Inhibiting effects of chloroform on anaerobic microbial consortia as monitored by the Rantox biosensor

The Rantox biosensor was designed for anaerobic wastewater treatment process control, and detects modifications of the feed based on the response of the acetoclastic methanogenic microorganisms to periodic pulses of a concentrated solution of organic substrate. The biosensor was tested under various operating conditions at the laboratory scale, in parallel with a digester under control fed on the same substrate. The aim was to evaluate the response of the biosensor in the presence of an incoming organic toxic compound (CHCl3). The experimental set-up, i.e. the biosensor and the digester, was connected to an automated control system developed under LabVIEW„µ environment for data acquisition and operational sequence programming (the Rantox Virtual Instrument). Biomasses with different activities were used as inoculum, and inhibition was induced by dosing chloroform according to two different procedures. The results showed good sensitivity and rapid response of the biosensor to feed intoxication. The presence of chloroform was detected by the Rantox well in advance and with an enhanced response with respect to the digester