I’ve been collaborating with chemical engineers Mirella Di Lorenzo and Jon Chouler from University of Bath for the past few months as part of a project supported by South West Crucible that brings together scientists and composers. Their work is with microbial fuel Cells (MFCs), devices that generate electricity from any sort of domestic, industrial or agricultural wastewater through the action of ‘electrical’ bacteria. The bacteria are restricted in a specific part of the device, the anode chamber, where they spontaneously populate, in the form of a film, the surface of the negative electrode (the anode) during a process called enrichment. At the end of the enrichment, a steady electrical current is generated. This is a consequence of the normal living activities of the electrical bacterial film which, after consuming organic compounds in wastewater as food (the input), is ‘energized’ and releases electrons to produce electricity. If all the operating conditions of the MFC are kept steady, the electricity generated by the MFC can be used as a measure of how happily active the bacteria are with the given food. The higher the level of organics in the wastewater the more electricity is generated. On the other hand, the sudden introduction of a pollutant in the wastewater can disrupt the activity of the bacterial film with a consequent drop in the electricity produced. This enables MFCs to be used as smart devices that sense the presence of pollutants in water in real time.
In the piece I’ve made, titled different water environments, constantly varying waste audio produced by a shortwave radio is introduced as an input. The players respond to the timbre and volume of the input by varying the quality of their sounds to produce a control sound. Periodically additional audio inputs are introduced that differ from the radio input to a greater or lesser degree. The players respond to these sounds by matching their sonic characteristics where they are sufficiently different, altering the control sound.
The project also features a collaboration between Dominic Lash and biogeochemist Kate Hendry from University of Bristol to make a piece that engages with palaeoclimate methodology, which uses indirect chemical records to understand the links between past oceans and climate. Dominic’s piece explores the idea of indirect interpretation of data by having the musicians attempt to duplicate each other’s activity in various ways, “sampling” each other through various “filters”.
Both pieces will be performed by Set Ensemble in the crypt of St George’s Brandon Hill in Bristol on 31 May. The event will also include a short talk by each of the scientists. Doors open at 5pm, tickets are £3 on the door. The evening is sponsored by the South West Crucible. For more information see labnotesproject.wordpress.com.