New ways to combat water pollution
Today’s modern, developed life has left traces in the aquatic environment. Industrial chemicals, residues of medicines and personal care products can be found in almost all compartments of the water cycle, be it surface water or groundwater. Municipal and industrial wastewater contains pharmaceutical residues (e.g. sulfamethoxazole) and endocrine-disrupting chemicals (EDCs). Groundwater can be polluted with organic compounds from industrial activities. Bioremediation refers to processes that use microorganisms and their enzymes or any other living organism (e.g. plant, algae) to restore contaminated water, soil and air to a healthy state. With EU funding, the MINOTAURUS project explored the immobilisation of biocatalysts as a way to intensify the degradation of organic pollutants. For various target compounds, researchers identified or isolated suitable biocatalysts (enzymes, bacteria or a consortium of microorganisms) and tested them at laboratory scale. This included also the development of appropriate treatment processes. The technologies in focus were bioaugmented and enzyme membrane bioreactors, fixed-bed reactors, bioelectrochemical systems, and magnetic retention reactors, of which some were tested at contaminated sites or wastewater treatment facilities. Groundwater polluted with chlorinated aliphatic hydrocarbons, stemming from solvents, and components used in fuels were successfully treated in packed-bed reactors. The specialised microbial consortia grew on carrier material through which the water was passed. Efficient enzymes for degrading contaminants in biologically treated wastewater were immobilised on nanoparticles while retaining their biological activity. Rhizodegradation is a process of decontaminating soil using the symbiotic relationship of plants with microbes in the soil near their roots. MINOTAURUS explored various bench-scale rhizodegradation systems to degrade EDCs like bisphenol A and polychlorinated biphenyls. The project was completed with a final evaluation of the usefulness of each type of reactor system. This was based on the effectiveness of treatment, as well as on potential risks and current EU policy in the water sector. The consortium delivered a satisfying scientific output consisting of 30 peer-reviewed journal papers, 56 conference contributions (talks & posters) and one book. Using natural enzymes and microbes for remediation will reduce overall energy and chemical usage, costs and carbon footprint. MINOTAURUS hopes to provide decision makers with feasible options to deal with contaminants in soil and water with through its novel bioremediation technology.
Keywords
Bioremediation, polluted groundwater, industrial waste, wastewater, rhizodegradation