Search

The kinetics of ligand substitution reaction of Cu(methionine)2 complex by polyamines has been followed conductometrically above pH 9.0 at 25 oC. Millimolar solution of the Cu(NO3)2 and methionine in 1:2 molar ratio in water shows increase in conductance with time. When a polyamine (en, dien and trien) is added to the complex, the conductance increases at a rapid rate due to substitution of methionine by polyamine leading to the formation of [Cu(polyamine)2]. It was observed that the exchange of methionine by polyamine proceeds in a first order process. Since the rate of the reaction varies with the size of polyamines they can be placed in the following, en > dien > trien. In acidic pH range the absorption spectrum varies negligibly. However, the concentration of methionine does not have any influence on the absorption spectra.

This study entails the synthesis of molecularly imprinted polymers (MIPs) with good selectivity coefficients for azo dye as a potential sorbent material to extract azo dye from polluted aqueous media. A series of MIPs for methyl red (MR) as a template, were synthesized by changing the molar ratio of functional monomers, via precipitation polymerization format of non-covalent approach. Water-soluble functional monomer; acrylic acid (AA) was used to weave the frame work of polymers while ethylene glycol dimethacrylate (EGDMA) was utilized as crosslinking monomer. The impact of different experimental parameters, such as mole ratio of monomer (functional) to crosslinking monomer on the molecular recognition was investigated. The highly efficient and selective MR-MIP was used for the removal of spiked MR dye from different water samples. The selected imprinted polymer, MR1-MIP was able to selectively remove the MR molecules from aqueous media. A significant amount of dye was removed by MR1-MIP from the river water samples with a high degree of removal efficiency i.e. 92.25%. The imprinting factor of 3.75 for MR1-MIP indicated that the high selectivity in terms of adsorption for MR. A minimum loss of only ~ 3.35% in the removal efficiency within ten sequential cycles of adsorption–desorption study evidenced that MR-MIPs could be used as the most cost effective and best sorbent for the removal of MR from polluted water. Furthermore, the structural properties of MR-MIPs were characterized by FTIR and EDX, whereas TGA, SEM and BET were used to describe the thermal, morphological and surface structures of the particles, respectively. Graphical Abstract

In this study, zinc oxide (ZnO) as well as ZnO/GO (zinc oxide/graphene oxide) were successfully synthesized. The Carica papaya leaf extract was used to synthesize ZnO and oil palm empty fruit bunch biomass to obtain graphene, which was further used to obtain graphene oxide. The samples were characterized through a variety of analytical methods such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy and UV–Visible spectroscopy in order to understand their morphology, size, structural phase purity, functional groups and optical properties. Various peaks such as O-H, Zn-OH and Zn-O were found in the case of ZnO. Some additional peaks, such as C-C and C=C, were also been detected while analyzing the sample by Fourier-transform infrared spectroscopy. The results of the XRD and SEM studies demonstrated that the synthesized material shows the crystalline nature of the substance in the case of ZnO, and the crystallinity decreases for ZnO/GO. The average crystallite size was found to 80.0 nm for ZnO and 74.0 nm for ZnO/GO. Further, a red shift was shown in the case of ZnO/GO, which was indicated by the UV–Vis absorption spectrum. In the TEM analysis, the particles were shown to be nanosized. For instance, the highest number of particles was found in the range of 100 to 120 nm in the case of ZnO, while 80–100 nm sized particles were found for ZnO/GO. Using synthesized ZnO and ZnO/GO, the decolorization of methylene blue was found to be 64% and 91%, respectively.

Molecularly imprinted polymer (MIP) nanoparticles of Sudan III dye as template were synthesized by using non-covalent approach. The molecularly imprinted polymers were synthesized in a microemulsion contained Sudan III as a template, acrylic acid (AA) as a monomer, 1,4-butanediol dimethacrylate as a cross-linker and 2,2-azo-bisisobutyronitrile (AIBN) as an initiator. The synthesized beads were characterized by TEM and FTIR. The TEM results revealed the nanosize beads of polymers were produced. The efficiency of imprinted and non-imprinted polymers was evaluated by batch binding studies. The results showed that the MIP 3 (0.1: 6: 10, Sudan III: AA: 1,4-butanediol dimethacrylate) was best among all polymers with highest rebinding efficiency. The removal efficiency of selected MIP 3 in the spiked Sudan III dye river water sample was about 80%. This study was conducted to produce nanosized molecularly imprinted polymers by using microemulsion polymerization technique.

The use of agricultural by-products has been widely studied to develop effective and inexpensive adsorbent for heavy metal removal. In this study, sago (M.sagu) fly ash (FA) was chemically modified to afford an operational adsorbent for Pb (II) elimination from water. Chemical modification was carried out via acid-base treatment using NaOH and HCl. The chemically modified fly ash (MFA) was characterized via proximate, surface morphology, and functional groups' surface area analyses. The effects of adsorption parameters, namely, Pb (II) initial concentration, sorbent dosage and contact time on the eradication of Pb (II) by MFA was analyzed in batch experiments with Langmuir and Freundlich isotherms. Optimization of Pb (II) removal by MFA was studied via response surface methodology (RSM) approach. Results revealed that chemical modification has successfully enhanced the adsorptive properties of MFA (BET surface area: 231.4 m2/g, fixed carbon: 55.83%). MFA exhibits better Pb (II) removal efficiency (90.8%) compared to FA (63.6%) at the following adsorption condition: Pb (II) initial concentration (5 ppm), contact time (30 min) and agitation speed (150 rpm). The adsorption of Pb (II) by FA and MFA fitted well with Freundlich isotherm (R2>0.9). RSM study suggested that the optimum Pb (II) removal was 99.4% at the following conditions: Pb (II) initial concentration (20 ppm), contact time (2 h) and sorbent dosage (0.6 g/50 mL). The results concluded the potential optimum operational condition for Pb (II) removal from aqueous environment by MFA as a low cost adsorbent, at larger scale.

BackgroundVirgin coconut oil is mostly made up of saturated fatty acids in which approximately 72% are medium chain triglycerides. Medium chain triglycerides can be digested into medium chain fatty acids and medium chain monoglycerides which are bioactive components. Therefore, it is very important to study the in-silico ability of some Virgin coconut oil derivatives, namely, medium chain fatty acids and medium chain monoglycerides to inhibit Cyclooxygenase 2 (COX-2) protein for prevention of excessive inflammatory response.ResultsPharmacophore study displayed monolaurin with two hydrogen bond donor, three hydrogen bond acceptor and five hydrophobic interactions, while lauric acid presented two hydrogen bond acceptor, five hydrophobic interactions and a negative ion interaction. Molecular docking underlined the ability of monolaurin in the inhibition of COX-2 protein which causes inflammatory action with a decent result of energy binding affinity of − 7.58 kcal/mol and 15 interactions out of which 3 are strong hydrogen bond with TYR385 (3.00 Å), PHE529 (2.77 Å), and GLY533 (3.10 Å) residues of the protein. Monolaurin was employed as hydrogen bond acceptor to the side of residue TYR385 of COX-2 protein with an occupancy of 67.03% and was observed to be long-living during the entire 1000 frames of the molecular dynamic simulation. The analysis of RMSD score of the Monolaurin–COX-2 complex backbone was calculated to be low (1.137$$\pm$$±0.153 Å) and was in a stable range of 0.480 to 1.520 Å. Redocking of this complex still maintained a strong hydrogen bond (2.87 Å) with the main residue TYR385. AMDET results where promising for medium chain fatty acids and medium chain monoglycerides with good physicochemical drug scores.ConclusionsThis can be concluded from the results obtained that the monolaurin has strong interactions with COX-2 protein to disrupt its function due to significant hydrogen bonds and hydrophobic interactions with amino acid residues present in the target protein’s active site. These results displayed a very significant anti-inflammatory potential of monolaurin and a new promising drug candidates as anti-inflammatory agent.Graphical Abstract

Electrical energy generation can be achieved in microbial fuel cells (MFCs) through the catalytic action of microorganisms which can oxidize organic matter and convert it into a biofilm. In MFCs, the exoelectrogens play a crucial role. MFCs is eco-friendly promising technology that produces electricity from various organic substrates. It is a novel and environmentally friendly approach for bioremediation and sustainable electricity production. The fact that heavy metals contributing adversely to the environmental pollution thus the microbial fuel cell technology has a solution for this as well, performing the removal and recovery of heavy metals by using both single and doublechambered MFCs. Many studies show that the new strains of microbes can produce power densities individually as high as strains from mixed communities. However, the implementation of this technology is just limited to the laboratory scale because of a few challenges like low efficiencies, low production rates. This review article focuses an introduction about the role and mechanism of different microorganisms towards energy production, biofilm formation, high power producing microbes inside the microorganisms, the electron transfer mechanism to the electrodes and vice-versa and the removal of heavy metals.

The molecularly imprinted polymers (MIPs) were prepared by using the non-covalent approach. In the polymerization process, xylenol orange was used as a template (T), acrylic acid as a functional monomer (M), divinylbenzene as a cross-linker (CL) and 2,2’-azobisisobutyronitrile (AIBN) as an initiator and microemulsion as a solvent. The synthesized polymers were characterized by using FTIR and SEM micrograph. The batch binding analysis was used to evaluate the rebinding efficiency of imprinted polymers. The highest rebinding efficiency was obtained from the MIP-R2 (0.1:0.6:2, T:M:CL). The selected MIP-R2 was used for the removal of xylenol orange from the water sample and have shown removal efficiency of about 80%.

Congo red (CR) is an anionic azo dye widely used in many industries including pharmaceutical, textile, food and paint industries. The disposal of huge amount of CR into the various streams of water has posed a great threat to both human and aquatic life. Therefore, it has become an important aspect of industries to remove CR from different water sources. Molecular imprinting technology is a very slective method to remove various target pollutant from environment. In this study a precipitation polymerization was employed for the effective and selective removal of CR from contaminated aqueous media. A series of congo red molecularly imprinted polymers (CR-MIPs) of uniform size and shape was developed by changing the mole ratio of the components. The optimum ratio (0.1:4: 20, template, functional monomer and cross-linking monomer respectively) for CR1-MIP from synthesized polymers was able to rebind about 99.63% of CR at the optimum conditions of adsorption parameters (contact time 210 min, polymer dosage 0.5 g, concentration 20 ppm and pH 7). The synthesized polymers were characterized by various techniques such as Fourier Infra-red spectroscopy (FTIR), scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDX), and Brumauer–Emmett–Teller (BET). The polymer particles have successfully removed CR from different aqueous media with an efficiency of about ~ 90%.

Although regarded as environmentally stable, bioelectrochemical fuel cells or, microbial fuel cells (MFCs) continue to face challenges with sustaining electron transport. In response, we examined the performance of two graphene composite-based anode electrodes—graphene oxide (GO) and GO–polymer–metal oxide (GO–PANI–Ag)—prepared from biomass and used in MFCs. Over 7 days of operation, GO energy efficiency peaked at 1.022 mW/m2 and GO–PANI–Ag at 2.09 mW/m2. We also tested how well the MFCs could remove heavy metal ions from synthetic wastewater, a secondary application of MFCs that offers considerable benefits. Overall, GO–PANI–Ag had a higher removal rate than GO, with 78.10% removal of Pb(II) and 80.25% removal of Cd(II). Material characterizations, electrochemical testing, and microbial testing conducted to validate the anodes performance confirmed that using new materials as electrodes in MFCs can be an attractive approach to improve the electron transportation. When used with a natural organic substrate (e.g., sugar cane juice), they also present fewer challenges. We also optimized different parameters to confirm the efficiency of the MFCs under various operating conditions. Considering those results, we discuss some lingering challenges and potential possibilities for MFCs.

Magnetic mesoporous silica nanoparticles (Fe3O4-MSNs) were successfully synthesized with a relatively high surface area of 568 m2g−1. Fe3O4-MSNs were then modified with poly(2-diethyl aminoethyl methacrylate) (PDEAEMA) brushes using surface-initiated ARGET atom transfer radical polymerization (ATRP) (Fe3O4@MSN-PDMAEMA). Since the charge of PDEAEMA is externally regulated by solution pH, tertiary amines in the polymer chains were quaternized using 2-iodoethanol to obtain cationic polymer chains with a permanent positive charge (Fe3O4@MSN-QPDMAEMA). The intensity of the C−O peak in the C1s X-ray photoelectron spectrum increased after reaction with 2-iodoethanol, suggesting that the quaternization process was successful. The applicability of the synthesized materials on the removal of methyl orange (MO), and sunset yellow (E110) dyes from an aqueous solution was examined. The effects of pH, contact time, and initial dyes concentrations on the removal performance were investigated by batch experiments. The results showed that the Fe3O4@MSN-PDMAEMA sample exhibited a weak adsorption performance toward both MO and E110, compared with Fe3O4@MSN-QPDMAEMA at a pH level above 5. The maximum adsorption capacities of MO and E110 using Fe3O4@MSN-QPDMAEMA were 294 mg g−1 and 194.8 mg g−1, respectively.

Recognition of sustainability issues around water resource consumption is gaining traction under global warming and land utilization complexities. These concerns increase the challenge of gaining an appropriate comprehension of the anthropogenic activities and natural processes, as well as how they influence the quality of surface water and groundwater systems. The characteristics of water resources cause difficulties in the comprehensive assessment regarding the source types, pathways, and pollutants behaviors. As the behavior and prediction of widely known contaminants in the water resources remain challenging, some new issues have developed regarding heavy metal pollutants. The main aim of this review is to focus on certain essential pollutants’ discharge from anthropogenic activities categorized based on land-use sectors such as industrial applications (solid/liquid wastes, chemical compounds, mining activities, spills, and leaks), urban development (municipal wastes, land use practices, and others), and agricultural practices (pesticides and fertilizers). Further, important pollutants released from natural processes classified based on climate change, natural disasters, geological factors, soil/matrix, and hyporheic exchange in the aquatic environment, are also discussed. Moreover, this study addresses the major inorganic substances (nitrogen, fluoride, and heavy metals concentrations). This study also emphasizes the necessity of transdisciplinary research and cross-border communication to achieve sustainable water quality using sound science, adaptable legislation, and management systems.

Silver nanowires and Ag@polycarbazole nanocables have been effectively fabricated. Polyol-reduction and ion adsorption process were used to fabricate pure silver nanowires and Ag@polycarbazole nanocomposite by using an oxidant (iron acetate). Ions of oxidant were adsorbed on the surface of pure silver nanowires to oxidize carbazole monomers for efficient polymerization. The morphology of nanowires and Ag@PCz composite were characterized by using SEM, FT-IR and photoluminescence analysis. The SEM shows the presence of a smooth polymeric sheath. FT-IR and photoluminescence analysis shows dominant peaks that indicate the presence of silver nanowires and polycarbazole (PCz) with a smooth polymeric coating. Nanoparticle analyzer was used to determine z-average and actual size of sample. UV-visible spectrum shows two bands that were dominant at 345 and 410 nm. These are π to π* transitions that indicates the presence of polycarbazole nanocables.

In present study, the molecular imprinting polymer (MIP) of p-coumaric acid was synthesized by using p-coumaric acid as a template, acetonitrile as solvent, 1,4-butanediol dimethacrylate as cross-linker, acrylic acid as monomer and 2,2-azobisisobutironitrile (AIBN) as the initiator. The synthesized polymers were characterized by FTIR and SEM. The results from SEM revealed that the polymer was in spherical shape with size in micro-range. The binding efficiency of polymers was analyzed by adsorption study. The highest rebinding efficiency for MIP was ~ 80% while for non-imprinted polymer (NIP) it was only 24%.

Background:2,4,6-Trichlorophenol (2,4,6-TCP) is one of the most significant pollutants among chlorophenols due to its harmful effects. It has been classified as priority pollutants by the U.S. Environmental Protection Agency. Therefore, highly selective separation and sensitive recognition of 2,4,6-TCP from complex samples are in great demand.Methods:For this purpose , the preparation of MIPs selective for 2,4,6-TCP was carried out by precipitation polymerization. A non-covalent approach was employed to establish an interaction between template and monomer (methacrylic acid).Results:The resulted polymers were characterized by scanning electron microscopy (SEM), EDX, Fourier-transform infrared spectroscopy(FT-IR) and BET. The batch binding assay was carried out to select the most selective polymer in terms of binding efficiency towards the target template. The adsorption parameters such as initial concentration, dosage of polymer, pH effect and selectivity with structural analogues were determined . The selectivity of MIP towards the 2, 4, 6-TCP was higher as compared to its structural analogue melamine with a good adsorption efficiency. Furthermore, the MIP as an extracting material was applied for extraction of 2, 4, 6-trichlorophenol from the spiked blood serum (88%) and river water sample (94%). The results showed that the optimized MIP could successfully extract 2,4,6-TCP from the blood serum and river water.Conclusion:The molecularly imprinted polymers for 2,4,6-TCP have been prepared by precipitation polymerization with a non-covalent approach. The optimized MIP has been successfully used for the extraction of 2,4,6-TCP from blood serum and river water.

In this article, molecularly imprinted polymer (MIP) of melamine was synthesized by non-covalent approach using microemulsion medium. In this study, melamine is used as a template molecule, acrylic acid as a functional monomer, N,N′-methylenebis(acrylamide) (MBAm) as a cross-linker and 2,2′-azobisisobutyronitrile (AIBN) as an initiator and microemulsion as a solvent. The produced polymers were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) and thermogravimetric analysis (TGA). The batch binding analysis was conducted for the evaluation of MIP and NIP rebinding efficiency with the melamine template. The adsorption studies including the adsorbent dosage of polymer, initial concentrations and pH of melamine solution were successfully carried out on both MIP and NIP. For selectivity test, 2,4,6-trichlorophenol was chosen as the competitive molecule against melamine template. A very good relative selectivity coefficient was achieved. The removal of melamine from different samples were conducted successfully by achieving a good removal efficiency in milk, river water and human blood serum 84.30, 94.26 and 93.32 %, respectively.

Molecularly imprinted polymers (MIPs) of melamine (MEL) were synthesized by non-covalent approach with precipitation polymerization. In this research, MEL was used as the template molecule,...

Molecularly imprinted polymers (MIPs) were prepared by precipitation polymerization using thymol as a template molecule, acrylamide as a functional monomer and N,N-methylbisacrylamide as the crosslinker with a non-covalent approach. The polymers were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), fourier-transform infra red spectroscopy(FT-IR) and Brunauer-Emmett-Teller (BET). The SEM results depicted that the shape of polymer particles is spherical with uniform size (micro-meters). The BET results also showed better surface area, pore size and pore volume of MIP as compared to non-imprinted polymer (NIP). A series of parameters such as initial concentration, polymer dosage, effect of pH and slectivity with structural analogue were conducted. The selectivity of MIP towards thymol was appreciable as compared to its structural analogue gallic acid with a relative selectivity coefficient of 3.59. Finally, MIP has been successfully used for extraction of thymol from the spiked blood serum (84 %) and river water sample (98 %).

Stimuli-responsive polymers are materials that can display remarkable changes in their properties with slight change in environmental conditions. Substantial change in the structure and properties can be made to the textiles by the incorporation of smart polymers into them. The following characteristics for intelligent polymers viz., thermal-, moisture-, and light-responsive polymers, and thermal- and pH-responsive hydrogels, have been incorporated into the fabrics to improve or achieve smart fabric functionalities. The functional components include esthetic appeal, comfort, drug release, fantasy design (color changing), wound monitoring, smart wetting properties, and protection against tough environmental alterations. In this chapter, the applications of stimuli-responsive polymer/composites in fabrics and the clothing field have been deliberated upon; the related issues on the fabrication of clothing and their potential applications in the years to come are elucidated.

Polymers have a sacred space in science. It is a well-known fact that due to some unique and specific properties polymers are used in a wide range of applications. Among them smart biopolymers have gained attention of researchers worldwide due to their unique properties such as biodegradability, biocompatibility, inexpensiveness, and renewability. Furthermore, these smart biopolymers show a characteristic property of responsiveness to stimuli such as temperature, pH, magnetic and electrical field, chemical, mechanical stress, and light. Consequently, succeeding chapter will briefly shed light about such smart biopolymers, their classification, and applications. Special attention is laid on the potential applicability of such smart biopolymers in the field of drug delivery, tissue engineering scaffolds, bioseparation, biotechnology, other medicinal fields, etc. The versatility and unique potential of these smart polymers make them one of the important parts of science, specifically medicine and drug delivery.

Microbial fuel cells (MFCs) are a sustainable approach for the remediation of metals and the simultaneous production of energy. This paper highlighted the usage of mango extract to produce electricity as an organic source for bacteria and reduce metal ions from wastewater. The observed results were 51 mV in 15 days with 500 Ω of external resistance. The whole operation was carried out at room temperature. The observed current and power density were 28.947 mA/m2 and 0.972 mW/m2, respectively. The internal resistance was 150 Ω, which is lower than external resistance. The remediation performance varied with the metal ions as follows: Pb (II) shows 75%, Cd (II) shows 74.11%, and Cr (III) shows 80.50%. Finally, the detailed working mechanism of the present study, MFC challenges, and future research directions are covered in this paper.

A new bioelectrochemical approach based on metabolic activities inoculated bacteria, and the microbial fuel cell (MFC) acts as biocatalysts for the natural conversion to energy of organic substrates. Among several factors, the organic substrate is the most critical challenge in MFC, which requires long-term stability. The utilization of unstable organic substrate directly affects the MFC performance, such as low energy generation. Similarly, the interaction and effect of the electrode with organic substrate are well discussed. The electrode-bacterial interaction is also another aspect after organic substrate in order to ensure the MFC performance. The conclusion is based on this literature view; the electrode content is also a significant challenge for MFCs with organic substrates in realistic applications. The current review discusses several commercial aspects of MFCs and their potential prospects. A durable organic substrate with an efficient electron transfer medium (anode electrode) is the modern necessity for this approach.

Graphene has obtained an excessive amount of interest and popularity from worldwide owing to its atypical physiochemical, chemical, thermal and mechanical stability-based properties. Graphene, a one atom thick plain sheet with sp2 bonding and the carbon atoms are compactly packed in structure to form crystal lattice. Many approaches are known to synthesize the graphene derivatives and therefore, it is essential to discuss a list of distinguished approaches like exfoliation and cleavage, thermal chemical vapor deposition etc. The most commonly used hybrid graphene nanocomposite synthesis approaches and their significant applications are also summarized in this chapter.

Polysaccharide nanocomposites have drawn attention for their peculiar property of being renewable and green alternatives. Starch is a naturally renewable polymer having great potential owing to properties such as total compostability, biocompatibility, biodegradability, and are without toxic residues, besides few limitations including low mechanical properties, high water sensitivity, and poor processability. However, insertion of nanofillers into starch nanocomposites results in substantial changes and improvements in the stability and applicability of starch-based nanocomposites. This chapter aims to provide the fundamental knowledge on the role of starch nanocomposite polysaccharides, as specific in the field of biomedical applications, especially in gene delivery, as well as recent developments in this area.

Enzymes play a vital role in a broad spectrum of fundamental physiological processes and therefore could be exploited as biological triggers to achieve a controlled release of cargo at the desired site. Enzyme-responsive materials are a class of stimuli-responsive materials with a variety of applications in biological systems. They have been proved to be potential biomaterials, biomedicine, and biosensing candidates. These types of smart materials undergo macroscopic changes when triggered by a selective action of enzymes. This idea has been applied successfully for the development of drug carrier systems where the tissue of interest is targeted by the release of cargo triggered by the catalytic action of an enzyme. This chapter mainly emphasizes on the few key enzyme-responsive nanomaterials such as proteases, lipases, and glucosidases and oxidoreductases for various biomedical applications.

Xanthan gum (XG) is a naturally occurring exo-polysaccharide produced by the class of bacteria Xanthomonas campestris. This hetero polysaccharide produced from Gram-negative bacteria has various unique properties such as biocompatibility, biodegradability, cytocompatibility, highly viscous and pseudo-plastic nature, nontoxicity, and solubility in both cold and hot water, which make it a promising agent in biomedical and tissue engineering applications. Traditionally, XG is an important component for various industrial and biomedical applications as a thickener, emulsion stabilizer, and additive, and is widely used in food and food packaging, cosmetics, toiletries, drug delivery, etc. Recently, it has been used in tissue engineering applications after undergoing various chemical and physical modifications through incorporation of NPs. In this chapter, we discuss the applicability of XG nanocomposites obtained through various modifications in the field of biomedicine and tissue engineering.

Waterborne pollutants and associated diseases are a widespread public health issue in the world. These diseases are connected directly to the degradation and contamination of the environment. In recent years, aerogels have drawn the interest of researchers and technologists in the field of water purification because of their ultra-low density, high surface area, higher adsorption power, good mechanical strength, ultra-high porosity, ultra-low thermal conductivity, ultra-low dielectric constant. This chapter includes up-to-date information on the use of aerogels/hybrid aerogels to eliminate waterborne pollutants including metal ions, pathogens, colorants, oil waste, and other toxic compounds. The use of aerogels/hybrid aerogels for microbe removal techniques is surprisingly understudied. Studies revealed that compared with aerogels, hybrid aerogels showed excellent adsorption performance. Unlike metal oxide, graphene, and carbon nanotube-derived aerogels, bio-based aerogels are more cost-effective, safe, and environmentally friendly. Despite the different applications and benefits of aerogels in the purification of waterborne pollutants, some problems related to their use remain unresolved.

Benthic microbial fuel cells (BMFCs) are considered to be one of the eco-friendly bioelectrochemical cell approaches nowadays. The utilization of waste materials in BMFCs is to generate energy and concurrently bioremediate the toxic metals from synthetic wastewater, which is an ideal approach. The use of novel electrode material and natural organic waste material as substrates can minimize the present challenges of the BMFCs. The present study is focused on cellulosic derived graphene-polyaniline (GO-PANI) composite anode fabrication in order to improve the electron transfer rate. Several electrochemical and physicochemical techniques are used to characterize the performance of anodes in BMFCs. The maximum current density during polarization behavior was found to be 87.71 mA/m2 in the presence of the GO-PANI anode with sweet potato as an organic substrate in BMFCs, while the GO-PANI offered 15.13 mA/m2 current density under the close circuit conditions in the presence of 1000 Ω external resistance. The modified graphene anode showed four times higher performance than the unmodified anode. Similarly, the remediation efficiency of GO-PANI was 65.51% for Cd (II) and 60.33% for Pb (II), which is also higher than the unmodified graphene anode. Furthermore, multiple parameters (pH, temperature, organic substrate) were optimized to validate the efficiency of the fabricated anode in different environmental atmospheres via BMFCs. In order to ensure the practice of BMFCs at industrial level, some present challenges and future perspectives are also considered briefly.

Ligand-based pharmacophore modelling approach using four established antiviral drugs, namely remdesivir, lopinavir, ritonavir and hydroxychloroquine were analysed for COVID-19 inhibitors as training sets. Twenty vanillin derivatives together with monolaurin were used as test sets to evaluate potential as SARS-CoV-2 inhibitors. Structure-based pharmacophore modelling approach was also performed using Protein Data Bank information: PDB-5RE6, 5REX and 5RFZ in order to analyse the binding site and ligand-protein complex interactions. The pharmacophore modelling mode of 5RE6 displayed two Hydrogen Bond Acceptors (HBA) and one Hydrophobic (HY) interaction. Besides, the pharmacophore model of 5REX showed two HBA and two HY interactions. Finally, the pharmacophore model of 5RFZ showed three HBA and one HY interaction. Based on ligand-based approach, 20 Schiff-based vanillin derivatives, namely vanillin associated with methyl-6- aminopyridine-3-carboxylate (1), sepiapterin (2), 6-aminopyridine-3-carboxylic acid (3), 6-aminopyridine-2-carboxylic acid (4), pemoline (5), α-phenylglycine (6), 2-amino-4-hydroxy-3-methylpentanoic acid (7), 4-hydroxyphenylglycine (8), β-homoserine (9), allylglycine (10), oxamic acid (11) benzophenone hydrazine (12), 2-aminoadipic acid (13), D-alanyl-D-alanine (14), p-bromophenylalanine (15), nicotinic hydrazide (16), 4-hydroxybenzhydrazide (17), benzohydrazide (18), isonicotinic hydrazide (19), and phenylhydrazine (20) showed strong MPro inhibition activity. This was due to their good alignment and common features to PDB-5RE6. Similarly, monolaurin and tetrodotoxin displayed some significant activity against SARS-CoV-2. From structure-based approach, vanillin derivatives (1) to (12) displayed some potent MPro inhibition against SARS-CoV-2. Favipiravir, chloroquine and hydroxychloroquine also showed some significant MPro inhibition. Favipiravir showed good alignment and common pharmacophore features to PDB- 5RFZ, whereas chloroquine and hydroxychloroquine showed good alignment and common pharmacophore features to PDB-5REX.

This review focuses on the various types of supports used for immobilization of titanium dioxide nanomaterial catalyst for degradation of organic pollutants in wastewater. Several supports suitable to particular immobilization technique used for the degradation of pollutants in wastewater streams are explained. In general, a coating of catalyst on supports is carried out either by physical (e.g., thermal treatment) or by chemical (e.g., sol–gel). Among a range of the supports used, some of the prominent ones include glass, silica, activated carbon, stainless steel, cellulose, clay. Also, characterization methods in use such as X-ray diffraction, transmission electron microscope, scanning electron microscope, and UV-spectroscopy are discussed. The operating parameters such as temperature for the selected immobilization techniques are also explained.

Background The 2-phenylphenol is used as an agricultural fungicide. It is generally applied for the post-harvest treatment of fruits and vegetables to protect against microbial damage. It is also used for waxing of citrus fruits and for disinfection of seed boxes. It has been reported that 2-phenyphenol has some toxic effects human beings due to its disposal in the environment. Therefore, preparation of selective materials for the extraction of 2-phenylphenol is important. For this purpose, molecular imprinting polymer (MIP) were prepared by precipitation polymerization using 2-phenylphenol as the template molecule, styrene as the functional monomer, and divinyl benzene as the cross-linker with a non-covalent approach. Results The polymers were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infra red spectroscopy (FT-IR), and Brunauer–Emmett–Teller (BET). The results obtained from SEM depicted that the shape of polymer particles is spherical with uniform size in micrometers. The BET results also showed better surface area (131.44 m2 g−1), pore size (7.9587 Å), and pore volume (5.23 cc g−1) of MIP as compared to NIP. The batch adsorption test was conducted to select a most specific polymer in terms of affinity towards the template. A series of parameters such as initial concentration, polymer dosage, effect of pH, and selectivity with structural analog were conducted. The selectivity of MIP towards the 2pp was very appreciable as compared to its structural analog biphenyl with a good adsorption capacity. Moreover, the MIP as an extractant was successfully applied for extraction of 2-phenylphenol from the spiked blood serum (93%) and river water sample (88%). Conclusion Molecular imprinting polymer has been successfully synthesized for the selective extraction of 2-phenylphenol from biological and environmental samples. The synthesized material has been applied for the extraction of 2-phenylphenol from blood serum and river water.

Titanium dioxide (TiO2) is added in sunscreens due to its ability to absorb ultraviolet (UV) light. However, upon irradiation of UV light, reactive oxygen species particularly hydroxyl radical which can damage human skin will be generated. In this study, lignin/TiO2 composites were employed to quench the hydroxyl radicals generated by the TiO2. The lignin was extracted from oil palm empty fruit bunch (OPEFB) via kraft and soda pulping processes. The kraft lignin composite was labelled as KL/TiO2 whereas the soda lignin composite was labelled as SL/TiO2. The lignins and the composites were characterized by FTIR, UV spectroscopy, 13C NMR, SEM, EDX, and XRD. The relative hydroxyl radical production of composites and TiO2 were compared through photo-oxidation of coumarin to 7-hydroxycoumarin as a test medium. The effect of types and amounts of lignin used were studied. The KL/TiO2 composite showed the least radical production due to higher phenolic hydroxyl content of kraft lignin. The activity of the hydroxyl radicals will be quenched when it abstract hydrogen atoms from the phenolic hydroxyl groups.

This review provides insight into various techniques utilized for the treatments of palm oil mill effluents (POME). Generally, POME treatment is achieved in two ways, these are (1) pre-treatment stages, involving majorly the reduction of oil and grease and suspended matter and (2) an advanced treatment stage, in which wastewater contaminants (e.g. BOD5, COD) are reduced to standard discharge limits. Different methods utilized in the treatment of POME such as coagulation-flocculation, anaerobic, aerobic and membrane technology are explained fully and recent trends in their advancement and improvement are outlined. Though, various pilot or industrial scale treatment plants have been reported in scientific literature for POME treatments methods such as anaerobic, aerobic and membrane technology, the literature is still scarce for application of photocatalytic degradation technology to POME treatment as the technology is still in development stage and has not been fully utilized on an industrial scale in palm oil mill industries. This is mainly as a result of inadequate investigation involving POME degradation. The review presented here is focused on photocatalytic degradation technology and reflects published outcomes with the aim of offering the technique as an attractive and sustainable process units. Also the potential of the process to replace some of the well-known separation and degradation technologies has been highlighted at advanced treatment stage for POME.

Biopolymers are derived from natural sources and are abundant in nature. Biopolymers have received a great deal of attention in drug delivery compared with conventional polymers because they are nontoxic, biocompatible, biodegradable, and relatively cheap. The drug-delivery systems can be synthesized with controlled composition, morphology (shape, size), and functionality. The surface properties can be modified to enhance the solubility, immunocompatibility, and cellular uptake. The application of biomaterials in living systems would reduce immunological reactions and toxicity. Biomaterials with nano-scale organizations have been projected to tune release kinetics, regulate biodistribution, and reduce toxic side effects and thereby increase the therapeutic index of a given drug. In this chapter mainly nanostructured biopolymers based on proteins and polysaccharide are discussed.

Since ages human kind is using natural and synthetic compounds for the cure of diseases. By large synthetic compounds have edged the natural compounds. Discovery of nanomaterials paved way for smart treatment of diseases which were considered incurable. Nanomedicine and nano drug delivery systems are developing at a very fast pace offering multiple benefits in the treatment of chronic human ailments such as cancer, HIV and many other diseases by target-oriented and site-specific delivery of medicines. A detailed importance of nanomaterials in drug delivery systems is given in this chapter. This chapter also presented a comprehensive scrutiny of the nanomaterials that are handy in targeted and site specific delivery of drugs, their synthesis and applications in the field of drug delivery.

Graphene is 2-D structure of a single-atom-thick sheet of sp2-hybridized carbon atoms arrayed in a honeycomb pattern with a bond length of 0.141 nm. It is undoubtedly the most intensively studied material with extraordinary properties that are even more promising than other nanostructured carbon allotropes. It is the thinnest, strongest, and stiffest material, with large specific surface area and good chemical stability, is an excellent conductor of both heat and electricity, and also has other superior characteristics of electronic, mechanical, optical, and transport natures. Graphene, with such specific properties, holds great promise for the removal of pollutants from water through adsorption and photocatalytic degradation. The strong π–π stacking interactions in graphene result in cluster formation, which is not conducive for the adsorption of pollutants. Overcoming this limitation functionalization of graphene has been done via covalent and noncovalent interactions.