Online toxicity monitoring of industrial influents for the protection of wastewater treatment plants

The composition of industrial wastewater is often complex and very dynamic due to varying production lines. Moreover, some substances in industrial wastewater and their degradation products are not always known. The substances contained in wastewater can not only cause damage to a water body if they are not degraded completely; even before degradation they have the potential to cause lasting damage to the biology of the wastewater treatment plant, which can subsequently have an even greater negative effect on the receiving waters. It is therefore essential to prevent any possible toxicity in the biology of the wastewater treatment plant. The degradability of the wastewater can be monitored with so-called degradation tests.

An additional way to continuously monitor the degradability of industrial wastewater are specific toxicity analyzers; these measure the respiration inhibition of microorganisms contained in the sewage sludge and trigger an alarm in case of excessive deviation. To evaluate the sensitivity of these biomonitors, we conduct substance toxicity and degradability studies and compare their effects in conventional degradation tests. The long-term goal is to enable a practice-oriented application of biomonitors for the protection of the biological treatment step in the WWTP.