Sung Yeon Hwang’s research while affiliated with Kyung Hee University and other places

Plastic films have accumulated in soil ecosystems over decades of agricultural activities. These films potentially disrupt the soil structure, hinder nutrient cycling, and deteriorate soil quality. However, there is still a substantial knowledge gap in understanding how real‐world waste polyethylene films (WPEFs), with varied shapes and sizes, influence soil quality and plant performance in the fields. This study investigated the effects of WPEFs on soil quality, crop growth, and changes in plastic characteristics. In situ soil incubation was conducted for 4 months under natural field conditions, and lettuce (Lactuca sativa) was cultivated during the period. Soils with 0%–2% of WPEFs were analyzed for physicochemical and biological properties, and lettuces from each soil condition were analyzed for growth indicators after harvest. WPEFs were examined for physicochemical changes using FTIR and SEM. After the incubation, the WPEF 2.0 treatment reduced soil bulk density significantly, from 1.03 to 0.77 g/cm³, and decreased microaggregates (< 500 μm) from 22.2% to 17.2%. Meanwhile, the urease activity increased by up to 208.5% at WPEF 0.5. Although the major chemical properties remained relatively stable, lettuce growth was suppressed considerably. At WPEF 2.0, shoot height decreased by 45%, whereas total fresh and dry biomass declined by 58% and 46%, respectively. The findings suggest that the reduction in plant growth performance is driven by WPEF‐induced changes in soil physical properties, particularly reduced bulk density and disrupted aggregate stability. The combined effects of soil structure and enzymatic imbalances might have contributed to the observed adverse effects on plant growth.

Biodegradable plastic degradation in soils is highly complex. Without effective management, degradation poses potential risks to environmental and human health, soil quality, food security and safety, and environmental sustainability.

This article presents a novel strategy for co-pyrolyzing biomass and plastic waste to produce advanced carbon materials. It systematically evaluates the reaction mechanisms, process dynamics, environmental benefits, and sustainable materials.

The biodegradability of plastic is a critical factor in environmental sustainability. However, plastic degradation has been focused on closed systems via physical changes and CO 2 generation. We innovated a methodology on open system degradation in soil environments to reveal the authentic process of plastic degradation in nature. Polybutylene succinate (PBS), polybutylene adipate- co -terephthalate (PBAT), poly3-hydroxybutyrate-co-3-hydroxyvalerate (PHVB), and polylactic acid (PLA) were buried in a soil equipped with the lysimeter, the field applicable instrument that preserves and measures the in-situ soil conditions. Over two years, we tracked the soil electrical conductivity (EC), temperature, water content, and the plastic degradation products in the leachate−the monomers. The seasonal change in soil EC proved the plastic degradation, due to the decomposed plastic particles increasing the electrolyte concentration. The quantity of monomers increased over time, spiking during the summer months. A correlation was observed between the soil EC and monomer concentration. Despite the degradation-derived soil properties fluctuating with seasonal changes, the resilience of soils was maintained. Through long-term field experiments, we identified the seasonal degradation conditions of the actual soil environment and proposed a methodology of degradability that allows plastic targeting without disturbing the degradation media. These insights provide crucial knowledge for the biodegradable plastics market.

Despite that biodegradable plastics are perceived as environmentally friendly, there is a lack of comprehensive understanding of their fate in soil. Current Environmental, Social, and Governance (ESG) frameworks, along with new UNEP regulations on plastic pollution, necessitate scientific information on plastic degradation in soils for developing sustainable biodegradable plastics. In this study, we examined the degradation rates of two biodegradable plastics, poly(butylene adipate-co-terephthalate) (PBAT) and poly(lactic acid) (PLA), in a laboratory microcosm experiment using uncontaminated soil, with PBAT or PLA added at 8.3% (w/w). Our aim was to further understand the impact of these plastic types on soil properties and microbial communities under different incubation temperatures. Both PBAT and PLA treatments elevated cumulative CO2 efflux compared with the control soil incubated at 25 and 58°C. After 33 weeks, 9.2% and 6.1% of the added PBAT and PLA degraded, respectively, at 58°C, while only 2.3% of PBAT and 1.7% of PLA degraded at 25°C, implying slower degradation rates of PBAT and PLA under the lower temperature. Degradation at 58°C increased total soil carbon by 0.6%, 1.9%, and 4.3% for Control, PBAT, and PLA, respectively, and soil electrical conductivity by 0.17, 0.33, and 2.38 dS m−1, respectively, but decreased soil pH. Microbial diversity and richness decreased under thermophilic conditions at 58°C compared with that at 25°C. We conclude that the degradation of PBAT and PLA varies with environmental condition, and influences soil properties.

Climate change, largely attributable to the extensive use of fossil fuels and deforestation, poses a critical global issue. There is a pressing need for innovative and sustainable solutions. This study highlights a significant advancement in materials science: a biomass-sourced transparent composite developed from cellulose nanofibers (CNFs) and isosorbide polycarbonates (ISB-PC). This green glazing material serves as a potential replacement for heavy, easily shattered glass in the construction and automotive industries, exhibiting remarkable thermal properties, light transmittance, and mechanical resilience. Notably, the thermal dimensional stability and transparency of the composite matches that of conventional glass. An integral accomplishment is the development of a multi-layered sheet with a thickness beyond 350 μm. These sheets achieved a light transmittance of 62.0% and coefficient of thermal expansion below 60 ppm K⁻¹ (30–120 °C). Another distinguishing feature of this composite is its potential for carbon sequestration owing to its non-degradability. This study underscores the composite’s potential as an eco-friendly alternative to glass.