A new process for the rapid and direct vermicomposting of the aquatic weed salvinia (Salvinia molesta)

Abstract Background The concept of high-rate vermicomposting was successfully used to achieve direct vermicomposting of the aquatic weed salvinia - without any precomposting or cow dung supplementation as previously reported processes for the vermicomposting of phytomass had necessitated. Results Both the epigeic species of earthworms that were explored, Eudrilus eugeniae and Eisenia fetida, provided efficient vermicast production with no mortality, persistent gain in body mass, and good fecundity over the 270-day-long course of the reactor operation. In this period, all reactors were pulse-fed at the solid retention time of 15 days and were operated in the pseudo-discretized continuous operation protocol developed earlier by the authors. With this, it was possible to almost completely dampen the influence of natural biodegradation of the feed or grazing by the earthworm born in the vermireactors. This has made it possible to link vermicast production directly to the ability of the earthworm to feed upon, and digest, salvinia. In turn, this enables accurate process monitoring and provides clear pointers on how to improve process efficiency. Conclusion The paper establishes the capability of high-rate vermicomposting technology developed earlier by the authors in direct and efficient vermicomposting of salvinia without any precomposting or manure supplementation. The findings have very significant implications in improving process economics and consequently process utility. No previous report exists in primary literature on the vermicomposting of salvinia.