Life cycle assessment of absorbent hygiene product waste: Evaluation and comparison of different end-of-life scenarios

In 2019 in the world, 45 ·103 Mt of Absorbent Hygiene Product (AHP) wastes were produced, and their current disposal through landfills and incineration is causing greenhouse gas emissions and economic issues. This study compared the environmental impacts of four AHP-waste treatments calculated through Life Cycle Assessment. The four AHP-waste treatments included three innovative treatments: the biological process, the mechanical-thermal conversion of AHP-waste into fluff, the recycling process to recover valuable materials, and the baseline scenario including landfill and incineration with energy recovery. The functional unit was 1 t of AHP-waste, and the approach was from bin to grave. The evaluation concerned climate change and human toxicity with ReCiPe 2016 Midpoint (H) and non-renewable energy with cumulative energy demand. Among the four treatments,only the recycling of AHP-waste achieved avoided environmental impacts; - 2.68 kg CO2 eq./t AHP-waste, -0.07 kg1,4 DB eq./t AHP-waste, and -26.36 MJ/t AHP-waste, because the rate of recovered material offset the efforts required to treat AHP-waste. The biological and mechanical-thermal treatment of AHP-waste reached the same rank position, but the latter could be further improved through an energy valorisation of fluff. The sensitivity analyses confirmed the trends of the four treatments and underlined the importance of the proper product recovery rate to counterbalance the effort required by the treatment.