Microbial diversity and potential health risks of household municipal solid waste in China: A case study in winter during outbreak of COVID-19.

Microbial (bacteria and fungi) community structures and their distributions in urban household municipal solid waste (HMSW) were characterized in a sampling campaign in 38 cities of China covering 5 climatic zones. All samples were collected from garbage containers in residential communities during the Winter of 2022, from January 11 to 26. A total of 247 bacterial genera belonging to 22 phyla were identified among the samples. Firmicutes (44.3 %), Bacteroidetes (33.77 %) and Proteobacteria (21.54 %) were the top 3 dominant phyla, and Arcicella (33.11 %) and Leuconostoc (21.87 %) were the dominant genera. Meanwhile, 124 fungal genera from 7 fungal phyla were detected. Ascomycota was the most dominant phylum, with an average relative abundance of 77.31 %. Hanseniaspora (24.03 %), Debaryomyces (13.47 %), Candida (12.18) were the top 3 dominant fungal genera. Alpha-diversity analysis showed that the species richness and diversity of bacterial and fungal communities of HMSW samples belonging to different climatic zones did not differ significantly. Nonmetric multidimensional scaling (NMDS) analysis confirmed that climatic had an effect on microbial communities but did not show a significant correlation. In addition, the distribution of microbial community in different samples from the same climate zone varied considerably, suggesting the HMSW source play important role in shaping microbial community composition. Considering that residential HMSW is relatively fresh, we speculates that the original microorganisms residing in different components of HMSW are key influencing factor for the community, while the reshaping force driven by environmental conditions are relatively weak. In addition, the study identified 13 bacterial and 16 fungal pathogens with Pseudomonas putida (0.25 %) and Sclerotinia sclerotiorum (2.12 %) as the most abundant potential pathogenic bacteria and fungi, respectively. These findings provide valuable information for characterizing microbial features and potential risks of HMSW in its management system.

As parcerias em programas de coleta seletiva de resíduos sólidos domésticos / Partnerships in selective domestic solid waste collection programs

Objetivo. Estudar experiências de gerenciamento de resíduos sólidos domésticos envolvendo parcerias, identificando pontos positivos e negativos nas relações inter-institucionais, e verificando a relação entre os dados da bibliografia e o constatado nos programas estudados. Métodos. Foram realizados estudos de caso de programas de coleta seletiva em Goiânia (GO), Campinas (SP), Embu (SP), Santos (SP) e Botucatu (SP). Foram feitas entrevistas e visitas técnicas em entidades envolvidas, incluindo órgãos do governo, empresas e OGNs. Os programas foram analisados nos aspectos sócio-ambiental, operacional, econômica e político-institucional. Resultados. As taxas de desvio observadas variaram entre 0,1 e 2,39 por cento e as taxas de recuperação entre 19 e 82 por cento e os custos de triagem entre 14 a 52 por cento. As dificuldades mais freqüentes relatadas pelos entrevistados são relacionadas aos aspectos humanos: comportamentais, políticos e educacionais. Conclusões. As parcerias podem disponibilizar recursos financeiros, equipamentos, materiais diversos e mão-de-obra para a implementação de programas de coleta seletiva. As parcerias são uma forma eficiente de redução de custos dos programas. Diversos programas municipais tem desenvolvido parcerias para a operação de triagem.As iniciativss espontaneas desempenham um papel importante e devem ser incentivadas. Os investimentos em recursos humanos e os incentivos as industrias locais de reciclagem são fatores-chave do sucesso dos programas. A reciclagem do lixo constitui-se uma alternativa importante de atividade economica, com geração de emprego e renda. A pesquisa doi apoiada pela FAPESP