Waste concrete is a key component of construction and demolition (C&D) waste produced in billions of tons. Exploring new technology for recycling waste concrete has become a global concern. Meanwhile, phosphorus (P) removal from wastewater consumes lots of natural minerals, leading to a heavy burden on the environment. In this study, the cement paste powder (HCPP) was used to remove phosphorus from wastewater. The results indicate that both HCPP and thermally modified HCPP (MHCPP) are effective phosphorus removal materials, with a maximum P-binding capacity of 3.9-mg P/g HCPP and 31.2-mg P/g MHCPP, respectively. The phosphorus removal mechanism of HCPP and MHCPP was also proposed: (1) Ca²⁺ and OH⁻ can release from the surface of the HCPP or MHCPP to wastewater, forming a high-alkaline and Ca-rich solution; (2) hydrolysis of phosphorus species in the high-alkaline solution environment creates HPO₄²⁻ species; (3) the HPO₄²⁻ combines with Ca²⁺ and H₂O, resulting in the formation of brushite; (4) the brushite precipitated from wastewater and adhered on the surface of the HCPP or the MHCPP particles. The study provides a new and low-cost material for treatment of phosphorus wastewater. Further, the study also offers a new approach for reusing of waste concrete fines.

A large amount of contaminated sites is shown around the world which may induce a health risk due to the presence of contaminants such as metal (loïd)s bearing phases. Health risk assessment is based on contaminant bioaccessibility. However, it is needed to understand every contaminant behavior in physiological matrix to be a realistic way to assess and interpret these sanitary risks. Due to the complexity of contaminated soil matrix, the use of synthetic minerals seems to be the better tool to understand their behavior in physiological matrix. Then, this study aims to highlight the environmental stability and the behavior during bioaccessibility ingestion (UBM) of selected synthetic lead-bearing phases. For this purpose, three Pb phases (galena, beudantite, and anglesite) commonly found in contaminated environments (particularly mining sites) were synthesized and characterized (structurally and morphologically). The sequential BCR extractions have shown that most of the lead is in a stable and non-mobilizable form (up to 93%). The lead present in these phases represents very few risks of migrating into the environment during physicochemical condition changes. The results of the bioaccessibility revealed a relatively high stability of the pure bearing phases in the physiological matrix. Lead is stable for 97.0% to 99.2% during the gastric phase and 97.0% to 99.9% during the gastro-intestinal phase. Moreover, the synthetic mixtures of galena/beudantite and anglesite/beudantite have been realized considering the proportions commonly found in the mining contexts. This has shown a similar behavior compared to pure phases except in the case of the anglesite mixture inducing a clear cocktail effect (drastic increase of Pb amount from gastro-intestinal phases). At last, this study is a first and interesting step to assess the behavior of these bearing phases in heterogeneous and complex medium such as soil.

Production of a large amount of gas during outbursts will cause greenhouse effects, which will impact the atmospheric environment. In this study, some inherent properties of pulverized tectonic coal were investigated. The results indicate that tectonic coal was more broken and exhibited a higher gas adsorption volume. No obvious changes were found in the micropore and mesopore volumes, whereas the macropore volume and pulverized tectonic coal porosity were significantly increased compared with those of intact coal. Additionally, the initial gas desorption capacities of pulverized tectonic coal were enhanced by tectonism, which might be related to the development of macropore structures and porosity. Analysis of gas expansion energy at the same particle size showed that the values increased with the increasing pressure. Pulverized tectonic coal had a higher gas expansion energy, which could result in a larger outburst of potential energy. Almost all outbursts occurred in tectonic development zones and released a large amount of gas, which greatly damaged the ecological environment. From the perspective of environmental protection, attention should be paid to gas control in the tectonic development zone.

Chlorination in a drinking water treatment plant is the critical process for controlling harmful pathogens. However, the reaction of chlorine with organic matter forms undesirable, harmful, and halogenated disinfection by-products. Carbonaceous disinfection by-products, such as trihalomethanes (THMs) and haloacetic acids (HAAs), are genotoxic or carcinogenic and are reported at high concentration in drinking water. This study is aimed at developing a mathematical model for predicting concentration levels of THMs and HAAs in drinking water treatment plants in South Korea because no previous attempts to do so have been reported for the country. The THMs concentration levels ranged from 29 to 39 μg/L, and those for the HAAs from 6 to 7 μg/L. Multiple regression models, i.e., both linear and nonlinear, for THMs and HAAs were developed to predict their concentration levels in water treatment plants using datasets (January 2015 to December 2016) from three treatment plants located in Seoul, South Korea. The constructed models incorporated principal factors and interactive and higher-order variables. The principal factor variables used were dissolved organic carbon, ultraviolet absorbance, residual chlorine, bromide, contact time, chlorine dose and temperature for treated water, and pH for both raw and treated water at the plant. The linear models for both THMs and HAAs were found to give acceptable fits with measured values from the water treatment plants and predictability values were found to be 0.915 and 0.772, respectively. The models developed were validated with a later dataset (January 2017 to July 2017) from the same water treatment plants. In addition, the models were applied to two different water treatment plants. Application and validation results of the constructed model showed no significant differences between predicted and observed values.

The environment is seriously affected by the release of hazardous heavy metals from the industries. The transformation of aquatic weeds into valuable nanosorbent has been considered as effective and efficient material in the wastewater treatment process. The aim of the study is to analyze the potential of nano-EC and nano-LM for the removal of chromium(VI) and nickel(II) ions. The characteristics of nanosorbent were analyzed using Fourier transform infrared spectroscopy (FTIR), Brunauer Emmett-Teller analysis (BET), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), and thermo gravimetric analysis (TGA), respectively. Adsorptive performance of nanosorbent was studied with respect to pH, contact time, nano adsorbent dosage, and metal ion concentration. The maximum monolayer adsorption capacity of Cr(VI) and Ni(II) with respect to nano-EC was found to be 79.04 mgg⁻¹ and 85.09 mgg⁻¹, respectively. Adsorption isotherm and kinetic studies were performed and it was reported that adsorption isotherm follows Langmuir model with regression coefficient R² > 0.9 for nano-EC and nano-LM respectively. The pseudo-second order model was found to fit well with experimental data. Experimental results suggested that nano-EC can be considered as a suitable nanosorbent for the removal of Cr(VI) and Ni(II) ions from effluents.

Both the epidemiological and animal experimental studies have reported the association between PM₂.₅ and respiratory, cardiovascular, and metabolic diseases. However, the study linking PM₂.₅ and hepatic injury is few, and the relative mechanism has not been fully elucidated. Thirty-two 6-week-old male C57BL/6 mice were exposed to filtered air (FA) or concentrated PM₂.₅ for 12 weeks using Shanghai Meteorological and Environmental Animal Exposure System (“Shanghai-METAS”), respectively. At week 11, the mice began to be treated with intraperitoneal injection of normal 0.9% saline or AMPK activator (AICAR). The mRNA levels of IL-6 and TNF-α, and protein expressions of AMPK, GLUT4, NF-κB, p38MAPK, ERK, and JNK in the liver and UCP-1 in brown adipose tissue (BAT) were measured. Meanwhile, histopathological examination both in the liver and BAT was performed to evaluate the histopathological changes. PM₂.₅ exposure induced steatosis, hepatocyte ballooning, lobular and portal inflammation in the liver, and the brown adipocyte swelling in BAT. The results found that PM mice displayed higher IL-6, TNF-α, NF-κB, and JNK expression and lower AMPK, GLUT4, and UCP-1 when compared with FA mice. The AICAR injection upregulated the expressions of GLUT4 in the liver of PM-AIC mice when compared with the PM mice. However, there were no significant effects of AICAR on histopathological condition. The current study showed that ambient PM₂.₅ exposure might induce the hepatic injury along with the lipid metabolism disorder in BAT. AMPK activation can ameliorate most of the harmful effects and might become the potential target for treating PM₂.₅-induced hepatic injury.

The objective of this paper is to appraise the decomposition along with decoupling elements that affected the nexus between energy-related CO₂ emissions and the economic development of Bangladesh by applying the logarithmic mean Divisia index and Tapio model. The paper provides an effective policy that will enable Bangladesh to improve its environmental aspect and stimulate sustainable economic development. The analysis comprehends three economic sectors, and the decoupling determinative is fragmented into five elements. The results revealed that Bangladesh achieved weak decoupling throughout the analysis cycles except between the cycles of 1990–1991, 1992–1993, 1995–1996, 1997–1999, 2003–2004, 2012–2013, and 2015–2017 in which a strong decoupling occurred. From the disintegration of various components’ frame of reference, it can be seen that change in scale effect causes a substantial increase in carbon emissions and economic structure together, whereas energy intensity plays an imperceptible role in the increase in carbon emissions. On the other hand, the emission is the only element that is responsible for a decrease in carbon emissions. From a comparative sectoral analysis point of view, scale effects are liable for increasing carbon emissions in all three sectors. Hence, precautionary information campaign should be taken to communicate a comprehensive countrywide moderation strategy and appropriate modification engagements for initiating a low-carbon community.

Nowadays, the sunscreen creams are composed of mostly synthetic chemicals and other organic compounds which were found to enter into the blood stream on topical application raising concerns in the scientific community. The scientific community has now shifted their attention to herbal formulations due to toxicity of these synthetic molecules. Aloe vera is a xerophitic plant having excellent anti-oxidant properties. The permeation effect and drug stability of the drug candidate can be significantly enhanced by formulating it into solid lipid nanoparticles (SLN). The main objectives of the study were to formulate and evaluate Aloe vera-loaded SLN sunscreen cream and to determine its photoprotective potential. The Aloe vera-loaded SLNs were formulated by microemulsification technique. The developed SLNs were studied for its entrapment efficiency, poly dispersity index (PDI), zeta potential, particle size, and other characterization techniques. Finally, the optimized SLNs were incorporated into the sunscreen cream and evaluated for its spreadability, viscosity, extrudability, drug content, in vitro drug release, ex vivo permeation, determination of sun protection factor (SPF), skin irritation test, and accelerated stability studies. The in vitro SPF was found out to be 16.9 ± 2.44 and the in vivo SPF observed to be approximately 14.81 ± 3.81, respectively. Stability studies were performed under accelerated conditions and no appreciable changes in the parameters were noticed. The solid lipid nanoparticles of Aloe vera were incorporated into a cream and the SPF of the resultant sunscreen cream was found to be on par with the sunscreens that were currently available in the market.

Environment-biased technological progress plays a critical role in carbon reduction, while the association among environment-biased technological progress, energy consumption, and carbon emissions has not been paid enough attention. Working with a unique spatial panel dataset of APEC economies spanning the 2000–2017 period, we employed the nonspatial panel model and the spatial panel model to investigate the role of fossil energy (FE) and clean energy (CE) consumption in carbon dioxide (CO₂) abatement through environment-biased technological progress (EBTP). We decomposed EBTP into both emission-reducing biased technological progress (ErBTP) and energy-saving biased technological progress (EsBTP). The results show that the direct effect of EBTP on CO₂ emissions was significantly negative and that the direct effect of ErBTP was significantly larger than that of EsBTP. EBTP reduced CO₂ emissions through CE consumption, whereas it increased CO₂ emissions through FE consumption, that is, EBTP had a “backfire effect” on FE consumption. More into detail, ErBTP had a larger effect on CO₂ emissions in developing economies, while EsBTP played a more important role in developed economies. Furthermore, the results of the robustness test were consistent with our findings. Finally, several policy options were suggested to reduce CO₂ emissions in APEC economies.

Here, Box-Behnken design (BBD) approaches were utilised to optimise synthesis methodology for the chitosan-calcite rich adsorbent (CCM) made from fishery-food waste material (crab carapace), using low-temperature activation and potassium hydroxide (KOH). The effect of activation temperature, activation time and impregnation ratio was studied. The final adsorbent material was evaluated for its phosphorus (P) removal efficiency from liquid phase. Results showed that impregnation ratio was the most significant individual factor as this acted to increase surface deacetylation of the chitin (to chitosan) and increased the number of amine groups (–NH₂) in the chitosan chain. P removal efficiency approached 75.89% (at initial P concentration of 20 mg/L) under optimised experimental conditions, i.e. where the impregnation ratio for KOH:carapace (g/g) was 1:1, the activation temperature was 105 °C and the activation time was 150 min. Predicted responses were in good agreement with the experimental data. Additionally, the pristine and CCM material were further analysed using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX), Brunauer-Emmett-Teller technique (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analysis (TGA). Characterisation showed enhancements in surface chemistry (introducing positively charged amine groups), textural properties and thermal stability of the CCM.