Publications by authors named "Yoonah Jeong"

Food-waste biochar holds significant potential as a bio-solid fuel for achieving carbon neutrality; however, its high content of sodium (Na), potassium (K), calcium (Ca), chlorine (Cl), and nitrogen, inhibits its potential use. This study explored the effects of post-treatment with ascorbic, acetic, citric, and iminodiacetic acids on the properties of food-waste biochar and volatile ionic substances to establish a foundation for assessing both the environmental impact and practical use of food waste. Post-treatment with organic acids achieved 92% Cl-removal efficiency and induced deformation of the functional groups of food-waste biochar surfaces, leading to the re-adsorption of alkali and alkaline earth metals.

View Article and Find Full Text PDF

The pyrolysis of food waste has high economic potential and produces several value-added products, such as gas, bio-oil, and biochar. In South Korea, biochar production from food waste is prohibited, because dioxins are generated during combustion caused by the chloride ions arising from the high salt content. This study is the first to examine the water quality and the applicability of food waste-based biochar as solid refuse fuel (SRF) based on a demineralization process.

View Article and Find Full Text PDF

Physical friction between a tire and the road surface generates tire wear particles (TWPs), which are a source of microplastics and particulate matter. This study investigated the trends of chemical leaching from TWPs depending on the treadwear rating of the tire. A road simulator was used to produce TWPs from tires with various treadwear ratings.

View Article and Find Full Text PDF

A significant amount of chlorine, and alkali and alkaline earth metal (AAEM) in food waste has been a major limitation to the utilization of food waste as fuel. The present study aims to investigate the behavior of chlorine and AAEM in food waste biochar during pyrolysis, demineralization, and combustion. Food waste compost (FWC) and food waste feedstock (FWF) were selected as raw materials.

View Article and Find Full Text PDF
Article Synopsis
  • Toxicity assessment of organic contaminant mixtures involves bioassays that require careful sampling and reproduction of bioavailable levels of the contaminants.
  • Passive sampling techniques can target bioavailable fractions but can lead to altered mixture profiles, complicating toxicity results.
  • The study suggests that combining equilibrium passive sampling and dosing provides the most accurate method for determining the combined toxicity of aquatic contaminants in bioassays.
View Article and Find Full Text PDF

The lag effect in the polar organic chemical integrative sampler (POCIS) equipped with a polyethersulfone (PES) membrane (POCIS-PES) is a potential limitation for its application in water environments. In this study, a POCIS with a poly(tetrafluoroethylene) (PTFE) membrane (POCIS-PTFE) was investigated for circumventing membrane sorption in order to provide more reliable concentration measurements of organic contaminants. Sampler characteristics such as sampling rates (R) and sampler-water partition coefficients (K) were similar for POCIS-PES and POCIS-PTFE, indicating that partitioning into Oasis HLB as the receiving phase dominates the overall partitioning from the aqueous phase to the POCIS.

View Article and Find Full Text PDF

This study investigated the possibility of applying pyrolysis as an alternative method to recycle powdered activated carbon-containing water treatment residuals (PAC-WTRs) discharged from the Cheongju water treatment plant as a multifunctional adsorbent. WTRs pyrolyzed for 1 h at 200-700 °C were compared with raw material. The carbon content of the PAC-WTR reaches 19.

View Article and Find Full Text PDF

Pentachlorophenol (PCP) is a widespread and persistent hydrophobic organic pollutant in the environment despite its restricted public use. Risk assessment of such hydrophobic organic compounds (HOCs) is challenging because sorption and volatilization issues during toxicity test often lead to inconsistent exposure concentration. Considering the hydrophobicity of the PCP, in this study, a passive dosing format was applied by adopting a silicone O-ring as a reservoir and evaluated its applicability on the determination of PCP on Daphnia magna.

View Article and Find Full Text PDF

This study proposes a novel method to directly treat reject water with a high ammonium content, without relying on dilution. The originality of this method resides in leveraging the coordinated action of a methane- and methanol-dependent bacterial consortium and the biogas generated from wastewater treatment facilities. Specifically, ammonium is removed through autotrophic assimilation in the glutamate cycle of methanotrophs and Methylophilus while, simultaneously, methanol generated by methanotrophs is treated through formaldehyde assimilation as Methylophilus undergo the same ribulose monophosphate cycle as methanotrophs.

View Article and Find Full Text PDF

The performances of an equilibrium and a kinetic passive sampler for monitoring a range of organic contaminants (Log K from -0.03 to 6.26) were evaluated in the effluent of a wastewater treatment plant, the receiving river Saar as well as the river Mosel in Germany.

View Article and Find Full Text PDF

In this work, Oasis HLB® beads were embedded in a silicone matrix to make a single phase passive sampler with a higher affinity for polar and ionisable compounds than silicone alone. The applicability of this mixed polymer sampler (MPS) was investigated for 34 aquatic contaminants (log K -0.03 to 6.

View Article and Find Full Text PDF
Article Synopsis
  • Oasis hydrophilic lipophilic balance (HLB) is used in solid phase extraction (SPE) and polar organic chemical integrative passive samplers (POCIS) to evaluate organic pollutants in water.
  • The study investigated how various factors like concentration, temperature, pH, and salinity affect the sorption of 28 different organic compounds, finding a wide range of partition ratios.
  • The findings suggest that interactions between the Oasis HLB and the pollutants significantly influence extraction efficiency, which can improve methods for analyzing environmental contaminants in complex mixtures.
View Article and Find Full Text PDF

Microbial toxicity bioassays such as the Microtox® test are ubiquitously applied to measure the toxicity of chemicals and environmental samples. In many ways their operation is conducive to the testing of organic chemicals. They are of short duration, use glass cuvettes and take place at reduced temperatures in medium lacking sorbing components.

View Article and Find Full Text PDF