2024-04-30, Breitenmoser, Lena, Behner, David, Baertsch, Alessia, Mondardini, Maria Rosa, Hugi, Christoph

Sustainable Development Goal 12 (SDG 12) and national waste reduction goals require frequent waste analyses for monitoring and governance decisions. We developed and tested a citizen science (CS)-based household waste diary for ten consecutive days with 89 volunteer households in Switzerland as a complementary monitoring option to official composition analyses. Discrepancies between the CS-based household diary data and the official composition analyses ranged between 55–65% less reported waste quantities for minerals, compound products, and plastics and 80–90% less for paper, avoidable food waste, and glass. Household waste diaries should be digitalized and prolonged to 21–28 days, and volunteers from different demographic groups are needed to produce stratified, representative results. We conclude that a hybrid CS study design involving waste composition analyses and waste diaries could reduce self-reporting biases while increasing the monitoring frequencies of household waste compositions. CS-based hybrid household waste projects can be a powerful means to complement the measures identified in the 2022 Swiss action plan against food waste and for data reporting for the SDG 12.3 Food Waste Index.

2023-04-25, Korkach, Hanna V., Kotuzaki, Olena M., Breitenmoser, Lena, Behner, David, Hugi, Christoph, Krusir, Galina V.

2021-07, Gross, Thomas, Breitenmoser, Lena, Hugi, Christoph, Wintgens, Thomas

Anaerobic digestion (AD) of biowaste seems promising to provide renewable energy (biogas) and organic fertilizers (digestate) and mitigate environmental pollution in India. Intersectoral analyses of biowaste management in municipalities are needed to reveal benefits and trade-offs of AD at the implementation-level. Therefore, we applied material flow analyses (MFAs) to quantify effects of potential AD treatment of biowaste on energy and fertilizer supply, water consumption and environmental pollution in two villages, two towns and two cities in Maharashtra. Results show that in villages AD of available manure and crop residues can cover over half of the energy consumption for cooking (EC) and reduce firewood dependency. In towns and cities, AD of municipal biowaste is more relevant for organic fertilizer supply and pollution control because digestate can provide up to several times the nutrient requirements for crop production, but can harm ecosystems when discharged to the environment. Hence, in addition to energy from municipal biowaste - which can supply 4-6% of EC - digestate valorisation seems vital but requires appropriate post-treatment, quality control and trust building with farmers. To minimize trade-offs, water-saving options should be considered because 2-20% of current groundwater abstraction in municipalities is required to treat all available biowaste with 'wet' AD systems compared to <3% with 'dry' AD systems. We conclude that biowaste management with AD requires contextualized solutions in the setting of energy, fertilizers and water at the implementation-level to conceive valorization strategies for all AD products, reduce environmental pollution and minimize trade-offs with water resources.