In this work, activated carbon was synthesized by the carbonization of kendu fruit peel followed by chemical activation using ammonium carbonate as an activating agent to get modified kendu fruit peel (MKFP). The SEM and FESEM images of the biomaterial illustrated a highly porous honeycomb-like structure, further supported by the N₂ sorption isotherm analysis. The FTIR spectra specified the presence of oxygen-containing functional groups such as carboxyl, carbonyl, and hydroxyl on the adsorbent surface. Batch experiments were performed for the optimization of methylene blue (MB) dye removal. The adsorption process followed pseudo-second-order kinetic model and Langmuir isotherm model with a maximum adsorption capacity of 144.9 mg g⁻¹. No desorption was found because the adsorbent surface was bonded with the chromophoric group of the MB dye by means of strong chemical interaction evident from the high adsorption energy (E = 10.42 kJ mol⁻¹) and enthalpy change (∆H = 42.7 kJ mol⁻¹). Hence, the MKFP has the potential to act as an efficient bioadsorbent for MB dye removal. Graphical abstract

Cr (chromium, with common valence states of III and VI) is one of the common broiler feed additives. Liver injury and metabolic disorders could be caused by Cr₍VI₎ (hexavalent chromium) poisoning in broilers. Oxidative damage and metabolic disorders of organisms caused by heavy metals could be antagonized by nano-Se (nano-selenium). Nano-Se was chosen to study the antagonism of Cr₍VI₎ poisoning in broilers. AMPK (Adenosine 5,-monophosphate-activated protein kinase) is known as a “cell energy regulator” and plays a key regulatory role in carbohydrate and lipid metabolism. AMPK pathway and ACACA/CPT1A two genes were selected to study the prevention and treatment of nano-Se on Cr₍VI₎ poisoning in broilers and its molecular mechanism. For this purpose, 180 1-day-old AA (Arbor Acres) broilers were selected and randomly divided into 6 groups (n = 30) for further testing. After feeding as planned for 35 days, the livers of such broilers were taken for further examination including histopathological examination, differential gene expression analysis, and further validation on both mRNA and protein levels using related techniques like RT-qPCR, western blot, and immunohistochemistry (IHC). The histopathological examination suggested that the liver cells of the Cr₍VI₎ poisoning group were more severely injured than the nano-Se addition group. RT-qPCR results showed that the relative expression of ACACA gene in the Cr₍VI₎ poisoning group was significantly increased (P < 0.05), while the CPT1A gene’s expression was significantly decreased (P < 0.01). Those results were reversed in the nano-Se addition group. Western blot results were consistent with RT-qPCR and both suggested antagonism of nano-Se on Cr₍VI₎. Through morphological and histopathological observation, as well as the measurement of the mRNA and protein expression levels of ACACA and CPT1A genes in AMPK pathway, it was confirmed that nano-Se has certain preventive and protective effects on Cr₍VI₎ poisoning in broiler chickens. Furthermore, the adverse effects of Cr₍VI₎ on carbohydrate and lipid metabolism in broilers can be antagonized by nano-Se through AMPK pathway. A new method and experimental basis were provided to the future study of Cr₍VI₎ poisoning in broilers.

Water quality in the Mexican Caribbean is affected by increases in tourism infrastructure and poor wastewater treatment. Additionally, karst geomorphology facilitates the infiltration of organic matter to subterranean water and coastal fresh water that originates from submarine groundwater discharges (SGDs), altering the environment. The tourism infrastructure grows at different rates along the Caribbean coast, characterizing zones with diverse levels of tourism impact. The aim of this work was to measure nutrient concentrations in superficial coastal water and fresh water to evaluate the water quality through different zones along a gradient from intermediate- (Riviera Maya) to low-tourism (Costa Maya) development regions. Furthermore, this study aimed to compare the measured nutrient concentrations with the Mexican ecological criteria of water quality 001/89 (CE-CCA-001/89), detect possible contributions by SGDs, and determine whether the nitrogen (N) sources are anthropogenic using stable nitrogen isotopes in the seagrass Thalassia testudinum. According to the results, nutrient concentrations (ammonium, nitrate, nitrite, and orthophosphate) differed significantly between the Riviera Maya and Costa Maya (P = 0.0001). Sites such as Shambala, Chávez, Tankah, Mahahual 2, Tulum, Akumal, and Xahuayxol exceeded the upper levels set by the CE-CCA-001/89. Tankah, Shambala, and Chávez were influenced by SGDs. The nitrogen isotope ratio in Akumal and Tulum coast water shows that they are under N loading derived to the sewage percentage of δ¹⁵N in Akumal, Tulum, and Mahahual, showing that these sites suffer N loading due to sewage. Our study recommends continuous monitoring and coastal characterization to detect SGD and to regulate, treat, and dispose of sewage.

Metal(loid) contamination of vital food grains such as wheat and rice is a very serious problem throughout the world because consumption of such contaminated food can lead to severe health effects in humans. Metal(loid) contamination of food crops can occur from different sources such as contaminated soil, irrigation water, and aerial deposition. Therefore, the present study was conducted to analyze potential non-carcinogenic and carcinogenic health impacts posed by different metal(loid)s (As Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, and Zn) via consumption of wheat and rice grown on metal(loid)-contaminated soils in areas around rivers (Beas and Sutlej) of Punjab, India. Among the metal(loid)s analyzed in wheat and rice samples, contents of As, Cd, Cr, Ni, and Pb were found to be above the international (FAO/WHO and EU) maximum permissible limits. The non-carcinogenic and carcinogenic health risk assessment of individual metal(loid)s revealed that As posed highest risk followed by Cd, Cu, Fe, Mn, and Pb. The values of indices calculated for analysis of combined non-carcinogenic, i.e., (hazard index; range 3.49–15.94) and carcinogenic (total carcinogenic risk index; range 8.30 × 10⁻⁴–131.62 × 10⁻⁴) risks for both crops were found to be many fold higher than the prescribed limits of 1.0 and 1.0 × 10⁻⁴, respectively. Thus, the analysis of combined risks posed by metal(loid)s indicated that human population consuming wheat and rice from the study area faced both non-carcinogenic and carcinogenic health risks. Therefore, immediate steps must be taken to reduce the levels of metal(loid)s in wheat and rice from the study area.

In this study, HAP/ZnFe₂O₄ nanocomposite has been synthesized in two simple steps. The different characterization techniques confirm the fabrication of HAP/ZnFe₂O₄ magnetic binary nanocomposite. The composite was successfully applied as nanoadsorbent for the elimination of Cd(II) ions from its aqueous solution. The composite was able to remove 89.6% of Cd(II) ions under optimum experimental conditions. The equilibrium sorption data were very much in agreement with the Freundlich adsorption model, and the maximum sorption capacity was recorded to be 120.33 mg/g. Kinetic data of the cadmium ion removal was well concurrent with the pseudo-second-order kinetics rate model. This magnetic HAP/ZnFe₂O₄ nanocomposite can be applied as an environmentally friendly, low-cost, productive sorbent for the evacuation of Cd(II) ions from wastewater in light of its high sorption capacity.

Identifying the environmental factors and analyzing the causal mechanism of flash floods help to manage the risk. Maximum 24-h precipitation (MP), digital elevation (DE), slope degree (SD), soil type (ST), drainage density (DD), and vegetation cover (VC) are selected as the risk factors of flash floods in this study. Precipitation is the important meteorological components in flash floods; thus spatial characteristics of precipitation trend have been analyzed by using Mann-Kendall tests, and a positive trend of precipitation in Upper Hanjiang River is detected. Then, association rule mining approach is proposed to investigate the multiple environmental factors of flash floods, in which both single and multiple dimension data mining have been conducted by Apriori algorithm. Considering the high rate of 5-year return period floods in the flash flood inventory, further association rule mining after sampling has been conducted in order to deeply mine the causal patterns of flash floods in different risk magnitudes. Results show that soil type, slope degree, and digital elevation are the dominant environmental factors of flash floods in the study area, and precipitation is one of the important causal factors in severe flash flood hazards. It is also highlighted that flash floods might easily occur even with a slight rainfall present due to the instability of sand clay and saturated soil moisture. The proposed novel use of field data and data mining has the potential for providing procedures and solutions for an effective interpretation of flash flood mechanism. The results are expected to be applicable for decision-making and sustainable management in flooding risk.

In conditions of intensive development of gas fields, environmental safety issues are becoming increasingly important. High rates of gas production and growth of its chemical processing have turned gas industry enterprises into a powerful source of environmental pollution, which poses a real threat to public health and contributes to an increase in morbidities and environmentally determined pathological conditions. The development of methods for the diagnosis, treatment and prevention of such conditions is an important task for modern science. The aim of the research is to make a comprehensive assessment of serum markers of bone synthesis and resorption in children with short stature living in the oil and gas processing regions. A total of 240 children aged 8–17 years, living in the oil and gas processing region (Kenkiyak), and 409 schoolchildren (8–17 years old), living in the environmentally favourable region (Kobda village), during 3 years were examined. It was established that emissions of pollutants by oil processing enterprises account for almost 80% of all emissions into the atmosphere. Gas flaring at oil production sites plays a special role in this process. Speaking of the effects of environmental factors on children’s health, it should be noted that there is no consensus on the mechanisms and consequences of exposure to low doses of chemical atmospheric pollutants in children and adolescents so far.

Egypt’s limited water resources, rapid population growth, and climate change are increasing the gap between water demand and supply. Meanwhile, significant amounts of rain fall in some regions in Egypt during specific storm events, which in some cases, lead to disasters like flash floods and inundations. Rainwater harvesting (RWH) can be considered as a sustainable promising solution to water shortage and inundation problems. In this work, the feasibility of RWH for urban areas was assessed over 22 cities throughout Egypt. Results show that the annual volume of rainwater harvested can reach 142.5 MCM in the considered cities, provided that all rain falling on the urban areas is collected. High potential of rainfall harvesting was found for cities that located on the North Coast, e.g., the potential water saving from the share of RWH in Alexandria can satisfy around 12% of its future supplementary domestic water needs. In contrast, rainfall over the cities located on the middle and the south of the country is insignificant to be harvested. A case study for the 5th settlement region in Cairo was discussed in terms of groundwater recharge and surface runoff estimation for two conditions: No–RWH and RWH systems by implementing recharge wells to store rainwater into the aquifer. Land cover classification maps of urban areas were created by using the ARCGIS software to estimate equivalent infiltration coefficients. The results demonstrate that the implementation of such RWH system has a significant impact on the regional water cycle, where the effective infiltration coefficient increased from 10% (No–RWH) to 75% (RWH) in the case study. Accordingly, the runoff coefficient decreased in the case study from 0.8 (No–RWH) to 0.15 (RWH), and the volume of runoff decreased in the case of RWH by around 82% lower than that of the No–RWH condition. Thus, direct infiltration of RWH into an aquifer can play an important role in sound water management for urban environments, as this may lead to a significant reduction in risks of flooding and expenses of municipal drainage systems installation and operation.

Despite the fact that amphotericin B (AmB) is currently considered as the first choice for treatment of visceral leishmaniasis, it is associated with some side effects. This study was designed to investigate the protective effects of vitamins A and E against amphotericin B-induced adverse effects in the kidney and liver of rat. Thirty male Wistar rats aged 7–8 weeks and weighing around 200 g were randomly divided into five groups, each one containing six rats. The first to fifth groups received olive oil as the control groups, AmB, AmB + vitamin A, AmB + vitamin E, and AmB + vitamins A + E, respectively. Rats received vitamins by gavage (vitamin A, 1000 IU/kg and vitamin E, 100 IU/kg) and amphotericin B by injections (5.5 mg/kg body weight). The treatment was constantly continued for 5 days and days 7 and 21. At the end of the study, serum level of TAC, TOS, MDA, liver enzyme activity (ALT, AST, ALP, LDH), renal factors (urea, uric acid, and creatinine), lipid profile as well as histopathological changes of the liver and kidney were investigated. AmB significantly increased serum level of creatinine, urea, uric acid, ALP, TOS, MDA, and kidney and renal tissue damage (p < 0.05). Supplementation AmB with vitamins A and E alone or combination improved oxidative stress status, liver and renal tissue structure, and functional parameters and serum lipid profile. This study highlighted the effects of vitamin A and vitamin E on attenuation of amphotericin B-induced side effects on the kidney and liver of male Wistar rats. Combination of the two vitamins is more effective than either alone improving the oxidative stress status, serum lipid profile, or liver and renal tissue structure and functional parameters.

The current study examines the importance of asymmetric modelling of tourism-CO₂ emissions relationship by incorporating real income per capita and the newly developed globalization index in a multivariate time series model between 1970 and 2014 for Turkey. We used a non-linear autoregressive distributed lag model in analyzing the asymmetric cointegration association between the selected variables. Using Hatemi-J (2012) asymmetric causality testing method, we examined the asymmetric causal relationship among the variables. The empirical outcomes provide evidence for the existence of asymmetric long-run cointegration nexus among the variables. Asymmetric causality results show that both the positive and negative shock of tourism influence the CO₂ emissions in the long-term, while in the short-term, only the negative shock of tourism contributes to CO₂ emissions. Also discussed are the policy implications with regard to Turkey’s environmental and economic policies.