Scaling up of waste water treatment plant based on the use of BSF larvae: design optimisation, construction and operation.

The use of Black Soldier Fly (BSF) larvae has been recently studied as a promising biological treatment process for high organic content wastewater. After proper setting of the operational conditions (providing efficient physical support for the larvae mobility), subject to a patent, several studies have been carried out aimed at achieving a better understanding of the process influencing variables and removal kinetics. Based on the results of previous studies, the research aimed at determining the optimising process operating conditions, in terms of feeding loads, larvae densities, solid supporting material and water depth. The final goal was the designing, building and operating the first continuous semi pilot plant for the wastewater treatment using BSF larvae. The preliminary studies consisted in the operation of a small scale continuous reactor to evaluate the hydraulic set up and the consistency of the removal kinetics with those obtained under batch test conditions. Moreover, a “Big Brother” test was carried out, watching larvae behaviour 24/7, to evaluate the maximum diving depth under different larvae densities and supporting material. Based on the preliminary tests and literature results, the semi pilot plant was designed, built and operated for four weeks.