Environmental and health concerns arising from the toxicity of organic dye effluents is still the issue of the twenty-first century. In that regard, this study presents iron sulfide (FeS₂) for its use in environmental remediation application. Amorphous phase FeS₂ nanowires were synthesized by PVP-assisted solvothermal reaction and were characterized using XRD, XPS, BET, FE-SEM, and EDS techniques. The amorphous phase FeS₂ is attractive from material synthesis point of view as its synthesis does not require delicate control over the process parameters, unlike the crystalline phase. The 1-D nanowire FeS₂ had a high surface-to-volume ratio with negative zeta potential within a wide pH range. Having those surface and microstructural properties, these nanowires exhibited excellent adsorption property towards model organic dyes, Congo red (anionic), and methylene blue (cationic), with theoretical adsorption capacity of 118.86 and 48.82 mg g⁻¹, respectively. Adsorption kinetics and isotherm models were implemented to study the adsorption processes at different adsorption conditions (pH, adsorbent loading, initial adsorbate concentration). The pH dependence of the adsorption and FT-IR analysis evidenced the prevalence of both physisorption and chemisorption during the adsorption of Congo red. Recyclability test proved the excellent performance of this amorphous FeS₂ nanowire adsorbent for three consecutive cycles. Considering its ease of synthesis, excellent adsorption property, and cyclic performance, the as-prepared adsorbent could be a promising material for dye effluents treatment.

Exposure to fine particulate matter (PM₂.₅) could induce lung impairment aggravation. Moreover, endogenous substances are known to play a significant role in lung impairment. Therefore, the research objectives was to investigate the influence of PM₂.₅-induced lung impairment on the levels of the eight endogenous substances, γ-aminobutyric acid (GABA), acetylcholine (ACh), glutamate (Glu), serotonin (5-HT), 5-hydroxyindole-3-acetic acid (5-HIAA), noradrenaline (NE), dopamine (DA), and 3, 4-dihydroxyphenylacetic acid (DOPAC). A sensitive UPLC-MS/MS method for the simultaneous determination of these endogenous substances in rat plasma and lung tissues was developed. The validated method was successfully applied for comparing profiles of analytes in rat plasma and lung tissues. The results indicated that five endogenous substances, namely, GABA, Ach, Glu, DA, and DOPAC, had a significant change in the rats with PM₂.₅-induced lung impairment.

In this study, TiO₂ nanotubes (TNTs) and AgCl-modified TNTs nanocomposites with multiple crystal phases were synthesized through a hydrothermal method without calcination. The resultant samples had a large Brunauer-Emmett-Teller surface area. Additionally, the Ag modification process reduced the recombination rate of electron-hole pairs in the synthesized sample and possessed more oxygen vacancy sites. The surface area of the AgCl-modified TNTs was smaller than that of non-modified TNTs sample; however, the nanocomposites exhibited outstanding photocatalytic performance and adsorption properties. AgCl compounds present on the TNTs surface effectively interacted with Hg⁰, improving the dye photodegradation efficiency. The Hg⁰ removal efficiencies of the TNTs and AgCl-modified TNTs samples were about 63% and 86%, respectively. The crystal violet (CV) and malachite green (MG) removal efficiencies of the AgCl-modified TNTs sample were around 57% and 72%, respectively. Both dyes photodecomposition efficiencies for AgCl-modified TNTs sample are higher than those of TNTs sample. The oxygen vacancy on the AgCl-modified TNTs surface was determined to be advantageous for OH⁻ and arsenate adsorption through ligand exchange. The maximum adsorption quantity of As⁵⁺ calculated by Langmuir equation was 15.38 mg g⁻¹ (TNTs) and 21.10 mg g⁻¹ (AgCl-modified TNTs).

A novel hybrid UV-C/microfiltration process for water disinfection is presented, and its application in continuous mode operation to the removal of different pathogen germs (Escherichia coli, Enterococcus faecalis, and Candida albicans) present in urban wastewater. The membrane photoreactor is based on porous stainless steel membranes coated with a TiO₂ layer and illuminated by a UV-C lamp (254 nm). A valve actuator in the outlet of the UV-C stream allows operation of the system under conditions of constant transmembrane pressure (TMP) keeping the UV-C contact time in few seconds, significantly lower than the typical irradiation time employed in TiO₂ photocatalytic processes. An E. coli removal of up to 4-log in the permeate stream and up to 2-log in the UV-C outlet was achieved with a 0.2 μm membrane operating with a TMP of 0.5 bar and a UV-C contact time as low as 8 s. The microbial balance data from the cells recovered from the membrane confirmed that 96–98% of the removed microorganisms died due to the UV-C action over the membrane surface. Modification of the membrane with a TiO₂ layer has been also shown to be a suitable way to improve both the UV-C inactivation and the filtration efficiency. The results reported in this work constitute a proof of concept of the synergy between UV-C and filtration that can be achieved in a hybrid UV-C/microfiltration system, being a good example of process intensification where two products of different quality can be simultaneously obtained.

Preparation of the value-added products from e-waste resources is an important step in the recycling process. The present paper aims to propose a methodology for the recovery of In from scrap LCD panel via preparation of InBO₃ nanostructure. Discarded LCD panel was subjected to a recycling process through crushing, milling, and oxalic acid leaching to prepare In₂(C₂O₄)₃·6H₂O. Through the leaching process, B(OH)₃ from glass part (alumina borosilicate) has been leached out along with indium oxalate hydrated. Further thermal treatment on these extracted materials at 600 °C could result in the formation of InBO₃ nanostructures with an average particle size of 20 nm. A multistep mechanism based on thermodynamic calculations for the recycling of the InBO₃ form extracted precursors was proposed. Graphical abstract

Pakistan has an abundant solar power potential which can be effectively utilized for the electricity generation. There are various sites across the country which have sufficient solar irradiation across the year, and thus, suitable for the installation of solar photovoltaic (PV) power projects. This study, therefore, aims to undertake research on the establishment of solar power project site selection in Pakistan. In this context, 14 promising cities of Pakistan are considered as alternatives and studied in terms of economic, environmental, social, location, climate, and orography criteria and further supplemented with 20 sub-criteria. Initially, the analytical hierarchy process (AHP) method has been used to prioritize each of the main criteria and sub-criteria. Later, fuzzy VlseKriterijuska Optimizacija I Komoromisno Resenje (F-VIKOR) method has been employed to prioritize the 14 alternatives. The present investigation reveals that Khuzdar (C2), Badin (C3), and Mastung (C7) are the most suitable cities for the installation of solar PV power projects in Pakistan. Finally, the outcome of the sensitivity analysis revealed that obtained results are reliable and robust for the installation of solar PV power projects in Pakistan. This study shall assist government, energy planners, and policymakers in making cities sustainable by establishing solar power projects in Pakistan.

Heavily chromium-polluted areas, where people are prohibited from entering, are paradises for stray dogs. In this study, stray dogs were used to study the effects of chromium exposure on the heart of dogs in severely Cr(VI)-contaminated rural areas of China. The dogs were given water (control), low dose (L, 0.92 mg/kg), medium dose (M, 1.15 mg/kg), and high dose (H, 1.38 mg/kg) of Cr(VI). The changes of electrocardiogram (ECG), myocardial enzyme parameters, inflammatory factors, oxidative kinase, and ATPase were measured to determine the toxicity of chromium on the heart of dogs. Results showed that the ST segment of ECG increased significantly, and the amplitude of T wave increased in the experimental group. The myocardial enzyme (CK-MB, AST, CK, and LDH) content in groups M and H increased significantly over time. The values of CAT, T-SOD, IL-10, and ATPase (K⁺-Na⁺-ATPase and Ca²⁺-Mg²⁺-ATPase) decreased with the increase of Cr(VI) dose, and the content of MDA, IL-1β, IL-8, and TNF-α increased with the increase of Cr(VI) dose. Our study suggested that the heart of Chinese rural dog was damaged by Cr(VI), and Cr(VI) could cause oxidative damage and alteration of ATPase content in dogs.

CeO₂/Ag₂CrO₄ composite photocatalyst was successfully fabricated using electrospinning and calcination and chemical precipitation method based on CeO₂ ribbon-like fibers and characterized by field-emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (DRS) and Fourier-transform infrared spectroscopy (FT-IR). The as-obtained CeO₂/Ag₂CrO₄ composite used photocatalytic performance in the sonophotodegradation of rhodamine B in aqueous solution under visible-light (LED) irradiation. DRS analysis illustrates that CeO₂/Ag₂CrO₄ composite exhibited enhanced absorption in the visible region-attributed CeO₂ nanofibers. The effect of four effective parameters including initial concentration of rhodamine B (RhB), photocatalyst dosage, pH, and irradiation time was studied and optimized using central composite design. The kinetic studies confirmed ability of pseudo first-order reaction based on the Langmuir–Hinshelwood model for fitting empirical data, while its rate constant (kₒbₛ), L–H rate constants (kᵣ), and L–H adsorption constants (KA) were 0.0449 min⁻¹, 11.66 mg L⁻¹ min⁻¹ and 1.09E−3 mg L⁻¹, respectively. The enhanced photocatalytic activity could be ascribed to the ultrasound field and formation of a heterojunction system among CeO₂ and Ag₂CrO₄, which lead to a better mass transfer and higher efficiency of charge electron–hole separation, respectively.

Industrial transfer has swept through in China. However, there is still a knowledge gap about its environmental effects. In this study, industrial transfer status was assessed and evaluated by industrial ratios (%; the gross product contributions of the secondary industry to the whole industry) and the impact of such transfer on atmospheric environment (SO₂, NO₂, PM₁₀ (particles with aerodynamic diameter less than 10 μm), precipitations of SO₄²⁻, NO₃⁻, and NH₄⁺) in the 38 districts and counties in Chongqing was analyzed and discussed for the period of 2006–2015. Results showed that industries were transferred obviously from the main urban region (MUR) into the 1-h economic region (OHER). Atmospheric sulfur and PM₁₀ were efficiently put in control, but atmospheric nitrogen (NO₂; precipitations of NO₃⁻ and NH₄⁺) was increasing and posted a potential threat to air quality especially during 2011–2015. Correlations showed that industrial ratios had significantly positive relationships with concentrations of ambient SO₂ and PM₁₀ in the MUR and ambient NO₂ in the OHER (p < 0.05) while a remarkably negative one with concentrations of ambient SO₂ in the OHER (p < 0.05) during 2006–2015, implying that industrial transfer could be effective in transferring sulfur pollution but not as efficient in transferring atmospheric nitrogen and PM₁₀ pollutions as SO₂ between in the MUR and OHER. More measures should be taken to reduce nitrogen and PM₁₀ emission and a regional monitoring network of ambient NH₃ is in urgent need.

Acid gases such as carbon dioxide and hydrogen sulfide are common contaminants in oil and gas operations, landfill gases, and exhaust stacks from power plants. While there are processes currently used to treat these effluents (e.g., amine absorption and adsorption using zeolite), many of these processes require high energy, space, and hazardous chemicals. Removal using biochar derived from the fast pyrolysis of forestry residues represents a more sustainable option. In this study, adsorption using CO₂ as a surrogate for acid gases was investigated using various biochars produced from fast pyrolysis of sawmill residues. Response surface methodology was used to determine operating conditions for maximum adsorption and assess interaction of the adsorption parameters, i.e., temperature, inlet feed flow rate, and CO₂ concentration, on biochar adsorption capacity. The Freundlich isotherm best represented the equilibrium adsorption, and the kinetic model was pseudo first-order. Thermodynamic analysis indicated the adsorption process was spontaneous and exothermic. The biochar had better adsorption capacity relative to commercial zeolite. Our results suggested that biochar could be used as a sustainable and cost-effective option for contaminant removal from acid gases produced in landfill gas treatment, fossil fuel extraction, and/or combustion.