Environmental sustainability assessment of a new food waste anaerobic digestion and pyrolysis hybridization system.

This research conducted an environmental life cycle assessment (LCA) to evaluate an anaerobic digestion-co-pyrolysis (ADCo-Py) system in which pyrolysis was added to traditional food waste (FW) anaerobic digestion (AD) systems to treat the solid fraction and impurities separated from FW. The solid fraction, including impurities such as wooden chopsticks, plastics, eggshells, and bones, is usually incinerated, while pyrolysis can be a viable alternative to optimize FW treatment. The environmental impact of ADCo-Py was compared with stand-alone AD, pyrolysis, and ADCo-INC (AD with incineration of separated solids). The results indicated that both ADCo-Py (-1.726 kg CO2-Eq/kgFW) and ADCo-INC (-1.535 kg CO2-Eq/kgFW) outperform stand-alone AD (-0.855 kg CO2-Eq/kgFW) and pyrolysis (-0.181 kg CO2-Eq/kgFW) in mitigating global warming potential (GWP). Additionally, pretreatments were found to have the most significant influence on GWP, ecotoxicity potential (ETP), and acidification potential (AP). The two-step pretreatment in ADCo-Py, including the separation of solids and drying, significantly improved the environmental sustainability of the system when compared with standalone pyrolysis.

Experimental study and techno-economic analysis of co-processing system for treatment of food waste with various impurities.

The study assessed a co-processing system segregating food waste (FW) with different impurities into liquid (slurry) and solid fractions and treated using anaerobic digestion (AD) and pyrolysis (Py), respectively, which is defined as ADCo-Py. Biomethane potential tests showed higher methane yield from the FW slurry fraction (572.88 mL/gVSFW) compared to the whole FW (294.37 mL/gVSFW). Pyrolyzing the FW solid fraction reduced nitrogen compounds in bio-oil by 62 % compared to the whole FW. The energy balance and economic feasibility of ADCo-Py were compared with stand-alone AD, Py, and AD integrated with incineration (ADCo-INC). While all systems required extra energy, stand-alone Py and ADCo-INC needed 3.8 and 2.8 times more energy than ADCo-Py, respectively. Techno-economic analysis favored ADCo-Py, with a net present value (NPV) of $15 million and an internal rate of return (IRR) of 34 %. These findings highlighted FW separation as a promising approach, aligning with energy and economic goals in sustainable FW management.

Cost-effectiveness of expanded antiviral treatment for chronic hepatitis B virus infection in China: an economic evaluation.

Background: China, which has the largest chronic hepatitis B virus (HBV) burden, may expand antiviral therapy to attain the World Health Organization (WHO)-2030 goal of 65% reduction in mortality. We evaluated health outcomes and cost-effectiveness of chronic HBV infection treatments based on alanine transaminase (ALT) antiviral treatment initiation thresholds and coverage in China to identify an optimal strategy. Methods: A decision-tree Markov state-transition model evaluated the cost-effectiveness of expanded antiviral treatment for chronic HBV infection by simulating 136 scenarios by ALT treatment initiation thresholds (40 U/L, 35 U/L for males and 25 U/L for females, 30 U/L for males and 19 U/L for females, and treating HBsAg+ individuals regardless of ALT values), population age groups (18-80, 30-80, and 40-80 years), implementation durations (2023, 2028, and 2033) under and treatment coverages (20%, 40%, 60%, and 80%). Deterministic and probabilistic sensitivity analyses explored model uncertainty. Findings: Besides the status quo, we finally simulated 135 treatment-expanding scenarios based on the cross combination of different thresholds of ALT, treatment coverages, population's age groups and implementation time. For the status quo, a cumulative incidence of 16,038-42,691 HBV-related complications and 3116-18,428 related deaths will happened between 2030 and 2050. When the treatment threshold is expanded to 'ALT > 35 in males & ALT > 25 in females' immediately without expanding treatment coverage, it will save 2554 HBV-related complications and 348 related deaths compared to the status quo among the whole cohort by 2030, and US$ 156 million more will be costed for gaining 2962 more QALYs. If we just expand the ALT threshold to ALT > 30 in males & ALT > 19 in females, 3247 HBV-related complications and 470 related deaths will be prevented by 2030 under the current treatment coverage of 20%, which will cost US$ 242 million, US$ 583 million or US$ 606 million more by the year of 2030, 2040 or 2050, respectively. Treatment expanded to HBsAg+ will save the largest number of HBV-related complications and death. This expanding strategy also results in large complications or death reduction when it is limited to patients older than 30 years or 40 years. Under this strategy, four scenarios (Treating HBsAg+ with coverage of 60% or 80% for patients older than 18 years or 30 years) showed the effectiveness in reaching the target before the year 2030. Among all the strategies, treatment expanded to HBsAg+ would cost the most while providing the highest total QALYs compared to other strategies with similar implementation scenarios. ALT thresholds of 30 U/L and 19 U/L for males and females, respectively, with 80% coverage for 18-80 years, can attain the goal by 2043. Interpretation: Treating HBsAg+ individuals with 80% coverage for 18-80 years is optimal; earlier implementation of expanded antiviral treatment with a modified ALT threshold could decrease HBV-related complications and deaths to support the global target of 65% reduction in viral hepatitis B deaths. Funding: This study was funded by Global Center for Infectious Disease and Policy Research (BMU2022XY030); Global Health and Infectious Diseases Group (BMU2022XY030); The Chinese Foundations for Hepatitis Control and Prevention (2021ZC032); National Science and Technology Project on Development Assistance for Technology, Developing China-ASEAN Public Health Research and Development Collaborating Center (KY202101004); in part by National Key R&D Program of China (2022YFC2505100).