Environmental Chemistry Commons^™

Exploring The Metric Dimension Of The Graph Representing A Four-Ring Polycyclic Aromatic Hydrocarbon: Interstellar 1-Cyanopyrene, Andrei Matthew V. Robino, Sebastian Alex C. Traviña, Karl Benedict P. Narag, Mark Anthony B. Casao, Helix Raven C. Llanes, Azriel C. Alejo, Jonel C. Celamor

Sinaya: A Philippine Journal for Senior High School Teachers and Students

A graph's metric dimension is a parameter that denotes the minimum possible number of vertices in a subset that gives each vertex in the graph a unique representation. Despite extensive research on the metric dimension of polycyclic aromatic hydrocarbons (PAHs), there is currently no focused analysis on the metric basis and metric dimension of 1-cyanopyrene. In chemistry, graphs can be used to depict molecular structures. In this study, graph theory, specifically the concept of metric dimensions, is applied to the molecular structure of 1-cyanopyrene, which was detected in space for the first time in 2024. 1-cyanopyrene is a molecule made …

Microplastic Degradation Using Laccase Enzyme From Trametes Hirsuta: In The Silico Study, Hanzhola Gusman Riyanto, Diana Sylvia

Makara Journal of Science

Microplastics are a serious global problem that arises worldwide because of their widespread use. Exposure to microplastics can negatively affect human and environmental health. In this study, we used molecular docking methods with MOE software (version 2014.0901) to investigate the interaction between the laccase enzyme and several microplastic compounds as a preliminary study of microplastic degradation using enzymes. The Quantitative Structure Analysis Relationship (QSAR) analysis revealed that all microplastic ligands had higher Pa values than Pi, indicating that the laccase enzyme may be biologically active. The findings of the present study show that polyamide (PA) has the lowest binding energy …

Health Implications Of Heavy Metal Contamination In Commercially Available Deodorant And Antiperspirant Products Sold In Benghazi, Libya, Maysson Yaghi, Khaled Elsherif

Al-Bahir

The extensive usage of deodorants and antiperspirants raises concerns about the potential health risks posed by heavy metal content. This study quantified the levels of five heavy metals: Aluminum, Zirconium, Lead, Cadmium, and Chromium in 22 commercial products widely used in Benghazi, Libya, and assessed the associated health risks. Samples, categorized into gel, stick, and roll-on formulations, were analyzed using iCAP TQ ICP-MS. Al and Zr showed the widest concentration ranges, reflecting their intentional use as active ingredients. Al levels ranged from trace amounts (0.032 mg/kg) up to a maximum of 99.10 mg/kg, while Zr was found exclusively in gel …

Divergent Responses Of Branched-Chain And Straight-Chain Lipid Membranes To Butanol Stress Revealed By All-Atom Molecular Dynamics Simulations, Joshua Olaf Aggrey

Electronic Theses and Dissertations

Membrane integrity under chemical stress is critical to cellular survival and industrial microbial bioproduction, yet the molecular basis of bilayer resilience remains poorly understood. Using all-atom molecular dynamics simulation, we compare the effect of increasing concentrations of 1‑butanol on membranes composed of straight-chain (1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC) and branched-chain (1-anteiso-palmitoyl-2-palmitoyl-sn-glycero-3-phosphocholine, APPC) lipids, which differ in the point of attachment of a single methyl group. In the absence of butanol, both membranes exhibit well-ordered architectures consistent with experimental benchmarks; however, under increasing solvent stress, their behaviors diverge markedly. DPPC membranes display gradual thinning, modest area per lipid …

Direct And Indirect Effects Of Water-Table Levels On Redox-Active Organic Matter Reduction In An Alaskan Rich Fen, J. E. Rush, E. S. Kane, Jason K. Keller, J. C. Bowen, Cassandra A. Zalman, E. S. Euskirchen, K. H. Wyatt, A. R. Rober, E. S. Hinckley

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Redox-active organic matter (RAOM) reduction is an important control on methane production in northern peatlands, but it is unclear how global climate change will affect RAOM reduction. We investigated the effects of water-table levels on RAOM reduction by leveraging a long-term water-table manipulation experiment in an Alaskan fen, which includes Lowered and Raised treatment plots relative to a Control. Common substrate peat was incubated in each plot during one summer of experimental manipulation and another summer of site-wide flooding. During experimental manipulation, common substrate RAOM was more reduced in the Raised plot than the Lowered plot at both 10–20 cm …

Dramatic Biases In Terrestrial Nitrogen Fixation In Earth System Models Revealed By Natural Isotope Signatures, Maoyuan Fang, Shushi Peng, Philippe Ciais, Daniel S. Goll, Benjamin Z. Houlton, Ying-Ping Wang, Yilong Wang, Pan Liu, Joshua B. Fisher, Pierre Regnier

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Biological nitrogen fixation (BNF) is the primary input of new reactive nitrogen to natural terrestrial ecosystems. However, this flux is poorly constrained due to its unclear drivers and associated control mechanisms. Here, we extend the existing theory of nitrogen (N) isotope mass balance to estimate BNF rates and then use a Bayesian approach to constrain the BNF rates in natural terrestrial ecosystems by using measurements of natural N-isotope ratios (δ¹⁵N) in plants (δ_P) and soil (δ_S). Together with pairwise δ_P and δ_S measurements from 18 forest sites covering diverse climates and thousands …

Day-Night Shifts In Water-Soluble Ions Of Size-Resolved Aerosols Before And After The Covid-19 Lockdown In A Coastal Megacity: Metro Manila, Philippines, Grace Betito, Paola Angela Bañaga, Rachel A. Braun, Maria Obiminda Cambaliza, Melliza Templonuevo Cruz, Alexander B. Macdonald, James Bernard Simpas, Connor Stahl, Armin Sooroshian

SOSE Affiliate: Manila Observatory

The COVID-19 pandemic-driven lockdowns offer a unique opportunity to examine how reductions in anthropogenic emissions impacted atmospheric aerosol composition in urban environments. This study investigates the day-night variability of size-resolved water-soluble ions in ambient particulate matter (PM) collected in Metro Manila before (November 2019–February 2020) and after (November 2020–February 2021) lockdown implementation. Using tandem Micro-Orifice Uniform Deposit Impactors (MOUDIs), aerosol samples were collected during daytime (06:00–18:00) and nighttime (18:00–06:00) periods and analyzed for key ionic species (sulfate, ammonium, nitrate, oxalate, sodium, chloride, calcium, and magnesium) via ion chromatography. Submicrometer water-soluble mass declined post-lockdown, particularly during daytime, reflecting suppressed secondary formation …

Adsorption Of Cu(Ii) Ions From Aqueous Solutions Using A Magnetite Biochar Composite Material, Widi Aprilia Ta'bi, Paulina Taba, Abdul Wahid Wahab, Maming Gappa, Muhammad Zakir, Nur Umriani Permatasari

Makara Journal of Science

Water contamination from heavy metals, such as Cu(II) ions, poses severe threats to human health and the environment. This necessitates the development of efficient and eco-friendly treatment methods. In this study, a magnetite–biochar composite (MBC) was developed as an effective adsorbent for reducing Cu(II) ions from liquid waste. Biochar was produced through the pyrolysis of water hyacinth at 500 °C, while magnetite was synthesized using FeSO₄·7H₂O and FeCl₃·6H₂O with molar ratio of 1:2. The MBC was formed using a co-precipitation method and characterized by Fourier transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Brunauer–Emmett–Teller, and vibration sample magnetometer instruments. FTIR analysis …

Unraveling Crop Nitrogen-Water Dynamics With Hyperspectral-Thermal Sensing In Northern Central Valley, California, Shahryar Fazli, Surendra Maharjan, Wenzhao Li, Joshua B. Fisher, Rejoice Thomas, Fernando Romero Galvan, Gabriela Shirkey, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Ensuring global food security in the face of climate change requires optimizing crop water use and nutrient management. This study investigates the relationship between canopy nitrogen (N) and evapotranspiration (ET) across sunflower, rice, walnut, alfalfa, and plum crops using advanced remote sensing technologies. High-resolution hyperspectral data from NASAs Earth Surface Mineral Dust Source Investigation (EMIT) and thermal multispectral data from the Landsat-based OpenET system were analyzed over 1,135 km² in California. Regression analysis revealed strong spatial association between canopy N and ET for sunflower (R² = 0.82), rice (R² = 0.71), and walnut (R² = 0.68), …

Antibacterial Activity Of Zno/Geopolymer Composite Granules And Their Potential Application In Water Treatment, Ziyan Tirta Maulitia, Putri Nur Angelina, Pipit Erlita Sari, Sri Sugiarti, Irma Isnafia Arief, Zaenal Abidin

Makara Journal of Science

Water pollution has become a major global concern owing to its complexity and widespread impact. Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) are the most common bacterial contaminants in water sources, which pose significant threats to public health. To mitigate water contamination by these pathogenic microorganisms, developing and implementing effective water treatment technologies are essential. A promising approach involves using antibacterial water filtration systems. Herein, zinc oxide (ZnO) nanoparticles were synthesized via hydrothermal and precipitation methods as antibacterial agents for water treatment. These preparation methods required considerably low synthesis time. A capping agent was …

The Effect Of Ozone Treatment On The Quality Of Biodiesel From Waste Cooking Oil, Sri Redjeki Setyawati, Singgih Wibowo

Makara Journal of Science

This research demonstrates the successful production of biodiesel from waste cooking oil (WCO) using the transesterification method. A methoxide solution, formed by employing a base catalyst and alcohol, facilitated the conversion of triglycerides into methyl esters and glycerol as the byproduct. The conversion process yielded 74% biodiesel and 13.5% glycerol content, with the remaining proportion consisting of water and contaminants. The application of ozone (O₃) aeration proved effective in reducing contaminants—such as alcohol, unreacted catalysts, food residues and water—by approximately 60%. Furthermore, Fourier transform infrared (FTIR) testing affirmed that the biodiesel product—treated with O₃ aeration—maintained its original …

The Quality Of Bio-Pellets Made By Combining Walnut Kernel Shells (Canarium Indicum L.) From Bogor, Indonesia, And Palm Kernel Shells As Renewable Energy, Ani Iryani, Linda Jati Kusumawardani, Ronaldo Juniansyah

Makara Journal of Science

Using biomass as an energy source helps overcome the declining supply of fossil fuels. Bio-pellets—an energy product made from biomass—is one option that can be utilized. One source of biomass energy is walnut kernel shells. The walnut plant (Canarium indicum L.) is a forest tree grown in eastern Indonesia. The walnut plant is also located in the GOR Pajajaran area of Bogor City and has not been utilized for energy production. This study consists of three stages: 1) raw material preparation, 2) bio-pellet production, and 3) bio-pellet characterization in accordance with the Indonesian National Standard (SNI) 8951:2020. Based on …

Effect Of Seasonal Variability In Methane Emissions And Iron Redox Chemistry At Terrestrial-Aquatic Interfaces, Hermes C. Ruiz

Master's Theses

Methane (CH₄) emissions at terrestrial–aquatic interfaces (TAIs) are significant contributors to the global carbon budget, yet the mechanisms driving methanogenesis remain poorly understood. Limited data exist on how seasonal variations and redox processes influence CH₄ fluxes in these dynamic ecosystems. This study addressed two questions: (1) How are CH₄ fluxes in riverine floodplains and adjacent hillslopes impacted by seasonal variations? (2) What roles do metal redox processes (e.g., iron (Fe)) play in regulating methanogenesis?

In-situ CH₄ flux and solid-phase Fe speciation were quantified in East River, CO, under flooded and drained conditions. Groundwater chemistry, gas flux, and soil physical properties …

Effects Of Ambient Temperature On Nox Emissions From Heavy-Duty Diesel Vehicles Measured In Utah, Amber L. Gurecki Allen, Darrell B. Sonntag, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

This study investigates the effects of ambient temperature on NOx (NO + NO2) emissions from model year 2011 and later heavy-duty (HD) diesel vehicles. Emission measurements were collected in Perry, Utah, using the Fuel Efficiency Automobile Test (FEAT) remote sensing device. Data were limited to model year 2011 and later to focus on vehicles likely equipped with selective catalytic reduction (SCR) systems, which control tailpipe NOx emissions and are shown to be temperature sensitive. HD diesel vehicles measured in the winter of 2020 had consistently higher NOx emissions than those measured in the summer of 2023, most significantly for vehicles …

Milkfish (Chanos Chanos) Bones As A Biosorbent For Mercury (Ii) Contamination In Water, Seth Uriel K. Neri, Ethan Kyle Mangao, Christian Kevin F. Redoblado, Anthony Cesar Y. Ponce, Roby Boy P. Riego, Jupiter O. Yap

Sinaya: A Philippine Journal for Senior High School Teachers and Students

Heavy metals, such as mercury contamination in water sources are a major environmental and public health issue in many countries. Traditional methods for removing heavy metals from water are effective but often costly and unsustainable and may produce secondary waste. Recent trends favor more sustainable alternatives, such as biosorbents in treating water with heavy metals. Milkfish (Chanos chanos), a common fish in the Philippines, contains hydroxyapatite in the bones that can bind with heavy metals through physical and chemical adsorption mechanisms. This study aims to evaluate the mercury (II) reduction capacity of biosorbent derived from milkfish bones in water, specifically …

New Precipitation Is Scarce In Deep Soils: Findings From 47 Forest Plots Spanning Switzerland, Emily I. Burt, Scott T. Allen, Sabine Braun, Simon Tresch, James W. Kirchner, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

As precipitation infiltrates into soils, it can recharge them, displace previously stored waters, or bypass already-filled pores. Using 3,697 δ2H and δ18O measurements of water collected nearly monthly over >3 years in 47 forest plots across Switzerland, we present a systematic investigation of the controls on mobile soil water transport. We quantified the lags and damping of water as it percolates downward using young water fraction analysis (Fyw), and the fractions of soil water composed by precipitation that fell within the previous month (new water fractions, Fnew). The Fnew of water sampled in surface soils ranged …

Extreme Value Theory View Of High Emitter Diesel Vehicles In The Us From 1991 To 2021, M. Matti Maricq, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

Extreme value theory (EVT) is a statistical method to characterize the tails of distributions, such as high emitter vehicle emissions. The present work addresses the United States (US) diesel fleet. EVT confirms that high emitters contribute disproportionately to adverse air quality. It further reveals that high emitter emissions have responded differently to progressively tighter emissions standards compared to fleet averages. Carbon monoxide (CO) and hydrocarbons (HC) high emitter emissions fell in concert with the fleet average after widespread implementation of the diesel oxidation catalyst to meet US Environmental Protection Agency (EPA) Tier 1 emissions standards, but remained unchanged after introduction …

Mixture Effects On Metal Accumulation In The Asian Clam, Corbicula Fluminea, Mark A. Huff

Electronic Theses and Dissertations

Field collected Corbicula fluminea were exposed to trace level copper, lead, and zinc with the aim of examining the preferential accumulation between the soft tissue and shell. Metal levels were based on those in a permitted industrial effluent. At 1X effluent and 2X effluent exposure levels, copper was found to preferentially accumulate in the clam soft tissue, lead was found to preferentially accumulate in the clam shell, and zinc was found to excrete back into the diluent after preferentially accumulating in the clam soft tissue. When exposed as a mixture at 1X effluent levels, copper and lead were found to …

Highly Contaminated Sediments From The Gowanus Canal (New York) Superfund Site: An Environmental Forensic Approach, Michael A. Kruge, Kevin K. Olsen, Eric A Stern, Maria Mastalerz, Albert Permanyer

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The 2.5 km long Gowanus Canal (Brooklyn, NY, USA) is a severely contaminated urban waterway dating from the mid-19th century, listed as a US Environmental Protection Agency (USEPA) Superfund site since 2010. Applying an environmental forensics approach to the extensive USEPA data set, we detect systematic variations in parent PAH ring number distributions in the canal sediments, as well as an extraordinary enrichment in organic carbon. We subjected a supplemental sample set to a more detailed analysis by quantitative pyrolysis-GC-MS, Rock-Eval pyrolysis, and organic petrology. With these sensitive methods, we can confirm the alkyl-PAH fingerprint of coal tar (a legacy …

Removal Of Heavy Metals From Motorcycle Washing Wastewater Using A Zeolite-Embedded Sheet, Noverita Dian Takarina, Hanies Ambarsari, Sekar Arum Pramudyawardhani, Maria Fatima Niken Kris Rahmawati, Erni Johan, Naoto Matsue, Mohammad Afdhal Adidharma

Makara Journal of Science

The increased use of motorcycles for transportation has heightened environmental challenges related to their washing, particularly the discharge of untreated wastewater containing heavy metals, such as copper (Cu) and lead (Pb), into drainage systems. This study explored the effectiveness of zeolite-embedded sheets (ZESs) in the removal of these pollutants from motorcycle washing wastewater. ZESs were prepared through treatment of nonwoven sheets with Linder Type A (LTA Zeolite) powder and heat treatment, washing, and drying. Characterization was performed via scanning electron microscopy with energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. Over a 60 min adsorption period, the ZES achieved removal …