Publications by authors named "Ajit Sarmah"

The emerging toxicants, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6PPD-Q), resulting from environmental exposure to N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), have gained considerable attention owing to their ubiquitous occurrence and high toxicity. We performed a scientometric analysis on this topical area of research over the past two decades, spanning from 2004 to April 2024. The overarching aim was to reveal potential future directions in this research area, exploring several key aspects.

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  • PFAS are harmful due to their persistence in the environment and ability to accumulate in living organisms, necessitating effective remediation strategies for contaminated soil and water.
  • Biochar has shown promise as a low-cost option for adsorbing PFAS, with this review highlighting its ability to immobilize these substances and reduce their ecological impact.
  • The study emphasizes the need for further research on enhancing biochar's effectiveness for short-chain PFAS and understanding the role of surface charge and different forces in adsorption processes.
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  • The study explores the effective removal of toxic elements (Lead and Copper) and pharmaceutical compounds (metoprolol) from water using modified biochar made from waste cabbage leaves, kaolinite, and anthocyanin.
  • Ball milling is used to enhance the surface area and functional properties of biochar, resulting in significant increases in adsorption capacities for Lead (105%), Copper (71%), and metoprolol (213%).
  • The research indicates that the removal processes work through various mechanisms such as surface complexation and H-bonding, with the best performance seen in the ball-milled composites, particularly for Lead and Copper.
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The increasing presence of oxytetracycline (OTC) in agricultural soils has raised global environmental concerns. We investigated the environmental behavior and fate of OTC in two types of tropical agricultural soils, focusing on the impact of dissolved organic matter (DOM) from biogas slurry. Techniques such as three-dimensional excitation-emission matrix fluorescence spectroscopy (3D-EEM), Fourier Transform Infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and Ultraviolet-visible spectrophotometer (UV-vis) were used to explore the adsorption mechanisms.

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Metal nanoparticles offer promising prospects in agriculture, enhancing plant growth and ensuring food security. Silver, gold, copper, and zinc nanoparticles possess unique properties making them attractive for plant applications. Understanding molecular interactions between metal nanoparticles and plants is crucial for unlocking their potential to boost crop productivity and sustainability.

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  • The COVID-19 pandemic has led to a significant increase in biomedical waste (BMW) due to the rise in healthcare activities, creating challenges for health, environment, and waste management.
  • The surge in BMW raises concerns about infection risks, illegal disposal, and toxic emissions from treatment facilities, indicating an urgent need for improved waste management practices.
  • This review examines current BMW disposal guidelines and technologies, aiming to identify effective solutions that enhance the economic and environmental sustainability of waste treatment systems.
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Polylactic Acid (PLA) based compostable bioplastic films degrade under thermophilic composting conditions. The purpose of our study was to understand whether sample pre-treatment along with bioaugmentation of the degradation matrix could reduce the biodegradation time under a simulated composting environment. Sepcifically, we also explored whether the commercial composts could be replaced by landfill-mined soil-like fraction (LMSF) for the said application.

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In Australia, trifluralin is one of the commonly used herbicides to manage annual grasses and some broadleaf weeds. However, it may have some ecosystem impacts such as high toxicity to terrestrial and aquatic life, so it is vital to monitor the degradation of trifluralin for a considerable period for environmental safety. For risk assessment purposes, it is necessary to estimate the half-life of trifluralin, which is often evaluated using derived mathematical dissipation models.

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Chemical products (CPs) such as carbamazepine and naproxen, present in aquatic environments, pose significant risks to both aquatic life and human health. This study investigated the use of hydrothermally carbonized food waste-derived hydrochar (AC-HTC) at three distinct temperatures (200, 250, and 300 °C) as an adsorbent to remove these CPs from water. Our research focused on the impact of hydrothermal carbonization temperature on hydrochar properties and the effects of chemical activation with phosphoric acid on adsorption capacity.

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We investigated the photocatalytic property of etched iron‑aluminum layered double hydroxide (LDH) composites using urea-modified biochar (N-BC) carrier to degrade para-aminobenzoic acid (PABA), a refractory organic pollutant. The prepared FeAl-LDH@FeSx-N-BC composite exhibited excellent photocatalytic performance, attributed to the enhanced photogenerated charge-carrier separation by the etched LDH and the improved comparative surface areas by the doped N-BC. The composite photocatalytically degraded 96 % of PABA.

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The effects of adding green-synthesized magnetic iron-containing nanoparticles (GSMFe) onto biochar in aqueous solution for the adsorptive removal of hexavalent chromium [Cr(VI)] were investigated in this study. Nanocomposites, denoted as green synthesis magnetic biochar (GSMB), were created using a green synthesis technique with white tea residue to introduce GSMFe into biochar. Six adsorbents, varying in GSMFe content, were tested for their effectiveness in eliminating Cr(VI), a globally significant hazardous heavy metal.

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Indonesia plans to mitigate the environmental emissions, particularly the carbon emissions, from the transport by replacing conventional buses with battery electric buses (BEBs). However, there are limited studies on the potential environmental benefits of BEBs and mostly focused on carbon emissions. In this study, the environmental impacts of adopting BEBs in Jakarta's public transportation system were examined using Life Cycle Assessment (LCA) to better understand its potential environmental impacts.

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Due to the 'forever' degrading nature of plastic waste, plastic waste management is often complicated. The applications of plastic are ubiquitous and inevitable in many scenarios. Current global waste plastics production is ca.

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Spruce wood and Typha (wetland plant) derived biochars pyrolyzed at 350 °C and 600 °C were tested for their sorption affinity for organic pollutants (diclofenac, methylparaben, benzotriazole and sodium 1-decanesulfonate) and nutrients (nitrate, ammonium, phosphate and boron) commonly found in greywater. Batch and column studies combined with molecular dynamics modelling determined the sorption capacity, kinetics, and described the underlying mechanisms. The spruce biochar (600 °C) exhibited the highest sorption capacity mainly for the tested organics.

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Substituting synthetic plastics with bioplastics, primarily due to their inherent biodegradable properties, represents a highly effective strategy to address the current global issue of plastic waste accumulation in the environment. Advances in bioplastic research have led to the development of materials with improved properties, enabling their use in a wide range of applications in major commercial sectors. Bioplastics are derived from various natural sources such as plants, animals, and microorganisms.

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Sulfamethoxazole (SMX) is a common antibiotic used mainly for bacterial treatment. In this study, a novel three-dimensional cobalt-manganese bimetallic layered double hydroxide graphene hydrogel (CoMn-LDHs/rGO) has been prepared for photo-assisted permonosulfate (PMS)-activated degradation of SMX in water. Compared with the CoMn-LDHs/rGO + PMS and CoMn-LDHs/rGO + Vis systems, the degradation effect of CoMn-LDHs/rGO + PMS + Vis system is the best, and the degradation effect of CoMn-LDHs/rGO system could reach more than 98% under the optimal conditions.

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New Zealand's goal to be carbon neutral by 2050 has led to the development of strategic policies and schemes to encourage the use of electric vehicles (EVs). However, most studies are focused on the greenhouse gas emissions of EVs while limited studies are available on their other potential environmental impacts. Using life cycle assessment (LCA), the environmental impacts of EV adoption, specifically the battery electric vehicle (BEV), were assessed to determine the future environmental challenges for New Zealand.

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The soil-insect interaction has gathered significant attention in the recent years due to its contribution to bio-cementation. Termites, as a group of cellulose-eating insects, alter physical (texture) and chemical (chemical composition) properties of soil. Conversely, physico-chemical properties of soil also influence termite activities.

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Ecosystem including food chain may be modified over time because of the continued use of pesticides, piscicides including the use of veterinary antibiotics (VA) in agricultural, aquaculture and animal production. Regulatory authorities including government agencies have implemented various standard regulations across different parts of the world on the use of these products and monitoring the levels of these compounds in aquatic and soil environment has become an important aspect. Estimation of the half-life and reporting these values for regulatory authorities are paramount to safeguard human health and the environment.

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A novel biochar-based magnetic nanocomposite (GSMB) was prepared from white tea waste via green synthesis method. The sorption properties and regeneration of GSMB were studied using Pb(II) and Cd(II) to better understand its ability in heavy metal recovery. The adsorption kinetics data were modelled using pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion models, while Pb(II) and Cd(II) isotherms were modelled with Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models.

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Green synthesized magnetic nanoparticles were impregnated into biochar matrix (EWTWB) to produce biochar-supported magnetic nanocomposite (GSMB). Instead of chemicals, organic matters in white tea waste extract were used as reductant, surfactant and functional capping materials. Magnetic biochar produced from traditional methods of pyrolysis (PMB) and co-precipitation (Co-PreMB) were prepared to compare their properties with GSMB.

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Construction and Demolition (C&D) waste is solid wastes generated from the construction, demolition, and renovation activities that constitute almost 30-40 % of globally generated solid wastes. Improper disposal and management of these materials can cause negative impacts on the environment, economy, and human health. Most research on C&D waste is limited to reduction, recycling, and reuse of the wastes.

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We investigated the feasibility of two novel engineered biochar composites by pyrolyzing cabbage leaves at 350 °C after pre-treating them with anthocyanin, followed by a post-treatment with kaolinite for the removal of two potentially toxic elements (copper and lead) and a pharmaceutical compound, metoprolol. Results showed that the Kaolinite-biochar composite (KB) exhibited the highest adsorption capacity, 188.67 and 48.

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Empty fruit bunch oil palm (EFBOP) is one of the byproducts after oil palm fruitlet is removed in oil palm processing and is considered as waste. In this study, EFBOP was converted to biochar (BC-EFBOP) at 350-700 °C, with an overarching aim of determining the feasibility of adsorptive removal of manganese (a second dominant element in acid mine drainage) from water. Results showed that with increasing temperature, the BC-EFBOP yield decreased from 44.

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Over the past few years, persistent organic pollutants (POPs) exhibiting high ecotoxicity have been widely detected in the environment. Persulfate-oxidation hybrid system is one of the most widely used novel advanced oxidation techniques and is based on the persulfate generation of SO and ∙OH from persulfate to degrade POPs. The overarching aim of this work is to provide a critical review of the variety of methods of peroxide activation (e.

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