This paper investigates analytically the effect of dissimilarity of mass flow rate [Formula: see text] and number of collectors (N) on exergo-enviro-economic parameters for solar still of single slope type integrated with N similar photovoltaic thermal flat plate collectors having series connection (NPVTFPC-SS) keeping water depth as 0.14 m. All four kinds of weather conditions for New Delhi have been taken for the computation of different parameters. All relevant equations obtained using energy balance equations for all components of the system have been fed to a computer code inscribed in MATLAB-2015a for computing different parameters. The computation of different relevant parameters has been performed for various values of [Formula: see text] and N while keeping water depth as constant to know the effect of variation of [Formula: see text] and N on exergo-enviro-economic parameters for NPVTFPC-SS. It has been concluded that the value of carbon credit earned, enviroeconomic and exegoeconomic parameters, and productivity diminishes with the enhancement in [Formula: see text] at given N. The optimum value of N for given value of [Formula: see text] has been found to be 10 from exergoeconomic parameter viewpoint and 6 from productivity viewpoint.

Accessibility to clean drinking water often remains a crucial task at times. Among other water pollutants, arsenic is considered a more lethal contaminant and has become a serious threat to human life globally. This review discussed the sources, chemistry, distribution, and toxicity of arsenic and various conventional technologies that are in option for its removal from the water system. Nowadays, biosorbents are considered the best option for arsenic-contaminated water treatment. We have mainly focused on the need and potential of biosorbents especially the role of chitosan-based composites for arsenic removal. The chitosan-based sorbents are economically more efficient in terms of their, low toxicity, cost-effectiveness, biodegradability, eco-friendly nature, and reusability. The role of various modification techniques, such as physical and chemical, has also been evaluated to improve the physicochemical properties of biosorbent. The importance of adsorption kinetic and isotherm models and the role of solution pH and pHPZC for arsenic uptake from the polluted water have also been investigated. Some other potential applications of chitosan-based biosorbents have also been discussed along with its sustainability aspect. Finally, some suggestions have been highlighted for further improvements in this field.

The Metropolitan Region of São Paulo (MRSP) faces an intense water crisis, which requires measures to guarantee water supply. However, it neglects urban water bodies, often using them as sewage receptors. To improve the quality of urban rivers, it is necessary to study and to mitigate the sources of pollutants. Thus, the objective of this study was to evaluate the Water Quality Index (WQI) of the Comprido stream, an urban freshwater ecosystem which flows into the Tamanduateí River and this to Tietê River, the most important river of São Paulo State, Brazil. Eight occasions over 4 months in 2017 of surface water were conducted at three sampling stations along the longitudinal axis of the stream. The following parameters were evaluated in triplicate: pH, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand (COD), temperature, apparent color, turbidity, total solids, total dissolved solids, total suspended solids, sedimentable solids, electrical conductivity (EC), ammonia nitrogen, total phosphorus, and coliforms. The water quality parameters and the WQI revealed an alarming scenario regarding the environmental and sanitary conditions of Comprido stream. COD (up to 1,000 mg L⁻¹) and EC (~ 500 µS cm⁻¹) presented very high values. The WQI was always between bad and very bad (20–40), which allows us to conclude that the waters of the Comprido stream are quite degraded. The pollution was associated with sewage discharges. The study points to the need to carry out the integrated management of urban micro-watersheds to preserve streams and, consequently, improve the quality of adjacent water bodies and the maintenance of ecosystem services to the population.

Remote sensing dynamic monitoring methods often benefit from a dense time series of observations. To enhance these time series, it is sometimes necessary to integrate data from multiple satellite systems. In particular, the Landsat and Sentinel series provide a rich source of data for Earth observations. National Aeronautics and Space Administration (NASA) scientists proposed a method that creates global fixed per-band transformation coefficients to reduce the reflectance difference between Landsat-8 and Sentinel-2 for the harmonized Landsat and Sentinel-2 (HLS) surface reflectance product. However, the coefficient has yet to be further validated in the target study area and the coefficient can only be used for Landsat-8 and Sentinel-2, and is not useful for other sensors. The purpose of this study is to evaluate the potential of integrating surface reflectance data from Landsat-7, Landsat-8, and Sentinel-2. Some differences in the surface reflectance of the sensor pairs were identified, based upon which a cross-sensor conversion model was proposed, i.e., a suitable adjustment equation was fitted using an ordinary least squares (OLS) linear regression method to convert the Sentinel-2 reflectance values closer to the Landsat-7 or Landsat-8 values. The results show that the model adjusted the Sentinel-2 surface reflectance to match Landsat-7 or Landsat-8. The maximum MRE of the adjusted sensor for surface reflectance was reduced from 17.96 to 12.15%. Differences in reflectance produce corresponding differences in estimates of biophysical quantities, such as NDVI, with MRE as high as 18.33%. However, adjusting the Sentinel-2 sensor was able to reduce this part of the discrepancy to about 12.56%. The study believes that despite the differences in these datasets, it appears feasible to integrate these datasets by applying a linear regression correction between the bands.

The water quality of mine water is obviously improved after being stored in underground reservoir, but the process of water–rock interaction and the purification mechanism of mine water quality are not clear. In this study, the water samples and rock samples collected in the underground reservoir of Daliuta coal mine were taken as the research object. Based on the analysis of the hydrochemical characteristics of the reservoir water samples and the characterization of the rock samples, combined with PHREEQC analysis, the mechanism of water quality purification of mine water was discussed. The results showed that the rocks in the underground reservoir had layered silicate structure and flaky kaolinite structure, with some irregular edges and microcracks, and higher specific surface area and total pore volume. These characteristics made the rocks have a certain adsorption and removal capacity for heavy metal ions and other pollutants in the mine water. The water–rock interaction, such as the dissolution of albite and halite, the precipitation of gypsum and kaolinite, and the cation exchange, resulted in the increase of the concentration of Na⁺ and the decrease of the concentration of Ca²⁺, Mg²⁺, and TDS in the outlet water, and the hydrochemical type changed from SO₄²⁻-Cl⁻/Ca²⁺ type to SO₄²⁻-Cl⁻/Na⁺ type. Moreover, this study shows that PHREEQC analysis can be used to analyze the water–rock interaction of coal mine underground reservoir and can obtain more detailed information; therefore, it may have the potential ability to help assess the migration and transformation of pollutants during the storage process of mine water in underground reservoirs.

Aging is an ultimate reality that everyone has to face. D-galactose (D-gal) has been used extensively to develop aging model. Trace elements such as selenium (Se) have been used as a potential antioxidant for neuro-protection. The present work aims to develop therapeutic agents such as Se for the treatment of aging-induced neurological ailments such as anxiety, depression, and memory impairment. For this purpose, mice were treated with D-gal at a dose of 300 mg/ml/kg and various doses of Se (0.175 and 0.35mg/ml/kg) for 28 days. Behavioral tests were monitored after treatment days. After the behavioral assessment, mice were decapitated and their brains were collected. Hippocampi were removed from the brain for biochemical, neurochemical, and histopathological analysis. The present findings of behavioral analysis showed that D-gal-induced anxiety- and depression-like symptoms were inhibited by both doses of Se. D-gal-induced memory alteration was also prevented by repeated doses of Se (0.175 and 0.35mg/ml/kg). Biochemical analysis showed that D-gal-induced increase of oxidative stress and inflammatory markers and decrease of antioxidant enzymes and total protein contents in the hippocampus were prevented by Se administration. An increase in the activity of acetylcholinesterase was also diminished by Se. The neurochemical assessment showed that D-gal-induced increased serotonin metabolism and decreased acetylcholine levels in the hippocampus were restored by repeated treatment of Se. Histopathological estimations also exhibited; normalization of D-gal induced neurodegenerative changes. It is concluded that D-gal-induced dysfunction in mice hippocampus caused anxiety, depression, memory impairment, oxidative stress, neuro-inflammation, and histological alterations that were mitigated by Se via its antioxidant potential, anti-inflammatory property, and modulating capability of serotonergic and cholinergic functions.

Groundwater salinization and interaction between Playa Lake and regional groundwater were investigated using multi-chemo-isotopic evidences. Forty groundwater and 26 Kashan Playa Lake (KPL) water samples were collected and analyzed for their geochemical compositions. The evolution of hydrochemical facies in Kashan Plain Aquifer (KPA) to KPL is Ca-HCO₃ (19%), Mix Ca–Cl (9%), Ca–Cl (17%), and Mix Na-Cl and Na-Cl (55%). Also, the Hydrochemical Facies Evolution Diagram (HFE-D) proposed cation exchange as the main process of salinization in KPA. Based on the binary hydrogeochemical diagrams of (Na⁺/Cl⁻)/Cl⁻, (Ca²⁺ + Mg²⁺)/HCO₃⁻ + SO4²⁻, and Cl/Br, dissolution of halite and gypsum in the Miocene marlstone in the KPA is the main source of salinity. The δ¹⁸O of water in aquifer and playa water samples varies from –10.03 to 7.03‰ (VSMOW) with an average of –6.95‰ and –60.73 to 25.08‰ with average of –45.82‰ for δ²H. Based on the results, the relation between δ¹⁸O and δ²H, and δ¹⁸O and Br, approves discharge of saline water from KPA to KPL. Likewise, the isotopic composition of δ³⁴SO₄, varies from 5.95 to 22.55‰ CDT in KPA, and 5.95 to 9.99 ‰ CDT in KPL. Also, the relations between δ¹⁸O-δ³⁴SSO₄ and Cl-δ³⁴S were non-linear, indicating that sulfur concentration in KPA and KPL changed due to sulfide oxidation and sulfate reduction in the freshwater and deep brines in the aquifer and mixed during the over-pumping in the KPA. Oxidation of sulfide minerals in the mineralized region in the western part of the aquifer (recharge zone) may have been the source of sulfur leached by seasonal runoff. Water–rock interaction, ion exchange, and hydraulic gradient have been the dominating factors in changing the water chemistry between aquifer and playa leading to saline groundwater discharged to the playa.

This study uses a consumer-based accounting approach to evaluate the CO₂ emission factors of 17 countries in Asia and the Pacific region by including all emissions in the supply chain from commodity location to final consumption location in country consumption patterns. In addition, the number of emissions connected with each country’s consumption of products and services in Asia and the Pacific region has received little attention. This study contributes to understanding the effects of countries’ consumption of products and services on carbon emission peaks and formulates efficient carbon mitigation plans for governments and decision-makers. Accelerating economic growth and industrialization have posed significant challenges to global carbon mitigation efforts and climate change responses. The Monte Carlo simulation technique was used to create a dynamic scenario simulation model to investigate possible future peaks in the carbon emissions of countries in Asia and the Pacific region while taking into account factor uncertainties. The results show that total consumption-based CO₂ emissions are remarkable in three Asian countries, including China (387,451.95 metric tons Mt CO₂), Japan (185,259.60 Mt CO₂), and India (100,720.46 Mt CO₂). In South Korea, Brunei, and Taiwan, annual consumption emissions are 1.77, 1.62, and 1.49 tons of CO₂ per person, respectively. In terms of final consumption, the household sector is the most noteworthy contributor to consumption-based emissions, accounting for 27–56%. The household sector probably peaks at 19.7 Gt CO₂ as per the dynamic scenario simulation. For the three other types of final demand, government expenditure will possibly reach a maximum of 44.0 Gt CO₂ in the next 30 years, while capital formation will probably reach its highest emission level at 149.5 Gt CO₂.

An in-depth analysis of the spatial distribution characteristics and overall pattern of industrial heritage sites in China provides not only a comprehensive understanding of the current status of industrial heritage but also a reference for its protection and ongoing utilization. A total of 170 industrial heritage sites that were included in the List of National Industrial Heritage of China were selected as the research objects. Their spatial structure characteristics were quantitatively analyzed based on a kernel density analysis of ArcGIS and imbalance and Gini coefficient index of function calculations. The results show that the distribution of industrial heritage sites in China presents a strong aggregation trend and a distribution pattern of four cores, six centers, and multiple scattered points. The distribution of industrial heritage sites in 34 administrative regions is extremely imbalanced. A total of 170 industrial heritage sites are distributed across 27 administrative regions; 52.35% are concentrated in the East and Southwest divisions. According to the index definitions, this research analyzed their influencing factors from perspectives of the natural and social environments. The results show that the industrial heritage sites in China are mainly distributed in traditional agricultural and commercial areas with rich natural or water transport resources. The current study of major historical events in modern China and the growth curve of industrial heritage concludes that China’s industry has experienced five stages of development: Ancient, Beginning, Accelerated Development, Climax, and Slowdown. The geographical divisions and distribution of categories show colonial and socialist characteristics.

The growing presences of conventional and emerging contaminants make the wastewater treatment increasingly difficult and expensive on a global scale. ZVI tends to be an expectable material for the detoxification of some difficult contaminants such as chlorinated solvents and nitroaromatics. In this work, together use with calcium carbonate (CaCO₃), which serves as a green supporter to ZVI and also direct participant toward the purification process, has been carried out by cogrinding to give a synergistic effect, particularly for treating multiple pollutants including both inorganic and organic compositions. Based on a set of analytical methods of XRD, FTIR, SEM, XPS, and other test methods, the activation mechanism of the ball milling process and the removal performances of the prepared composites were examined. The results prove that the mechanically activated calcium carbonate and ZVI composite samples exhibited extremely high removal capacity on a variety of pollutants contaminated water. The decolorization of azo dyes is mainly attributed to the breaking of chromogenic functional group nitrogen and nitrogen double bonds, and the removal mechanism of aromatic series occurs through a hydrogenation substitution reaction. As to the inorganic pollutant removals, besides the efficient heavy metal ion precipitations, phosphate and fluoride ions are co-precipitated through the formation of fluorapatite to achieve a simultaneous and synergistic removal effect. Under the optimal reaction conditions, the concentration of PO₄³⁻ is reduced from 250 to 0 mg/L, and that of F⁻ is reduced from 51.07 to 1.20 mg/L. The prepared composite sample of ZVI rand calcium carbonate allowed simultaneous removals of both inorganic and organic pollutants, simplifying the remediation process of complicated multiple contaminations.