Abstract

Compliance with current guidelines for composting based on time-temperature requirements does not always translate into safe compost products. This review’s objective is to assess what pathogens are inactivated during composting and how inactivation could be improved to address that issue. While most pathogens are inactivated by the heat generated during composting, spore-forming bacteria and Group II viruses are likely to survive the process. Other bacteria may also survive the composting process and regrow. Reports of protozoa and helminths inactivation are contradictory due to the lack of cheap and reliable technologies to ascertain their viability. Other factors contribute to pathogen inactivation by promoting the activity of beneficial microorganisms that produce antimicrobial compounds, compete for nutrients or prey on pathogens. Volatile acids are effective against bacteria and viruses by targeting their envelope (if any) and their genome. Ammonia affects most pathogens including Ascaris eggs and exhibits a strong effect against ssRNA viruses. Future research should focus on better understanding the role of the batching recipe and mesophilic and maturation phases in inactivating pathogens. Understanding how pathogens present in a feedstock are inactivated is also crucial to predict what factors are important and optimize the composting process. More appropriate indicators should be used for high-risk wastes containing human or animal wastes. Enterococci have been suggested as an additional indicator but the relation between the presence of enterococci or other indicator and the survival of other types of pathogens should be further investigated.

摘要

遵守基于时间-温度要求的当前堆肥指南并不总是可以转化为安全的堆肥产品。这项审查的目的是评估堆肥过程中哪些病原体被灭活以及如何改善灭活以解决该问题。尽管大多数病原体会被堆肥过程中产生的热量灭活，但形成孢子的细菌和II型病毒很可能在整个过程中存活下来。其他细菌也可能在堆肥过程中幸存并再生。关于原生动物和蠕虫灭活的报道相互矛盾，因为缺乏确定其生存能力的廉价可靠技术。其他因素通过促进有益微生物的活性来促进病原体失活，这些有益微生物会产生抗微生物化合物，竞争营养或捕食病原体。挥发性酸通过靶向包膜（如果有的话）及其基因组来有效抵抗细菌和病毒。氨会影响大多数病原体，包括scar虫卵，对ssRNA病毒有很强的作用。未来的研究应侧重于更好地理解配料配方以及中温和成熟阶段在灭活病原体中的作用。了解原料中的病原体如何被灭活对于预测哪些因素很重要并优化堆肥过程也至关重要。对于包含人类或动物废物的高风险废物，应使用更合适的指标。肠球菌已被建议作为附加指标，但应进一步研究肠球菌或其他指标与其他类型病原体存活之间的关系。