Solubilisation effect of spent wash on oxide-ores of manganese and iron

Samples of iron ore (haematite) and manganese ore (pyrolusite) of known compositions were equilibrated with aliquots of analysed sample of spent wash. The concentrations of iron(II), iron(III), complexed iron, manganese(II) ions and complexed Mn-ions were determined after increasing durations. One litre of the spent wash was found to extract out 141 mg of total iron and 161 mg of total manganese. In case of iron, the predominance was of iron(II) (92%), whereas in case of manganese it was of the complexed form (95%).     

Translocation of metals and its effects in the tomato plants grown on various amendments of tannery waste: evidence for involvement of antioxidants

A field experiment was conducted to study the effect of different amendments of tannery sludge on physiological and biochemical parameters of tomato plant (Lycopersicon esculentum L. Mill). The accumulation of metals (Cr, Fe) in different parts of tomato plants grown on tannery sludge amended soil increased in a concentration and duration-dependent manner. The accumulation of both the metals was found lowest in the fruits of the plant. The statistical analysis of the results showed an increase in chlorophyll and protein contents in lower sludge amendment ratio at all exposures followed by a decrease at highest (100%) sludge amendment ratio. Lipid peroxidation enhanced in both root and leaves of sludge grown plants of tomato at all the sludge amendments and exposure periods, which is evidenced by increased malondialdehyde content, however the maximum increase was found in the roots (43.63%) and leaves (56.66%) of the plant grown on 100% tannery sludge at 60 d, over respective controls. The level of antioxidants, cysteine, non-protein thiol and ascorbic acid increased in the sludge grown plants of tomato to cope up with stress induced by the excess amount of the heavy metals present in the tannery sludge. The maximum increase was found in cysteine content (75.53% in the leaves), non-protein thiol content (92.68% in the roots) and ascorbic acid content (29.66% in the roots) of the plant at 75% tannery sludge after 30 d. The tomato plants were found well adopted for minimizing damage induced by reactive oxygen species, when grown on tannery sludge amendments in the present study.     

Metal remediation potential of naturally occurring plants growing on barren fly ash dumps

The present study aimed to elucidate the remediation potential of visibly dominant, naturally growing plants obtained from an early colonized fly ash dump near a coal-based thermal power station. The vegetation comprised of grasses like Saccharum spontaneum L., Cynodon dactylon (L.) Pers., herbs such as Tephrosia purpurea (L.) Pers., Sida rhombifolia L., Dysphania ambrosioides (L.) Mosyakin & Clemants, Chromolaena odorata (L.) King & H.E. Robins along with tree saplings Butea monosperma (Lam.) Taub. The growth of the vegetation improved the N and P content of the ash. Average metal concentrations (mg kg^?1) in the ash samples and plants were in order Mn (345.1)?>?Zn (63.7)?>?Ni (29.3)?>?Cu (16.8)?>?Cr (9.9)?>?Pb (1.7)?>?Cd (0.41) and Cr (58.58)?>?Zn (52.74)?>?Mn (39.09)?>?Cu (10.71)?>?Ni (7.45)?>?Pb (5.52)?>?Cd (0.14), respectively. The plants showed fly ash dump phytostabilization potential and accumulated Cr (80.19–178.11 mg kg^?1) above maximum allowable concentrations for plant tissues. Positive correlations were also obtained for metal concentration in plant roots versus fly ash. Saccharum spontaneum showed highest biomass and is the most efficient plant which can be used for the restoration of ash dumps.

     

Using intra-flock association patterns to understand why birds participate in mixed-species foraging flocks in terrestrial habitats

Bird species are hypothesized to join mixed-species flocks (flocks hereon) either for direct foraging or anti-predation-related benefits. In this study, conducted in a tropical evergreen forest in the Western Ghats of India, we used intra-flock association patterns to generate a community-wide assessment of flocking benefits for different species. We assumed that individuals needed to be physically proximate to particular heterospecific individuals within flocks to obtain any direct foraging benefit (flushed prey, kleptoparasitism, copying foraging locations). Alternatively, for anti-predation benefits, physical proximity to particular heterospecifics is not required, i.e. just being in the flock vicinity can suffice. Therefore, we used choice of locations within flocks to infer whether individual species are obtaining direct foraging or anti-predation benefits. A small subset of the bird community (5/29 species), composed of all members of the sallying guild, showed non-random physical proximity to heterospecifics within flocks. All preferred associates were from non-sallying guilds, suggesting that the sallying species were likely obtaining direct foraging benefits either in the form of flushed or kleptoparasitized prey. The majority of the species (24/29) chose locations randomly with respect to heterospecifics within flocks and, thus, were likely obtaining antipredation benefits. In summary, our study indicates that direct foraging benefits are important for only a small proportion of species in flocks and that predation is likely to be the main driver of flocking for most participants. Our findings apart, our study provides methodological advances that might be useful in understanding asymmetric interactions in social groups of single and multiple species.     

Classification of floristic composition of mangrove forests using hyperspectral data: case study of Bhitarkanika National Park, India

The aim of the present work is to unveil the potential of some of the unexplored remote sensing techniques for mangrove studies. The paper deals with the classification of an Earth Observing–1 Hyperion image of the mangrove area of Bhitarkanika National Park, Odisha, India into mangrove floristic composition classes. Out of 196 calibrated bands of the image, 56 were found to be highly uncorrelated and contained maximum information; therefore, these 56 bands were used for classification. Amongst the three full–pixel classifiers tested in the investigation, Support Vector Machine produced the best results in terms of training pixel accuracy with overall precision of 96.85 %, in comparison to about 70–72.0 % for the other two classifiers. A total of five mangrove classes were obtained – pure or dominant class of Heritiera fomes, mixed class of H. fomes, mixed Excoecaria agallocha with Avicennia officinalis, mixed class of fringing Sonneratia apetala and class comprising of mangrove associates with salt resistant grasses. Post–classification field data also established the same. Pure or dominant classes of H. fomes occupied more than 50 % of the total mangrove vegetation in the forest blocks of the National Park. Spectral profile matching of image pixels with that of in–situ collected canopy reflectance profile revealed good match for H. fomes (pure or dominant stands). Red–edge index, which was a preferred criterion for matching was notably correlated in case of H. fomes and E. agallocha. The outcomes indicated the efficacy of hyperspectral canopy reflectance library for such kind of work. It is hoped that the methodology presented in this paper will prove to be useful and may be followed for producing mangrove floristic maps at finer levels.     

Assessment of urban air pollution and it's probable health impact

The present study deals with the quantitative effect of vehicular emission on ambient air quality during May 2006 in urban area of Lucknow city. In this study SPM, RSPM, SO2, NOx and 7 trace metals associated with RSPM were estimated at 10 representative locations in urban area and one village area for control. Beside this, air quality index (AQI), health effects of different metals and mortality were assessed. The 24 hr average concentration of SPM, RSPM, SO2 and NOx was found to be 382.3, 171.5, 24.3 and 33.8 microg m(-3) respectively in urban area and these concentrations were found to be significantly (p < 0.01) higher by 94.8, 134.8, 107.4 and 129.6% than control site respectively The 24 hr mean of SPM and RSPM at each location of urban area were found to be higher than prescribed limit of National Ambient Air Quality Standard (NAAQS) except SPM for industrial area. The 24 hr mean concentration of metals associated with RSPM was found to be higher than the control site by 52.3, 271.8, 408.9, 75.81, 62.7, 487.54 and 189.5% for Fe, Cu, Pb, Zn, Ni, Mn and Cr respectively. The inter correlation of metals Pb with Mn, Fe and Cr; Zn with Ni and Cr; Ni with Cr; Mn with Fe and Cu with Cr showed significant positive relation either at p < 0.05 or p < 0.01 level. Metals Pb, Mn and Cr (p < 0.01) and Cu (p < 0.05) showed significant positive correlation with RSPM. These results indicate that ambient air quality in the urban area is affected adversely due to emission and accumulation of SPM, RSPM, SO2, NOx and trace metals. These pollutants may pose detrimental effect on human health, as exposure of these are associated with cardiovascular and respiratory diseases, neurological impairments, increased risk of preterm birth and even mortality and morbidity.     

Resources and international climate change policy gridlock

Few other policy zones are as complex as the issue of climate change. If the more pessimistic projections of climate change doom are correct, then the failure to address the issue is likely to be catastrophic and irreversible. The Inter-governmental Panel on Climate Change has predicted the potential extinction of many species and that the existence of small-island and other vulnerable countries will be threatened if business-as-usual greenhouse gas emissions continue. Climate change is a transboundary problem and requires unprecedented levels of cooperation between states and serious and sustained responses from major emitters. However, the growing demand and consumption of natural resources for continued energy security and cornucopian economic growth have undermined the outcomes of international climate change negotiations. It is argued here that there is a strong connection between the major emitters’ positions at United Nations’ climate talks, their possessions, dependence and consumption of natural resources, and the continued undermining of international climate change policy for unsustainable growth. This paper assesses the resource politics of the US, China, India, Canada, Russia, and Saudi Arabia and their positions at climate talks to show the link between lack of climate change policy progress and the positions of these main players.     

Worldwide cases of water pollution by emerging contaminants: a review

Environmental Chemistry Letters - Water contamination by emerging contaminants is increasing in the context of rising urbanization, industrialization, and agriculture production. Emerging...     

Property-enhanced paraffin-based composite phase change material for thermal energy storage: a review

Environmental Science and Pollution Research - Research on phase change material (PCM) for thermal energy storage is playing a significant role in energy management industry. However, some hurdles...     

Evolution in mitigation approaches for petroleum oil-polluted environment: recent advances and future directions

Environmental Science and Pollution Research - Increasing petroleum consumption and a rise in incidental oil spillages have become global concerns owing to their aquatic and terrestrial toxicity....