Bioengineering of systems for the removal of selected micropollutants under cold climate conditions in small-scale wastewater treatment systems
In the last decades, the occurrence of different organic micropollutants, which usually occur in low concentrations (ng/L to µg/L), in natural environments has emerged as an important issue. This includes pharmaceuticals, personal care products, steroid hormones, industrial chemicals, and pesticides. The point of entry of the majority of micropollutants into water sources (rivers, lakes, etc.) is sewage discharge. Even though concentrations of individual compounds are normally lower than concentrations able to cause direct negative effects, synergetic and long-term exposure effects of different chemicals might cause harm in water environments. Bioaccumulation via the food web is also likely to occur in the case of some substances such as estrogen. The main concern is that imperceptible effects can gradually accumulate, finally leading to irreversible changes on both wildlife and human beings.
Some microorganisms are capable of completely degrading micropollutants to harmless products. In bioaugmentation, a system is inoculated with one or more specific strains of microorganism which can degrade the target micropollutant(s) and can thus improve their degradation and their removal. Bioaugmentation of wastewater treatment systems has been suggested as a feasible technology for enhancing the removal of micropollutants, N or P in natural and conventional systems. However, successful application of bioaugmentation techniques in small-scale wastewater treatment systems the are used in sparsely populated areas has not been reported to date. Development of technology and methodologies in this field can lead to cost effective, less energy intensive and sustainable solutions for removal of micropollutants than methods applied in conventional wastewater treatment plants.
The BioAug project focusses on the possibilities of utilizing highly efficient micropollutant degraders in small-scale wastewater treatment systems, aiming to test bioaugmentation with microorganisms capable of micropollutant removal on the laboratory scale. The work will be conducted in cooperation with Prof. Bodo Philipp at the WWU Münster, who is an expert on microbial degradation of steroid compounds. The focus will be on the removal of steroid hormones (e.g. estrogen). The results of this study can be transferred to a larger scale and help to improve removal of micropollutants in small-scale wastewater treatment, thus preventing the discharge of those bioaccumulating and potentially dangerous compounds to water bodies.
The project objectives are:
- Finding suitable micropollutant degrading microorganisms that can be used for bioaugmentation in small-scale wastewater treatment units
- Testing their potential to degrade micropollutants under conditions that are commonly found in small-scale wastewater treatment units in Finland
- Optimizing wastewater treatment units through bioaugmentation with suitable strains of microorganisms at the laboratory scale
Project coordinatorUniversity of Oulu
- enrichments of micropollutant degraders has been successfully started
- biofilm-forming microorganisms seem to grow well with our target micropollutants
- some isolates have been obtained
- first upscaling tests started: micropollutant-degrading microorganisms are being tested in 1L flow-through systems
This project is conducted in close collaboration with the Microbial Biotechnology Workgroup at the WWU Münster (Prof. Bodo Philipp).