Monitoring toxicity in anaerobic digesters by utilizing the RANTOX biosensor: calibration tests

A new biosensor, the RANTOX (Rapid ANaerobic load and TOXicity tester), pri marily designed for anaerobic process control, has been tested to evaluate its potential to detect toxic loads in wastewaters. The biosensor is made o f a laboratory-scale reactor. Two different prototypes have been tested: an expanded granular bed anaerobic reactor (EGBR), fed on synthetic solutions , and a fluidized anaerobic reactor fed on yeast production wastewaters. So dium chloride was used as a toxicant because it reversibly inhibits acetocl astic methanogens and allows the carrying out of repeated experiments on th e same biomass. According to the experimental results, the RANTOX biosensor could be successfully used to monitor full-scale anaerobic reactors and de tect unexpected toxicants in their feed. (C) 1998 Elsevier Science Ltd. All rights reserved.