Novel 1-butyl-3-methylimidazolium bromide impregnated chitosan hydrogel beads nanostructure as an efficient nanobio-adsorbent for cationic dye removal: Kinetic study

A review on recent trends in the removal of emerging contaminants from aquatic environment using low-cost adsorbents

Emerging contaminants (ECs), a class of contaminants with low concentrations but significant harm, have received a lot of attention in recent times. ECs comprises of various chemicals that enter the environment every day. In today's modern lifestyle, we use many chemical-based products. These persist in wastewater and ultimately enter the water bodies, causing serious problems to the human and aquatic ecosystem. This is because the conventional wastewater treatment methods are inefficient in identifying and removing such contaminants. Aiming for a long-term, effective solution to this issue, Adsorption was proposed. Although several adsorbents are already present in the market, which have proved beneficial in removing such ECs, not all are affordable. This article reviews replacing costly adsorbents with agriculture-based biomass that are abundant, inexpensive, and biodegradable and possess excellent adsorption capacity. The objectives of this article is to look at adsorption as a viable treatment option for emerging pollutants, as well as sophisticated and cost-effective emerging contaminants treatment options.

Production of bioethanol from carrot pulp in the presence of Saccharomyces cerevisiae and beet molasses inoculum; A biomass based investigation

Nowadays, ethanol (ethyl alcohol, bioethanol) is one of the most commonly used liquid biofuels, playing a vital role in industrial development. There are some advanced technologies available to produce ethanol by fermentation of agricultural wastes, fruit wastes, municipal and industrial wastes. Herein, the dried carrot pulp as a source of raw material has been utilized for the production of bioethanol by using the yeast Saccharomyces cerevisiae and beet molasses inoculated at 28 °C for 72 h. The results have revealed that the highest amount of alcohol (10.3 ml (40.63 g/l)) has been obtained in a sample containing 50 ml of inoculum, 150 ml of water, and 10 g of dried waste. This study has proved the potential of dried carrot pulp to be converted into a value-added product such as ethanol.

A review on recent advancements in recovery of valuable and toxic metals from e-waste using bioleaching approach

This review is intent on the environmental pollution generated from printed circuit boards and the methods employed to retrieve valuable and hazardous metals present in the e-wastes. Printed circuit boards are the key components in the electronic devices and considered as huge e-pollutants in polluting our surroundings and the environment as a whole. Composing of toxic heavy metals, it causes serious health effects to the plants, animals and humans in the environment. A number of chemical, biological and physical approaches were carried out to recover the precious metals and to remove the hazardous metals from the environment. Chemical leaching is one of the conventional PCBs recycling methods which was carried out by using different organic solvents and chemicals. Need of high cost for execution, generation of secondary wastes in the conventional methods, forces to discover the advanced recycling methods such as hydrometallurgical, bio-metallurgical and bioleaching processes to retrieve the valuable metals generate through e-wastes. Among them, bioleaching process gain extra priority due to its higher efficiency of metal recovery from printed circuit boards. There are different classes of microorganisms have been utilized for precious metal recovery from the PCBs through bioleaching process such as chemolithoautotrophy, heterotrophy and different fungal species including Aspergillus sp. and Penicillium sp. The current status and scope for further studies in printed circuit boards recycling are discussed in this review.

Graphene derivatives in bioplastic: A comprehensive review of properties and future perspectives

The research and technological advancements observed in the latest years in the nanotechnology field translated into significant application developments in various areas. This is particularly true for the renewable polymers area, where the nano-reinforcement of biobased materials leads to an increase in their technique and economic competitiveness. The efforts were predominantly focused on materials development and energy consumption minimization. However, attention must also be given to the widespread commercialization and the full characterization of any particular potential toxicological and environmental impact. Some of the most important nanomaterials used in recent years as fillers in the bioplastic industry are graphene-based materials (GBMs). GBMs have high surface area and biocompatibility and have interesting characterizations such as strangeness and flexibility. In this paper, the current state of the art for these GBMs in the bioplastics area, their challenges, and the strategies to overcome them are analyzed.

Zn0.94Mn0.06O for adsorption and photo-degradation of methyl orange dye under visible irradiation: Kinetics and isotherms study

Three photocatalyst-adsorbents consist of Zn_0.97Mn_0.03O, Zn_0.94Mn_0.06O, and Zn_0.92Mn_0.08O were synthesized by hydrothermal method and calcined at 800 °C. The structural and optical properties of the sample Zn_0.94Mn_0.06O were characterized by using XRD; TEM; SEM; EDS; DLS; and DRS. The surface of the sample Zn_0.94Mn_0.06O consists of nano-particles (<100 nm) and nano-holes (18.4 nm), also the band-gap of it was obtained 2.89 eV. Adsorption and photo-degradation of methyl orange (MO) dye was investigated in darkness and under visible light irradiation (200 W tungsten). The sample Zn_0.94Mn_0.06O showed the most decolorization efficiency in the shortest time, so that 0.15 g of it adsorbed and destroyed the MO dye molecules (99 ± 1 %) in 40 s under irradiation. The most adsorption capacity of Zn_0.94Mn_0.06O was obtained 30.06 mg/g and the mechanism of the dye adsorption was investigated by using BET analysis and zeta potential. Also the adsorption isotherm and kinetics were calculated for describing the adsorption of MO onto the Zn_0.94Mn_0.06O.

Effect of Polysaccharide-Based Film on Morphometric Parameters of Rat liver

In the modern world, most manufacturers try to use film coatings that have the following properties: manufacturability, safety, biodegradability, and economic availability. The provided materials present the results of studying the effect of a film based on polysaccharides on the morphology of rat liver. An experiment was carried out on laboratory animals, in the course of its carrying out the morphological structure of the rat liver was studied, which showed that use of films based on polysaccharides is safe for laboratory animals.

Sustainable multilayer biomass carbon and polymer hybrid column as potential antibacterial water filter

Stipulation of fresh water for domestic use without any microbial, organic and inorganic contaminants is of high need. Sustainable, efficient, cost-effective and robust water purification technologies is of high need and it can be achieved using nanomaterials and their composite. Nanostructured graphene has unique properties like high surface to volume ratio, higher absorbability, reusability with minimal chemical alterations, and low cytotoxicity. From the validation of these properties, we have developed PLLA-Ag@graphene sandwich structures as an effective adsorbate for water purification application. As the real water bodies have lot of bacterial contaminants, the material is also designed as efficient adsorbate with antibacterial efficacy. In view of achieving these objectives, we have synthesized PLLA fibre mats by electrospinning method, followed by PLLA-Graphene and Ag decorated PLLA-graphene mats. The crystallite size for graphite and Ag@graphene was calculated as 30.82 nm and 43.79 nm, respectively. Furthermore, the UV analysis of Ag@graphene shows two peaks corresponding to graphene and Ag NP at 285 nm and 407 nm respectively. The layers were assembled in the order of polymeric fibre, as-fired biomass graphite, Ag@graphene for methodical filtration process. The filtration efficacy of the filtrate was tested using sewage water and the results shows higher contamination removal percentage of 87 % with TDS values in the drinking water standards after filtration. The antibacterial efficacy results also evidence of the potentialities of the hybrid system towards water purification application.

Feasibility of magnetic nano adsorbent impregnated with activated carbon from animal bone waste: Application for the chromium (VI) removal

Chromium is the heavy metal which existing in the effluents cause extensive discomfort to the environmental components. Bone waste is widely generated in food processing industries and restaurants. It is now used by switching into activated carbon. By co-precipitation procedure, the activated carbon is coated with a nano adsorbent. The Fe₃O₄-BAC adsorbent potential was established in this study via several batch tests. The adsorbing adverts had super magnetic behavior, and the magnetization value was 22 emu/g. The SEM imaging of the Fe₃O₄-BAC shows an improved morphology of 100-446 nm, and the nanoparticles were monodispersed. The present investigation also delves into the study of system parameters on the removal of metal ions. Optimal adsorption has been found at the acidic pH at the contact time of 60min for the adsorbent amount of 5 g/L. Maximum capacity of adsorption by nano adsorbent was 27.86 mg/g. Thermodynamic and isotherm tests have established the process viability. In addition, the kinetic studies establish the inclination of the studied Fe₃O₄-BAC towards pseudo-first order models. Hence, Fe₃O₄-BAC could be potential adsorbent to remove chromium from an aqueous solution.

A comprehensive review on MXenes as new nanomaterials for degradation of hazardous pollutants: Deployment as heterogeneous sonocatalysis

MXene-based nanomaterials (MBNs) are two-dimensional materials that exhibit a series of sought after properties, including rich surface chemistry, adjustable bandgap structures, high electrical conductivity, hydrophobicity, thermal stability, and large specific surface area. MBNs have an exemplar performance when applied for the degradation of hazardous pollutants with various advanced oxidation processes such as heterogeneous sonocatalysis. As such, this work focuses on the sonocatalytic degradation of various hazardous pollutants using MXene-based catalysts. First, the general principles of sonocatalysis are examined, followed by an analysis of the main components of the MXene-based sonocatalysts and their application for pollutant degradation. Lastly, ongoing challenges are highlighted with recommendations to address the issues.

Fabrication of Electrochemical Sensor for Epinine Determination Amplified with MgO/CNTs Nanocomposite and Ionic Liquid

Background:

Catecholamines are a large group of pharmacological and biological compounds that are widely used in biological systems. These compounds are prepared both naturally and synthetically with many key roles in the human body and its activities. Therefore, many researchers focused on the identification and determination of catecholamines in biological samples.

Methods:

MgO/SWCNTs were synthesized through the chemical precipitation method. In addition, cyclic voltammetry, differential pulse voltammetry, and chronoamperometric methods were used for the electro-oxidation reaction study of epinine at the surface of the modified electrode.

Results:

Carbon paste electrode (CPE) modified with MgO/SWCNTs nanocomposite and 1-butyl- 3-methylimidazolium methanesulfonate (BMMS) was used as an electrochemical sensor for the determination of epinine. The results showed a linear dynamic range of 5.0 nM-250 μM with a detection limit of 0.1 nM for epinine determination using MgO/SWCNTs/BMMS/CPE as a sensor.

Conclusion:

In the present study, a highly sensitive electrochemical sensor was designed and fabricated as an analytical tool for the determination of epinine. MgO/SWCNTs/BMMS/CPE was successfully used for the determination of epinine in water and dextrose saline with an acceptable recovery range of 98.7%-102.72%.

Graphene-based materials for metronidazole degradation: A comprehensive review

Due to its cytotoxic effect, metronidazole (MNZ) is a drug commonly used to treat bacterial, protozoal, and microaerophilic bacterial infections. After consumption, it undergoes a series of metamorphic reactions that lead to the degradation of oxidized, acetylated, and hydrolyzed metabolites in the environment. To eliminate such pollutants, due to their high potential, adsorption and photocatalysis extensive processes are used in which graphene can be used to improve efficiency. This review analyses the use of graphene as an absorbent and catalyst with a focus on absorption and photocatalytic degradation of MNZ by graphene-based materials (GBMs). The parameters affecting the adsorption, and photocatalytic degradation of MNZ are investigated and discussed. Besides, the basic mechanisms occurring in these processes are summarized and analyzed. This work provides a theoretical framework that can direct future research in the field of MNZ removal from aqueous solutions.

Sequestration of toxic Pb(II) ions using ultrasonic modified agro waste: Adsorption mechanism and modelling study

Treating the effluents from industries by using biological and agricultural wastes is an emerging field of research. In this study, three different biosorbents are prepared from tamarind seeds such as; raw, sulphuric acid-modified and ultrasonic-assisted surface-modified tamarind seed powder has been utilized to expel the Pb (II) ions from synthetic solution. The surface characteristics of the newly synthesized raw and surface modified agro-waste biomass were studied by FTIR and SEM. An experimental study was carried out to investigate the effect of different parameters on adsorption of Pb(II) ions using raw, sulphuric acid-modified and ultrasonic-assisted surface-modified tamarind seeds. The maximum Pb(II) ions adsorption was found at pH - 6.0, temperature - 303 K, biosorbent dosage - 3.5 g/L and contact time - 60 min for raw tamarind seeds and 30 min for sulphuric acid-modified and ultrasonic-assisted surface-modified tamarind seeds. The adsorption mechanism was described by Langmuir isotherm and pseudo-first order kinetic model. Among the three biosorbents, ultrasonic-assisted surface-modified tamarind seeds show higher adsorption capacity (18.86 mg/g) of Pb(II) ions removal from the synthetic solution. The thermodynamic study declared that the present Pb(II) ions adsorption onto the prepared biosorbents was spontaneous, exothermic and followed physical adsorption process. Results have shown that tamarind seed was found to be the best adsorbent in the expulsion of Pb(II) ions from the wastewater environment.

Kinetics, equilibrium and thermodynamic investigations of methylene blue dye removal using Casuarina equisetifolia pines

Casuarina equisetifolia pines are degradable biopolymeric substance with dye-sequestering property was utilized as biosorbent to expel a cationic dye; methylene blue dye from simulated wastewater. The prepared adsorbent material was characterized for their structural, morphological and elemental features to understand their suitability in augmenting in dye-wastewater remediation. The results infer that 0.5 g/L biosorbent was proficient in removing 100 mg/L methylene blue (pH 7.0 ± 0.2) when agitated at 150 rpm for 120 min. Isothermal behavior were evaluated using non-linear isotherm models like Temkin, Langmuir and Freundlich models while the rate-limiting steps were found using kinetic models. Temkin isotherm and pseudo-first order model explained the removal mechanism among the models evaluated, which infers that the biosorption followed physisorption with the maximum adsorption capacity of 41.35 mg/g. Thermodynamic behavior of methylene blue removal by C. equisetifolia pines powder described the feasibility of biosorption as well as the type of heat involved. Equilibrium sorption capacities, rate constants and correlation coefficients explains that MB dye removal by C. equisetifolia pines is presumably physisorption, spontaneous and endothermic in nature.

Voltammetric sensor based on bimetallic nanocomposite for determination of favipiravir as an antiviral drug

A novel and sensitive voltammetric nanosensor was developed for the first time for trace level monitoring of favipiravir based on gold/silver core–shell nanoparticles (Au@Ag CSNPs) with conductive polymer poly (3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT:PSS) and functionalized multi carbon nanotubes (F-MWCNTs) on a glassy carbon electrode (GCE). The formation of Au@Ag CSNPs/PEDOT:PSS/F-MWCNT composite was confirmed by various analytical techniques, including X-ray diffraction (XRD), ultraviolet–visible spectroscopy (UV–Vis), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and field-emission scanning electron microscopy (SEM). Under the optimized conditions and at a typical working potential of + 1.23 V (vs. Ag/AgCl), the Au@Ag CSNPs/PEDOT:PSS/F-MWCNT/GCE revealed linear quantitative ranges from 0.005 to 0.009 and 0.009 to 1.95 µM with a limit of detection 0.46 nM (S/N = 3) with acceptable relative standard deviations (1.1-4.9 %) for pharmaceutical formulations, urine, and human plasma samples without applying any sample pretreatment (1.12–4.93%). The interference effect of antiviral drugs, biological compounds, and amino acids was negligible, and the sensing system demonstrated outstanding reproducibility, repeatability, stability, and reusability. The findings revealed that this assay strategy has promising applications in diagnosing FAV in clinical samples, which could be attributed to the large surface area on active sites and high conductivity of bimetallic nanocomposite.

Environmentally Friendly Polyvinyl Alcohol-Alginate/Bentonite Semi-Interpenetrating Polymer Network Nanocomposite Hydrogel Beads as an Efficient Adsorbent for the Removal of Methylene Blue from Aqueous Solution

Hazardous chemicals like toxic organic dyes are very harmful to the environment and their removal is quite challenging. Therefore there is a necessity to develop techniques, which are environment friendly, cost-effective and easily available in nature for water purification and remediation. The present research work is focused on the development` and characterization of the ecofriendly semi-interpenetrating polymer network (semi-IPN) nanocomposite hydrogels composed of polyvinyl alcohol (PVA) and alginate (Alg) hydrogel beads incorporating natural bentonite (Bent) clay as a beneficial adsorbent for the removal of toxic methylene blue (MB) from aqueous solution. PVA-Alg/Bent nanocomposite hydrogel beads with different Bent content (0, 10, 20, and 30 wt%) were synthesized via external ionic gelation method. The designed porous and steady structure beads were characterized by the use of Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). The performance of the beads as MB adsorbents was investigated by treating aqueous solutions in batch mode. The experimental results indicated that the incorporation of Bent (30 wt%) in the nanocomposite formulation sustained the porous structure, preserved water uptake, and increased MB removal efficiency by 230% compared to empty beads. Designed beads possessed higher affinity to MB at high pH 8, 30 °C, and fitted well to pseudo-second-order kinetic model with a high correlation coefficient. Moreover, the designed beads had good stability and reusability as they exhibited excellent removal efficiency (90%) after six consecutive adsorption-desorption cycles. The adsorption process was found be combination of both monolayer adsorption on homogeneous surface and multilayer adsorption on heterogeneous surface. The maximum adsorption capacity of the designed beads system as calculated by Langmuir isotherm was found to be 51.34 mg/g, which is in good agreement with the reported clay-related adsorbents. The designed semi-IPN PVA-Alg/Bent nanocomposite hydrogel beads demonstrated good adsorbent properties and could be potentially used for MB removal from polluted water.

The Fenton-like reaction for Arsenic removal from groundwater: Health risk assessment

In this paper, the heterogeneous Fenton like-reaction for Arsenic-contaminated groundwater remediation based on the performance of FeSO₄ as an efficient and green catalyst and CaO₂ as a source of H₂O₂ was investigated. To intensify the heterogeneous Fenton process, three oxidants were tested: sodium percarbonate (SPC), sodium persulfate (SPS), and calcium peroxide (CP). The results showed that CP and SPC had a synergetic effect on the rate of Arsenic degradation, while SPS had an antagonistic effect. On the other hand, inorganic ions such as Na⁺, Mg²⁺ have a very low impact on the Arsenic removal efficiency, while the anions Cl^- and NO₃^- exhibited significant inhibition of Arsenic degradation. This effect may be imputed to the reaction and conversion of hydroxyl (HO^•) radicals to less reactive. Thus, HCO₃^- and humic acid dramatically raised the degradation rate. Also, the response Surface method based on Box-Behnken design was applied to examine the suitable modeling, and optimized condition of the Fenton like-reaction process, the maximum Arsenic removal efficiency of 94.91% is obtained when [Fe³⁺]₀ = 1.97 mM, [CaO₂]₀ = 1.74 mM and initial pH = 4.67. The obtained results showed that the Fenton-like reaction is an effective and reliable process for arsenic removal from groundwater with low non-carcinogenic risk (HQ) and carcinogenic risk (CR) values.

Adsorptive removal of Pb(II) ions onto surface modified adsorbents derived from Cassia fistula seeds: Optimization and modelling study

Cassia fistula seeds has been utilized for the abstraction of Pb(II) ions from the aqueous environment. Raw Cassia fistula seeds (RCF) and three different surface modified (physically treated - PMCF and chemically treated - HMCF and SMCF) adsorbent material were taken for investigation. The adsorption properties of these materials and their contact amongst the Pb(II) ion and sorbent materials were characterized by FTIR and SEM analysis. The parameters influencing the adsorption capacity of varied adsorbents were evaluated: maximum solution pH for Pb(II) is 5.0; interactive time is 30 min; dosage is 8.0 g/L for RCF, 4.0 g/L for HMCF, 2.5 g/L for PMCF and 1.0 g/L for SMCF. The modelling study reveals that Freundlich isotherm and Pseudo first order kinetics fits well and the utmost adsorption measurements for the varied adsorbents were found to be 13.22, 28.28, 48.66 and 129.3 mg/g, respectively.

Analysis on the removal of emerging contaminant from aqueous solution using biochar derived from soap nut seeds

For clearing pollutants and emerging contaminants like ciprofloxacin-500mg from wastewaters generated from pharmaceutical industries, soapnut seeds biochar was synthesized and used as an adsorbent for the effective removal process. Tubular furnace operated under nitrogen gas environment was used to synthesize biochar. The batch analysis were carried out successfully to study the removal mechanism and the removal efficiency of the chosen pollutant. The soapnut seeds biochar showed excellent adsorption of ciprofloxacin at pH 6 and temperature 303 K when the dosage was 0.07 g. The Langmuir removal capacity of 33.44 mg/g was received and the Freundlich model provided the best-fits. The ciprofloxacin-500mg adsorption process correlated well with the pseudo-second-order kinetics equation, and the intraparticle diffusion mechanism mainly controlled the process. The characterization of biochar concluded that O-H groups, CO groups, COO^-groups and C-F groups, and π-π interactions, pore-filling effect, and cation exchange interactions played a role in the adsorption process. Therefore, the findings of the present work revealed that soapnut seeds biochar would be an excellent low-cost adsorbent for the removal of ciprofloxacin-500mg from wastewater.

Genotypic diversity of 17 cacti species and application to biosynthesis of gold nanoparticles

The genotypic diversity of 17 cacti species were examined and grouped in four clusters using seven inter simple sequence repeat (ISSR) markers. Group representatives (five species) were chosen for AuNPs synthesis in the cacti syrups. To synthesize the Gold nanoparticles (AuNPs), reducing and capping potential of five species of cacti rich in the polyphenolics were explored. Based on the synthesized AuNPs traits (concentration, pH, temperature, and synthesis time), Opuntia pycnacantha with the highest absorption peak at 540 nm was chosen for further characterizations. Varieties of diffraction peaks confirmed the successful synthesis of AuNPs. AuNPs functionalization with the phenolic compounds was confirmed by Fourier transform infrared (FTIR) spectroscopy. At the optimum conditions (pH = 5.0 and T = 60 °C), both dynamic light scattering (DLS) and transmission electron microscopy (TEM) revealed more than 87% of AuNPs to be 2.5 nm in size with Zeta potential to be equal to -19.9 mV.

The photocatalytic rate of ZnO supported onto natural zeolite nanoparticles in the photodegradation of an aromatic amine

Aniline and its derivate are critical environmental pollutants, and thus, the introduction of an eco-friendly catalyst for removing them is an important research future. The ZnO supported on the ball-mill prepared clinoptilolite nanoparticles (CNPs) was prepared via an ion-exchange process followed by the calcination process. The amount of loaded ZnO in the ZnO-CNP (CZ) samples varied as 0.54, 0.63, 0.72, and 0.86 meq/g as the Zn(II) concentration in the ion-exchange solution varied from 0.1 to 0.5 M. The ZnO-CNP catalyst was briefly characterized by XRD, FTIR, and DRS techniques. The pHpzc value for the various ZnO-CNPs was about 7.1 that had no change with the ZnO loading. By applying the Scherrer equation on the XRD results, a nano-dimension of about 50 nm was obtained for the catalyst. Bandgap energy of the ZnO-CNP samples was estimated by applying the Kubelka-Munk equation on the DRS reflectance spectra. The value for the CZ2 catalyst was about 3.64 eV. The supported ZnO-CNP sample was then used in the photodegradation of 2,4-dichloroaniline (DCA). Raw zeolite showed a relatively low photocatalytic activity. The degradation efficiency was followed by recording the absorbance of the DCA solution by UV-Vis spectrophotometer. The effects of the essential critical operating factors on the degradation efficiency were kinetically studied by applying the Hinshelwood equation to the results. The ZnO-CNP catalyst with 2 w% ZnO showed the best photocatalytic rate in the optimal conditions of 0.75 g/L, C_DCA: 15 ppm, and the initial pH: 5.8. Finally, HPLC analysis of the blank and the photodegraded DCA solutions at 180 and 300 min confirmed 74 and 87% of DCA molecules were degraded during these times. The results confirm that supported ZnO onto clinoptilolite caused enhanced photocatalytic activity because the zeolite internal electrical field prevents the e^-/h⁺ recombination.

Cu2O/Fe3O4/MIL-101(Fe) nanocomposite as a highly efficient and recyclable visible-light-driven catalyst for degradation of ciprofloxacin

Nowadays, the widespread production and use of antibiotics have increased their presence in wastewater systems, posing a potential threat to the environment and human health. The development of advanced materials for treating antibiotics in wastewater has always received special attention. This study aimed to synthesize a novel Cu₂O/Fe₃O₄/MIL-101(Fe) nanocomposite and use it to degrade ciprofloxacin (CIP) antibiotics in an aqueous solution under visible light irradiation. The optical, structural, and morphological attributes of the developed nanocomposite were analyzed by XRD, FTIR, FE-SEM, TGA, DRS, BET, VSM, and UV-Vis techniques. Optimum circumstances for CIP photocatalytic degradation were acquired in 0.5 g L^-1 of catalyst dosage, pH of 7, and CIP concentration of 20 mg L^-1. The degradation efficiency was achieved 99.2% after 105 min of irradiation in optimum circumstances. The chemical trapping experiments confirmed that hydroxyl and superoxide radicals significantly contributed to the CIP degradation process. The results of this study indicated that Cu₂O/Fe₃O₄/MIL-101(Fe) nanocomposite was a highly stable photocatalyst that could effectively remove antibiotics from aqueous solutions. The CIP degradation efficiency only decreased by 6% after five cycles, indicating the excellent recyclability of Cu₂O/Fe₃O₄/MIL-101(Fe) nanocomposites.

Heterogeneous UV-Switchable Au nanoparticles decorated tungstophosphoric acid/TiO2 for efficient photocatalytic degradation process

In the present study, gold nanoparticles were locally well-decorated on the surface of TiO₂ using the tungstophosphoric acid (HPW), as UV-switchable reducing intermediate linkers. The prepared Au NPs/HPW/TiO₂ nanostructure was characterized using FTIR, XRD, EDS, SEM and TEM, which confirmed the successful attachment of quasi-spherical Au NPs in the range of 20-30 nm on the surface of HPW modified TiO₂. Also, the FTIR results show that the Au NPs were binded to TiO₂ through the terminal the oxygen atoms HPW. The photocatalytic performance of prepared nanostructures was assessed in degradation of nitrobenzene. The nitrobenzene photodegradation kinetic study revealed that it well followed the Langmuir-Hinshelwood kinetic model with the apparent rate constant of 0.001 min^-1 using anatase TiO₂, 0.0004 min^-1 using HPW, 0.0014 using HPW/TiO₂, while it was obtained 0.0065 min^-1 using Au NPs@HPW/TiO₂ nanostructure. It shows that the photocatalytic rate of the prepared nanocomposites increased by 6.5- and 4.6-fold compared to photoactivity of anatase TiO₂ and HPW/TiO₂ respectively. Also, the photocatalytic mechanism of process was proposed. Moreover, the reusability study confirmed that its photocatalytic activity still remained high after three cycles.

Developing a simple box-behnken experimental design on the removal of doxorubicin anticancer drug using Fe3O4/graphene nanoribbons adsorbent

This paper aims to develop a Box-Behnken experimental design system to optimize the removal process of doxorubicin anticancer drugs. For this goal, Fe₃O₄/graphene nanoribbons was selected as adsorbent and removal of doxorubicin anticancer drug optimized using Box-Behnken experimental design with a selection of four effective factors. A three-level, four-factor Box-Behnken experimental design was used to assess the relationship between removal percentage as a dependent variable with adsorption weight (0.0015-0.01 mg), pH (3-9), temperature (15-45 °C) and time (1-15 min) as independent variables. Optimized condition by Behnken experimental design (pH = 7.36; time = 15 min; adsorbent weight = 0.01 mg and temperature = 29.26 °C) improved removal of doxorubicin anticancer drug about 99.2% in aqueous solution. The dynamic behavior, adsorption properties and mechanism of doxorubicin molecule on Fe₃O₄/graphene nanoribbon were investigated based on ab initio molecular dynamics (AIMD) simulations and density functional theory calculations with dispersion corrections. A closer inspection of the adsorption configurations and binding energies revealed that π-π interactions were the driving force when the doxorubicin molecule adsorbed on Fe₃O₄/graphene nanoribbon. The observed negative adsorption energy signifies a favourable and exothermic adsorption process of the various adsorbate-substrate systems. Besides, AIMD and phonon dispersion calculations confirm the dynamic stability of Fe₃O₄/graphene nanoribbon.

Occurrence, bioaccumulation and toxicological effect of drugs of abuse in aquatic ecosystem: A review

Drugs of abuse are a group of emerging contaminants. As the prevalence of manufacture and consumption, there is a growing global environmental burden and ecological risk from the continuous release of these contaminants into environment. The widespread occurrence of drugs of abuse in waste wasters and surface waters is due to the incomplete removal through traditional wastewater treatment plants in different regions around the world. Although their environmental concentrations are not very high, they can potentially influence the aquatic organisms and ecosystem function. This paper reviews the occurrence of drugs of abuse and their metabolites in waste waters and surface waters, their bioaccumulation in aquatic plants, fishes and benthic organisms and even top predators, and the toxicological effects such as genotoxic effect, cytotoxic effect and even behavioral effect on aquatic organisms. In summary, drugs of abuse occur widely in aquatic environment, and may exert adverse impact on aquatic organisms at molecular, cellular or individual level, and even on aquatic ecosystem. It necessitates the monitoring and risk assessment of these compounds on diverse aquatic organisms in the further study.

Green Synthesis and Characterization of Carboxymethyl Cellulose Fabricated Silver-Based Nanocomposite for Various Therapeutic Applications

Purpose

The current study proposed the simple, eco-friendly and cost-effective synthesis of carboxymethyl cellulose (CMC) structured silver-based nanocomposite (CMC-AgNPs) using Syzygium aromaticum buds extract.

Methods

The CMC-AgNPs were characterized by ultraviolet (UV) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transmission infra-red (FTIR), energy-dispersive X-ray (EDX), and dynamic light scattering (DLS) techniques. The synthesized nanocomposites were evaluated for their bactericidal kinetics, in-vivo anti-inflammatory, anti-leishmaniasis, antioxidant and cytotoxic activities using different in-vitro and in-vivo models.

Results

The spherical shape nanocomposite of CMC-AgNPs was synthesized with the mean size range of 20–30 nm, and the average pore diameter is 18.2 nm while the mean zeta potential of −31.6 ± 3.64 mV. The highly significant (P < 0.005) antibacterial activity was found against six bacterial strains with the ZIs of 24.6 to 27.9 mm. More drop counts were observed in Gram-negative strains after 10 min exposure with CMC-AgNPs. Significant damage in bacterial cell membrane was also observed in atomic force microscopy (AFM) after treated with CMC-AgNPs. Nanocomposite showed highly significant anti-inflammatory activity in cotton pellet induced granuloma model (Phase I) in rats with the mean inhibitions of 43.13% and 48.68% at the doses of 0.025 and 0.05 mg/kg, respectively, when compared to control. Reduction in rat paw edema (Phase II) was also highly significant (0.025 mg/kg; 42.39%; 0.05 mg/kg, 47.82%). At dose of 0.05 mg/kg, CMC-AgNPs caused highly significant decrease in leukocyte counts (922 ± 83), levels of CRP (8.4 ± 0.73 mg/mL), IL-1 (177.4 ± 21.3 pg/mL), IL-2 (83.7 ± 11.5 pg/mL), IL-6 (83.7 ± 11.5 pg/mL) and TNF-α (18.3 ± 5.3 pg/mL) as compared to control group. CMC-AgNPs produced highly effective anti-leishmaniasis activity with the viable Leishmania major counts decreased up to 36.7% within 24 h, and the IC₅₀ was found to be 28.41 μg/mL. The potent DPPH radical scavenging potential was also observed for CMC-AgNPs with the IC₅₀ value of 112 μg/mL. Furthermore, the cytotoxicity was assessed using HeLa cell lines with the LC₅₀ of 108.2 μg/mL.

Conclusion

The current findings demonstrate positive attributes of CMC fabricated AgNPs as a promising antibacterial, anti-inflammatory, anti-leishmaniasis, and antioxidant agent with low cytotoxic potential.

Recent Advances in Biopolymer-Based Dye Removal Technologies

Synthetic dyes have become an integral part of many industries such as textiles, tannin and even food and pharmaceuticals. Industrial dye effluents from various dye utilizing industries are considered harmful to the environment and human health due to their intense color, toxicity and carcinogenic nature. To mitigate environmental and public health related issues, different techniques of dye remediation have been widely investigated. However, efficient and cost-effective methods of dye removal have not been fully established yet. This paper highlights and presents a review of recent literature on the utilization of the most widely available biopolymers, specifically, cellulose, chitin and chitosan-based products for dye removal. The focus has been limited to the three most widely explored technologies: adsorption, advanced oxidation processes and membrane filtration. Due to their high efficiency in dye removal coupled with environmental benignity, scalability, low cost and non-toxicity, biopolymer-based dye removal technologies have the potential to become sustainable alternatives for the remediation of industrial dye effluents as well as contaminated water bodies.

Impacts of heavy metals and medicinal crops on ecological systems, environmental pollution, cultivation, and production processes in China

Heavy metals are widely distributed in the environment due to the natural processes and anthropogenic human activities. Their migration into no contaminated areas contributing towards pollution of the ecosystems e.g. soils, plants, water and air. It is recognized that heavy metals due to their toxicity, long persistence in nature can accumulate in the trophic chain and cause organism dysfunction. Although the popularity of herbal medicine is rapidly increasing all over the world heavy metal toxicity has a great impact and importance on herbal plants and consequently affects the quality of herbal raw materials, herbal extracts, the safety and marketability of drugs. Effective control of heavy metal content in herbal plants using in pharmaceutical and food industries has become indispensable. Therefore, this review describes various important factors such as ecological and environmental pollution, cultivation and harvest of herbal plants and manufacturing processes which effects on the quality of herbal plants and then on Chinese herbal medicines which influence human health. This review also proposes possible management strategies to recover environmental sustainability and medication safety. About 276 published studies (1988-2021) are reviewed in this paper.

Doxorubicin Anticancer Drug Monitoring by ds-DNA-Based Electrochemical Biosensor in Clinical Samples

In this research, glassy carbon electrode (GCE) amplified with single-wall carbon nanotubes (SWCNTs) and ds-DNA was fabricated and utilized for voltammetric sensing of doxorubicin with a low detection limit. In this technique, the reduction in guanine signal of ds-DNA in the presence of doxorubicin (DOX) was chosen as an analytical factor. The molecular docking study revealed that the doxorubicin drug interacted with DNA through intercalation mode, which was in agreement with obtained experimental results. The DOX detection performance of ds-DNA/SWCNTs/GCE was assessed at a concentration range of 1.0 nM-20.0 µM. The detection limit was found to be 0.6 nM that was comparable and even better (in many cases) than that of previous electrochemical reported sensors. In the final step, the ds-DNA/SWCNTs/GCE showed powerful ability for determination of the DOX in injection samples with acceptable recovery data.

Effects of silver nanoparticles added into polyurea coating on sulfate-reducing bacteria activity and electrochemical properties; an environmental nano-biotechnology investigation

In the present work, Ag nanoparticles were added to polyurea coating in order to improve its antibacterial and electrochemical properties in sulfide-reducing bacteria-containing media. To this end, Ag nano-powder was mixed with two component polyuria, and then the antibacterial behavior of the nanocomposite coating was studied in sulfate-reducing bacteria (SRB)-containing medium. The results revealed the inhibitory effects of nanocomposite coating on the formation of SRB biofilms on the samples. Moreover, the SRB population decreased in contact with the Ag nanoparticles-mixed coating over 7 days. Investigation of the growth and activity of the bacteria represented the effective antibacterial properties of Ag nanoparticles in the polyurea matrix. Furthermore, EIS (electrochemical impedance spectroscopy) measurements indicated that the corrosion properties of the nanocomposite coating improved considerably over 7 days. The coating resistance increased 2 times by adding Ag nanoparticles after 1 day and 3.3 times after 7 days. In accordance with the same results, the charge transfer resistance increased 1.5 times and 1.1 times by adding Ag nanoparticles after 1 day and 7 days, respectively. The improvement in the protective properties of the nanocomposite coating are reflected in the increase in both film and charge transfer resistance.

Application of adsorption process for effective removal of emerging contaminants from water and wastewater

Emerging pollutants in the marine ecosystem, as well as their possible impact on live species, have become a rising cause of worry. A traditional wastewater treatment plants alone are not successful in eliminating such massive contaminant groups and therefore additional water treatment is required which is to be cost effective. Since standard primary and secondary treatment plants are unsuccessful at eliminating or degrading these harmful chemicals, a cost-effective tertiary treatment approach is proposed. Adsorption is a successful approach for Contaminants removal globally, because it is low installation expense, high performance and has easy operational design. Emerging pollutants have been removed from wastewaters using various adsorbents like activated carbons, improved bio chars, Nano adsorbents, hybrid adsorbents, and others. The purpose of this paper is to review the source of contaminants and the concept of adsorption when separating emerging contaminants. The present study aims to examine the adsorption mechanism as an effective approach for treating emerging contaminants. Then, the analysis of natural and man-made adsorbents for the separation of contaminants is examined along with its comparison. Also, future view on emerging contaminants and adsorbents in modern generation has been discussed.

Investigation of the mechanical properties of a bony scaffold for comminuted distal radial fractures: Addition of akermanite nanoparticles and using a freeze-drying technique

One of the methods of repairing the damaged bone is the fabrication of porous scaffold using synergic methods like three-dimensional (3D) printing and freeze-drying technology. These techniques improve the damaged and fracture parts rapidly for better healing bone lesions using bioactive ceramic and polymer. This research, due to the need to increase the mechanical strength of 3D bone scaffolds for better mechanical performance. Akermanite bioceramic as a bioactive and calcium silicate bioceramic has been used besides the polymeric component. In this study, the porous scaffolds were designed using solid work with an appropriate porosity with a Gyroid shape. The prepared Gyroid scaffold was printed using a 3D printing machine with Electroconductive Polylactic Acid (EC-PLA) and then coated with a polymeric solution containing various amounts of akermanite bioceramic as reinforcement. The mechanical and biological properties were investigated according to the standard test. The mechanical properties of the porous-coated scaffold showed stress tolerance up to 30 MPa. The maximum strain obtained was 0.0008, the maximum stress was 32 MPa and the maximum displacement was 0.006 mm. Another problem of bone implants is the impossibility of controlling bone cancer and tumor size. To solve this problem, an electroconductive filament containing Magnetic Nanoparticles (MNPs) is used to release heat and control cancer cells. The mechanical feature of the porous scaffold containing 10 wt% akermanite was obtained as the highest stress tolerance of about 32 MPa with 46% porosity. Regarding the components and prepare the bony scaffold, the MNPs release heat when insert into the magnetic field and control the tumor size which helps the treatment of cancer. In general, it can be concluded that the produced porous scaffold using 3D printing and freeze-drying technology can be used to replace broken bones with the 3D printed EC-PLA coated with 10 wt% akermanite bioceramic with sufficient mechanical and biological behavior for the orthopedic application.

Modeling analysis on the effective elimination of toxic pollutant from aquatic environment using pyrolysis assisted palmyra palm male inflorescence

In this study adsorption of Cd(II) ions using the pyrolysis assisted Palmyra palm male inflorescence (PAPMI) was systematically examined. A batch adsorption study was carried out to determine the type of interactions and removal efficiency which is based on the surface property of PAPMI. The diverse parameters which affect the adsorption performance of PAPMI for Cd(II) ion removal were optimized: biosorbent dose - 1.25 g/L, pH - 6.0, temperature - 303 K, initial cadmium ions concentration - 50 mg/L and contact time - 40 min. Pseudo-first order kinetics and Langmuir isotherm models were more suitable to describe the adsorption kinetics and isotherm, respectively. Therefore, modeling studies portrayed the present Cd(II) ions adsorption on PAPMI as monolayer adsorption occurs on the homogeneous surface and follows the physisorption mechanism. The maximum adsorption capacity of the synthesized PAPMI was examined as 233.2 mg/g from the equilibrium isotherm investigation. Based on the calculated thermodynamic parameters (ΔG^o, ΔH^o and ΔS^o) values, the present Cd(II) ions adsorption on PAPMI was explicated as feasible, and exothermic. The outcome proposed that Palmyra palm male inflorescence can be a suitable adsorbent for expulsion of Cd(II) ions from aqueous environment. In the interim, the utilization of pyrolysis assisted is a viable and fast uptake innovation for the removal of heavy metals from water environment.

A review on cleaner strategies for extraction of chitosan and its application in toxic pollutant removal

Existence of human beings in this world require a cleaner environment, in which, water is the main requirement for living. Owing to the considerable development in civilisation and considerable population explosion, an increase in the contamination of natural water resources by means of non-biodegradable contaminants like heavy metals is observed thereby increasing the need for treatment of water before usage. Despite the existence of specific limits for disposal of heavy metals in water resources, studies still show high contamination of heavy metals in all these water resources. This review provides a brief note on sources and toxicity of different heavy metals in various oxidation states, their effects as well as highlights the numerous available and advanced techniques for heavy metals removal. Of all techniques adsorption is found to be beneficial as it doesn't inculcate any secondary pollutants to the environment. Additionally, this article has investigated the advantages of polymer nanocomposites in adsorption and mainly focused on biopolymer chitosan owing to its abundance in natural environment. The cleaner techniques for the extraction of chitosan and its functionalisation using different types of nanofillers are comprehensively discussed in this review. This article suggests a better alternative for conventional adsorbents as well as aids in remediation of wastes.

A New Electrochemical Platform for Dasatinib Anticancer Drug Sensing Using Fe3O4-SWCNTs/Ionic Liquid Paste Sensor

A new electrochemical platform was suggested for the sensing of the dasatinib (DA) anticancer drug based on paste electrode modification (PE) amplified with Fe₃O₄-SWCNTs nanocomposite and 1-hexyl-3-methylimidazolium tetrafluoroborate (mim-BF₄⁻). The new platform showed a linear dynamic range from 0.001–220 µM with a detection limit of 0.7 nM to determine DA at optimal condition. Electrochemical investigation showed that the redox reaction of DA is relative to changing the pH of solution. Moreover, Fe₃O₄-SWCNTs/mim-BF₄⁻/PE has improved the oxidation current of DA about 5.58 times which reduced its oxidation potential by about 120 mV at optimal condition. In the final step, Fe₃O₄-SWCNTs/mim-BF₄⁻/PE was used as an analytical platform to determine the DA in tablets and a dextrose saline spike sample, and the results showed recovery data 99.58–103.6% which confirm the powerful ability of the sensor as an analytical tool to determine the DA in real samples.

Novel magnetic lignosulfonate-supported Pd complex as an efficient nanocatalyst for N-arylation of 4-methylbenzenesulfonamide

This study presents a novel, economical, and environmentally technique for synthesizing magnetic palladium complex conjugated to activated calcium lignosulfonate with triethylenetetramine (Fe₃O₄@lignosulfonate@triethylenetetramine@Pd complex (FLT-Pd complex)) as a practical and air-stable catalyst. FLT-Pd complex is used as a catalyst for the fabrication of 4-methyl-N-phenyl-benzenesulfonamide derivatives via N-arylation of 4-methylbenzenesulfonamide in good yields. Furthermore, because of the complex magnetic reparability and high stability, it could be removed easily from the reaction media using a magnet and reused 5 cycles without a remarkable loss of catalytic prowess.