Removal of Mercury from Wastewater by Nanoparticle Pyrite (FeS2) and Ultrafiltration (UF) Membrane System

This research investigated the removal of mercury by Reactive Adsorbent Membrane (RAM) hybrid filtration process to attain high quality water from wastewater or water resources contaminated with Hg(II), while producing stable final residuals. Pyrite (FeS2) nanoparticles were employed as the reactive adsorbent and the FeS2-contacted mercury residuals were separated by either Dead End Ultrafiltration (DE-UF) or Cross Flow Ultrafiltration (CF-UF) system. The first task of this research was to synthesize pyrite nanoparticles with high purity in short reaction time. Microwave irradiation process was used to synthesize pyrite as microwave digestion method has the advantage of producing fine particles of highly pure pyrite with minimal reaction time. Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDS/EDX) were used to characterize pyrite. Synthesized pyrite were used in all experiments. Reaction mechanism for Hg(II) removal by pyrite and behavior of the treatment system were characterized by observing flux decline, pH change, and Hg and Fe concentration in permeate water with time. Effects of the presence of anions (Cl-, SO42-, NO3-) and natural organic matter (HA) on Hg(II) removal were investigated. Also, stability of final residuals was evaluated by using thiosulfate solution (Na2S2O3) as desorbing reagent. This study also examined the possibility of continuous removal of mercury by reusing Hg/pyrite laden membrane to remove additional Hg(II) contaminated water. Analytical techniques used in this study included cold vapor atomic absorption spectrometry (CV-AAS) for mercury measurement, inductively coupled plasma optical emission spectrometry (ICP-OES) for Fe measurement and thermo triode pH meter calibrated with 4, 7 and 10 pH buffers for pH measurement. The surface of Hg/pyrite-deposited membranes were characterized using surface analysis techniques, including scanning electron microscopy (SEM) for sample's surface topography and X-ray photoelectron spectroscopy (XPS) to analyze the surface chemistry (oxidation state) of solids. Results of this research indicated that the Hg(II)-contacted FeS2 was completely rejected by both dead-end and cross-flow ultrafiltration membrane system regardless of the presence of anions and humic acid. However, Hg(II) removal was accompanied by considerable flux decline and pH change. Desorption tests were conducted using thiosulfate and almost no release of Hg(II) or iron was observed in permeate water indicating that the formed residuals are very stable. Recycle test showed that this system successfully achieved the goal of continuous and complete removal of mercury from water

Obesity and Hypertension in Students of Jahangirnagar University: Alarming Issues

The prevalence of obesity and hypertension (HTN) in university students of Bangladesh has not reported yet. Considering the proper health maintenance of this population in mind, the study was aimed to determine the prevalence of obesity and HTN as well as relationship among them in the students of a residential university of Bangladesh, Jahangirnagar University. This descriptive cross sectional study included 500 randomly selected students (250 males and 250 females). Participants completed a questionnaire on physical activity, sedentary behaviour, dietary factors, smoking and family history of obesity, HTN, and coronary artery disease. Blood pressure and anthropometric parameters such as height, weight, waist and hip circumferences were measured following standard procedure. The Statistical analyses were performed using the software SPSS.The prevalence of overweight was 25% (31.1% males, 15.6% females) and obesity 7.2% (9.4% males, 4% females). Pre-HTN was found at 27.1% (38% males, 11.2% females) and HTN at 2.2% (3.3% males, 0.4% females). A high rate of smoking, sedentary behavior, physical inactivity, excessive consumption of unhealthy food, and caffeine-rich drinks was also observed. Significant correlation was found between parameters of obesity and HTN. High prevalence of pre-HTN in males and central obesity in females were found which is immediately needed to control for better health maintenance of this population

Status and economic valuation of ecosystem services of Tanguar haor: A wetland of Bangladesh

Tanguar haor wetland is one of the listed Ramsar sites enrich with biodiversity variety and provides several ecosystem services with significant contribution to the national economy of Bangladesh. But these services were decreasing day by day due to natural and anthropogenic activities. The purposes of this study were to identify the utilized ecosystem services by communities, economic values of utilized ecosystem services and the basic reasons for depleting of ecosystem services. Data were collected through baseline survey, checklists, face to face questionnaire survey and focus group discussion (FGD) from 120 residential respondents and 50 tourist respondents by accepting random sampling techniques during November, 2016 to September, 2017. Physiochemical characteristics of the water were determined where the mean temperature and pH were 28.26°C and 7.72 respectively. The highest TDS, EC, DO, NO3 and PO4 values were 1020 (mg L−1), 1460 (μS cm−1), 8.56 (mg L−1), 1.769 (mg L−1) and 0.078 (mg L−1), respectively. Commonly utilized ecosystem services were crops, vegetables, fuel, fresh water, fishes and migratory birds, climate regulation, water purification, natural hazards protection, aesthetic, social relations, recreation & tourism, health benefit, primary production, nutrient cycling, water cycling habitats for species and provision of habitat etc. Market Value Method (MVM) and Contingent Value Method (CVM) were applied to measure the economic value of Tanguar haor wetland services. DPSIR framework and Impact Matrix (IM) were applied for conceptual analysis to identify the effects on ecosystem services. Total economic value of 39 ecosystem services of Tanguar haor was estimated at 174039980 BDT year−1. Mismanagement of biodiversity, over exploitation, sedimentation of haor, climate change, illegal hunting, land use changes and habitat changes were the responsible factors for depleting ecosystem services. The impact factor (4.161) was identified by natural and anthropogenic factors on ecosystem services. There have a vast prospect of the Tanguar haor wetland services for near communities. Finally the research suggested several sustainable management approaches which have the potentiality to protect the services of the wetland

Mass media utilization to promote public behavior change during COVID-19 situation: A population survey of Dhaka city

A huge amount of information associated with the novel coronavirus disease 2019 (COVID-19) outbreak was circulated by mass media in Bangladesh. There has been a rare example so far of how media intervention during the epidemic can affect the public behaviour of Bangladesh. We aimed to assess mass media's influence on changing public behaviour during the second wave of COVID-19. An online cross-sectional survey among 416 Bangladeshi respondents was conducted between August and September 2021. Besides descriptive statistics, datasets were analyzed through a set of statistical methods such as Pearson’s correlation coefficient, and stepwise multiple regression model. The results showed that knowledge level change towards COVID-19 (10 items) had the highest association with behaviour change towards COVID-19 (16 items), indicating a high adoption of public behavior change. There was a positive significant relationship between the behaviour change towards COVID-19 (16 items) with the media's role in making awareness regarding COVID-19 (r= 0.342, p < .001), while there was a negative relationship between the behaviour change towards COVID-19 (16 items) of the respondents with age of participants (r= -.234, p < .001). The results also disclosed that knowledge level, media credibility, and media check-in had the largest contribution to influence the public behavior change. We also found that social media was highly used media as expected during the COVID-19 outbreak. The outcomes of the survey have vital implications for public behavior change and may support infectious disease suppression and control. Our outcomes also stress the significance of the reliability of information shared via mass media outlets and practical strategies to counter misinformation during the COVID-19 outbreak

Computer Assisted Drug Design of Tinosporide for treatment of Cancer: a Combined Density Functional and Molecular Docking Study

This article discusses theory behind the most important methods and recent successful applications of halogen‑directed tinosporide, ligand-based methods use only ligand information for predicting activity depending on its similarity/dissimilarity to previously known active ligands. We review widely used ligand-based methods such as ligand-based pharmacophores, molecular descriptors, and quantitative structure-activity relationships. In addition, important tools such as target/ligand data bases, homology modeling, ligand ADMET etc., and necessary for successful implementation of various computer-aided drug discovery/design methods in best analogue of tinosporides discovery are discussed. Finally, computational methods for toxicity prediction and optimization for favorable physiologic properties are discussed with successful lead for tinosporides from literature. The therapeutic potential of tinosporide has been studied extensively and the active compounds of tinosporide are shown to be involved in modulating multiple physiological responses. Moreover this article will review the structure of series of halogen-directed tinosporides before illustration on how the molecules exert their functions via interactions with various signal transducer and activator proteins of transcription which were designed by homology modeling. Strategies for CADD vary depending on the extent of structural and other information available regarding the target (enzyme/receptor) and the ligands. The process by which a new tinosporide product is brought to market stage is referred to by a number of names most commonly as the development chain and consists of a number of distinct stages. Keywords: CADD; ADMET; Molecular Modeling; Tinosporide

CQDs embed g-C3N4 photocatalyst in dye removal and hydrogen evolution : An insight review

Recent research has highlighted heterogeneous photocatalysts as a feasible contender for addressing energy shortages and environmental cleanup. One of the best semiconducting photocatalysts used in wastewater treatment, disinfection, and energy evolution is graphitic carbon nitrate (g-C3N4). Researchers have used carbon quantum dots (CQDs) to maximize and enhance the photocatalytic activity of g-C3N4 and to get over the material's limits due to photoinduced charges, partial surface area, and insufficient light-capturing difficulties. In this context, the fundamentals of CQDs and g-C3N4 are described in length, along with their structural state, synthesis, and modification techniques. The classification, manufacturing procedure, and characterization of CQDs/g-C3N4 are then highlighted in this paper. Following that, it is shown how CQDs/g-C3N4 photocatalysts are used in dye removal and hydrogen evolution studies. The discussion of CQDs/g-C3N4's present hurdles, unmet needs, and future research prospects concludes while keeping in mind their practical applications. This study shows that by embedding CQDs, the influence of charges, morphological modification, and textural quality of g-C3N4 have been altered. It is anticipated that this review will offer a practical overview and comprehension of CQDs embedded with g-C3N4 photocatalysts in order to promote their utilization. The ultimate goal of this review may be to impart a fundamental understanding of photocatalysis while also providing an expository evaluation of the most recent advancements in g-C3N4/CQDs photocatalysts in the sectors of energy and environmental security

A comprehensive review on advances in TiO2 nanotube (TNT)-based photocatalytic CO2 reduction to value-added products

The photocatalytic reduction of CO2 into solar fuels by using semiconductor photocatalysts is one of the most promising approaches in terms of pollution control as well as renewable energy sources. One of the crucial challenges for the 21st century is the development of potential photocatalysts and techniques to improve CO2 photoreduction efficiency. TiO2 nanotubes (TNTs) have recently attracted a great deal of research attention for their potential to convert CO2 into useful compounds. Researchers are concentrating more on CO2 reduction due to the rising trend in CO2 emissions and are striving to improve the rate of CO2 photoreduction by modifying TNTs with the appropriate configuration. In order to portray the potential applications of TNTs, it is imperative to critically evaluate recent developments in synthesis and modification methodologies and their capability to transform CO2 into value-added chemicals. The current review provides an insightful understanding of TNT production methods, surface modification strategies used to enhance CO2 photoreduction, and major findings from previous research, thereby revealing research gaps and upcoming challenges. Stability, reusability, and the improved performance of TNT photocatalysts under visible light as well as the selection of optimized modification methods are the identified barriers for CO2 photoreduction into valuable products. Higher rates of efficacy and product yield can be attained by synthesizing suitable photocatalysts with addressing the limitations of TNTs and designing an optimized photoreactor in terms of the proper utilization of photocatalysts, incident lights, and the partial pressure of reactants

Recent progress in TiO2-Based photocatalysts for conversion of CO2 to hydrocarbon fuels: A systematic review

Photocatalytic conversion of CO2 by using sunlight and TiO2 photocatalysts is a promising approach which produce hydrocarbon fuels to meet the future energy demands with hardly affecting the environment. This systematic review aims to provide rigorous overview of recent progress in TiO2-based CO2 photoreduction to produce hydrocarbon fuels along with future challenges. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method was adopted to perform this systematic review. It uses explicit systematic approaches that are chosen to prevent bias, resulting in accurate data collection which helps to draw reliable conclusions. Peer-reviewed articles published in English language between year 2018–2022 were chosen from two main databases, namely Web of Science and Scopus. Depending on the search criteria 62 articles were selected for reviewing critically. Literature suggests that TiO2-based photocatalysts have been increasingly used for reducing CO2 to hydrocarbon fuels. Morphological alterations and surface modification techniques have been widely utilized to improve the photocatalytic performance and minimize limitations of pure TiO2. Despite extensible efforts in this field, the utilization of hydrocarbon fuels still far away from practical applications. There are some challenges need to be addressed like environment friendly low-cost synthesis and modification method development, maximum visible light utilization, design of photoreactor with suitable product selectivity and kinetic model development for CO2 reduction. This study portrays increased clarity regarding the advances and way forwards of crucial topics TiO2-based CO2 photoreduction. Such systematic review is crucial for researchers and academicians for setting future planning

Performance evaluation of dye wastewater treatment technologies: A review

Dye wastewater released from several dyes induced industries are harmful towards the living, non-living environment and human. Consequently, existence of dye in water bodies is becoming a rising concern to environmentalists and citizens. Dye wastewater should be treated prior to release in an open water body to minimize its negative impacts. A long term sustainable and efficient treatment methods should be established to reduce and overcome the impacts. Although there have been significant advances in the management and treatment of such effluent using physical, chemical and biological methods. However, due to lack of information on effective dye removal methods, it is difficult to decide on a single unique technique that resolves the prevailing dye wastewater. Therefore, this paper reviews recent research on various (physical, chemical, biological, advanced oxidation process (AOPs) and hybrid) dye removal methods to compare efficiency, evaluation performance, merits and demerits. Among the existing methods, most of them have a common disadvantage which is the generation of secondary pollutes, takes long time and costly. This paper especially highlights AOPs method for dye removal as these are known as one of the promising and most effective dye removal techniques these days. This paper also suggests the application of AOPs methods possess the best performance in terms of faster dye removing as well as cost effective, time oriented and environmentally friendly. Additionally, this paper addressed the difficulties and future prospects of this emerging method that links to sustainable development

In silico Analysis of the Functional and Structural Impacts of Non-synonymous Single Nucleotide Polymorphisms in the Human Paraxonase 1 Gene

Computational approaches could help in identifying deleterious non-synonymous single nucleotide polymorphisms (nsSNPs) in a disease related gene which is a difficult and laborious task through laboratory experiments. In the present study, we analyzed the impacts of nsSNPs on structure and function of Paraxonase 1 (PON1) using different bioinformatics tools. The human PON1 protein sequence and its corresponding gene's SNP information were collected from UniProt and dbSNP databases, respectively. We utilized SIFT, Polyphen, I-Mutant 2.0, MutPred, SNP and GO, PhD-SNP and PANTHER tools in order to examine the total 39 nsSNPs occurring in the PON1 coding region. We filtered the most pathological mutations by combining the scores of the aforementioned servers and found 8 SNPs (G344C, S302L, W281C, D279Y, H134R, F120S, L90P, C42R) as deleterious and disease causing. The PDB structure of PON1 protein was obtained from RCSB Protein Data Bank (PDB ID: 1V04). The deleterious SNPs in native PON1 were introduced using Swiss-PDB Viewer package and changes in free energy were observed for six out of eight mutant structures. Two SNPs, S302L (substitution of serine to leucine at 302 position in amino acid sequence) and L90P (substitution of leucine to proline at 90 position in amino acid sequence) caused the highest energy increase amongst all. The findings implicate that these nsSNPs would be analyzed further in detail to enumerate their possible association with the protein deteriorating and disease causal potentialities