This is the recommendation from researchers based at the Concordia Faculty of Arts and Science. According to project lead Louise Hénault-Ethier vermicomposting is the way forward, and this can lead to the inactivation of specific bacteria. There are, however, different approaches to the subject.
In a research note, Hénault-Ethier explains: “Centralized composting, which is one of the fastest growing industrial composting methods, has strict governmental guidelines, requiring thermal sanitation to prevent the survival of harmful bacteria.”
Hénault-Ethier is challenging these guidelines and argues they are not the most efficient. Current U.S. regulations require compost to reach and maintains a heat of 55 degrees Celsius over a three-day period. The heat is generated by bacteria. Instead Hénault-Ethier has been looking at a process that runs at room temperature, and one that continues to remove harmful bacteria. The organism of concern in a recent study is Escherichia coli, an organism often associated with fecal matter.
The study considered several variables: the size of the compost lot; the quantity of naturally occurring compost microbes; and the rate of E. coli survival. By deploying worms, a process was developed that produced a compost – at room temperature – which met the regulations for permitted levels of the E. coli pathogen.
The downside is that the process takes longer – up to 21 days – on the upside it is lower cost and more efficient. The process could see more biodegradable waste put forward for composting.
A further advantage is that the worms can be re-used or even used as an animal feed (providing a protein source). With the value of the compost and the worms, the venture falls under the term ‘upcycling’, which means the end product, once recycled, is of a greater value than the initial product (in this case, waste material).
The research is published in the journal Waste Management, with the study titled “Persistence of Escherichia coli in batch and continuous vermicomposting systems.”
