for lodges/hotels and other related infra-structure and super-structure facilities and amenities in the area was enormous, and it imposed a great stress on the natural environment.The data collected showed that from 1958 to 1988 the number of tourists had increased gradually but that from 1989 tourism in the town escalated following the political disturbances in the Kashmir Valley. The main purpose of the tourism was recreation (80%). It was recorded that the greatest number (60%) of the tourists were middle aged, 53% of the tourists worked in professional services. The majority of the tourists preferred to use the indigenous hotels and about 96% of the tourists used a private vehicle rather than public transport.The installation of modern tourist related facilities and infra-structure has led to the aesthetic degradation of the landscape. Tourist facility development is often disorderly and scattered. To reduce the traffic to Mussoorie town it is suggested that some nearby places like Dhanolti and Park estate should be developed for tourism.