Operational and environmental barriers to centralized composting in two small Brazilian municipalities: A longitudinal study

Abstract

Municipal solid waste management in small cities faces severe logistical and financial barriers regarding organic fraction treatment. This study evaluates biological selective collection in two small Brazilian municipalities (Astorga and Sabáudia), comparing dynamics between gated communities (GC) and public thoroughfares (PT) over an annual cycle. Results indicate distinct behavioral responses: while GCs achieved high operational compliance (81%) and produced stable biofertilizers (C/ N < 20), this rigor contracted dry recycling volumes, suggesting a motivation crowding‐out effect. Conversely, PTs exhibited a divergence between volume and quality, with stream recovery rate decreasing from 85% to 25%, potentially indicating Hawthorne effect exhaustion. Extrapolating these data yields a marginal landfill diversion of 1.98%–2.29%. Furthermore, the logistical carbon penalty of dedicated fleets reduced the 10‐year net greenhouse gas mitigation to 0.4%–0.8%. Consequently, similar small municipalities should consider prioritizing decentralized social technologies to sustainably meet circular economy targets.