Chromium originates from geogenic and extensive anthropogenic activities and significantly impacts natural ecosystems and human health. Various methods have been applied to remove hexavalent chromium ...(Cr(VI)) from aquatic environmental matrices, including adsorption via different adsorbents, which is considered to be the most common and low-cost approach. Biochar materials have been recognized as renewable carbon sorbents, pyrolyzed from various biomass at different temperatures under limited/no oxygen conditions for heavy metals remediation. This review summarizes the sources, chemical speciation & toxicity of Cr(VI) ions, and raw and modified biochar applications for Cr(VI) remediation from various contaminated matrices. Mechanistic understanding of Cr(VI) adsorption using different biochar-based materials through batch and saturated column adsorption experiments is documented. Electrostatic interaction and ion exchange dominate the Cr(VI) adsorption onto the biochar materials in acidic pH media. Cr(VI) ions tend to break down as HCrO4−, CrO42−, and Cr2O72− ions in aqueous solutions. At low pH (∼1–4), the availability of HCrO4− ions attributes the electrostatic forces of attraction due to the available functional groups such as −NH4+, −COOH, and −OH2+, which encourages higher adsorption of Cr(VI). Equilibrium isotherm, kinetic, and thermodynamic models help to understand Cr(VI)-biochar interactions and their adsorption mechanism. The adsorption studies of Cr(VI) are summarized through the fixed-bed saturated column experiments and Cr-contaminated real groundwater analysis using biochar-based sorbents for practical applicability. This review highlights the significant challenges in biochar-based material applications as green, renewable, and cost-effective adsorbents for the remediation of Cr(VI). Further recommendations and future scope for the implications of advanced novel biochar materials for Cr(VI) removal and other heavy metals are elegantly discussed.
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•Cr(VI) has significant adsorption to modified biochars due to functional groups.•Summarizes Cr(VI) adsorption via batch and column experiments from wastewaters.•Optimal Cr(VI) removal was observed at low pH values.•Cr(VI) removal is based on electrostatic interaction and surface complexation.
Plastic pollution is ubiquitous in terrestrial and aquatic ecosystems. Plastic waste exposed to the environment creates problems and is of significant concern for all life forms. Plastic production ...and accumulation in the natural environment are occurring at an unprecedented rate due to indiscriminate use, inadequate recycling, and deposits in landfills. In 2019, the global production of plastic was at 370 million tons, with only 9% of it being recycled, 12% being incinerated, and the remaining left in the environment or landfills. The leakage of plastic wastes into terrestrial and aquatic ecosystems is occurring at an unprecedented rate. The management of plastic waste is a challenging problem for researchers, policymakers, citizens, and other stakeholders. Therefore, here, we summarize the current understanding and concerns of plastics pollution (microplastics or nanoplastics) on natural ecosystems. The overall goal of this review is to provide background assessment on the adverse effects of plastic pollution on natural ecosystems; interlink the management of plastic pollution with sustainable development goals; address the policy initiatives under transdisciplinary approaches through life cycle assessment, circular economy, and sustainability; identify the knowledge gaps; and provide current policy recommendations. Plastic waste management through community involvement and socio-economic inputs in different countries are presented and discussed. Plastic ban policies and public awareness are likely the major mitigation interventions. The need for life cycle assessment and circularity to assess the potential environmental impacts and resources used throughout a plastic product’s life span is emphasized. Innovations are needed to reduce, reuse, recycle, and recover plastics and find eco-friendly replacements for plastics. Empowering and educating communities and citizens to act collectively to minimize plastic pollution and use alternative options for plastics must be promoted and enforced. Plastic pollution is a global concern that must be addressed collectively with the utmost priority.
This study aims to synthesize activated magnetic biochar using a single-step approach and explore solute-solvent mechanisms for removing hexavalent chromium Cr(VI) from the aqueous solution. ...Agricultural waste rice husk was pre-treated in iron chloride and zinc chloride solution and pyrolyzed at 500°C. Obtained activated magnetic biochar were characterized by SEM, EDS, FTIR, XRD, VSM, and BET to analyze physicochemical features. Adsorption experiments indicated that activated magnetic biochar achieved an adsorption capacity of 9.97 mg/g with removal efficiency of 99.7% for an initial Cr(VI) concentration of 10 mg/L at pH 2 and 351 K. In aqueous solutions, Cr(VI) break down to HCrO4−, CrO42−, and Cr2O72− ions. However, at low pH (∼1–4), HCrO4− ion attributes electrostatic force of attraction, which encourages higher adsorption of Cr(VI) ions. Overall, batch experiments demonstrated that initial pH, Cr(VI) concentration, biochar dose, temperature, and co-existing ions significantly affected the Cr(VI) adsorption using activated magnetic biochar. Therefore, electrostatic interaction and ion exchange dominate Cr(VI) adsorption onto activated magnetic biochar at low pH. Experiments showed heterogeneous non-linear monolayer and spontaneous sorption, which were validated via Temkin isotherm and pseudo-second-order kinetic for Cr(VI) ions. As a result, Cr(VI) adsorption onto activated magnetic biochar occurred due to chemisorption on heterogeneous non-linear monolayers, mainly governed by electrostatic attraction and ion-exchange mechanisms due to enriched oxygen-containing surface groups with activated magnetic biochar. In terms of thermodynamics, the adsorption process for Cr(VI) ions using activated magnetic biochar was endothermic and spontaneous, as a positive ΔS° value indicates randomness during Cr(VI) adsorption at the solution-solute interface. In contrast, the negative value of ΔG° (−15855.3 kJ/mol) at 351 K shows that adsorption was spontaneous. Overall, the activated magnetic biochar synthesized from rice husk was more efficient than raw biochar in removing Cr(VI) ions from the aqueous solution.
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•Activated magnetic biochar pyrolyzed from rice husk via single-step pyrolysis.•Activation and magnetization played a significant role in Cr(VI) adsorption.•Removal efficiency up to 99.7% was achieved for Cr(VI) ions at pH 2.•Electrostatic attraction and ion exchange govern maximum Cr(VI) removal at low pH.•Temkin, pseudo-second-order, and endothermic were best-fitted adsorption models.
•This perspective discusses increasing concern of microplastic in Sundarbans delta of Bay of Bengal.•Meghna, Brahmaputra, and Ganges rivers transport the micro/plastic to Sundarban.•Fishing, tourism, ...and wastewater are the possible sources of microplastic in Sundarban.•A collective monitoring mechanism for microplastics can be developed by India and Bangladesh.•This article acclaims for monitoring, management, and risk assessment in Sundarban.
Microplastics have been reported in sediments, surface water, and aquatic organisms, including seafood, and thus transferred to food chains. This paper summarizes the emerging concern of microplastic pollution and highlights mitigation policies and action plans in the Sundarban Delta regions in Bay of Bengal. Sundarban is the largest mangrove forest with vibrant and rich biodiversity, facing severe threats because of human activities and climate change. Anthropogenic plastic litter has been found in the Bay of Bengal and thus also in Sundarban, which can cause substantial threats to mangrove forests. More than 56 tons of plastic wastes were found in the Sundarban immediately after the cyclone ‘Amphan’ in 2020 due to unregulated relief packaged materials using plastics. Interestingly, microplastics have also been found in the Bay of Bengal and Sundarban, ultimately transported from various rivers and waved off to the Sundarban mangrove. It has been observed that 4 million tonnes of microplastics have been discharged annually from various rivers of India and Bangladesh to Sundarban and the Bay of Bengal. Trophic transfer of microplastics and their bioaccumulation can result in significant ecological damage to the Sundarban delta. Although the governments of India and Bangladesh have been taking different policy measures for protecting the mangrove forest areas, more policy interventions are required to tackle emerging contaminants like microplastics. Other issues may also arise from huge load of microplastics, such as degradation of natural resources, unsustainable livelihoods, and poverty. In this regard, joint initiatives of both countries are required to consider pollution risk assessments, biodiversity conservation, and sustainable development.
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Fluoride is widely found in soil–water systems due to anthropogenic and geogenic activities that affect millions worldwide. Fluoride ingestion results in chronic and acute toxicity, including ...skeletal and dental fluorosis, neurological damage, and bone softening in humans. Therefore, this review paper summarizes biological processes for fluoride remediation, i.e., bioaccumulation in plants and microbially assisted systems. Bioremediation approaches for fluoride removal have recently gained prominence in removing fluoride ions. Plants are vulnerable to fluoride accumulation in soil, and their growth and development can be negatively affected, even with low fluoride content in the soil. The microbial bioremediation processes involve bioaccumulation, biotransformation, and biosorption. Bacterial, fungal, and algal biomass are ecologically efficient bioremediators. Most bioremediation techniques are laboratory-scale based on contaminated solutions; however, treatment of fluoride-contaminated wastewater at an industrial scale is yet to be investigated. Therefore, this review recommends the practical applicability and sustainability of microbial bioremediation of fluoride in different environments.
Social media platforms provide an enormous public repository of textual data from which valuable information can be extracted. We show that firms can extract business intelligence from social media ...data bearing on an important business application, measuring brand personality. Specifically, we develop a text analytics framework that integrates different distinct sources of social media data generated by consumers, employees, and firms, to measure brand personality. Based on Elastic-Net regression analyses of a large corpus of social media data, including self-descriptions of 1,996,214 consumers who followed the sample of brands on social media, 312,400 employee reviews of the brands' firms, and 680,056 brand official tweets, we develop a brand personality model that achieves prediction accuracy as high as 0.78. Among key insights, we find that the profile of individuals who choose to associate with brands on social media is an important predictor of brand personality; this provides the first real-world evidence for a consumer identity-brand personality link. We also identify a link between an organization's internal corporate environment as perceived by employees and brand personality as judged by consumers. We further illuminate the practical implication of our predictive model by building a cloud-based information system that allows managers and analysts to explore and track personality of their own brands and their competitors' brands.
Significant gaps remain regarding the pathomechanisms underlying the autoimmune response in vitiligo (VL), where the loss of self-tolerance leads to the targeted killing of melanocytes. Specifically, ...there is incomplete information regarding alterations in the systemic environment that are relevant to the disease state.
We undertook a genome-wide profiling approach to examine gene expression in the peripheral blood of VL patients and healthy controls in the context of our previously published VL-skin gene expression profile. We used several in silico bioinformatics-based analyses to provide new insights into disease mechanisms and suggest novel targets for future therapy.
Unsupervised clustering methods of the VL-blood dataset demonstrate a "disease-state"-specific set of co-expressed genes. Ontology enrichment analysis of 99 differentially expressed genes (DEGs) uncovers a down-regulated immune/inflammatory response, B-Cell antigen receptor (BCR) pathways, apoptosis and catabolic processes in VL-blood. There is evidence for both type I and II interferon (IFN) playing a role in VL pathogenesis. We used interactome analysis to identify several key blood associated transcriptional factors (TFs) from within (STAT1, STAT6 and NF-kB), as well as "hidden" (CREB1, MYC, IRF4, IRF1, and TP53) from the dataset that potentially affect disease pathogenesis. The TFs overlap with our reported lesional-skin transcriptional circuitry, underscoring their potential importance to the disease. We also identify a shared VL-blood and -skin transcriptional "hot spot" that maps to chromosome 6, and includes three VL-blood dysregulated genes (PSMB8, PSMB9 and TAP1) described as potential VL-associated genetic susceptibility loci. Finally, we provide bioinformatics-based support for prioritizing dysregulated genes in VL-blood or skin as potential therapeutic targets.
We examined the VL-blood transcriptome in context with our (previously published) VL-skin transcriptional profile to address a major gap in knowledge regarding the systemic changes underlying skin-specific manifestation of vitiligo. Several transcriptional "hot spots" observed in both environments offer prioritized targets for identifying disease risk genes. Finally, within the transcriptional framework of VL, we identify five novel molecules (STAT1, PRKCD, PTPN6, MYC and FGFR2) that lend themselves to being targeted by drugs for future potential VL-therapy.
Cutaneous lesions feature prominently in lupus erythematosus (LE). Yet lupus and its cutaneous manifestations exhibit extraordinary clinical heterogeneity, making it imperative to stratify patients ...with varying organ involvement based on molecular criteria that may be of clinical value. We conducted several
bioinformatics-based analyses integrating chronic cutaneous lupus erythematosus (CCLE)-skin and blood expression profiles to provide novel insights into disease mechanisms and potential future therapy. In addition to substantiating well-known prominent apoptosis and interferon related response in both tissue environments, the overrepresentation of GO categories in the datasets, in the context of existing literature, led us to model a "disease road-map" demonstrating a coordinated orchestration of the autoimmune response in CCLE reflected in three phases: (1) initiation, (2) amplification, and (3) target damage in skin. Within this framework, we undertook
interactome analyses to identify significantly "over-connected" genes that are potential key functional players in the metabolic reprogramming associated with skin pathology in CCLE. Furthermore, overlapping and distinct transcriptional "hot spots" within CCLE skin and blood expression profiles mapping to specified chromosomal locations offer selected targets for identifying disease-risk genes. Lastly, we used a novel
approach to prioritize the receptor protein CCR2, whose expression level in CCLE tissues was validated by qPCR analysis, and suggest it as a drug target for use in future potential CCLE therapy.
A series of imidazole based compounds were synthesized by reacting simple imidazoles with alkyl halides or alkyl halocarboxylate in presence of tetrabutylammonium bromide (TBAB). The compounds ...bearing carbethoxy group undergo amidation with different amines in the presence of DBU to give respective carboxamides. The synthesized compounds were screened against
Mycobacterium tuberculosis where compound
17 exhibited very good in vitro antitubercular activity and may serve as a lead for further optimization.
A series of imidazole based compounds were synthesized by reacting simple imidazoles with alkyl halides or alkyl halocarboxylate in the presence of tetrabutylammonium bromide (TBAB). The compounds bearing carbethoxy group undergo amidation with different amines in the presence of DBU to give respective carboxamides. The synthesized compounds were screened against
Mycobacterium tuberculosis where compound
17 exhibited very good in vitro antitubercular activity and may serve as a lead for further optimization.
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