Isoprene Emission from the Forest of Haryana State

Tropical and sub tropical regions are regarded as dominant source of biogenic volatile organic compounds emission (BVOC). However, measurement studies from these regions are limited and largely confined to South Africa and Amazonia. Consequently, global BVOC estimates are mainly based on modeling studies. Moreover, BVOC emission estimate is altogether lacking for any region of the Indian sub continent. This study attempts to estimate isoprene emission capacity of forest of Haryana state. Individual plant species isoprene emission capacity is found to vary from below detection limit (BDL) to 12.01 mg Cm^{− 2} h^{− 1}. Maximum emission capacity (12.01 mg Cm^{− 2} h^{− 1}) is noticed in case of Dalbergia sissoo. The area average isoprene emission capacity for the Haryana forest is found to be 19.98 mg Cm^{− 2} h^{− 1}, which is significantly (2.4 times) higher than the reported isoprene emission value of 8.2 mg Cm^{− 2} h^{− 1} for the Kalahari woodland of Africa.     

Holistic approach for quantification and identification of pollutant sources of a river basin by analyzing the open drains using an advanced multivariate clustering

Global scarcity of freshwater has been gearing towards an unsustainable river basin management and corresponding services to the humans. It needs a holistic approach, which exclusively focuses on effective river water quality monitoring and quantification and identification of pollutant sources, in order to address the issue of sustainability. These days, rivers are heavily contaminated due to the presence of organic and metallic pollutants released from several anthropogenic sources, such as industrial effluents, domestic sewage, and agricultural runoff. It is astonishing to note that even in many developing countries, most of these contaminants are carried through open drains, which enter river premises without proper treatment. Such practice not only devastates riverine ecosystem but also gives rise to deadly diseases, such as minimata and cancer in humans. Considering these issues, the present study develops a novel approach towards simultaneous identification of major sources of pollution in the rivers, along with critical pollutants and locations using an advanced hierarchical cluster and multivariate statistical analysis. A systematic approach has been developed by agglomerating both R-mode and Q-mode analysis, which develops monoplots, two-dimensional biplots, rotated component matrices, and dendrograms (using “SPSS” and “Analyse It” software) to reveal relationships among various quality parameters to identify the pollutant sources along with clustering of critical sampling sites and pollutants. A case study of the Ganges River Basin of India has been considered to demonstrate the efficacy and usefulness of the model by analyzing 85 open drains. Both organic and metallic pollutants are analyzed simultaneously as well as separately to get a holistic understanding of all the relationships and to broaden the perspective of water characterization. Results provide a comprehensive guidance to the policy makers and water managers to optimize corrective efforts, minimize further damage, and improve the water quality condition to ensure sustainable development of the river basin.     

Effects of silver nanoparticles on stress biomarkers of Channa striatus: immuno-protective or toxic?

Environmental Science and Pollution Research - Nanotechnology is a novel arena with promising applications in the field of medicine, industry, and agriculture including fisheries....     

Oxidative and cellular stress as bioindicators for metal contamination in freshwater mollusk Lamellidens marginalis

Environmental Science and Pollution Research - The concentrations of 14 metals, namely, chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), selenium (Se), arsenic (As),...     

Validation and Applications of a Chemical Equilibrium Model for Struvite Precipitation

Removal of nutrients like nitrogen and phosphorus from wastewater can be accomplished by precipitating these as the mineral struvite (NH₄MgPO₄. 6H₂O). Predicting struvite precipitation potential, yield, and purity is important for designers and operators of reactors for struvite precipitation. In this paper, a mathematical model of this precipitation process is developed using physicochemical equilibrium expressions, mass balance equations for nitrogen, phosphorous and magnesium, and charge balance. The model was simulated to explicitly solve for equilibrium concentrations of eighteen species that included dissolved (three), ionic (ten), and solid (five) species for a given set of initial concentrations of ammonium–nitrogen, magnesium and phosphate–phosphorus, and pH. The model simulations were validated against literature experimental data, which used synthetic as well as actual wastewater, and data from our experiments. The model satisfactorily predicted most data. Struvite fraction in the precipitate ranged from 27% to 100%. The purity of struvite in the precipitate and the pH that maximizes struvite fraction was dependent on the initial concentrations of ammonium, magnesium, and phosphate. Optimum pH and struvite fraction was, respectively, 8.5 and 29.3% for an equimolar mixture of ammonia, magnesium, and phosphate and 9.8 and 98.3% for 10:1.7:3.4 mM ratio. Struvite fraction in the precipitate increased as magnesium became limiting or as ammonia to phosphate ratio increased and magnesium to phosphate ratio decreased. Since the struvite component is only a fraction of the total solids, it is erroneous to report the total precipitate produced as being struvite as is conventionally done.     

Tree seedling establishment in dry tropics: an urgent need of interaction studies

The current anthropogenic activities and climate change are increasingly becoming a growing global concern for dry tropical forests. Worldwide, these ecologically important forests have degraded considerably since the past few decades due to such factors. These factors have harmful consequences on the vegetation structure and diversity especially tree seedlings, which may further aggravate climate change. Generally, the vegetation recovery is very slow and unpredictable in the dry tropics due to complex interaction among tree seedling, site (particularly, soil) and climatic conditions. We inculcated that a better understanding of the behavior of individuals of different tree species at seedling stage in dry forests is of immense importance. It is increasingly being recognized for explaining and managing the future composition of plant communities under changing environmental conditions. In this regard, the multi-factorial interaction studies under various resource–disturbance combinations are needed in dry tropical ecosystems to understand the: (1) impact of relative variability in resources and disturbances on the responses of tree seedlings of native species and (2) how the later relates to distinct functional and life history traits of the individual tree species. Most importantly, such studies would improve our limited understanding of how variation (natural and man-made) in nutrient availability, under the influence of other local environmental factors (such as water, light, grass competition, herbivory, fire, allelopathy and enhanced CO₂ conditions), would affect the dynamics of dry tropical forest community. It may help in the proper management of these forests. Moreover, it may prove helpful in the current climate change scenario, as change in forest community dynamics may have consequences on soil C sequestration and CO₂ efflux at global scale.     

Framework for environmental impact analysis—with special reference to India

This article reviews the present status of environmental impact analysis (EIA) with special reference to India. In India, legislation already exists that makes EIA mandatory for every new project proposal. Critically analyzing the shortcomings of the present EIA practices, this article proposes a new framework to conduct an EIA, emphasizing that it should be part of the environmental management of the area or region. Among other things, we suggest the following important points: (1) that a comprehensive database of the region be developed for use for conducting an EIA; (2) that emission standards for the proposed industry be set and the existing standards for old industries be reviewed; (3) that a directory of experts be developed; and (4) that the Department of Environment should take responsibility for conducting EIA studies by forming a study team and an evaluation team for every EIA study with members drawn from the directory of experts.     

Changes in morphology and growth of the mudskipper (Periophthalmus argentilineatus) associated with coastal pollution

In this paper a comparison is made between the growth and morphology of barred mudskippers (Periophthalmus argentilineatus) from six mangrove forests along the coast of Tanzania. The fish populations from unpolluted sites consisted of different size classes, whereas only small sized fish were present in the polluted Mtoni mangroves. Age estimation based on the examination of otoliths revealed that the mudskippers followed similar growth patterns in all sites with limited pollution. However, the age estimates from the polluted Mtoni site revealed an abnormal growth pattern. The occurrence of unilateral anophthalmia in the Mtoni mudskippers suggested that these fish were affected by pollutants during early development. The study showed that the presence of urban and industrial wastes from Dar es Salaam city, as indicated by isotopic enrichment, correlated with abnormal growth and developmental effects in mudskippers. We hypothesize that pollution might also affect fish species that use the mangroves as a temporary habitat.     

Impact of osmotic stress on seed germination and seedling growth in black gram (Phaseolus mungo)

An experiment was conducted to see the impact of osmotic stress as it is one of the main cause in various soil and water disorders in agricultural field crops, speciallythe seed germination and seedling growth. The osmotic stress was generated using PEG-6000 and the seed germination, seedling growth were evaluated including the status of pigments i.e. chlorophyll (a, b and total), total carotenoids, pheophytin (a, b and total) and different enzymes like amylase, peroxidase, catalase and superoxide dismutase. The various osmotic potentials generated (-2, -5 and -10 bars) showed significant decrease in germination percentage as at the osmotic potential of -10 bars it was observed 70 in comparison to 90% of control. All the seedling growth parameter also showed inhibition with increase in osmotic potential. Increase in osmotic stress decreased Chlorophyll 'a', while Chlorophyll 'b' was increased in -5 bars while total chlorophyll showed decrease in -5 bars osmotic potential. Total carotenoids and pheophytin (a, b and total) were highly increased in -5 bars and decreased in -10 bars osmotic concentration. Enzymatic activity was found to be decreased in amylase while peroixidase, catalase and SOD were increased at different osmotic gradients in comparison to control. The data observed in the experiment can be helpful to assess the impact of any kind of osmotic stress on plant growth and development in crops.     

Analysis of urban heat island effect in Visakhapatnam,India, using multi-temporal satellite imagery: causes and possible remedies

The thermal data sets of Landsat for the years 2014 and 2019 are used to assess the transients of land surface temperature (LST) in Visakhapatnam, India. The variation in estimated temperature fields is compared with the land use pattern to validate temperature with reference to land use land cover (LULC). During the considered period, the built-up area in the study region increased by 63%. The aerial extent of water bodies has come down by 12.5%, and there is a significant drop in vegetation cover. The LST of the regions with the densely built-up area is high compared to the other types of land use. A mean rise of 4.8 °C in the LST has been noticed over the study area during this period. Few monitoring points representing rural areas within the proximity of the study region have been established, and the LST is monitored explicitly. As a result, it has been observed that the temperature in rural areas is relatively lower than the city region, which confirms the urban heat island effect. A micro-level study has been conducted by dividing the study area into four zones as per administrative boundaries. Statistical analysis using the zonal attributes affirms a positive correlation of 0.55 between LST and the built-up area. In contrast, a negative correlation of 0.52 between LST and vegetation cover is observed. The LULC results are validated using Google Earth Images captured at a finer resolution. Being selected as one of the cities under the smart city mission by the Urban Development Ministry of Govt. of India, it is expected that the land use pattern in Visakhapatnam will change drastically in the coming years. The findings of this study foster the relationship between LST and LULC, and the conclusions thus drawn would help planners for the sustainable development of Visakhapatnam.