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Background: In the past decade, a rising trend has seen in the use of plant-based medicines because of fewer/no side effects. Plants are always the major source of traditional medicines in every culture. The main objective of this review is to shed a light on phytochemical composition and pharmacological research of Valeriana wallichii. Methods: Electronic databases like Google Scholar, PubMed, Scopus, etc., were searched for traditional uses, extraction of phytoconstituents, therapeutical uses and pharmacology of V. wallichii. Results: V. wallichii has been used as a sleep remedy since ancient times in the Indian traditional system of medicines. It is also used as diuretic, spasmolytic and pain relieving agent. It is used for the treatment of epilepsy, dyspeptic symptoms, failing reflexes, habitual constipation, insanity, nervous debility, obesity, spastic disorders, and in snake poisoning, and also reported to have cytotoxic potential. The pharmacological activity of the plant is due to presence of different types of secondary metabolites, including valerianic acid, valerosidatum glycoside, valepotriates, dihydrovaltrate, 6-methylapigenin, hesperidin, sesquiterpenoids, bornylisovalerianate, isovalerenic acid, 1-camphene, 1-pinene, terpineol, valerianine, bornylisovalerianate, valerianine and so on. This review focuses on detailed phytochemistry of the plant and its therapeutic indication. The main emphasis is given on anticancer potential of V. wallichii, with in vitro cytotoxic as well as in vivo antitumor description. Conclusion: The review reveals that further research, as well as clinical trials, are needed to know this plant as an effective drug for the treatment of cancer in future with exact molecular mechanisms.

Fifteen star-category hotels in the National Capital Region of India were surveyed to assess the mixed fruit and vegetable waste generated. Based on the survey, a model mixed waste was prepared and used to identify the optimal procedure for recovery of bioactive phytochemicals and Trolox equivalent antioxidant capacity (TEAC) followed by preliminary identification of phytochemical constituents. The optimization procedure was done over (i) level I focusing on sample type (fresh, oven dried, vacuum dried), extraction technique (maceration, ultrasound assisted extraction), removal of interfering components by treatment with dichloromethane (DCM) and extraction in different solvents, and (ii) level II focusing on solvent concentration and extraction time, in both non DCM and DCM treated samples. The model mixed waste consisted of peels of pineapple, papaya, potato, pomegranate, apple, onion and citrus. The optimal conditions for recovery of phytochemicals and TEAC were non DCM treated vacuum dried samples subjected to ultrasonic assisted extraction for 60 min using ∼ 63% acetone. This resulted in recovery of appreciable amounts of total extractable phytochemicals consisting of polyphenols and flavonoids as the major components with relatively smaller amounts of flavones and flavanols. High TEAC values were obtained with both aqueous phase (ABTS) and organic phase (DPPH) assays. Preliminary investigation revealed the presence of various high-value compounds particularly gallic acid, ferulic acid, rutin and catechin in the phytochemicals extract. Consequently, there is significant potential to recover value-added phytochemicals from mixed fruit and vegetable waste from hotels contributing towards a circular bioeconomy.

Background The coronavirus disease 2019 (COVID-19) pandemic challenged the healthcare infrastructure, with health-service providers (HSPs) offering unconditional and unprejudiced service to admitted patients. During the first wave, due to the novelty of the disease and the lack of clarity regarding its transmission in the initial phases of the evolution of the disease, the predominant fear was of contracting the disease while caring for patients. With the prevailing uncertainty in knowledge and management, this study was planned to identify the barriers to delivering optimal healthcare to COVID-19 patients. Methodology A cross-sectional study was conducted among HSPs working in the first phase of a dedicated 500-bed government COVID-19 hospital at Kalinga Institute of Medical Sciences using an online questionnaire with the following five aspects: workplace guidelines and support, protective equipment, access to information regarding updates on the epidemic, overall self-reported stress and workplace stress about self-infection with COVID-19 and family being infected, and demographics. All HSPs aged 18 years or above, who were working either on a full- or a part-time basis, were able to understand the English language, and who were working in the COVID-19 hospital and gave digital informed consent (via Google Forms) were included in the study. All data were collected, coded, tabulated, and analyzed using Google Forms in an Excel format and Epi Info software version 7.2.5.0. Results Of the 144 respondents contacted, 132 completed the survey, with a participation rate of 91.67%. About 52.27% of respondents were aged 21-30 years, 68.18% were females, and 56.06% were nurses. Challenges faced were "working in a new context" (40.91%), "the uncertainty and fear of being infected and infecting others"(31.06%), and "exhausted by the workload and protective gear" (18.94%). Moreover, 64.12% were aware of a workplace policy. Only 0.75% felt that their workload needed to be reduced; 2.27% felt the need for a penalty policy for hiding travel history, lack of quarantine compliance, avoiding the accumulation of face masks, and price inflation of face masks. The overall self-reported stress level was significantly associated with a lack of awareness of workplace policies and the fear of getting infected. Furthermore, 93.94% reported that they had an adequate supply of personal protective equipment. As high as 81.06% of the HSPs were "worried about being infected from COVID-19 during work," and 94.69% were "worried about their family being infected from COVID-19 due to their working in COVID-19 hospitals." Conclusions HSPs' perception of barriers in providing healthcare gave an insight into the problems being faced and helped improve the quality of services. The study highlighted the need of increasing awareness regarding the existing workplace policies among HSPs to promote preparedness during crisis management.

Herein, the α-Bi2O3 nanocrystal decorated by nitrogen dopant and its heterojunction nanocomposite with g-C3N4 (N0.1/Bi2O3/g-C3N4) is successfully fabricated for the first time, for photo-oxidation of RhB and photo-reduction of Cr(VI) to Cr(III). The resulting N0.1/Bi2O3/g-C3N4 (3%) nanocomposite showed an optimal Cr(VI) photo-reduction and RhB photo-oxidation rates under visible-light irradiation, being 3–4 times higher than that of pure α-Bi2O3. The results from XPS confirmed the substitution of nitrogen with various oxidation states from N3+ to Nx+ (x < 5), due to the existence of different nitrogen oxides including N−O, O−N=O, and NO3− in the crystal structure. We investigated the reaction mechanism using catalytic tests, impedance spectroscopy, EPR technique, and density functional calculations. The DFT calculations presented the appearance of a new mid-gap hybrid of p states, comprised of N 2p, O 2p, and Bi 6P states, which enhance light absorption capacity and narrow band gap. The theoretical results were in excellent agreement with experimental UV-Vis data. The N0.1/Bi2O3/g-C3N4 nanocomposite exhibited acceptable practical application value and recycling ability for removal of the contaminants. Such improved photocatalytic activity is originated from the modified band positions, new electron evolution pathway, introducing defects in α-Bi2O3 by insertion of N atoms into the Bi sites, and the enhanced charge carrier mobility between N0.1/Bi2O3 and g-C3N4. The strategy to form nitrogen-doped bismuth-based nanocomposites may open a new opportunity to design atomic-level electronic defects by feasible methods to obtain a versatile photocatalyst material with simultaneous photo-reduction and photo-oxidation ability for removal of Cr(VI) and organic dyes from water.

Economic growth and the rapid increase in the world population has led to a greater need for natural resources, which in turn, has put pressure on said resources along with the environment. Water, food, and energy, among other resources, pose a huge challenge. Numerous essential resources, including organic substances and valuable nutrients, can be found in wastewater, and these could be recovered with efficient technologies. Protein recovery from waste streams can provide an alternative resource that could be utilized as animal feed. Membrane separation, adsorption, and microbe-assisted protein recovery have been proposed as technologies that could be used for the aforementioned protein recovery. This present study focuses on the applicability of different technologies for protein recovery from different wastewaters. Membrane technology has been proven to be efficient for the effective concentration of proteins from waste sources. The main emphasis of the present short communication is to explore the possible strategies that could be utilized to recover or restore proteins from different wastewater sources. The presented study emphasizes the applicability of the recovery of proteins from various waste sources using membranes and the combination of the membrane process. Future research should focus on novel technologies that can help in the efficient extraction of these high-value compounds from wastes. Lastly, this short communication will evaluate the possibility of integrating membrane technology. This study will discuss the important proteins present in different industrial waste streams, such as those of potatoes, poultry, dairy, seafood and alfalfa, and the possible state of the art technologies for the recovery of these valuable proteins from the wastewater. Graphical abstract

Developing new and efficient technologies for environmental remediation is becoming significant due to the increase in global concerns such as climate change, severe epidemics, and energy crises. Air pollution, primarily due to increased levels of H

The high-performance photocatalysts have received considerable attention in the field of environmental remediation. Herein, the synthesis of multi-phase BiOx nanocrystals decorated by phosphorus dopant is reported through a facile one-pot solvothermal method. The resulting P0.15BiOx photocatalyst exhibited an optimal Cr (VI) reduction and RhB oxidation rates of 84% and 96% under visible light irradiation, being nearly 2 times higher than that of pristine BiOx sample. The improved photocatalytic performance could be ascribed to the synergetic effects of well-matched band positions via formation of new electron evolution pathway, efficient charge carrier mobility and introducing electronic defects by insertion of P5+ ions into the structure. Furthermore, DFT presented formation of mid-gap hybrid of p states, which enhanced the light absorption capacity. The photocatalytic mechanism revealed the photogenerated holes were dominant. Moreover, the P0.15BiOx had quite stable crystal structure and recycling ability. In this work, we obtained a single metal oxide with polycrystalline nature which obtains better charge separation compared to the pure phases, leading to capability of the photocatalyst for both photo-oxidation and photo-reduction processes. The present study provides new insights into the design of atomic-level structural defects in the photocatalysts by a facile method, for efficient removal of heavy metal ions and dyes from the wastewater.

The research aimed to develop a novel mesoporous aluminosilicate/zeolite composite by the template co-precipitation method. The effect of aluminosilicate (AlSi) and zeolite (NaY) on the basic properties and adsorption capacity of the resultant composite was conducted at different mass ratios of AlSi/NaY (i.e., 5/90, 10/80, 15/85, 20/80, and 50/50). The adsorption characteristics of such composite and its feedstock materials (i.e., aluminosilicates and zeolite) towards radioactive Sr2+ ions and toxic metals (Cu2+ and Pb2+ ions) in aqueous solutions were investigated. Results indicated that BET surface area (SBET), total pore volume (VTotal), and mesopore volume (VMeso) of prepared materials followed the decreasing order: aluminosilicate (890 m2/g, 0.680 cm3/g, and 0.644 cm3/g) > zeolite (623 m2/g, 0.352 cm3/g, and 0.111 cm3/g) > AlSi/NaY (20/80) composite (370 m2/g, 0.254 cm3/g, and 0.154 cm3/g, respectively). The Langmuir maximum adsorption capacity (Qm) of metal ions (Sr2+, Cu2+, and Pb2+) in single-component solution was 260 mg/g, 220 mg/g, and 161 mg/g (for zeolite), 153 mg/g, 37.9 mg/g, and 66.5 mg/g (for aluminosilicate), and 186 mg/g, 140 mg/g, and 77.8 mg/g for (AlSi/NaY (20/80) composite), respectively. Ion exchange was regarded as a domain adsorption mechanism of metal ions in solution by zeolite; meanwhile, inner-surface complexation was domain one for aluminosilicate. Ion exchange and inner-surface complexation might be mainly responsible for adsorbing metal ions onto the AlSi/NaY composite. Pore-filling mechanism was a less important contributor during the adsorption process. The results of competitive adsorption under binary-components (Cu2+ and Sr2+) and ternary-components (Cu2+, Pb2+, and Sr2) demonstrated that the removal efficacy of target metals by the aluminosilicate, zeolite, and their composite remarkably decreased. The synthesized AlSi/NaY composite might serve as a promising adsorbent for real water treatment.

This study focuses on the synthesis of nanocomposites named CCA and CZA that were prepared by the incorporation of cellulose (CL) in the Ca/Al and Zn/Al layered double hydroxide (LDH), respectively. These materials were then used for the uptake of As(III) and As(V) from aqueous medium. Characterization of both nanocomposites (CCA and CZA) was done using FTIR and Raman analysis to identify the functional groups, N2 adsorption-desorption isotherms to determine the specific surface area and pore geometry and XPS analysis to obtain the surface atomic composition. Some other characters were investigated using simultaneous TGA and DTA and elemental chemical analysis (CHNS/O). The crystallinity of the prepared nanocomposites was displayed by XRD patterns. Furthermore, the sheet-like structure of the LDHs and the irregularity of surface morphology with porous structure were observed by TEM and SEM microphotographs. Optimization of maximum adsorption capacity was adjusted using different parameters including pH, contact time and adsorbent dosage. The pseudo-second-order model was in good fitting with kinetics results. The adsorption isotherm results showed that CZA exhibits better adsorption capacity for As(III) than CCA and the Langmuir isotherm model described the data well for both nanocomposites. Thermodynamic studies illustrated the endothermic nature of CCA and exothermic nature on CZA, as well as the fact that the adsorption process is spontaneous. A real water sample collected from well located in Gabes (Tunisia), has also been treated. The obtained experimental results were confirmed that these sorbents are efficient for the treatment of hazardous toxic species such as.

Accurate Object Detection was always a big deal and an important part of the Information Technology era. After the arrival of Machine Learning and Deep Learning technologies, the efficiency and accuracy for Object Detection increased significantly. These technologies greatly assisted in the evolution of the computer vision systems. This project focuses to integrate state-of-the-art technique for object detection with the aim of the achieving high accuracy. In this project we are using a deep learning part which is Tensorflow and OpenCV, which is a library of programming functions mainly aimed at real-time computer vision. There are few other libraries used which helped in object detection to make the system more accurate and reliable in the long run. We trained the network on various objects which are ordinary and easily available in the market. This projects aim to reduce the billing time in super markets with fast and accurate detection.

The photocatalytic degradation of carbamazepine (CBZ) in ultra-pure water was investigated by using neodymium (Nd)-doped antimony trioxide (Sb2O3)/titanium dioxide (TiO2) photocatalyst under the UVC irradiations of 254 nm wavelength. The hydrothermal method was used for the fabrication catalyst samples with different ratios of Nd (0%–2%) dopant, and characterised by X-ray diffraction pattern (XRD) to investigate the crystallinity. Scanning electron microscopy (SEM) provided the surface morphologies, Bruanuer-Emmer-Teller (BET) analysis gave the textural properties, and UV–Vis diffuse reflectance absorption spectroscopy (DRS) was used for the investigation of the optical properties of synthesized catalysts. TEM images of Sb2O3 showed a nanorod-like structure while, in the Nd-doped Sb2O3/TiO2, a small dot-like structure was observed along with the nanorods. The surface area and band gap of 1% Nd-doped Sb2O3/TiO2 were found to be 9.56 m2 g−1 and 3.0 eV respectively. It was observed that the CBZ cannot be degraded in the absence of catalyst under UV light, while photocatalyst 1% Nd-doped Sb2O3/TiO2 at 0.5 g/L of catalyst dose showed the best photocatalytic activity towards CBZ degradation. The main degradation products were identified with high-resolution mass spectrometry. Moreover, the degradation of CBZ followed pseudo first-order kinetics and the rate constant was 0.017 min−1. Quenching tests by the addition of methanol from 100 to 500 mM were carried out to determine the major reactive oxygen species, which showed that OH radicals was involved in the CBZ degradation. Active species-trapping experiments revealed that ∙O2− is also responsible for the degradation of CBZ.

The present work describes a series of two-dimensional architecture of CTAB-assisted X-Bi2MoO6 (X: F, Cl, Br, I) with open surfaces for adsorption and photodegradation of RhB. The effects of Halogen-doping and surfactant on the physicochemical properties of Bi2MoO6 are investigated by different analysis. Based on the XRD patterns, the crystal planes of Bi2MoO6 were affected by the substitution of X− anions for the host O2− (mainly by F−). FESEM images confirmed the confined growth of nanoplates under the influence of CTAB template, which leads to surface doping of more halogen ions within oriented nucleation process. The results indicated all of the X-doped catalysts, especially F-doped sample, show enhanced photocatalytic activity with different levels, due to lower band gap, improved charge separation, and surface properties. The results from density functional theory (DFT) calculations revealed in all the X-Bi2MoO6 cases, the valance band maximum and conduction band minimum is mostly composed of O 2p and Mo 4d states, and the gaps decrease with the insertion of halogen atoms, which are in excellent agreement with experimental data. The study of the template-confined Halogen-doped Bi2MoO6 may furnish new perspective into the fabrication of a series of photocatalysts with better light-harvesting capacity in a sustainable manner.

Engineering and Applied Science Research, 49, 6, 753-762

The treatment of stormwater to remove and recover nutrients has received increasing interest. The objective of this study was to develop a novel adsorbent that is easy to handle, has good adsorption capacity, and is economical to use. A novel nanocomposite of montmorillonite (MT)-anchored magnetite (Fe3O4) was synthesised by co-precipitation as an adsorbent for ammonium. The MT/Fe3O4 nanocomposite had pore sizes (3–13 nm) in the range of narrow mesopores. The dispersion of the anchored Fe3O4 was confirmed by transmission electron microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy (XPS). The nanocomposite exhibited higher affinity towards ammonium than the original MT. The Langmuir isotherm model was found to be the most suitable model to explain the ammonium adsorption behaviour of the nanocomposite. The maximum adsorption capacity for ammonium was 10.48 mg/g. The adsorption mechanism was a combination of ion exchange and electrostatic interaction. In an authentic stormwater sample, the synthesised adsorbent removed 64.2% of ammonium and reduced the amount of heavy metal contaminants including Mn, Ni, Cu and Zn. Furthermore, the ammonium loading on MT/Fe3O4 during adsorption functionalised the adsorbent surface. Additionally, the spent nanocomposite showed potential for rare earth elements (REEs) adsorption as a secondary application, especially for the selective adsorption of Sc3+. The versatile application of montmorillonite-anchored magnetite nanocomposite makes it a promising adsorbent for water treatment. Graphic abstract

The catalytic behavior of magnesium ferrites doped with lanthanide ions (La3+, Ce3+, Sm3+, Gd3+, and Dy3+) on Methylene Blue (MB) degradation using Fenton process was studied. A slow increase in cubic Fd3m crystalline structure parameters and increase in crystallite size of doped samples magnesium ferrites were observed. A dramatic decrease in catalytic activity of catalysts obtained at 600 °C as compared to catalysts obtained at 300 °C was explicitly observed and this was grossly attributed to the elimination of surface hydroxyl groups as ascertained by FT-IR analysis. The initial magnesium ferrite demonstrated the highest catalytic activity under dark- (kˈ 0.0555 min−1) and visible-light (kˈ 0.1029 min−1) conditions. Catalytic efficiency of the lanthanides doped catalysts under UV-irradiation in accordance with the maximum appearance rate constant kˈ decreased in the following order Ce3+ > Dy3+ > La3+ ≈ MgFe2O4 > Sm3+ > Gd3+. The most active ferrites provided up to 99% of MB degradation in 60 and 20 min for visible- and UV-driven Fenton processes. Findings obtained from this study were observed to be competitive with other heterogeneous Fenton catalysts.

Octahydro-1, 3, 5, 7-tetranitro-1, 3, 5, 7-tetrazocine (HMX) is extensively exploited in the manufacturing of explosives; therefore, a significant level of HMX contamination can be encountered near explosive production plants. For instance, up to 12 ppm HMX concentrations have been observed in the wastewater effluent of a munitions manufacturing facility, while up to 45,000 mg/kg of HMX has been found in a soil sample taken from a location close to a high-explosive production site. Owing to their immense demand for a variety of applications, the large-scale production of explosives has culminated in severe environmental issues. Soil and water contaminated with HMX can pose a detrimental impact on flora and fauna and hence, remediation of HMX is paramount. There is a rising demand to establish a sustainable technology for HMX abatement. Physiochemical and bioremediation approaches have been employed to treat HMX in the soil, groundwater, and wastewater. It has been revealed that treatment methods such as photo-peroxidation and photo-Fenton oxidation can eliminate approximately 98% of HMX from wastewater. Fenton’s reagents were found to be very effective at mineralizing HMX. In the photocatalytic degradation of HMX, approximately 59% TOC removal was achieved by using a TiO2 photocatalyst, and a dextrose co-substrate was used in a bioremediation approach to accomplish 98.5% HMX degradation under anaerobic conditions. However, each technology has some pros and cons which need to be taken into consideration when choosing an HMX remediation approach. In this review, various physiochemical and bioremediation approaches are considered and the mechanism of HMX degradation is discussed. Further, the advantages and disadvantages of the technologies are also discussed along with the challenges of HMX treatment technologies, thus giving an overview of the HMX remediation strategies.

The present study is aimed at developing a synergistic combination to enhance learning and memory in Alzheimer’s patients with the help of eight common medicinal plants used in the AYUSH system. Aqueous and hydroalcoholic extracts of eight medicinal plants from the AYUSH system of medicine were prepared. These were subjected to in vitro anticholinesterase activity, to find out the combination index of synergistic combination. The synergistic combination and their individual extracts were subjected to total phenol, flavonoid and antioxidant activity estimation. Further, in vivo neurobehavioral studies in rats were carried out followed by TLC-MS-bioautographic identification of bioactive metabolites. Out of the sixteen extracts, aqueous extracts of Withania somnifera (L.) Dunal (WSA) and Myristica fragrans (L.) Dunal (MFA) were selected for the development of synergistic combination based on their IC50 value in vitro anticholinesterase assay. The synergistic combination inhibited the anticholinesterase activity significantly as compared to the individual extracts of WSA and MFA. The synergistic combination also showed more phenolic and flavonoid contents with potential antioxidant activity. The TLC-bioautography showed four white spots in WSA, signifying sitoindosides VII, VIII, quercetin, isopelletierine and Withanolide S as AChE inhibitory compounds while showing five white spots of anti-cholinesterase active metabolites identified as eugenol, methyl eugenol, myristic acid, galbacin and β-sitosterol in MFA. The observation of neurocognitive behavior in amnesia induced subjects manifested that both the synergistic combinations showed comparable results to that of standard piracetam, though the synergistic combination containing a higher concentration of WSA showed more appreciable results in ameliorating dementia in rats. The study suggests that the synergy based combination successfully enhanced memory and learning by abating free radical and acetylcholine levels, and increased learning and memory in rats, providing a strong rationale for its use in the treatment of dementia and Alzheimer’s disease.

International audience; The goal of this study was to introduce an effective visible-light induced photocatalytic system with a good ability for photocatalytic oxidative desulfurization (PODS) and denitrogenation (PODN) using molecular oxygen (O2) as an oxidant. In this regard, tungestophosphoric acid (PW12) was supported onto cerium-doped NH2-UiO-66 (PW12/Ce-NUiO-66) and employed for the photo-oxidation of dibenzothiophene (DBT) and quinoline (Qu). Herein, using cerium (Ce) as a “mediator” facilitated the separation of charge carriers, while NH2-UiO-66 remarkably enhanced the surface area with plentiful adsorption sites and shifted the adsorption edge of PW12to the visible region. The sum of these factors resulted in superior photocatalytic ability and maximum efficiency of 99 ± 1% was achieved by using 30PW12/Ce-NUiO-66 as the optimum photocatalyst in the PODN system and 89 ± 1% in the PODS system under visible light irradiation for 90 min. The traditional Z-scheme mechanism was proposed as the main pathway for this photocatalytic system.

The peroxymonosulfate (PMS) and peroxydisulfate (PDS) were activated using plain and S-doped MgO (S-MgO) for oxidation of acetaminophen (ACT) in the contaminated water. The findings indicated that S-MgO was more efficient than plain MgO in activating the oxidants and that PMS was much better activated than PDS using S-MgO. The complete degradation and significant mineralization (up to 62.4%) of 50 mg/L ACT could be achieved in the S-MgO/PMS process using 1.4 mM PMS within a reaction time of 30 min and 60 min, respectively. Both SO 4 · - and HO · species were simultaneously generated in the S-MgO/PMS process with the contributions of 73.8% and 26.2%, respectively, in the ACT removal attained in the process. ACT removal in the S-MgO/PMS process was not considerably affected by the solution pH between 4 and 10 and the maximum ACT removal of 93.4% was achieved at the neutral condition and optimum PMS to catalyst ratio of 0.07 mM L/g. The performance of S-MgO/PMS process for removal of ACT was not affected by the presence of conventional anions in natural waters. The pathway of ACT degradation in the S-MgO/PMS process was proposed based on the Liquid chromatography–mass spectrometry (LC/MS) analysis of the effluent. Accordingly, the S-MgO is a very active catalyst to activate the PMS for simultaneous generation of SO 4 · - and HO · reactive species hence S-MgO/PMS process is an emerging AOP for high rate degrading the pharmaceutical compounds present in contaminated waters.

The reusability of spent adsorbents is the most important characteristic for their practical application. The process of MgFe2O4 regeneration after methylene blue (MB) adsorption was studied. The effect of the nature (HCl, HNO3, and MgCl2) and the concentration (10−3–10−1 M) of regeneration agents was established. All the regeneration agents at 10−3 and 10−2 M had high efficiency and adsorption capacity recovery reached 80–90%, whereas for 10−1 M concentration the adsorption efficiency was in the range of 4.5–36.2%. It was shown that the concentration of desorbed MB was much less than what had been previously adsorbed and did not correlate with regeneration efficiency. The unusual behavior of MgFe2O4 during regeneration could be due to different mechanisms of regeneration by OH3+ and Mg2+ ions: (i) for acidic regeneration the main process was the non-specific adsorption of OH3+ ions in a diffusion layer and the substitution of adsorbed MB due to electrostatic forces; (ii) in the case of Mg2+ as a regeneration agent, there was specific adsorption due to the completion of a crystal lattice of MgFe2O4 nanoparticles by Mg2+ ions (according to the rules of Fayans-Pannet) with the formation of new Mg-OH adsorption sites and the super-equivalent adsorption of Mg2+ ions (according to DLVO (Derjaguin, Landau, Verwey, and Overbeek) theory) accompanied by a recharge of the MgFe2O4 surface. These phenomena of MgFe2O4 regeneration using Mg2+ ions must be taken into account in the theory and practice of adsorption.

The main objective of this work comprises the investigation of biodiesel production from rapeseed oil using potassium impregnated Fe3O4-CeO2 nanocatalyst. The various concentration of potassium impregnated Fe3O4-CeO2 was screened for catalytic conversion of rapeseed oil to triglyceride methyl ester. The 25 wt % potassium impregnated Fe3O4-CeO2 nanocatalyst showed best biodiesel production. Nanocatalyst was characterized by FTIR, XRD, SEM, TEM, BET and Hammett indicator for basicity test. The characterization of biodiesel was performed with GC-MS, 1H and 13C NMR. Moreover, the optimum reaction parameters such as catalyst amount (wt %), oil to methanol ratio, reaction time and reaction temperature for transesterification reaction was analyzed and yield was determined by 1H NMR. The maximum yield of 96.13% was obtained at 4.5 wt % catalyst amount, 1:7 oil to methanol ratio at 65 °C for 120 min. The properties of biodiesel such as acid value and kinematic viscosity were observed as 0.308 mg KOH/g and 4.37 mm2/s respectively. The other fuel parameters such as flash point and density were also determined. The reusability of catalyst was observed and it showed stability up to five cycles without considerable loss of activity. The recovery of excess methanol after transesterification reaction was achieved using distillation process setup.

To overcome the shortage of freshwater resources and provide clean water for worldwide population, along with the elimination or reduction of water contamination, we have synthesized the mixed-lanthanide metal–organic framework (MOF) with the formula m(x)M(1–x)BTC(DMF) {m = Ce(III), M = La(III), x = 0.8} via the solvothermal technique to separate Nd ions from water. The cooperative interaction between La(III) and Ce(III) has intensified the nonlinear properties of Ce0.8La0.2BTC(DMF) resulting in the high interaction between fabricated MOF and Nd ions. The as-prepared MOF was considered for various structural analyses and experimental conditions. Significantly, over 80% of Nd ions have been removed within 5 min and the maximum Nd uptake capacity (qmax) determined by the Langmuir isotherm was 142.8 mg/g.

Heterojunction z-scheme based Ag,F co-doped Bi2MoO6/reduced graphene oxide (Ag,F@BMO/rGO) photocatalysts were synthesized via a facile solvothermal method. The present work describes the improved photocatalytic activity of BMO/rGO nanocomposite by co-doping of F− and Ag+ ions, to remove RhB from aqueous solution. The XRD, N2 adsorption, SEM, TEM, EDS, UV–Vis DRS, FT-IR, Raman, and PL measurements were employed to characterize the crystallographic, morphological, and optical properties. X-ray diffraction analysis suggests that crystal growth of all the as-prepared nanoparticles with different F− and Ag+ contents has occurred in Aurivillius phase and the crystal structure did not affected by doping. The insertion of Ag+ and F− into Bi2MoO6 led to a red-shift in the absorption edge of nanocomposite and decrease the band gap energy from 2.78 eV to 2.6 eV, due to the synergetic effects of Surface Plasmon Resonance and surface oxygen vacancy induced by Ag+ and F−, respectively. These beneficial properties are explored toward the photodegradation of RhB under visible-light source, resulting in better yields at lesser exposure time. The photocatalytic activity was significantly influenced by rGO in the nanocomposite, which was 2 times higher than that of pure Bi2MoO6, by effective separation of the charge carriers. The separation behaviors of photogenerated electron-hole were also systematically investigated by the PL. Based on the radical trapping experiments, photogenerated holes and O2•− were the main active species in RhB photodegradation and the detailed decolorization pathway has been suggested, using liquid chromatography/mass spectrometry (LC/MS) technique. In addition, the Ag,F@BMO/rGO nanocomposite does not display dramatic reduction of catalytic performance after four recycles, reveals its great prospect and promising application for water purification.

Magnesium ferrite (MgFe2O4) and metal-loaded (Mn2+, Co2+, Ni2+, and Cu2+) MgFe2O4 nanoparticles were used as Fenton-like catalysts for methylene blue (MB) degradation in aqueous solutions under visible light. Primarily investigated here were the effects of metal ions adsorbed onto MgFe2O4 and the conditions of catalytic MB degradation. The results of catalytic tests indicated that in the optimal conditions (catalyst dose of 0.5 g/L, pH 6.0, and H2O2 concentration of 20 mmol/L), the mineralization rate of MB reached approximately 98% in 30 min under visible light. There were no significant changes of crystal structure, morphology, particle size, and textural properties of studied catalysts after the adsorption and MB degradation tests. The kinetic studies indicated that the pseudo-first order model fitted well to the experimental data. The catalytic activity of metal-loaded samples rose with increasing Fe3+ and M2+ mobility and this activity ranged from approximately 91 to 97% after 4 consecutive cycles. The main role of OH radicals and holes h В C + in the MB degradation was established. Magnesium ferrite can serve as an effective material for catalytic and adsorption treatment of multi-component aqueous solutions containing organic pollutants and toxic metal ions. High efficiency of MgFe2O4 Fenton-like catalyst for MB mineralization under visible light was indicated. A catalytic mechanism in metal-loaded MgFe2O4/ H2O2 systems was proposed.

This article reports on the macronization of self-supported 3D CNT foam inter-connected by heteroatom-enriched porous shells derived from renewable baking ingredients via mild pyrolysis. The synthesized hybrids enabled disintegrating peroxymonosulfate (PMS) into reactive oxidants (sulfate radicals, hydroxyl radicals, and singlet oxygen) for the degradation of atenolol, iopamidol, metformin, trimethoprim, and phenol in water. Hierarchically structured nitrogen- and oxygen-doping significantly enhanced adsorptive and catalytic performance whereas the magnetic 3D framework promoted mass transport, multicycle use and induced synergetic effects via the Me-Nx-C interfaces. The samples were highly efficient for degradative removal of model pollutants at low catalyst and PMS dose. The catalyst loading, PMS dose, contact time, and temperature positively influenced the removal potency while pH and water matrix governed the rates differently. Spin trapping, oxidant quenching and solvent isotope effect study coupled with liquid chromatography and Fourier transform ion cyclotron resonance mass spectrometry analysis suggested the footprints of transformation products via a dual-mode (radical and non-radical) activation of PMS. This durable, magnetic carbofoam might be a promising catalyst for the oxidative abatement of pharmaceutical micropollutants from contaminated waters.

The article presents the results of the synthesis and research of a new biodegradable hybrid nanosized polymer-inorganic system possessing the double nature of heavy metal ions extraction from solutions. Firstly, the sorption of metal ions takes place by the ion-exchange properties of porous manganese oxide and, secondly, due to specific interaction and chelating with functional groups of polysaccharides in terms of nanochitin (ChNC). The synthesis is based on the colloid-chemical processes of interaction between polysaccharide and manganese oxide nanosized particles. Using the mathematical model of the Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory, it has been shown that this interaction occurs due to the formation of hydrogen bonds and electrostatic interactions of oppositely charged particles. Hybrid sorbents were characterised by X-ray diffraction, Fourier transform infrared spectroscopy, Transmission electron and Atomic force microscopy. The highest value of sorption capacity for hybrid materials was obtained for Ni2+ extraction and reached 114.0 ± 1.1 mg/g. It was shown that biodegradation of hybrid sorbents increases with the concentration of manganese oxide nanoparticles and almost complete degradation of the organic part can be performed within 6 days. The obtained biodegradable sorbents were designed to address ecological problems connected with the pollution of natural waters by toxic metallic ions.

The photocatalytic degradation of an artificial sweetener, acesulfame-K (ACE) was investigated using an ultraviolet light emitting diode (UV-LED) based irradiation in presence of titanium dioxide (TiO2), zinc oxide (ZnO), hydrogen peroxide (H2O2), peroxomonosulfate (PMS, HSO5−) and peroxodisulfate (PDS, S2O82−). The pH of ACE solution showed significant effect on the degradation of ACE. It was observed that low pH value enhanced the ACE degradation rate. After 120 min by UV-LED/TiO2 treatment, the degradation of ACE reached up to 90%, while in UV-LED/ZnO, UV-LED/H2O2, UV-LED/PMS, and UV-LED/PDS degradation rate were found to be 63%, 87%, 76% and 86% respectively. PMS and PDS both oxidant showed good results without the generation of any secondary sludge like other heterogeneous catalysts. The present study showed that in presence of catalysts and oxidants, UV-LED illumination significantly enhanced the degradation rate of ACE in comparison to direct photolysis by UV-LED. Possible degradation pathway of ACE was determined by gas chromatography-mass spectrometry (GC–MS) which confirmed the ACE degradation by generation of three byproducts.

Endosulfan is a highly polluting and toxic pesticide which has been used in many areas globally to control pests in view to improve productivity. Concomitantly, endosulfan has also been associated with many cases of environmental pollution and various types of irreversible metabolic dysfunctions in living organisms both on lands and in waters. Subsequently, since over the last three decades, several endosulfan remediation methods have been studied and many are gradually bringing hope towards efficient clean-up. This article specifically reviews endosulfan degradation and endosulfan removal by discussing the recent findings reported and the trends observed in studies reporting bacterial and fungal bioremediation, photocatalytic degradation, adsorption and membrane separation processes. The salient observations from this review are: there are many bacterial species which degrade endosulfan isomers with relatively high efficiencies; many studies indicate the merits of plants in phytoextracting and accumulating endosulfan but the identification of endosulfan hyperaccumulators remains; photocatalytic systems involving one or two metals also bring about significant endosulfan degradation but issues related with variations in rates of reactions, catalyst deactivation due to fouling, intricacy of metal-based nanocatalyst structures and their complex fabrication methods and lack of control of morphology of the nanosized structures have to be addressed; and membrane retention systems specifically treating endosulfan-contaminated aqueous media are scanty and more analysis is also needed to optimize the shear force-membrane structural integrity-membrane stability rapport of the membranes being developed. In the end, a number of research and development avenues which need further attention and probing towards the development of suitable endosulfan-remediation routes are pointed out. Post-print / Final draft

The present work encompasses the effect of Li+ ions on CaO nanoparticles for the transesterification of lard oil. The modification of CaO nanoparticles was achieved by the impregnation of different molar ratios of lithium hydroxide. Later, each catalyst was screened for the catalytic conversion of lard oil to a fatty acid methyl ester (FAME). The nanocatalyst CaO–0.5LiOH (1 : 0.5 molar ratio) showed the best conversion rate for FAME. The synthesized nanocatalyst was characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) analysis, and Hammett indicators for the basicity test. The obtained FAME was analyzed by gas chromatography with mass spectrometry (GC-MS) and 1H and 13C nuclear magnetic resonance (NMR). The effect of optimum reaction parameters such as catalyst weight percentage, oil-to-methanol ratio, reaction time, reaction temperature, and reusability of the catalyst for the transesterification reaction was analyzed by 1H NMR. The maximum FAME yield of 97.33% was obtained with 4 wt% catalyst amount and 1 : 6 oil-to-methanol ratio at 65 °C in 120 minutes. The physical properties of the synthesized FAME were also determined. peerReviewed