There have been growing concerns and uncertainty about reports attributing the metabolic disturbance induced by a commercial formulation of glyphosate-based herbicide to its active ingredient. We therefore compared the effects of Roundup Original® and its active ingredient glyphosate on some hypothalamic-pituitary-adrenal (HPA) hormones and oxidative stress markers, biochemical and hematological profiles in 56 adult male albino rats randomly assigned to seven treatments of eight rats per treatment. The rats were orally exposed to Roundup Original® and its active ingredient daily at 3.6 mg/kg body weight (bw), 50.4 and 248.4 mg/kgbw of glyphosate equivalent concentrations for 12 weeks, while control treatment received distilled water. Serum concentrations of corticosterone, adrenocorticotropic hormone, aldosterone and concentration of oxidative stress marker, biochemical and hematological profiles in the blood were determined. Concentrations of corticosterone and aldosterone were significantly higher (p < 0.05) in rats treated with Roundup in a dose-dependent manner. Reduced glutathione concentration, catalase, and butyrylcholinesterase activities reduced significantly in rats treated with Roundup relative to those treated with the active ingredient. Lipid peroxidation was observed in rats treated with Roundup. Biochemical and hematological profiles of rats treated with Roundup were significantly altered (p < 0.05). However, significant changes in only acid phosphatase, lactase dehydrogenase, bilirubin, and white blood cells in rats treated with the active ingredient at 50.4 mg/kg were observed. The severe metabolic disturbance and stress observed in rats treated with the commercial formulation of Roundup herbicide may not be associated with the mild changes induced by the active ingredient.

Thermodynamic and kinetic aspects for the biosorptive removal of Pb, Cd, and Cr metals from water using Chemically Modified Leaves of Salvia moorcroftiana (CMSML) were determined. Different parameters including pH, temperature, metal’s initial concentration, biomass dosage, and contact time were optimized. Optimum biosorptions of Pb, Cd, and Cr were attained at pH values of 6.0, 7.0, and 3.0 respectively. Batch experiments showed maximum removal of both Pb and Cd at 40 °C and that of Cr at 30 °C. Biosorption capability of CMSML was observed to decrease with raising temperature. Optimal equilibrium times for Pb, Cd, and Cr uptake were 120, 60, and 120 min respectively. Based on the values of regression correlation coefficients (R²), the current data is explained better by applying Langmuir isotherms than the Freundlich model. Maximum biosorbent capabilities (qₘₐₓ) for Pb, Cd, and Cr were approximately 270.27, 100.00, and 93.45 mg/g respectively. Thermodynamically, removal of all the three metal ions was shown to be exothermic and spontaneous.

Cemeteries in Nigeria have never been perceived as having a significant potential contamination to the environment and are often located within residential setups. This work presents a study of special interest, because up till now, there are no known publications in the north-eastern states of Nigeria that investigated the relationship between cemeteries and the natural environment. The objective was to investigate whether burial practices affect the groundwater within the vicinity of an active municipal cemetery in the Gwange area of the Maiduguri metropolis, Borno State, Nigeria. Groundwater quality measurement from boreholes located at varying radial distances from the cemetery was also conducted. The result was compared with that of WHO and showed evidence of attenuation with distance. The method of burial is a chemical-free method and dictated by local culture in the area. The site is underlain by a sedimentary rock of the Chad Formation and is characterized by coarse-grained soils of high permeability coefficient (1.04 × 10⁻⁴–2.38 × 10⁻⁴ cm/s). The soil sample was composed of 3.2 to 8.4% fines which fall beneath the standard of 30% that is considered adequate for natural attenuation of contaminants. The soils were poorly graded and exhibit non-plastic properties. The grave invert, being predominantly higher than 1 m, seems to have significantly influenced the low levels or the absence of contaminants especially cations in the groundwater sample. The high levels of pH (9.5), EC (1874 μs/cm), NO₃ (67.4 mg/l), NO₂ (0.92 mg/l), PO₄ (344.5 mg/l), and NH₄ (1.03 mg/l) in groundwater samples (especially the cemetery borehole) are an indication that higher interment density over time presents a significant threat to groundwater quality.

The densely populated Greater Cairo (GC) region suffers from severe air quality issues caused by high levels of anthropogenic activities, such as motorized traffic, industries, and agricultural biomass burning events, along with natural sources of particulate matter, such as wind erosion of arid surfaces. Surface-measured concentrations of particulate matter (PM₁₀), sulfur dioxide (SO₂), and ozone (O₃) and its precursor’s gases (nitrogen dioxide, NO₂; carbon monoxide, CO) were obtained for the GC region. The PM₁₀ concentrations were found to exceed remarkably the Egyptian guidelines (150 μg/m³). These high levels of PM₁₀ were recorded throughout 68% of the period of measurement in some industrial areas (El-Kolaly). The measured data of pollutants were used for both the evaluation of environmental pollution levels and the validation of the online-integrated regional climate chemistry model “RegCM-CHEM4.” Calculation of the bias between the model results and the measured data was used to evaluate the model performance in order to assess its ability in reproducing the chemical species over the area. The model was found to reproduce the seasonal cycle of the pollutants successfully, but with a large underestimation of the PM₁₀ values. Validation of the RegCM-CHEM4 indicated that the emission inventories of mobile sources and anthropogenic activities need to be improved especially with respect to local and regional activities in order to enhance air quality simulations over the GC region.

Silver nanoparticles (AgNPs) were synthesized by incubating the mixture of AgNO₃ solution and whole-cell aqueous extracts (WCAEs) of Neochloris oleoabundans under light conditions. By conducting single-factor and multi-factor optimization, the effects of parameters including AgNO₃ concentration, pH, and extraction time were quantitatively evaluated. The optimal conditions in terms of AgNP yield were found to be 0.8 mM AgNO₃, pH 5, and 9-h extraction. The AgNPs thus synthesized were quasi-spherical with a mean particle diameter of 16.63 nm and exhibited decent uniformity as well as antibacterial activities, which may facilitate AgNP biosynthesis’s application in the near future.

In this work, it was analyzed the behavior of three commercial activated carbons with different textural and chemical properties to adsorb individually metronidazole and lead ions from aqueous solution. Afterwards, the activated carbons were modified with citric acid to remove both compounds simultaneously. Both sets of activated carbons were characterized chemically and texturally. XPS analysis was performed to corroborate the adsorption mechanism of lead on the surface of the carbons. Finally, the intraparticle diffusion of both adsorbates was elucidated by the application of diffusional model in three dimensions. The results evidenced that adsorption mechanism for MNZ and Pb(II) is independent, the adsorption for MNZ is governed by π–π dispersive interactions, whereas Pb(II) adsorption is mainly controlled by electrostatic interactions. The binary adsorption equilibrium shows that the adsorption of MNZ is independent from the concentration of Pb(II), whereas the adsorption of Pb(II) is affected by the presence of MNZ at low concentrations (0.1 mmol L⁻¹), but it remains almost constant at concentrations of MNZ between 0.1 and 1.5 mmol L⁻¹. Finally, the mass transport of MNZ was faster than Pb(II) from the solution to the external surface of activated carbon and the mass flux of MNZ inside the particle was superior to the mass flux of Pb(II). Lastly, there might be an obstruction phenomenon with MNZ impeding Pb(II) to reach the active sites placed into the carbon’s microporosity structure. Graphical abstract

In this work, a sunlight-sensitive photocatalyst of nanocubic-like titanium dioxide (TiO₂) and N-doped graphene quantum dots (N-GQDs) is developed through a simple hydrothermal and physical mixing method. The successful amalgamation composite photocatalyst characteristics were comprehensively scrutinized through various physical and chemical analyses. A complete removal of bisphenol A (BPA) is attained by a synthesized composite after 30 min of sunlight irradiation as compared to pure TiO₂. This clearly proved the unique contribution of N-GQDs that enhanced the ability of light harvesting especially under visible light and near-infrared region. This superior characteristic enables it to maximize the absorbance in the entire solar spectrum. However, the increase of N-GQDs weight percentage has created massive oxygen vacancies that suppress the generation of active radicals. This resulted in a longer duration for a complete removal of BPA as compared to lower weight percentage of N-GQDs. Hence, this finding can offer a new insight in developing effective sunlight-sensitive photocatalysts for various complex organic pollutants degradation.

The aim of the present study was to assess the concentrations of lead (Pb) and cadmium (Cd) in the liver and kidney from stray dogs (Canis lupus familiaris) and cats (Felis catus) found dead between 2014 and 2017 in the city of Naples and its surrounding areas. These organs from 290 dogs and 88 cats were collected after ordinary necropsy of stray animals. Heavy metal concentrations were determined by using atomic absorption spectrophotometry (AAS). Concentrations of Pb (up to 5.93 mg/kg) and Cd (ranging from 0.005 to 6.13 mg/kg) were detected in both livers and kidneys analyzed. Differences in concentration were found based on age class, gender, and kind of tissue for both elements, with a trend similar to those already reported in the literature for comparable studies from different countries. Cadmium levels in the kidney were significantly higher (p < 0.05) in females than those in males for both species. As regards to Pb, the highest concentrations were detected in the liver (3.45 mg/kg in dog and 5.93 in cat, respectively) followed by the renal tissue, with no significant difference depending on the animal gender. This study can be considered the first one in Italy regarding stray dogs and cats as bio-indicators of environmental contamination due to lead and cadmium, suggesting that pets could be sentinel animals to evaluate human exposure to these heavy metals.

Three different types of zirconium-modified bentonites (ZrMBs) including zirconium-modified original bentonite (ZrMOB), zirconium-modified magnesium-pretreated bentonite (ZrMMgB), and zirconium-modified calcium-pretreated bentonite (ZrMCaB) were synthesized and used as active covering materials to suppress the release of phosphorus (P) from sediments. To assess the covering efficiency of ZrMBs to inhibit P release from sediments, we examined the impact of ZrMB covering layer on P mobilization in sediments at different depths as well as the release of P through the interface between sediment and overlying water (SWI) by use of simulating P release control experiments and diffusive gradients in thin films (DGT) technology. The results showed that the amount of soluble reactive P (SRP) in the overlying water greatly decreased after covering with ZrMBs. Moreover, both pore water SRP and DGT-liable P (DGT-P) in the top sediments decreased after capping with ZrMBs. An obvious stratification of DGT-P was observed along the vertical direction after covering with ZrMBs, and static and active layers were found in the top sediment and in the lower sediment directly below the static layer, respectively. Furthermore, ZrMB covering led to the change of P species from easily released P to relatively or very stable P, making P in the top sediment more stable compared to that without ZrMB covering. Besides, an overwhelming majority of P immobilized by ZrMBs is hard to be re-released into the water column in a common environment. Overall, the above results demonstrate that sediment covering with ZrMBs could effectively prevent the transport of SRP from sediments into the overlying water through the SWI, and the control of P transport into the overlying water by ZrMB covering could be mostly due to the immobilization of pore water SRP, DGT-P, and mobile P in the top sediment by ZrMBs.

Three-dimensional (3D) batch ECC of raw health care facility wastewater (HCFWW) was adopted using stainless steel (SS) and aluminum (Al) scrap metal particle electrodes. ECC treatment was focused on priority quality parameters viz., chemical oxygen demand (COD), color, and other important water quality parameters. Sludge settling and filterability for post-ECC slurry were investigated after ECC. COD removals of 87.56 and 87.2% were achieved for current densities (CD) 83.33 and 125 A/m² using SS-3D electrodes, and similarly, 86.99 and 86.23% COD removal for Al-3D electrodes. Simultaneously, color removals were 88.50 and 87.60% for CD 166.66 A/m² (4A) using SS and Al-3D electrodes. Water quality parameters viz., nitrate, phosphates, and sulfate were also removed by 93.18%, 96.83%, and 41.07% for SS-3D electrodes, while Al-3D electrodes showed 93.15%, 96.72%, and 25.94% removal. Post-ECC slurry settling was good for all the applied CD using SS-3D electrodes generating dense and sturdy flocs. Al-3D electrodes showed excellent floc settling properties. SS-3D electrode flocs displayed good filterability at 1A with α: 2.497 × 10¹¹ m kg⁻¹ and Rₘ 1.946 × 10¹⁰ m⁻¹. Post-ECC slurry using Al-3D electrodes were viscous causing delayed filterability giving α: 1.1760 × 10¹¹ m kg⁻¹ and Rₘ 1.504 × 10⁹ m⁻¹ for 3A. E. coli was destroyed by 97 and 98% for 2A and 3A respectively. Clear water reclamation of 85–90% and pollutants/contaminants removed within a short HRT of 75 min proved the effectiveness of adopting 3D-ECC for treating raw HCFWW.