International Journal of Environmental Science and Technology最新文献

Remediation of textile wastewater with conventional technologies is challenging as it contains a significant amount of unfixed dyes in addition to various biodegradable and non-biodegradable chemicals. The present work aims at treating simulated textile wastewater in batch mode through Electro-coagulation by employing a novel perforated three-dimensional rotating aluminum electrode. This electrode aids in avoiding common issues associated with standard plate electrode systems. The combined effect of operating parameters on efficiency was examined using the Taguchi method. The experiments were also conducted on real textile effluents at optimum conditions identified for the simulated textile wastewater. At operating conditions of initial pH 6, electrolyte(sodium chloride) concentration of 3 g/L, current density of 20 mA/cm², rotational speed of 50 rpm and electrolysis time of 40 min, the color and Chemical oxygen demand removal efficiency for simulated textile wastewater of 99.99% and 85.63% were observed at Specific Electrical Energy Consumption of 0.191 J/mg of the Chemical oxygen demand removed and for real textile effluent, color and Chemical oxygen demand removal efficiencies of 92–98% and 80–85% respectively were observed for Specific Electrical Energy Consumption ranging between 0.025–0.031 J/mg. On comparing with the literature, it was observed that the energy consumption of three-dimensional rotating electrode for similar removal efficiency is much lower than plate electrodes.

The degraded air quality has become an international issue with rising cases of respiratory health issues across the globe while contributing to the symptoms of chronic health problems such as cardiovascular disease, lung cancer, and nervous system disorders. Therefore, it is important to leverage the potential of the latest technologies to address the concerns related to degrading air quality. This systematic review is focused on robot-assisted indoor air quality (IAQ) monitoring and assessment. This review is conducted based on the 14 most relevant papers included from 5 different databases, and the available information is synthesized with PRISMA guidelines to find answers to 6 potential research questions. The main contribution is to provide highlights to different types of ground robotic systems used by existing researchers for IAQ assessment. The synthesis shows that commercial robotic units are widely preferred for IAQ monitoring applications in comparison to the self-designed robot systems. The authors in this paper also put emphasis on energy consumption, power requirements, functionality details, and communication technologies used by existing researchers. This paper highlights potential challenges, gaps, and findings of the existing studies while creating a roadmap for future researchers, public health experts, and government agencies working in this domain application.

The use of natural deep eutectic solvents (NADES), combined with sustainable technologies for recovering bioactive compounds from plant matrices, aligns with the principles of green chemistry and the circular economy. This study utilized the Web of Science© database to explore scientific publications related to the extraction of bioactive compounds from fruits and their residues using natural deep eutectic solvents. The search terms included “natural deep eutectic solvent*” OR nades AND fruit* AND “phenolic compound*” OR “bioactive compound*” AND waste AND pomace AND “by-product*” AND agrowaste. Bibliometric analysis was conducted using VOSviewer and Bibliometrix software (R package) to survey scientific production and evolution from 2011 to September 2023. A total of 927 articles were retrieved, and 2022 was identified as having the highest number of documents (n = 248). China led in publications (n = 834), and there was a noteworthy cooperation network between countries (n = 72) with 483 collaboration records. The primary research areas involving the use of NADES for bioactive recovery from fruit waste were Chemistry (n = 226/24.4%), Food Science and Technology (n = 170/18.3%), Chemical Engineering (n = 135/14.6%), Biochemistry and Molecular Biology (n = 130/14.0%), and Physical Chemistry (n = 103/11.1%). Five main clusters were identified, revealing diverse interests in the physicochemical properties of NADES and methods for identifying compounds of interest. In conclusion, the bibliometric survey indicates a sustained and notable interest in elucidating extraction mechanisms with NADES, which will enable the application of extracts in several industries, including pharmaceutical, chemical, and food.

Microplastic contamination of lakes and rivers is an emerging environmental issue. Sources, environmental fate, in-situ behaviour, concentration and harmful impacts of microplastics on aquatic life are the focus of this review paper. Present review summarises the current state of information about microplastics in riverine ecosystems around the world. The tiny plastic particles can serve as substrate as well as transporters of a variety of toxicants, including recalcitrant chemical compounds from miscellaneous sources having potential to seriously harm people's health. Further, intake and entanglement of microplastics can inflict a number of adverse bio-physico-chemical impacts on people and other living creatures. Secondary microplastics are produced by the disintegration of bigger size primary plastic particles and ultimately end up in the terrestrial and aquatic habitats. Comprehensive information on microplastic pollution in fresh water ecosystems is still limited on a single platform. This review critically addresses the microplastic pollution in rivers, sources, and its impact around the world. Further, possible replacements for plastics like modified starch, cellulose, esters of cellulose, polylactic acid etc. derived from biomass and microorganisms are also examined.

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Chia mucilage-grafted-acrylamide was designed using a microwave-assisted method for removal of hazardous azodyes from aquatic environments. After testing different batches, batch with highest grafting efficiency and water retention capacity (50% ± 1.25 and 500% ± 2.5, respectively) was chosen for characterization and adsorption analysis. Fourier transform infrared spectroscopy confirmed the presence of functional groups corresponding to both Chia mucilage and Acrylamide in the hydrogel. Scanning electron microscopic images showed transition of initially smooth fibrillar structure of chia mucilage to comparatively rougher and granular copolymer arrangement. Hydrogel was found thermally stable up to 480 °C whereas dynamic light scattering analysis exhibited hydrodynamic size of 593.8 nm and zeta potential of 30 mV, indicating moderate stability of hydrogel. Upon optimization, maximum adsorption efficacies were observed at 50 mg/l Reactive Black-5 concentration, 50 mg hydrogel, pH-4 and 25 °C. Adsorption results showed slightly greater inclination towards Pseudo-first order kinetic model due to close proximity between experimental and calculated values of adsorbed amount at equilibrium i.e. q_e and q_cal values (19.30 and 20.71 mg/g respectively). Maximum monolayer adsorption capacity obtained from Langmuir isotherm was found as 100 mg/g. Additionally, adsorption behavior of Reactive Black-5 onto chia-based copolymer was more in line with the Freundlich isotherm (R² = 0.99) compared to Langmuir (R² = 0.92) and Sips (R² = 0.83) models, as shown by linear plots. Repeated experiments demonstrated that prepared hydrogel could be a sustainable adsorbent, offering an economical and swift solution for successful remediation of Reactive Black-5 from contaminated water bodies.

The current research explored the potential of CuSe nanoparticles for mineralizing a neonicotinoid insecticide Imidacloprid (C₉H₁₀ClN₅O₂) from aqueous solutions to ensure a safe, pollutant-free environment. A simple chemical precipitation method was used to synthesize CuSe hexagonal nanoplates. From a material science perspective, this synthetic approach is interesting because of the relatively low reaction temperature, the use of a single precursor, and the development of nanomaterials without the need for surfactants. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, band gap measurements, energy-dispersive X-ray crystallography, scanning electron microscopy, and thermogravimetric analysis were used to characterize CuSe nanostructured hexagons, which were approximately 56 nm in size. CuSe nanoparticles and UV light were used to test the photocatalytic degradation of imidacloprid present in aqueous solution. Furthermore, the effect of pH, temperature, photocatalyst concentration, and initial imidacloprid concentration on the activity of CuSe nano-photocatalyst and reaction kinetics were investigated. In the presence of UV light, CuSe demonstrated high photocatalytic ability to remove imidacloprid from an aqueous solution. The highest imidacloprid removal efficiency (R% 92) was achieved at [C₀] with as little as 15 mg L⁻¹ of imidacloprid, pH = 9, 45 °C temperature, and 18 W m⁻² of light intensity after 60 min of irradiation. The data on photocatalytic degradation was also validated by using the GC–MS and HPLC–UV methods. There were no dangerous degradation by-products produced, according to the GC–MS analyses.

Peanut shells (PS) were studied as a low-cost alternative biomaterial for removing Reactive Blue 203 dye from textile effluents. The crude biomass was characterized by chemical composition, Fourier-transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analyses. The biomass's thermodynamic parameters and kinetic profile of the dye adsorption process were evaluated. The biomass presented a zero-charge point of 6.9, having a wide pH range favorable for the adsorption of the azo-anionic RB 203 dye. High crude fiber (69.25 g 100 g⁻¹), polysaccharides (glucan: 20.90 g 100 g⁻¹ and xylan: 8.90 g 100 g⁻¹), lignin (39.4 g 100 g⁻¹), mineral residue (6.2 g 100 g⁻¹) and mesoporous surface were observed, and the pH and temperature greatly influenced the adsorption behavior. The peanut shell particles were thermally stable up to close to 150 °C, with 4 mass-loss events observed throughout the thermogravimetric analysis. The adsorption rate was proportional to the square of the number of accessible adsorption sites, following a pseudo-second-order kinetic pattern, suggesting that surface reactions governed the adsorption process and that both surface homogeneity and interactions among the adsorbed dye were present. The biosorption isotherm followed Langmuir’s model [maximum adsorption capacity (q_max) of 49.30 mg g⁻¹], and the adsorption was exothermic and considered a physical mechanism. In tests with industrial dye effluent, the biomass showed a removal efficiency of 66.8% color, 65.3% BOD₅, and 74.1% COD. Peanut shells showed an excellent affinity for RB 203 dye adsorption, revealing its potential as a cheap biomaterial for treating effluents rich in color.

This study aimed to investigate the contamination of heavy metals including cadmium (Cd), copper (Cu), zinc (Zn), and lead (Pb), and monitor the spatial distribution of soil contamination around the municipal landfill site in Gorgan, Iran. Samples were taken from the surface and deep soil to investigate changes in heavy metals from 110 spots all around the landfill site. The highest concentrations of heavy metals in the collected surface samples were related to zinc, lead, copper, and cadmium, respectively. The values of Cd, Pb, Cu, and Zn in the collected surface samples varied between 0.11–0.51, 18.2–53.9, 21.2–44.9, and 71.2–103 mg, respectively. The mean concentrations of cadmium, lead, copper, and zinc increased by 2.25, 1.08, 0.99, and 0.63 times compared to the initial values, respectively. The highest concentrations of heavy metals in the collected deep samples were related to zinc, lead, copper, and cadmium, respectively. The values of Cd, Pb, Cu and Zn in the collected deep samples varied between 0.09–0.41, 12.2–43.9, 14.0–37.9, and 43.1–72.9 mg respectively. The mean concentrations of cadmium, lead, copper and zinc increased by 1.57, 0.87, 0.61, and 0.56 times compared to the initial values, respectively. The spatial distribution maps show a high concentration of heavy metals located at the central and northwestern parts of the landfill site. The results showed a moderate contamination factor for all heavy metals in the surface soil of the landfill area. The geo-accumulation index ranged from un-contaminated to moderate pollution for zinc, lead, and copper and moderate pollution for cadmium.

Photocatalytic degradation of methylene blue on pure and Cr-doped CaTiO₃ particles under UV–visible light has been investigated. Samples were analyzed using a variety of spectroscopic methods, including X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and ultraviolet–visible diffuse reflectance spectroscopy. The results show that the visible light absorption capability of CaTiO₃ was significantly enhanced by Cr doping due to the reducing bandgap (~ 2.91 eV) compared to that (3.29 eV) of the pure sample. Successively, enhanced photocatalytic activity was achived for Cr-doped CaTiO₃.

Physicochemical characterization and lead removal from synthetic polluted water were evaluated onto Mg–Al based layered double hydroxides (LDHs) as novel low-cost adsorbents whose facile pH co-precipitation synthesis approach is reported. The well elaborated X-ray characterization ascertained the obtaining of crystalline phases belonging to hydrotalcite-type materials. Anionic clay functions have also been verified by infrared analysis, consisting of OH- and CO₃²⁻ intercalation anions, as well as O- metal bonds. These functional groups which corresponding peaks were attenuated after calcination, are important aspects identifying LDH structures. Typical adsorption–desorption isotherms confirmed the formation of cluster mesopores within LDH texture, with a sufficiently high specific surface area of 91 m²/g, reduced after calcination. The morphological characterization revealed the presence of aggregates with irregular shapes and sizes, getting greater when calcined, suggesting a lamellae collapsing with temperature rise. A total mass loss of 53% of the non calcined Mg–Al-CO₃-NC was deduced from thermogravimetric analysis. The impact of several influential parameters on lead sorption onto Mg–Al-CO₃-NC and 500 °C-calcined Mg–Al-CO₃-C materials, such as adsorbent dose, contact time, pH, and isoelectric point was investigated. It revealed a rapid kinetic behavior with high adsorption amounts, clearly improved by the catalytic effect of calcination. Sorption data were in good agreement with the pseudo-second order mode rather than pseudo-first order model with maximum adsorption quantities of, 168.7 mg.g⁻¹ for Mg–Al-CO₃-NC and 197.9 mg.g⁻¹ for Mg–Al-CO₃-NC. Pb(II) adsorption mechanism was not limited only to the diffusion process, as evidenced by Weber–Morris approach with non-zero intercept. The aforementioned findings are of great utility, confirming the importance of the synthesized Mg–Al-CO₃ systems to serve as potential candidates for water environmental remediation.

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