TITLE:
Feasibility of a novel vermitechnology using vermicast as substrate for activated sludge disposal by two epigeic earthworm species
AUTHORS:
Kui Huang, Fusheng Li, Xiaoyong Fu, Xuemin Chen
KEYWORDS:
Activated Sludge; Biology; Earthworms; Heavy Metals; Nutrients; Vermicomposting
JOURNAL NAME:
Agricultural Sciences,
Vol.4 No.10,
September
27,
2013
ABSTRACT:
This
study was conducted to investigate the feasibility of vermicomposting by
using vermicast as the substrate for the stabilization of municipal activated sludge,
called hereafter as direct vermistabilization, in which the
pre-treatment and bulking materials required in previous practices were all
omitted. For this purpose, two epigeic earthworm species, namely Eisenia foetida and Bimastus parvus, were inoculated into substrate for
composting fresh dewatered activated sludge. Direct vermistabilization resulted in significant reductions
in pH, TOC, C/N ratio and the content of heavy metals, as well as increases in
EC, total N, total P and total K in the final vermicast. Moreover, both Eisenia foetida and Bimastus parvus showed
faster growth rate and higher cocoon production. The results of
this study suggest that the direct vermistabilization has the advantages of
being simple, cost-effective and efficient, and can thus be used as a
feasible vermicomposting approach to
convert fresh dewatered activated sludge into a valuable product for agricultural use. The results also suggest
that Bimastus parvus can be used as a new potential candidate
for vermicomposting of municipal activated sludge.