Engineering Commons^™

Dystop: Dynamic Staleness Control And Topology Construction For Asynchronous Decentralized Federated Learning, Yizhou Shi, Qianpiao Ma, Yan Xu, Junlong Zhou, Ming Hu, Yunming Liao

Research Collection School Of Computing and Information Systems

Federated Learning (FL) has emerged as a potential distributed learning paradigm that enables model training on edge devices (i.e., workers) while preserving data privacy. However, its reliance on a centralized server leads to limited scalability. Decentralized federated learning (DFL) eliminates the dependency on a centralized server by enabling peer-to-peer model exchange. Existing DFL mechanisms mainly employ synchronous communication, which may result in training inefficiencies under heterogeneous and dynamic edge environments. Although a few recent asynchronous DFL (ADFL) mechanisms have been proposed to address these issues, they typically yield stale model aggregation and frequent model transmission, leading to degraded training performance …

Evaluating The Role Of Power Electronics In Enhancing Renewable Energy And Smart Grid Performance: A Review, Muhammad Irfan Habib

ASEAN Journal on Science and Technology for Development

The review article demonstrates the importance of power electronics in propelling the increase of renewables and increasing the efficiency of contemporary electrical grids. In particular, it highlights the need for bidirectional converters for effective energy management in vehicle-to-grid (V2G) systems with two-way power transfer. The paper examines the series of complications offered by the significantly large integration of power electronic converter-interfaced renewables, such as those related to system steadiness, power quality, and resignation bottlenecks. Also, it recognizes a mix of new technologies, such as wide bandgap (WBG) semiconductors like silicon carbide (SiC) and gallium nitride (GaN), that deliver superior performance …

Artificial Neural Network Based Protection For Dc Bus Using Solid State Dc Breaker, Eswaraiah Giddalur, Askani Jaya Laxmi

ASEAN Journal on Science and Technology for Development

Low voltage Direct Current (LVDC) microgrids have been extensively used as a hopeful technology with high access to distributed energy resources (DERs) and DC loads, due to the absence of multiple conversions. A high amplitude Fault current together with the vulnerability of electronic devices, poses a great challenge to the line protection in LVDC microgrids. Electromechanical switches are slow and take long tripping time to clear the short circuit fault. Power electronic circuit breakers are used to achieve fast fault interruption recent progress in areas like machine learning and natural language processing have affected nearly every assiduity and area of …

Unlocking Green Potential In Indonesian Small Medium Enterprises: Challenges And Opportunities For Sustainable Vermicelli Production, Togar W. S. Panjaitan, Karina Agustin, Prayonne Adi, Jani Rahardjo, I Nyoman Sutapa

ASEAN Journal on Science and Technology for Development

Due to limited initiatives and support, the transition to green manufacturing among small and medium enterprises (SMEs) in developing countries remains challenging. Through a critical literature review and case study of the Indonesian vermicelli industry, this study highlights the importance of collaboration and strong policies to address this. Other findings also reveal that the energy intensity and emissions in the sector exceed best practice benchmarks, with the cooking and drying stages contributing significantly to emissions due to high energy consumption. Lack of government regulations, company awareness, and understanding of applicable practices and technologies creates challenges in green manufacturing. The study …

Hybrid Model For Phishing Website Detection Using Transfer Learning, Atul Dubal, Mansi Subhedar, Santosh Dhamala, Manasi Patil

ASEAN Journal on Science and Technology for Development

The rapid digitization of human activities has intensified reliance on internet-based platforms, creating fertile ground for cybercriminal exploits such as phishing. Despite advancements in detection mechanisms, phishing attacks continue to evolve, leveraging sophisticated visual mimicry to deceive users. This paper proposes a robust vision-based phishing detection system using ensemble deep learning to analyse webpage screenshots. The framework integrates transfer learning with pre-trained VGG16 and DenseNet121 models, extracting complementary low-level texture features (edges, gradients) and high-level hierarchical patterns (logos, layouts). These features are fused through a custom classifier with dropout regularization to mitigate overfitting. A balanced dataset of 3,000 webpage screenshots …

Land Use And Land Cover Simulation Via Integrated Modelling With Gis Techniques For Sustainable Land Utilization Development In The Northeast Khong Subwatershed Of Thailand, ฺBanchongsak Faksomboon, Thipphaphone Keoviyavong

Applied Environmental Research

Land utilization is an important indicator of socioeconomic and environmental changes caused by both natural and man-made factors. Land use and land cover (LULC) simulation is a critical tool for monitoring and predicting LULC and is essential for sustainable development, land resource management and planning. The cellular automata (CA) Markov model is the basis for the current study’s prediction of LULC changes in the Northeast Khong Sub Watershed (NKSW). Landsat data from 2013 to 2023 were used to investigate LULC classification and determine the spatiotemporal distributions of LULC. In addition, LULC data from 2013 and 2023 were used to generate …

Reduction Of Cr(Vi) With Infrared Light And Chemical Adsorption Of Cr(Iii) By A God-Crown/Bentonite Composite For Electroplating Waste Remediation, Andre Taufik Kurniawan, Muhammad Djoni Bustan, Sri Haryati

Applied Environmental Research

Heavy metal pollution, particularly chromium (Cr) from electroplating industrial waste, has severely threatened environmental quality and human health. This study aims to develop a composite adsorbent material based on bentonite and god crown biomass capable of removing chromium ions from liquid waste through a combination of reduction and adsorption mechanisms. The god crown/bentonite (GC/Bt) composite was synthesized at a mass ratio of 2:1 and calcined at 900°C. FTIR characterization revealed active functional groups (–OH, C=O, Si–O, and Al–O–Si), whereas BET analysis revealed a mesoporous structure (surface area 31.12 m2 g-1, pore diameter 4.37 nm) suitable for ion diffusion. The reduction …

Fabrication Of Urea With Amorphous Silica To Increase Rice Growth In Saline Soils, Thi Ha Chi Nguyen, Thi Hang Thuc Ha, Minh Phuong Nguyen, Ngoc Chuc Pham, Quang Bac Nguyen, Nguyen Huy Tuan Do, Ngoc Nhiem Dao, Trung Kien Nguyen

Applied Environmental Research

In recent decades, the decrease in rice cultivation areas in Vietnam, particularly in the Mekong River Delta, caused by climate change and soil salinization, has posed serious challenges for sustainable development. In addition to irrigation and agronomic practices, fertilizers that sustain rice growth under saline conditions play a crucial role in improving crop productivity. Amorphous silica has been reported to increase plant tolerance to drought, salinity, and heavy metal stress. In this study, nanosilica-coated urea (UCS) fertilizers were synthesized by coating urea granules with 1–5 wt% amorphous silica. The products were characterized by SEM, XRD, FTIR, TG‒DSC, and EDX to …

Heavy Metals And Organic Carbon In Sediments Of Seagrass Sediments Of Trang Province, Thailand, Siriporn Pradit, Pornthep Wirachwong, Thongchai Nitiratsuwan, Sujaree Bureekul, Supraewpan Lohalaksanadech, Thawanrat Kobkeatthawin, Monticha Jirajaras, Prakrit Noppradit, Sanya Sirivithayapakorn

Applied Environmental Research

In this study, the accumulation of heavy metals (Cd, Cr, Cu, Fe, and Pb) in water, suspended sediments, sediments, and seagrass in Kalase Bay, Trang Province, Thailand, during the 2024 dry season was investigated. These findings indicate that the enrichment factor (EF) for all the metals was less than 1, suggesting that anthropogenic contamination is not a significant concern in the area. The translocation factor (TF) values were less than 1 for all the metals except Cu, whose TF was greater than 1; however, these values were not statistically significant, indicating limited phytoextraction capacity. The bioconcentration factor (BCF) values for …

Spatial Modeling Of Natural Disaster Risk By Integrating Hazard, Vulnerability, And Exposure Factors Using Geospatial Techniques : Evidence From Mueang Tak District, Thailand, Suphatphong Ruthamnong

Applied Environmental Research

This study presents a comprehensive multihazard risk assessment for Mueang Tak District, Thailand, that integrates hazard, vulnerability, and exposure (H-V-E) dimensions. By utilizing geographic information systems (GIS) and remote sensing, the analytic hierarchy process (AHP) was employed to prioritize critical risk factors. GIS analysis integrated multisource spatial data, including Landsat 9 and Sentinel-2 imagery, CHIRPS precipitation, and SRTM-derived topography, while AHP weights were established on the basis of expert judgment and socioeconomic indices such as the relative wealth index (RWI) and population statistics. The results delineate distinct spatial risk clusters: high landslide potential is concentrated in the steep terrain of …

Carbon Stock Assessment In Sonneratia Apetala Afforested Mangroves : A Case Study From Cox’S Bazar, Bangladesh, Mohammad Ismail, Sayed Abu Johany, Tanmoy Dey, Zakia Sultana Teasa, Trishna Das, Prabal Barua, Tonima Hossain, Sajib Ahmed

Applied Environmental Research

Sonneratia apetala is a key species for mangrove afforestation projects in Bangladesh and plays a crucial role in ecosystem restoration and carbon sequestration. The research on how the total carbon stock (TCS) varies across S. apetala plantations in Cox’s Bazar remains limited. Thus, in this study, the biomass and soil carbon stock were quantified across nine S. apetala afforested sites in Cox’s Bazar to assess spatial variation and influencing factors. The total biomass carbon (TBC) was calculated by summing the aboveground (AGBC) and belowground (BGBC) biomass carbon, while the soil organic carbon stock (SOCS) was determined from the 0–40 cm …

Seasonal Wastewater Monitoring And Quantitative Microbial Risk Assessment Of Escherichia Coli In A University Wastewater System, Pathum Thani, Central Thailand, Natsima Tokhun, Natagarn Tongphanpharn, Weerawat Ounsaneha, Montip Jankeaw, Wiriyabhorn Klomsungcharoen, Patsara Wongsudi, Yawanart Ngamnon, Cheerawit Rattanapan, Kwang Mo Yang

Applied Environmental Research

In this study, the physicochemical properties of wastewater were characterized, and a quantitative microbial risk assessment (QMRA) of E. coli was conducted in the wastewater treatment system of the Faculty of Science and Technology, Valaya Alongkorn Rajabhat University, under the Royal Patronage, Pathum Thani, Thailand (VRU-SciTech). This study was conducted because the current water-quality assessment does not include the QMRA or evaluate the occupa-tional and incidental public risk of infection. Over a one-year monitoring period, this study quantified wastewater generation (~6.09 L person-1 day-1; ~3.21 × 103 m3 year-1) and analyzed its physicochemical parameters and E. coli concentrations. High concentrations …

Evaluation Of Soil Moisture Content, Ph, And Dominant Microorganisms In Crude Oil–Contaminated Soil Treated With Cow Dung, Indole-3-Acetic Acid (Iaa), And Simulated Microgravity, Amenze Ovenseri, Tawari-Fufeyin P.

Applied Environmental Research

Crude oil negatively affects soil physicochemical properties and microbial activity, thereby hindering plant growth and posing notable environmental and agricultural issues. The combined effects of cow dung, indole-3-acetic acid (IAA), and simulated microgravity on the recovery of soil degraded by crude oil were explored using Zea mays as the test plant. Soil was contaminated with crude oil at different concentrations (0%, 1%, 3%, and 5% v/w), with each concentration comprising eight treatments: cow dung, Zea mays seeds exposed to microgravity, and IAA alone or in combination. Changes in plant height, soil pH, soil moisture content, and soil microbial diversity were …

Investigation Of Fine-Grain Cu And Cu Alloys For Low-Temperature Hybrid Bonding Applications, Sarabjot Singh

Electronic Theses & Dissertations (2024 - present)

Hybrid bonding has emerged as a key enabler for next-generation three-dimensional (3D) integration, offering fine-pitch interconnects and improved electrical performance. However, conventional Cu–Cu hybrid bonding typically requires elevated temperatures to achieve sufficient diffusion and interface quality, posing challenges for temperature-sensitive device integration and process compatibility. This work investigates materials engineering approaches to enable low-temperature Cu–Cu bonding through both microstructure design and alloying strategies.

This work begins by examining grain refinement in Cu as a pathway to enhance diffusion through increased grain boundary density, providing efficient atomic transport without introducing additional elements. Three Cu-based systems Cu–Co, Cu–Ag, and Cu–Al were systematically …

Scalable Single-Erbium Telecom Qudits With Record Room-Temperature Quantum Coherence In Silicon-Based Nanostructures, Alexander Kaloyeros

Electronic Theses & Dissertations (2024 - present)

Advancing quantum information science demands solid-state quantum systems that maintain long quantum coherence at elevated temperatures while supporting scalable, CMOS-compatible fabrication and telecom C-band operation. No existing platform has simultaneously achieved these requirements, as state-of-the-art demonstrations of coherent control of erbium ions, with an intrinsic telecom-band optical transition, have been confined to cryogenic temperatures below < 10 K under controlled vacuum conditions. This thesis introduces a new paradigm in which materials science and engineering provides the enabling pathway to quantum coherence.

A foundry-compatible nanofabrication approach, paired with targeted materials engineering, is developed to realize a new class of CMOS-scalable quantum system: arrays of spatially isolated single-erbium-ion qudits (five-level systems) embedded in silicon-based (e.g., silicon carbide (SiC) and SiC_xO_y) hollow nanopillars (HNPs). Non-lithographically …

Nanostructured Cathode Catalysts For Aem Electrolysis: From Catalyst Design To Degradation And Hydrogen Dynamics, Yamini Kumaran

Electronic Theses & Dissertations (2024 - present)

Anion exchange membrane water electrolysis (AEMWE) presents a promising pathway toward cost-effective and sustainable hydrogen production by integrating the chemical robustness of alkaline systems with the compact, zero-gap design of proton exchange membrane electrolyzers. However, the widespread implementation of AEMWE is limited by the availability of highly active and durable platinum-group-metal (PGM)-free catalysts and by an incomplete understanding of their degradation behavior under realistic operating conditions.

This dissertation focuses on the development, characterization, and mechanistic investigation of nanostructured MoNi₄–MoO₂-based electrodes for efficient and stable hydrogen generation under alkaline and membrane-integrated environments. MoNi₄–MoO₂ nanorods …

Investigating The Effects Of Pressure On Fe And Co Intercalated 2h-Tas2 Through First-Principle Calculations, Ronald E. Putnam Jr.

UNF Graduate Theses and Dissertations

Using first-principles methods, we investigate the effects of applied isotropic pressure on the electronic and magnetic properties of intercalated Fe1/3TaS2 and Co1/3TaS2. Fe1/3TaS2 has been shown to be a ferromagnet that undergoes structural and magnetic phase transitions under applied pressure. The magnetic phase transitions are observed to be linked to the structural shift, and a mixture of magnetic phase states is present between 3 GPa and 6 GPa. Co1/3TaS2 was found to be antiferromagnetic, as confirmed by experimental work. One- and two-unit-cell systems of Co1/3TaS2 are analyzed, both showing band splitting that disappears under pressure. The application of pressure forces …

A Novel Federated Llm Framework For Distributed Traffic Modelling In Intelligent Transportation Systems, Seerat Kaur

Theses and Dissertations (Comprehensive)

Intelligent transportation systems (ITS) depend on accurate traffic prediction to support congestion management, infrastructure planning, and real-time operational decisions. Despite substantial progress in data-driven forecasting, several challenges continue to limit practical deployment: traffic data is distributed across independent regional authorities, making centralized aggregation infeasible, standard federated aggregation strategies ignore traffic-specific characteristics that meaningfully affect model quality, and existing models produce only numerical outputs without interpretable reasoning that urban planners can act upon. This thesis addresses these challenges through four contributions that collectively advance privacy-preserving, explainable, and scalable traffic forecasting.

The first contribution provides a systematic review of 129 peer-reviewed publications, …

Assessing Dissolved Organic Matter Sources And Dynamics In Urban Stormwater: Implications For Greenhouse Gases, Harper W. Schmalz

Theses and Dissertations (Comprehensive)

Stormwater management ponds (SWMPs) are important aspects of land-use planning and increasingly recognized as active sites of biogeochemical processing that influence carbon cycling; however, little research has investigated the controls on dissolved organic and dissolved inorganic carbon (DOC and DIC) within these systems. This thesis examined the processing and transformations of dissolved carbon between three compartments to support the development of a greenhouse gas (GHG) box-model for urban stormwater ponds, including SWMP sediment, surface water, and vegetation. The objective of this thesis was to assess the biogeochemical processes that govern the rate and transformation of DOC and DIC between these …

Connecting The Existing Fiber Infrastructure To The Future With Antiresonant Hollow Core Fibers, Timothy Bate

Graduate Studies Theses and Dissertations 2026

Optical fiber systems based on solid-core silica waveguides underpin modern telecommunications, high-power laser delivery, precision sensing, and coherent optical systems. However, nonlinear effects, material absorption, and thermal limitations within silica increasingly constrain further scaling in both optical power and transmission performance. Antiresonant hollow-core fibers provide a promising alternative by guiding light predominantly in air, substantially reducing nonlinear interactions, latency, and optical damage while enabling transmission regimes inaccessible to conventional solid-core fibers. Despite rapid advances in antiresonant hollow-core fiber attenuation and power handling, one of the largest remaining barriers to widespread adoption is reliable integration with the existing solid-core fiber ecosystem. …

Integrated Optical Probes For Confocal Scanning Imaging And Adjustable Coherent-Gated Dynamic Sensing, Yonglin Huang

Graduate Studies Theses and Dissertations 2026

Optics and photonics have been one of the most important sciences and technologies that impact modern human life in a big way. For example, fiber-optics for communications and artificial intelligence. Optical probes are critical components for optical imaging and optical sensing technologies that have been actively researched and developed in the past decades. Advanced fiber-optic sensor probes with smaller size, better performance, lower noise, higher photon efficiency, rapid sensing time, and lower cost are needed in many applications, such as nanoscale material science, chemistry, and biomedical fields, etc.  In this project, new fiber-optic sensor probe technologies and integrated micro-optic devices …

Comparative Life Cycle Assessment Of End-Of-Life Crystal Silicon Photovoltaic Panels: Recovery Methods And Extended Life In Agricultural Application, Patima Chaichana, Vacharaporn Soonsin, Nattapong Tuntiwiwattanapun

Applied Environmental Research

The increasing deployment of crystalline silicon (c-Si) photovoltaic (PV) panels has raised concerns about their waste management. This study evaluated management strategies for discarded c-Si PV panels in Thailand, integrating environmental and economic analyses. Life cycle assessment (LCA) and cost-effectiveness analysis (CEA) were applied. The LCA can be divided into 2 parts: (1) secured landfill vs decentralized recycling by existing facilities vs centralized full recovery and (2) reusing PV panels in agricultural applications. The results revealed that secured landfills were the most environmentally burdensome (34.43 Pt), whereas centralized recycling achieved net benefits (-211.93 Pt) through emission reductions and recovery of …

Seasonal Variations In Co2 Emission From Poultry Manure-Amended Soils In Two Contrasting Tropical Agroecosystems, Gladys M. Akande, Adebayo J. Adeyemo, Chidozie J. Oraegbunam, Iduh J.J. Otene, Ezekiel C. Are, Babatunde S. Ewulo, Chioma M. Ahukaemere, Samuel O. Kolawole, Sunday E. Obalum

Applied Environmental Research

The soil remains the largest carbon sink, the capacity of which varies spatiotemporally and with anthropogenic activities, with implications for carbon dioxide (CO2) emissions and associated global warming. Despite the increasing popularity of organic amendments in the ecologically and anthropoculturally diverse farming systems of tropical Africa, manure-induced CO2 emissions in this region with high soil-carbon-sequestration potential are poorly documented. This study assessed seasonal CO2 emissions from poultry manure-amended sandy-clay-loam and sandy-loam soils in the Rainforest-Savannah and Southern Guinea Savannah zones, respectively, of Nigeria. Following manure application at 3 rates (0, 10, and 15 t ha-1), soil samples were collected during …

Life Cycle Assessment Of Co2-To-Methanol: Comparative Evaluation Of Direct And Alcohol-Assisted Hydrogenation Routes, Chayet Worathitanon, Naphat Chansonthi, Pawat Pinthong, Kritsana Suwanamad, Viganda Varabuntoonvit

Applied Environmental Research

The increasing severity of global warming, primarily driven by greenhouse gas emissions, underscores the urgent need for CO2 reduction and utilization strategies. Converting CO2 into methanol presents a promising approach, as methanol serves both as a fuel and a feedstock in various industries. This study evaluates the life cycle environmental impacts of three methanol production routes: (1) direct CO2 hydrogenation, (2) ethanol-assisted CO2 hydrogenation, and (3) propanol-assisted CO2 hydrogenation. Two energy scenarios are considered: conventional energy and wind power. Process simulations were performed using Aspen Plus V.14, and inventories were analyzed through Life Cycle Assessment (LCA) using the ReCiPe 2016 …

Activated Carbon Prepared From Residual Eucalyptus Wood For The Removal Of Methyl Orange: Equilibrium, Kinetics, Thermodynamics, And Desorption, Mathin Jaikua, Phuthidhorn Thanaphu, Sunisa Ungwiwatkul, Jakkrawut Maitip, Kanyarak Prasertboonyai

Applied Environmental Research

This research utilizes activated carbon derived from residual Eucalyptus wood (EW) for the removal of methyl orange (MO). The residual Eucalyptus wood-based activated carbon (EWAC) was produced through carbonization at 400 °C (EWC) followed by activation with a mass ratio of H3PO4 to EWC of 1:3, which was conducted at 800 °C for 1 h. The characterization of the EWAC involved various analytical techniques, including FTIR, XRD, BET, and CHN analysis. The adsorption parameters, such as pH (range: 3–8), adsorbent dose (range: 0.01–0.5 g per 50 mL of MO solution), contact time (range: 5–720 min), initial MO concentration (range: 5–600 …

Fabrication Of Acid-Modified Corn Plant By-Product-Based Biochar For Efficient Adsorption Of Sulfamethoxazole From Aqueous Solutions, Thi An Hang Nguyen, Thi Duyen Le, Thi Hang Bui

Applied Environmental Research

Antibiotic pollution is of great interest owing to growing concerns about antibiotic resistance worldwide. This study aims to fabricate acid-modified biochar (CBM-A) from corn plant byproducts (CRs) for sulfamethoxazole (SMX) adsorption in aqueous solutions. CBM-A was synthesized via pyrolysis at 700 °C and modified with 14% H3PO4. Kinetics, isotherms, and thermodynamics were investigated in combination with material characterization to elucidate the adsorption behaviors and mechanisms. The results showed that pyrolysis and acid modification effectively enhanced SMX adsorption by CR because of the increased number of binding groups, specific surface area, and porosity. SMX adsorption on CBM-A was optimized at a …

Blue Carbon Stock Assessment And Climate Resilience Potential Of Mangrove Forest In Hung Thang Commune, Vietnam, Hla Phong Ko, Pham Hong Tinh, Nguyen Thuy Duong

Applied Environmental Research

Mangrove forests are vital blue carbon sinks that contribute to climate change mitigation and coastal resilience. This study assessed the carbon stock and spatial‒temporal dynamics of a mangrove forest in Hung Thang commune, Hai Phong Province, Vietnam, via a combination of field measurements, soil organic carbon (SOC) analysis, and normalized difference vegetation index (NDVI)-based remote sensing models. The results revealed that mangroves in the Hung Thang community store an average of 87.42 tC ha-1, with SOC accounting for approximately 19% of the total carbon. A generalized additive model (GAM) analysis revealed a consistent increase in carbon stocks between 1996 and …

Bioremediation Potential Of Indigenous Stutzerimonas Stutzeri 08tbb Isolated From Mercury-Contaminated Gold Mining Sites In Indonesia, Uun Rohmawati, Juanita Hibatullah, Achmad Rodiansyah, Yunita Messe, Dwi Nur Aini Fajriah

Applied Environmental Research

Artisanal and small-scale gold mining (ASGM) widely uses mercury (Hg) in the amalgamation process, and the resulting waste is often discharged directly into the environment, posing serious risks to ecosystems and human health because of the high toxicity of Hg. This study aimed to isolate and screen indigenous Hg-tolerant bacteria from contaminated gold mining sites in Indonesia; characterize the most effective isolate using morphological, biochemical, and molecular approaches; evaluate Hg(II) degradation performance using ICP‒OES, FTIR, and SEM analyses; and identify key metabolites involved in Hg detoxification through untargeted LC–HRMS metabolomics. A total of 51 bacterial isolates were obtained from Hg-contaminated …

Assessment Of Chromosomal Abnormalities In Hybrid Catfish In Reservoir Contaminated With Heavy Metals From Municipal Landfill, Tanadol Savigun, Natchanon Thiratanaboon, Nuttawadee Maneesan, Manop Sriuttha, Lamyai Neeratanaphan

Applied Environmental Research

In this study, the concentrations of heavy metals (As, Cd, Cr and Pb) in water, sediment, and hybrid catfish (Clarias gariepinus x C. macrocephalus) as well as chromosomal abnormalities (CAs) from a reservoir affected by leachate from a municipal landfill were compared to those in an unaffected reservoir. Heavy metal concentrations were analyzed using inductively coupled plasma‒optical emission spectrometry (ICP‒OES). Chromosomes were prepared from kidney cells by direct methods. The As, Cd and Pb concentrations in the water and sediment from both reservoirs were within the Thailand water and soil standards. The concentrations of As and Cd in the water …

Ammonium Adsorption From Aqueous Solutions Using Mnfe2o4-Functionalized Coffee Husk Biochar Nanocomposites : An Evaluation Of Hno3 And Naoh Activation, Thuy-Tien Do, Huu-Tap Van, Thi-Minh-Thu Nguyen

Applied Environmental Research

This research investigated the development of MnFe2O4-based composite adsorbents (MFO@CFA and MFO@CFB) by activating coffee husk-derived biochar with HNO3 and NaOH, followed by synthesis through coprecipitation and hydrothermal techniques. The structural and chemical properties of the nanocomposites were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Batch adsorption experiments were used to assess ammonium removal efficiency across a range of conditions: solution pH (3–8), contact time (5–120 min), adsorbent dosage (0.2–3 g L-1), and initial ammonium concentration (10–60 mg L-1). The findings indicated that compared with MFO@CFB, which was synthesized from NaOH-activated biochar, MFO@ CFA, derived …