Achieving the sustainable waste management of medical plastic packaging using a life cycle assessment approach.

Hospital waste management often classifies all waste, including uncontaminated plastic packaging, as hazardous, leading to incineration as the primary treatment method. While effective for safe treatment, incineration incurs high costs and significant environmental impacts. This study explores an alternative approach through the segregation and sustainable management of plastic packaging waste derived from medical device use to mitigate these environmental consequences. Using a Life Cycle Assessment, this research evaluates and compares the environmental impacts of three waste disposal scenarios of plastic packaging: hazardous waste incineration, general waste landfill, and plastic recycling. The analysis focuses on 1 kg of plastic packaging waste generated from medical devices at the Limb Vascular Center, Konkuk University Hospital, South Korea. The results show that general waste landfill has an environmental impact of 79.7 % and plastic recycling has an impact of just 11.8 %, highlighting their significantly lower environmental impacts compared to hazardous waste incineration. These findings underscore the significant benefits of adopting more sustainable waste management practices in healthcare and offering valuable insights for enhancing environmental, social, and governance (ESG) practices within hospitals.

Machine learning prediction and interpretation of the impact of microplastics on soil properties.

The annual microplastic (MP) release into soils is 4-23 times higher than that into oceans, significantly impacting soil quality. However, the mechanisms underlying how MPs impact soil properties remain largely unknown. Soil-MP interactions are complex because of soil heterogeneity and varying MP properties. This lack of understanding was exacerbated by the diverse experimental conditions and soil types used in this study. Predicting changes in soil properties in the presence of MPs is challenging, laborious, and time-consuming. To address these issues, machine learning was applied to fit datasets from peer-reviewed publications to predict and interpret how MPs influence soil properties, including pH, dissolved organic carbon (DOC), total P, NO3--N, NH4+-N, and acid phosphatase enzyme activity (acid P). Among the developed models, the gradient boost regression (GBR) model showed the highest R2 (0.86-0.99) compared to the decision tree and random forest models. The GBR model interpretation showed that MP properties contributed more than 50% to altering the acid P and NO3--N concentrations in soils, whereas they had a negligible impact on total P and 10-20% impact on soil pH, DOC, and NH4+-N. Specifically, the size of MPs was the dominant factor influencing acid P (89.3%), pH (71.6%), and DOC (44.5%) in soils. NO3--N was mainly affected by the MP type (52.0%). The NH4+-N was mainly affected by the MP dose (46.8%). The quantitative insights into the impact of MPs on soil properties of this study could aid in understanding the roles of MPs in soil systems.

Nitrogen transformation in slightly polluted surface water by a novel biofilm reactor: Long-term performance and microbial population characteristics.

This study proposes a modular floating biofilm reactor (MFBR) for in situ nitrogen removal from slightly polluted water in rivers using enriched indigenous microorganisms. Its main structure is a 60 cm × 60 cm × 90 cm rectangular reactor filled with hackettens. After a 96-day startup, the removal efficiencies of ammonia-N and total N (TN) reached 80% and 25%, respectively, with a hydraulic retention time (HRT) of 10 h, whereas those in a control reactor (without biofilm) were only 4.9% and 0.2%, respectively. The influences of HRT and dissolved oxygen (DO) were also investigated. As a key factor, HRT significantly affected the removal efficiencies of ammonia-N and TN. When HRT was close to the actual value for a river studied (2.4 min), the removal efficiencies of ammonia-N and TN were only 8.7% and 3.1%, respectively. Aeration increased the concentration of DO in water, which enhanced nitrification but inhibited denitrification. When HRT was 2.4 min, aeration intensity was 20 L/min; the ammonia-N and TN removal rates were 9.5 g/(m2·d) and 11.3 g/(m2·d), respectively. The results of microbial community analysis indicated that the microorganisms forming the biofilm were indigenous bacteria. The findings demonstrated a concept-proof of MFBR, which may be evaluated in scaling up investigation for developing a new methodology for nitrogen removal from slightly polluted surface water in plain river networks.