Prediction and optimizing of methylene blue sequestration to activated charcoal/magnetic nanocomposites using artificial neutral network and response surface methodology.

Green synthesized magnetic nanoparticles (MNPs) linked with activated charcoal (AC) (AC/Fe3O4 NCs) were exploited for methylene blue (MB) confiscation in this study. The AC/Fe3O4 NCs produced were characterized using TEM, FTIR, UV/Vis and XRD spectrometry. The Response-Surface-Methodology (RSM) was utilized to improve the experimental data for the MB sorption to AC/Fe3O4 NCs, with 20 experimental runs implemented through a central composite design (CCD) to assess the effect of sorption factors-initial MB concentration, pH and sorbent dosage effects on the response (removal-effectiveness). The quadratic model was discovered to ideally describe the sorption process, with an R2 value of 0.9857. The theoretical prediction of the experimental data using the Artificial-Neural-Network (ANN) model showed that the Levenberg-Marquardt (LM) had a better performance criterion. Comparison between the modelled experimental and predicted data showed also that the LM algorithm had a high R2 of 0.9922, which showed NN model applicability for defining the sorption of MB to AC/Fe3O4 NCs with practical precision. The results of the non-linear fitting (NLF) of both isotherm and kinetic models, showed that the sorption of MB to AC/Fe3O4 NCs was perfectly described using the pseudo-second-order (PSOM) and Freundlich (FRHM) models. The estimated optimum sorption capacity was 455 mg g-1. Thermodynamically, the sorption of MB to AC/Fe3O4 NCs was shown to be non-spontaneous and endothermic.

Greenhouse Gas Emission: Perception during the COVID-19 Pandemic.

The period 2020/2021 was an unprecedented and historic time for industrial, economic, and societal activities all over the world with great challenges to human health, the ecosystems, and other aspects of human endeavors owing to the COVID-19 or SARS-CoV-2 (CV-19) pandemic which is now a topical aspect of research interest. Despite the negative impacts of the CV-19 pandemic, there are also positive reports during the CV-19 pandemic such as the reduction of gas flare, reduction in the burning of fossil fuels from automobile exhaust and a reduction in the other ensuing factors of greenhouse gases emissions (which is one of the major drives for global warming and climate change as well as other environmental effluences). Hence, this brief perspective review study is centered on greenhouse gas (GHG) emission. The study employs a methodical approach to analyze some already available research studies from existing publications and databases on GHG emission using the perception during the CV-19 pandemic. The specific findings from this review show that, from the meteorological perspective, the global response to the catastrophe ensuing from the CV-19 pandemic has a great influence on the reduction of GHGs, the reduction in the burning of fossil fuels from automobiles and industrial devices, and the reduction in the other ensuing factors of GHG emission. Hence, it will not be far from the truth to conclude that there is a possible positive connection between the CV-19 pandemic and GHG emissions. The study has a direct impact on the environment owing to the negative and positive environmental consequences of the CV-19 pandemic. Suggestions and recommendations in the form of future prospects of GHG emission vis-à-vis global warming and climate change are also discussed. Furthermore, suggestions on how to improve food security and agriculture during a pandemic such as the CV-19 outbreak period are highlighted.

Synthesis and characterization of copper zinc iron sulphide (CZFS) thin films.

In an aqueous bath, quaternary thin films (TFs) of copper zinc iron sulphide (CZFS) were deposited on glass (soda-lime) substrates. The present study aimed to analyse the effect of deposition periods on the properties of the prepared CZFS TFs using Chemical bath deposition (CBD). The precursor and films were examined by Fourier Transform Infrared (FTIR) spectroscopy to check for the chemical formation present. Rutherford backscattering spectroscopy (RBS) was used to determine the elemental compositions and stoichiometry of the deposited films. The optical characteristics were observed by a UV-Vis Spectrophotometer and a four-point probe (FPP) for the electrical properties. The optical characterization revealed a direct transition band-gap energy that decreased from 1.96 to 1.50 eV with an increase in deposition period. The optical constants were studied with respect to the wavelength within the range of 300-900 nm. The films exhibited high resistive properties with a conductivity that varied with an increase in deposition period. The effect of deposition periods on the optical properties of refractive index, extinction coefficient, and real and imaginary parts of dielectric constants has been reported. All these parameters were found to increase with deposition period except for the film deposited for 18 h (C3). These results confirm that the aqueous deposited CZFS films can be tuned for various optoelectronic applications.

A Methodical Review on the Applications and Potentialities of Using Nanobiosensors for Disease Diagnosis.

Presently, with the introduction of nanotechnology, the evolutions and applications of biosensors and/or nanobiosensors are becoming prevalent in various scientific domains such as environmental and agricultural sciences as well as biomedical, clinical, and healthcare sciences. Trends in these aspects have led to the discovery of various biosensors/nanobiosensors with their tremendous benefits to mankind. The characteristics of the various biosensors/nanobiosensors are primarily based on the nature of nanomaterials/nanoparticles employed in the sensing mechanisms. In the last few years, the identification, as well as the detection of biological markers linked with any form of diseases (communicable or noncommunicable), has been accomplished by several sensing procedures using nanotechnology vis-à-vis biosensors/nanobiosensors. Hence, this study employs a systematic approach in reviewing some contemporary developed exceedingly sensitive nanobiosensors alongside their biomedical, clinical, or/and healthcare applications as well as their potentialities, specifically for the detection of some deadly diseases drawn from some of the recent publications. Ways forward in the form of future trends that will advance creative innovations of the potentialities of nanobiosensors for biomedical, clinical, or/and healthcare applications particularly for disease diagnosis are also highlighted.

Fluoride ions sorption using functionalized magnetic metal oxides nanocomposites: a review.

Fluoride is an anionic pollutant found superfluous in surface or groundwater as a result of anthropogenic actions from improper disposal of industrial effluents. In drinking water, superfluous fluoride has been revealed to trigger severe health problems in humans. Hence, developing a comprehensive wastewater decontamination process for the effective management and preservation of water contaminated with fluoride is desirable, as clean water demand is anticipated to intensify considerably over the upcoming years. In this regard, there have been increased efforts by researchers to create novel magnetic metal oxide nanocomposites which are functionalized for the remediation of wastewater owing to their biocompatibility, cost-effectiveness, relative ease to recover and reuse, non-noxiousness, and ease to separate from solutions using a magnetic field. This review makes an all-inclusive effort to assess the effects of experimental factors on the sorption of fluoride employing magnetic metal oxide nanosorbents. The removal efficiency of fluoride ions onto magnetic metal oxides nanocomposites were largely influenced by the solution pH and ions co-existing with fluoride. Overall, it was noticed from the reviewed researches that the maximum sorption capacity using various metal oxides for fluoride sorption was in the order of aluminium oxides >cerium oxides > iron oxides > magnesium oxides> titanium oxides, and most sorption of fluoride ions was inhibited by the existence of phosphate trailed by sulphate. The mechanism of fluoride sorption onto various sorbents was due to ion exchange, electrostatic attraction, and complexation mechanism.

Environmental implications of petroleum spillages in the Niger Delta region of Nigeria: A review.

The issue of environmental pollution has been recognized as a typical example of an anthropogenic activity that constitutes a global challenge coupled with the influence of climate change. This has constituted several hazards which include bioaccumulation of toxic substances, pollution of the aquatic environment, and high rate of dilapidation of soil structure and texture, health hazards, high level of imbalance in the ecosystem and a high level of toxicity in humans and the environment. Despite the intervention of governments, industries, researchers and relevant stakeholders, these problems remain paramount in most regions. Therefore, given the aforementioned, it is essential to identify sustainable remediation techniques, innovative knowledge on remediation strategies and clean up techniques that could help in the mitigation of all these highlighted challenges. Moreover, several studies have revealed the deleterious influence of petroleum or oil spillages resulting in irreparable environmental dilapidation and other potential hazards to human health, agriculture, climate system, and the ecosystem in general. From the systematic analysis of the evidence-based, meta-data-based review and other reviewed literature, it is noticeable that there is scant holistic review study that will incorporate all these aforementioned environmental implications resulting from the activities of petroleum resources in the Niger Delta region of Nigeria (NDRN) in just a single study. In the interim, it is alleged that there is hardly a permanent and tangible solution to these petroleum spillage issues and their impacts on the region; albeit, awareness will be fundamental for its mitigation. Hence, this review study will attempt to fill this gap by holistically reviewing the selected environmental implications of petroleum spillages in the NDRN drawn from 219 evidence and meta-data-based reviews and other articles. Furthermore, the relevant legal frameworks that could guild in protecting against environmental issues and petroleum spillages, are discussed in this study. In conclusion, the study cautiously provides a way forward by submitting that effective research and development measures ranging from public health assessments of petroleum contamination to an all-embracing application of bioremediation technology should frequently be carried out as a matter of urgency with resilient adaptation, mollification and management of these menaces.

Effect of hexavalent chromium on the environment and removal techniques: A review.

Despite the importance of chromium (Cr) in most anthropogenic activities, the subsequent environmental adulteration is now a source of major concern. Cr occurs in numerous oxidation states, with the furthermost stable and frequently occur states being Cr(0), Cr(III) and Cr(VI). Cr(0) and Cr(III) are vital trace elements while Cr(VI) is dispensable and noxious to living organisms. Predominantly in plants, Cr at low concentrations of about 0.05-1 mg/L assist to boost growth as well as increase productivity. However, accumulation of Cr could represent a potential threat to living organisms. Cr absorption, displacement and accretion depend on its speciation, which also determines its toxicity which is often diverse. Indications of its toxicity include; reduction of seed germination, retardation of growth, reduction of yield, inhibition of enzymatic activities, weakening of photosynthesis, nutrient, oxidative disparities and genetic mutation in plants as well as several injurious diseases in animals and humans. In this study, we have presented a comprehensive review as well as an informative account of the influence of Cr on the environment drawn from researches carried out over the years following an analytical approach. Uniquely, this work presents a review of the effects and remediation of Cr from soil and wastewater drawn from several evidence and meta-data-based articles and other publications. Accordingly, the write-up is intended to appeal to the consciousness of the general public that the significance of Cr notwithstanding, its environmental toxicity should not be taken for granted.

Correction: Removal of fluoride ions using a polypyrrole magnetic nanocomposite influenced by a rotating magnetic field.

[This corrects the article DOI: 10.1039/C9RA07379E.].

Removal of fluoride ions using a polypyrrole magnetic nanocomposite influenced by a rotating magnetic field.

The impact of a varying rotating magnetic field in stimulating adsorption of fluoride ions onto a polypyrrole magnetic nanocomposite synthesized via in situ a polymerization process was evaluated. Under the effect of a rotating magnetic field, improved removal of adsorbate (10 mg L-1) from aqueous solution using the polypyrrole magnetic nanocomposite was observed, with a maximum removal of 78.2% observed at a magnetic field intensity of 0.019 T. Particle aggregation resulting from the force owing to the gradient on the particles as the magnetic field was increased resulted in improved fluoride removal. This aggregation of particles leads to an improved chain collision and expanse of particle interaction with the fluoride solution. The process of adsorption of fluoride by the PPy/Fe3O4 nanocomposite followed both the Freudlich isotherm and the Temkin isotherm. Interestingly, under the effect of the rotating magnetic field, the adsorption process was best described by the Freundlich isotherm.