Total Environment Research Themes最新文献

The present work was carried out to assess the elemental accumulation (Fe, Mn, Cu, Cd, Ni, Pb and Zn) in the selected species of coral skeletons from the Mandapam group of Islands, Gulf of Mannar Marine National Park. The coral skeleton samples were analysed for their metal content using the Inductively Coupled Plasma Atomic Emission Spectrometry (ICPAES), X-ray Diffractometer (XRD) and Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDS) techniques. The analyses suggest that the accumulated elements in the coral skeletons are largely derived from natural and riverine processes. The maximum concentration of Zn and Cu was noticed in Goniopora minor (38.79 and 15 µg/g) and Acropora valida (8.3 and 11.5 µg/g). The measured metal contents in the reef skeleton were compared with values obtained from the earlier work carried out around the world and found with low metal accumulation. The overall assessment of metal accumulation indicates that metal constituents are derived from natural sources followed by feeble anthropogenic stress. The present study is helpful to document the metal concentration of individual species and serves as baseline data for metal-related environmental issues.

The main objective of the present paper is to determine the groundwater quality in and around Suryapet district, Telangana, and also to define groundwater chemistry mechanisms. For this, groundwater samples from thirty locations were analyzed for physicochemical parameters such as pH, EC, TDS, TH, major cations, and anions. Most of the samples were beyond the World Health Organization (WHO, 2011) maximum permitted levels for drinking. Groundwater is alkaline in nature, very hard. The abundance of the cations and anions is Ca²⁺>Na⁺>Mg⁺>K⁺; Cl⁻>HCO₃⁻> CO₃²⁻>SO₄²⁻>NO₃⁻>F⁻ respectively. The major ion distribution is regulated by cation exchange and silicate weathering processes; Gibbs plots show that the evolution of groundwater geochemistry depends on the interaction of water–rock followed by the evapotranspiration mechanism. Cation-anion exchange and base-exchange reactions play a dominant role. Depending on the factor analysis results, four factors are contributing to 74 percent of groundwater contamination and spatial variation maps decipher nonionic and ionic concentration due to geogenic and anthropogenic activities. This study suggests that contaminated groundwater should be treated before being consumed by humans.

The coronavirus disease or COVID-19 pandemic continues imposing restrictions on the human population from full-scale normal/routine activities all over the world. This study primarily spotlights the consequences of the COVID-19-pandemic-lockdown on physicochemical parameters of water (samples) of the Karamana river system (KRS) during the pre-monsoons (or January) of 2021 and 2022, using the Weighted Arithmetic Index method and Geostatistical analysis (ArcMap 10.2). Even though the Karamana river supported the water needs of the people during the past several decades, the quality of water deteriorated due to the rising population and consequent anthropogenic activities. Hence, it is imperative to evaluate the water quality during the post-COVID-19 lockdowns and document the spatial distribution of parameters listed in the BIS (Bureau of Indian standard) IS10500, 2012. This was accomplished by establishing a water quality index (WQI), Geostatistical analysis, and weighted overlay analysis (WOA). The estimated WQI suggested that about 45.11km² (6.43%) area has declined from the excellent category of water quality between 2021 and 2022. Similarly, WOA results deciphered that the area under the poor category has drastically and negatively changed from 27.85 km² (4.0%) to 60.42 km² (8.6%) after revoking of lockdown restrictions. The lessons learned from syn-Covid-19, the spike or uptrend of the water quality compared to the past decades, offer ample scientific basis to policymakers, administrators, and environmentalists for restoration of river system health from huge anthropogenic stress.

Ghaghara river samples were analysed to determine their quality and fitness for household, agriculture, and industrial use. In Ghaghara River, the cations were present in order of Ca²⁺ > Mg²⁺ > Na^{+ >} K ^+, and anions were in order of HCO₃^– > SO₄²⁻ > Cl⁻ > NO₃^– > F⁻. Gibbs's diagram indicated that carbonate and silicate weathering significantly influence the Ghaghara River ion chemistry. Piper trilinear diagrams indicated that Ca²⁺+ Mg²⁺ exceeded the Na⁺+ K ⁺, and anions of weak acids dominated over the anions of strong acids, indicating Ca-HCO₃ type of water. Based on the WQI values, the water quality class varied from 'unsuitable for drinking' to 'excellent' quality, and the parameter of concern was pH and fluoride ion concentration as they exceeded their permissible limits in the post-monsoon season, thereby negatively affecting the WQI values to unsuitable category. The computed value of the agriculture indices, including the Sodium absorption ratio (SAR), Sodium percentage (Na %), Kelly ratio (KR), Permeability Index (PI) value, Magnesium absorption ratio (MAR), and Potential salinity (PS), indicated that water quality was suitable for agriculture use. The Langelier Saturation Index (LSI) values indicated that 39% of the collected samples were unsuitable due to scale formation problems. Ryznar Stability Index (RSI) values indicated that the water of the Ghaghara River is corrosive and unsuitable for industrial use.

Geochemical analyses of major oxides (SiO₂, Al₂O₃, Fe₂O₃, Na₂O, K₂O, CaO, MgO, P₂O₅ and TiO₂) were carried out on the Late Holocene core sediments in the Mullipallam Creek, Southeast coast of India to infer their texture, sediment classification and provenance for paleoweathering conditions. Based on their major oxides compositions, the sediments were classified as Fe-Shale. Bivariate plots of grain size parameters (mean against sorting) are distinguished between open and closed-basin conditions. Chemical Index of Alteration (C1-70.21; C2-69.02), Chemical Index of Weathering (C1-75.25; C2-74.68), Plagioclase Index of Alteration (C1-73.32; C2-72.44) indices and A-CN-K plot suggests moderate chemical weathering in the source area, which was favoured and accelerated under the existing humid conditions of the tropical climate. Al₂O₃ /TiO₂ ratio also proposes the intermediate to felsic source rocks and some of the sediments are derived from mafics. The provenance discrimination diagram explains that the plots appeared in mafic provenance fields indicating that they are derived from different environments.

Fourteen mine water samples were collected from mine water channels to assess the water quality for domestic and irrigation purposes. The pH of the mine water is moderately acidic to slightly basic. The major ion contents of the mine water suggest that the water is suitable for irrigation and domestic purposes. The calcium and magnesium concentration in the mine water may be derived from the dissolution of halites and dolomites. Whereas, the concentration of phosphate may be derived from agricultural practices and the application of phosphate fertilizers. Based on the Piper diagram, the major water types are mixed CaNaHCO₃, mixed CaMgCl followed by CaCl. The evaporation process is the main controlling factor that governs the water quality. Wilcox diagram of mine water shows the majority of the samples falling under the good to permissible and the permissible to doubtful category. The irrigation and domestic water quality standard calculation suggest that all the samples fall under the suitable category. However, most of the samples fall under the high salinity – low sodium hazard category. The comparative results suggest that the majority of the major ion concentration is similar to water data studied by various workers in this region.

The objective of the study is to analyse what and how researchers are covering sustainable low carbon recovery pathways in the post-COVID 19 scenario across various content categories. The unit or categories of content for thematic analysis taken under study includes a total of 121 content published within the year 2020–22. The study also assesses the focus and frames of research on sustainable low carbon recovery being conducted from 2020 to 2022 in order to gain a better understanding of the issues and best practises in global economies. For more valid results, the research design seeks novelty by concluding the qualitative and quantitative methodologies with statistical analysis of identified themes using thematic analysis. The data is analysed using Kruskal Wallis Test. The analysis shows that researchers are concerned about carbon emission and its impact on countries, sectors, industries, over the globe and are more inclined towards studying the impact of carbon emission, issues, and challenges posed in sustainable low carbon recovery pathways and measures. The studies also suggest the role of the public and policy in the recovery process with a focus on energy sector. The studies are primarily concerned with carbon emissions and green recovery measures for future sustainable development.

Cassava production and consumption in its raw or processed form have experienced a rise in recent times globally, with Nigeria being the major producer of cassava in the world. However, the increased consumption of this crop has resulted in an increase in its peels, which if not properly disposed of or recycled, would burden the environment. Previous studies have only been able to engage electrically-powered reactors for the thermochemical conversion of these peels, which is a challenge as these reactors cannot be used in regions with an insufficient supply of electricity. In this study, the authors utilized a top-lit updraft reactor with retort heating for the conversion of waste cassava peels into biochar. The reactor, which is relatively cheap, simple to use, and environmentally friendly and modified for biochar production, is biomass-powered. The carbonization process, which lasted for 160 min, obtained a peak reactor temperature of 338 ℃, and gave rise to a biochar yield of 55.13 %. FTIR analysis revealed that the cassava peel biochar consists of similar functional groups in relation to its precursor, but consists of more oxygenated functional groups. The BET surface area and BJH pore diameter of the biochar were obtained to be 319.784 m²/g and 2.447 nm, respectively. EDX analysis showed the biochar is majorly made up of carbon (56.93 %) and silver (22.97 %). SEM micrographs revealed that the biochar has a rough and porous surface. The DTA/TGA results showed that the carbonization process improved the thermal efficiency of the cassava peel material.

Mud and earthen plaster murals are frequently found in cave temples and have tremendous historical and artistic importance, they are unfortunately susceptible to salt deterioration from environmental humidity. NaCl and Na₂SO₄ are among the most common soluble salts that induce salt deterioration in this type of murals. It is still unidentified how the combination of NaCl-Na₂SO₄ and environmental humidity causes salt deterioration. As a result, the current contribution elucidated the mechanism by which salt deteriorates under the influence of humidity using the concepts of moisture sorption and crystal deliquescence and dissolution. The moisture sorption process of the NaCl-Na₂SO₄ salt particles and earthen plaster samples containing NaCl-Na₂SO₄ mixes were comprehensively examined using the moisture uptake curve method. Thermogravimetric analysis was utilized to investigate the moisture characteristics caused by short-range adsorption and condensation in earthen plaster. Finally, based on the findings from ultra-depth-of-field microscopy, the change of the crystalline NaCl-Na₂SO₄ mixtures during the deliquescence-crystallization process was discussed. In the process of absorbing moisture, mixed-salt particles proceeded through two stages: deliquescence, where the rate of moisture absorption was constant, and osmotic suction, where the rate of moisture absorption was decreasing. Salt in plaster has a similar moisture sorption process, and the majority of the moisture in plaster caused by short-range adsorption and condensation participated in salt dissolution. The ion transport mechanism of NaCl-Na₂SO₄ under the influence of water vapor has been investigated, and the NaCl-Na₂SO₄ mixture yielded more intense efflorescence than a single salt in the same environment and salt content in plaster.

The colloids serve as the medium of transport especially for the trace metals and radio nuclides and hence have attained significancein the recent times. Two bore wells were selected for the study representing hard rock formation (Anupram) and sedimentary formation (Kalpakkam). Samples were collected during northeast monsoon and south west monsoon. Colloidal fractions of 1.2 µm, 0.8 µm, 0.45 µm and 0.22 µm.sizes were extracted.The surface charge was determined by zeta potential and average particle size was determined by particle size analyses through dynamic light scattering. The morphological studies by scanning electron microscope (SEM) show that saccroidal texture in Anupram (Charnockite formation) and almost spherical structure in Kalpakkam due to sedimentary terrain condition (Clayey sand). The elongated octahedral texture proves that the predominance clay mineral is kaolinite. The mineralogical characterization studies reveal that the Muscovite, Chlorite, Illite and Kaolinite peaks in FTIR analysis. Sr concentration was observed to increase in the finer fractions in Anupuram and decreasing trend was observed in Kalpakkam but an irrespective value of Cs in colloidal fractions at Anupruam. The negative surface charges of particles indicate that the groundwater colloids present in the groundwater of this region tend to attach positive contaminants like Cs and Sr respectively.