Microbiological tests of detection of the toxicity.: Application to systems of residual water purification

The purifying capacity of a municipal sewage treatment plant is directly related with the activity and quality of the biomass into the biological system. Since toxicants in influent wastewater may inhibit the biological activity of the activated sludge and cause treatment plant process upsets, influent wastewater should be monitored for toxicity in order to take protective actions. In the same way, wastewater toxicity to activated sludge should be assessed by means of methods that use representative organisms of the whole system. However, few studies use a consortium of microorganisms isolated from the treatment process or activated sludge itself. The main purpose of this work is to review conventional and advanced microbial toxicity tests and recent technical developments that, in an early future, will carry out a very important role in the environmental studies.