This study investigated the influence of coal bottom ash (CBA) on the concrete properties and evaluate the effects of combined exposure of sulphate and chloride conditions on the concrete containing CBA. During concrete mixing, cement was replaced with CBA by 10% of cement weight. Initially, concrete samples were kept in normal water for 28 days. Next, the specimens were moved to a combined solution of 5% sodium sulphate (Na₂SO₄) and 5% sodium chloride (NaCl) solution for a further 28 to 180 days. The experimental findings demonstrated that the concrete containing 10% CBA (M2) gives 12% higher compressive strength than the water cured normal concrete (M1). However, when it was exposed to a solution of 5% Na₂SO₄ and 5% NaCl, gives 0.2% greater compressive strength with reference to M1. The presence of 10% CBA decreases the chloride penetration and drying shrinkage around 33.6% and 29.2% respectively at 180 days. Hence, this study declared 10% CBA as optimum that can be used for future research.

Optimization of different types of exposure to workers, public, and vegetation is a major issue for several institutions. The main exposure is due to the activities related to various ores of the subsoil such as phosphate which generates heavy metals during its exploitation. This study used the energy-dispersive X-ray spectrometry to investigate the heavy metal pollution that affects life on earth. Fifteen different heavy metals were detected in soil samples from sites dedicated to phosphate ore activities in southern Togo. Results showed that the concentrations of the different heavy metals decreased in the following order: Ca > Fe > K > Ti > Sr > Zn > Zr > Y > Ni > Cu > Pb > U > Br > Rb > Th. Cadmium was not detected while lead remained the most toxic element with a maximum level of 52.4 mg kg⁻¹. Basic statistics depicts strong positive correlations between Ni, Cu, Zn, and Fe which shows that their respective concentrations increased together. Principal component analysis was used to categorize all these data into three groups using two principal axes which recover 88.06% information. The geoacumulation index from Hahotoé-Kpogamé-Kpémé soil samples varies from class 0 to class 4 displaying that these areas are moderately polluted and was mainly due to Pb metal concentration. The potential ecological risk levels vary from 157 to 385, which corresponds to moderate and considerable levels. Therefore, these areas could be assumed to be safe regarding these levels. The moderate level observed on these various sites does not present a warning sign but should lead the legislators to establish routine monitoring in order to detect any change in the level of pollution due to heavy metals.

Industrial revolution markedly increased the environmental contamination by different pollutants, which include the metal lead (Pb). The phytoremediation potential of native species from tropical regions is little known, especially for woody plants. The present study aimed to evaluate the performance of Lonchocarpus cultratus (Fabaceae), a tree species from the Brazilian savanna, grown in soil that was artificially contaminated with increasing Pb concentrations (control and 4 Pb treatments, 56, 120, 180, and 292 mg kg⁻¹) for 6 months. The biomass of L. cultratus was not depressed by exposure to Pb, despite the high accumulation of this metal (up to 7421.23 μg plant⁻¹), indicating a high plant tolerance to this trace metal. Lead was mainly accumulated in roots (from 67 to 99%), suggesting that the low root-to-shoot Pb translocation is a plant strategy to avoid Pb-induced damages in photosynthetic tissues. Accordingly, the content of chlorophylls a and b was maintained at similar levels between Pb-treated and control plants. Moreover, increments in leaf area were noticed in Pb-treated plants in comparison to the control plants (on average, 24.7%). In addition, root length was boosted in plants under Pb exposure (22.6–66.7%). In conclusion, L. cultratus is able to endure the exposure to high Pb concentrations in soil, being a potential plant species to be used for Pb phytostabilization in metal-contaminated soils in tropical regions.

Currently, 2019-nCoV has spread to most countries of the world. Understanding the environmental factors that affect the spread of the disease COVID-19 infection is critical to stop the spread of the disease. The purpose of this study is to investigate whether population density is associated with the infection rate of the COVID-19. We collected data from official webpages of cities in China and in the USA. The data were organized on Excel spreadsheets for statistical analyses. We calculated the morbidity and population density of cities and regions in these two countries. We then examined the relationship between morbidity and other factors. Our analysis indicated that the population density in cities in Hubei province where the COVID-19 was severe was associated with a higher percentage of morbidity, with an r value of 0.62. Similarly, in the USA, the density of 51 states and territories is also associated with morbidity from COVID-19 with an r value of 0.55. In contrast, as a control group, there is no association between the morbidity and population density in 33 other regions of China, where the COVID-19 epidemic is well under control. Interestingly, our study also indicated that these associations were not influenced by the first case of COVID-19. The rate of morbidity and the number of days from the first case in the USA have no association, with an r value of − 0.1288. Population density is positively associated with the percentage of patients with COVID-19 infection in the population. Our data support the importance of such as social distancing and travel restriction in the prevention of COVID-19 spread.

Cartap is a thiocarbamate pesticide widely-used to protect rice crops, one of the most mass-produced cereals worldwide. Effluents containing cartap pose serious environment and health risks due to the acute toxicity of this emerging contaminant. This work evaluates the capabilities of the Fenton process to efficiently remove cartap from water matrices. Process parameters such as hydrogen peroxide dosage, ferrous ion concentration and operating pH were optimized using Box-Behnken design. Results showed complete cartap removal with Fenton oxidation in a fluidized-bed reactor while eliminating sludge generation during treatment. Fluidized-bed Fenton process had improved reduction in chemical oxygen demand and total organic carbon due to the contribution of heterogeneous Fenton catalysis to the overall degradation of cartap species compared to conventional Fenton in a batch reactor. Furthermore, competitive reactions and scavenging effects in complex natural water matrices were simulated with the use of inorganic ions such as nitrate, chloride, and phosphate. Results demonstrated the detrimental effect of phosphate ions on Fenton oxidation due to the precipitation of soluble catalysts as iron phosphates, which stops the catalytic Fenton cycle and thus the production of oxidants for contaminant degradation.

The present study reports the monitoring of viruses indicating fecal contamination in two distinct regions affected by poor management of wastewater located above the Guarani Aquifer, which is one of the biggest freshwater reservoirs in the world. In the city of Três Lagoas (located in the Midwest region, in the state of Mato Grosso do Sul), water samples were collected from Lagoa Maior, a lake used for recreation, and in Concórdia (located in the South region, in the state of Santa Catarina), from the Queimados River, which crosses the urban area. Four sampling sites were monitored from March to July 2018 in Lagoa Maior, and four sampling sites were monitored along the urban part of the Queimados River area over two periods (rainy and dry). Water samples were analyzed by concentration of Human adenovirus (HAdV), Norovirus (NoV), Rotavirus A (RAV), and Hepatitis A virus (HAV) for the Lagoa Maior samples and RVA, HAV, and Porcine circovirus 2 (PCV2) for the Queimados River samples. All sampling sites presented enteric viruses, demonstrating fecal input and potential contamination of groundwater. Results highlight the need for wastewater management to improve environmental health quality.

Activated carbons were produced from spent tyre pyrolysis char by steam or CO₂ activation and evaluated for their performance in rhodamine B (RhB) adsorption in aqueous solutions. The effect of RhB starting concentration (80–150 mg L⁻¹), contact time (0–80 min), temperature (298–318 K) and initial pH on the adsorption process was examined. Pseudo-first-order and pseudo-second-order models were carried out to fit the experimental data to derive RhB adsorption kinetics. Langmuir, Freundlich and Temkin isotherm models were applied to depict RhB adsorption behaviour of the prepared activated carbons. Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) were calculated. It has been found that the activated carbons can effectively adsorb RhB due to high mesoporosity and RhB equilibrium adsorption capacity (qₑ) increased almost linearly with increasing total mesopore volumes, regardless of the activation agents. When BET surface areas are similar, CO₂-activated carbon obtained higher qₑ than steam due to higher mesoporosity of CO₂-activated carbon. The results show that pseudo-second-order well fitted the experimental data. RhB starting concentration increased from 80 to 150 mg L⁻¹ causing qₑ increased from 158 to 251 mg g⁻¹ but RhB removal decreased from 99.7 to 84.5%. The RhB adsorption process follows the Langmuir model and thermodynamic calculation, indicating RhB adsorption is an endothermic, spontaneous process, dominated by both chemisorption and physisorption.

A genuine concern faced by the present world is global warming. Millions of human and animal lives are at risk due to global warming. Therefore, the subject has gained enormous attention from research and academia around the world. Literature shows that the primary cause of global climate change or global warming is carbon (CO₂) emissions. Hence, the role of a reliable carbon emission measurement is important for devising a relevant climate policy to deal with environmental problems. Based on trade-adjusted statistics of carbon emissions, a relevant climate policy response can be provided. Unlike the previous studies, this study examines the asymmetric impact of international trade on consumption-based carbon emissions from 1990 to 2017 in the G7 economies. To get empirical estimates, the study applies second-generation co-integration technique and nonlinear panel autoregressive distributive lag (NPARDL) model for estimating the relevant coefficients. The empirical results show that positive growth of exports significantly decreases consumption-based carbon emissions both in the short and long run, whereas the impact of negative growth of exports is insignificant. For imports, the results show that, over time, positive growth of imports significantly increases consumption-based carbon emissions in the long run, while the impact of negative growth of imports is insignificant. Finally, it is recommended for the policymakers to target the export industries for relevant policy interventions, which are less polluting and can generate other economic benefits as well.

The present study focuses on the possibility of applying fly ash to agricultural fields for enhancing the production of agricultural crops. In this study, Pisum sativum L. was grown from germination stage to maturation stage in phytoremediated and non-phytoremediated or raw fly ash-amended soil. All the morphological (height, biomass, number of leaf, and leaf size) and physiological parameters like, protein content, chlorophyll content, nitrate reductase activity, and peroxidase activity were monitored to understand the effects of fly ash or its usefulness for using it as a fertilizer for facilitating micronutrients. Major finding of this study is that 40% (w/w) of non-phytoremediated fly ash amendment could be used for field application. Percentage increase of toxic metals in below ground organs was 6% for Cd, 6% for Cr, 5% for Cu, 15% for Mn, and 7% for Pb when compared with the control. In the non-phytoremediated fly ash-amended set, heavy metals and metalloids were present in the grains only at higher amendments T3 (60%) and T4 (80%). However, except Cd, all the metals were below the permissible limits suggested by the WHO. Phytoremediated fly ash could be used as a fertilizer up to 100% for the cultivation of pea plant as metals concentrations were found either below detection limit or below the WHO permissible limit.

The economy of China is growing rapidly. With this overwhelming growth, the country is experiencing a higher level of carbon emissions. Amid this backdrop, China is under immense pressure to reduce carbon emissions up to a sustainable level. This study adapted 31 provincial panel data from 2007 to 2017 using factor analysis system SBM-undesirable model to calculate the agro-ecological output of each province respectively and used a carbon transfer network impact analysis panel to calculate ecological performance impacts. Results show that (1) overall agro-ecological efficiency in China shows an upward trend but regional differences are evident. The efficiency in the eastern region is higher than that in the central and western regions but the extent of informatization in the central region is higher than that in the western region. (2) Informatization will significantly promote agro-ecological efficiency. (3) Changes in agricultural planting structure, agricultural value-added per capita, employment of human capital in the agricultural sector, and agricultural scale management are also important factors affecting agro-ecological growth. (4) China’s amount of carbon transfer is growing year by year, and energy-intensive areas and heavy industry bases are undertaking carbon transfer from the eastern coastal regions; (5) Jiangsu, Henan, and Hebei (Hubei) have the highest centers between 2007 and 2012; (6) inter-provincial carbon transmission is concentrated mainly in the metal smelting and rolling processing industries as well as in the coal, heat, and supply industries.