Graphitic carbon nitride: a sustainable photocatalyst for organic pollutant degradation and antibacterial applications

Environmental Science and Pollution Research - Recently, graphitic carbon nitride (GCN) has been found to be of great interest in various sustainable applications. In this study, a simple...     

Coastal vulnerability assessment of the predicted sea level rise in the coastal zone of Krishna–Godavari delta region,Andhra Pradesh,east coast of India

The Krishna–Godavari coastal region in east coast of India has a 525.15-km-long coastline with low-lying tidal mudflats, beaches, mangrove swamp, creek and tidal channels. Recently, the increasing frequency of tropical cyclones in the Bay of Bengal, i.e., Phylin and Hudhud in Andhra Pradesh coast, and the devastating impact of the 2004 tsunami in India increased the significance in assessing the vulnerability of the coastal lands to inundation and flooding, notably in the context of climate change-induced sea level rise. This study aims to estimate a coastal vulnerability index (CVI) for the coastal subregion of Krishna–Godavari delta and to use the calculated index to evaluate the vulnerability of 14 coastal talukas of the Krishna–Godavari delta region. This CVI is calculated by using four geological and three physical parameters characterizing the vulnerability of the study coastal region, including regional slope, coastal elevation, geomorphology, significant wave height, mean tidal range and relative sea level using different conventional and remotely sensed data. Using a composite coastal vulnerability index based on the relative risk rating of those parameters, each of the 14 coastal talukas was classified according to their vulnerability. The CVI results depict that coasts are least and most vulnerable to inundation, flooding and erosion of coastal lands where geological parameters are more efficient to CVI. The paper alerts to decision makers and planners to mitigate the natural disaster and manage the coastal zone and is a primary step toward prioritizing coastal lands for climate change adaptation strategies in the view of increased storminess and projected sea level rise.     

Assessment of phenol infiltration resilience in soil media by HYDRUS-1D transport model for a waste discharge site

The movement of contaminants through soil imparts a variety of geo-environmental problem inclusive of lithospheric pollution. Near-surface aquifers are often vulnerable to contamination from surface source if overlying soil possesses poor resilience or contaminant attenuation capacity. The prediction of contaminant transport through soil is urged to protect groundwater from sources of pollutants. Using field simulation through column experiments and mathematical modeling like HYDRUS-1D, assessment of soil resilience and movement of contaminants through the subsurface to reach aquifers can be predicted. An outfall site of effluents of a coke oven plant comprising of alarming concentration of phenol (4–12.2 mg/L) have been considered for studying groundwater condition and quality, in situ soil characterization, and effluent characterization. Hydrogeological feature suggests the presence of near-surface aquifers at the effluent discharge site. Analysis of groundwater of nearby locality reveals the phenol concentration (0.11–0.75 mg/L) exceeded the prescribed limit of WHO specification (0.002 mg/L). The in situ soil, used in column experiment, possess higher saturated hydraulic conductivity (K _S ?=?5.25?×?10^?4 cm/s). The soil containing 47 % silt, 11 % clay, and 1.54 % organic carbon content was found to be a poor absorber of phenol (24 mg/kg). The linear phenol adsorption isotherm model showed the best fit (R ²?=?0.977, RMSE?=?1.057) to the test results. Column experiments revealed that the phenol removal percent and the length of the mass transfer zone increased with increasing bed heights. The overall phenol adsorption efficiency was found to be 42–49 %. Breakthrough curves (BTCs) predicted by HYDRUS-1D model appears to be close fitting with the BTCs derived from the column experiments. The phenol BTC predicted by the HYDRUS-1D model for 1.2 m depth subsurface soil, i.e., up to the depth of groundwater in the study area, showed that the exhaustion point was reached within 12 days of elapsed time. This clearly demonstrated poor attenuation capacity of the soil to retard migration of phenol to the groundwater from the surface outfall site. Suitable liner, based on these data, may be designed to inhibit subsurface transport of phenol and thereby to protect precious groundwater from contamination.     

Heavy Metal Accumulation in Lichens from the Hetauda Industrial Area Narayani Zone Makwanpur District, Nepal

Lichen samples collected in and around Hetauda Industrial area,(HIA) Narayani zone, Makwanpur district, Nepal, were analyzedfor Cr, Ni, Pb, Zn, Ca, Mn, Fe, Si, and Al. The samples fromthe location inside the industrial area have higher levels ofmetal than the outside areas. Pyxine meissnerina growinginside the industrial area accumulated higher levels of all themetals analyzed.     

Fire Management,Managed Relocation,and Land Conservation Options for Long‐Lived Obligate Seeding Plants under Global Changes in Climate,Urbanization, and Fire Regime

Most species face multiple anthropogenic disruptions. Few studies have quantified the cumulative influence of multiple threats on species of conservation concern, and far fewer have quantified the potential relative value of multiple conservation interventions in light of these threats. We linked spatial distribution and population viability models to explore conservation interventions under projected climate change, urbanization, and changes in fire regime on a long‐lived obligate seeding plant species sensitive to high fire frequencies, a dominant plant functional type in many fire‐prone ecosystems, including the biodiversity hotspots of Mediterranean‐type ecosystems. First, we investigated the relative risk of population decline for plant populations in landscapes with and without land protection under an existing habitat conservation plan. Second, we modeled the effectiveness of relocating both seedlings and seeds from a large patch with predicted declines in habitat area to 2 unoccupied recipient patches with increasing habitat area under 2 projected climate change scenarios. Finally, we modeled 8 fire return intervals (FRIs) approximating the outcomes of different management strategies that effectively control fire frequency. Invariably, long‐lived obligate seeding populations remained viable only when FRIs were maintained at or above a minimum level. Land conservation and seedling relocation efforts lessened the impact of climate change and land‐use change on obligate seeding populations to differing degrees depending on the climate change scenario, but neither of these efforts was as generally effective as frequent translocation of seeds. While none of the modeled strategies fully compensated for the effects of land‐use and climate change, an integrative approach managing multiple threats may diminish population declines for species in complex landscapes. Conservation plans designed to mitigate the impacts of a single threat are likely to fail if additional threats are ignored. Manejo de Incendios, Reubicación Administrada y Opciones de Conservación de Suelo para Plantas de Vida Larga con Sembrado Obligado bajo los Cambios Globales en el Clima, la Urbanización y el Régimen de Incendios     

An experimental study to evaluate musculoskeletal disorders and postural stress of female craftworkers adopting different sitting postures

This study aimed to evaluate musculoskeletal disorders (MSDs) and postural stress among female craftworkers. The study was carried out on 75 adult female craftworkers in different districts of West Bengal. The prevalence of MSDs, body part discomfort (BPD) rating and body joint angles of the workers were evaluated with standard methods. Electromyography (EMG) of the shoulder and back muscles was recorded with the BIOPAC system. The prevalence of MSDs, BPD rating and deviation of joint angle were comparatively lower in the case of sitting on the floor with folded legs than squatting and sitting on the floor with stretched legs postures. The EMG and rms values of the shoulder and back muscles were comparatively lower in this posture. Therefore, it was concluded that sitting on the floor with folded legs was less hazardous and it imposed less postural stress in comparison to other sitting postures.     

Impact of diesel oil effluent in the mucosal surface of the alimentary canal of Oreochromis nilotica (Linnaeus): a scanning electron microscopic study

Adverse effects of diesel oil on microanatomical structure of the alimentary canal of O. nilotica were studied using SEM observations. The study revealed irregular arrangement of the stratified epithelial cells along with fragmentation of the normal concentric pattem of microridges of the same cells in buccopharynx and oesophagus. The excessive secretion of mucus of buccopharynx and oesophagus were the salient changes caused by diesel oil pollution. The destruction and degeneration of the mucosal folds of stomach and intestine along with their epithelial cells exhibited a concrete hyperactivity resulting in abundant' secretion of mucus over the microridges of the epithelial cells. In the intestinal region the columnar epithelial cells showed tumefaction and microvilli of the plasma membrane of epithelial cells get heavily damaged. Disarray of the microridges of epithelial cells, excessive secretions of mucus formation of even cell sheet were the most conspicuous changes in rectum. It was concluded that chronic exposure of diesel oil may hamper the absorption of the nutrients through alimentary canal resulting into ill-growth and production of the fish.     

Large-Eddy Simulations of the Atmospheric Boundary Layer Using a New Subgrid-Scale Model – I. Slightly unstable and neutral cases

Subgrid-scale (SGS) modeling is a long-standing problem and a critical component in the large-eddy simulation (LES) of atmospheric boundary layer. A variety of SGS models with different levels of sophistication have been proposed for different needs, such as Smagorinsky's (1963) eddy viscosity model, Mason and Thomson's (1992) stochastic backscattering model, and Sullivan et al.'s (1994) near surface model. A modified Smagorinsky SGS model has been used in the LES version of Terminal Area Simulation System (TASS-LES). It has successfully simulated the buoyancy-dominated, convective atmospheric boundary layer flows, while simulations of the shear-dominated, slightly unstable, neutral, and stably stratified boundary layer flows are not so good. For the later, we used a simpler version of Sullivan et al.'s subgrid-scale model in which turbulent kinetic energy equation is not included and the model is still the first-order closure. A momentum profile matching approach is adopted in the proposed model. A series of simulations for shear-dominated, slightly unstable and neutral boundary layers are performed using different subgrid-scale models and different grid resolutions. The results are compared with those of Sullivan et al. (1994) and with empirical similarity relations for the surface layer. The simulations with the new SGS model appear to be far more satisfactory than those with the modified Smagorinsky model.     

Appraisal of stormwater-induced runoff quality influenced by site-specific land use patterns in the south-eastern region of Bangladesh

Environmental Science and Pollution Research - Urban stormwater runoff is considered as one of the major contributors to nonpoint source that contributes to the pollution of all water resources in...