Microbial indicators in municipal solid waste compost and their fate after land application of compost

Municipal Solid Waste Management in a Decentralized Composting Scenario: Assessment of the Process Reproducibility and Quality of the Obtained Composts

“…In relation to the rest of the microbial pathogen groups studied (total coliforms, Streptococcus faecalis, Clostridium perfringens and Listeria monocytogenes), in general, the contents were very low, especially of Clostridium perfringens and Listeria monocytogenes, except for Listeria in compost 1, also probably due to a recontamination of the pile during the maturity stage, which corroborates the effectiveness of the composting process and the absence of risk to human health [14]. The contents of these microbial groups were similar to those observed in previous works using municipal solid waste as raw material [14] and during the co-composting of OFSMW with pruning waste [15]. The relatively higher values for the microbial groups in compost 4 could be associated with the process conditions, as this pile had a low average temperature (39.9 • C), the shortest duration of the bio-oxidative phase (110 days) and the lowest number of days in which the temperature of the pile exceeded 60 • C (24 days).…”

“…and E. coli contents below the limit value (1000 MPN/g compost) established in the European and Spanish legislation [26,42]. In relation to the rest of the microbial pathogen groups studied (total coliforms, Streptococcus faecalis, Clostridium perfringens and Listeria monocytogenes), in general, the contents were very low, especially of Clostridium perfringens and Listeria monocytogenes, except for Listeria in compost 1, also probably due to a recontamination of the pile during the maturity stage, which corroborates the effectiveness of the composting process and the absence of risk to human health [14]. The contents of these microbial groups were similar to those observed in previous works using municipal solid waste as raw material [14] and during the co-composting of OFSMW with pruning waste [15].…”

“…However, currently, there is a lack of standardization concerning the control of the process and of the final product in these new composting scenarios, which is essential to guarantee the agronomic value, degree of stability and maturity, product quality and especially the hygienic conditions of the compost obtained [13] for its use in agriculture. In addition, when the composting process is not properly managed or controlled, it can induce the proliferation and spread of potentially pathogenic microorganisms, such as Salmonella and/or Listeria [14,15], as well as hinder seed germination by impeding plant growth [16]. Thus, this work aimed to study and monitor two examples of community composting of the organic fraction selectively collected from municipal solid waste generated in two municipalities located in the Valencian community (Spain) in real conditions and throughout three composting cycles in order to guarantee the efficiency of the composting processes at the community scale to produce a sanitized, stable, humified compost with properties that demonstrate its quality and assure its safe use in agriculture.…”