Engineering the household removal of micropollutants from wastewater

I aim to develop the "proof of principle" that micropollutant-degrading enzymes can be used in household washing powders and cleaning products to treat wastewater at source and thus obviate the need for energy-intensive end-of-pipe treatment technologies for micropollutant removal.

Globally, 300 Mt per annum of trace contaminants (micropollutants) from hundreds of different products enter natural water systems through wastewater, some of which have significant ecotoxicological effects and unknown human effects. The best evidence of ecotoxicological effects that propagate into wildlife population crashes has so far been provided for the synthetic hormone 17a-ethinyl estradiol, in the contraceptive pill, and diclofenac. Legislative environmental quality standard limits are being considered by the EU for these two pharmaceuticals and the natural estrogen (17B-estradiol, E2); a world first for such compounds. This has important and far-reaching ramifications.

Regulation of the thousands of pharmaceutical and household chemical products is slow and expensive and the possibility of replacing them with more benign alternatives is remote. Such legislation therefore places pressure on costly end-of-pipe wastewater treatment solutions such as advanced oxidation processes, which would cost up to £30 billion in the UK. These would increase the energy demand of existing assets by as much as 30%. Wastewater treatment already accounts for 1.5% of UK electricity use, and 0.5% of its CO2 emissions, in an age of increasing energy prices. Such solutions are unsustainable and inappropriate for the majority world and poorer sections of the rich world, where water affordability is an issue. Saving the river at the expense of the climate, and the poorest in society is not, in the long term, desirable.

I propose a radically different scalable approach that draws on; contemporary advances in next-generation sequencing, innovation in biotechnology, and the existing know-how, marketing and global reach of household product manufacturers. I envisage a world where micropollutants will be eliminated at source using enzymes delivered in household cleaning products.

The main beneficiaries of this research would be; i) the enzyme biotechnology industry, ii) household cleaning product manufacturers, iii) the water industry, and iv) the pharmaceutical industries. It would provide knowledge, procedures and assays for the former; a market advantage by improving the green credentials of the second through the provision of additional 'ecosystem services' (i.e. micropollutant degradation); the opportunity costs of avoiding expensive energy-intensive end-of-pipe treatment technologies for the third; and a technological and ethical solution that would allow the latter produce beneficial medicines without harming the environment. This research could lead to products that would contain specific enzymes tailored to the micropollutants of concern of any country. It could help stimulate further economic growth in sectors in which the UK is already an international leader.

The ultimate beneficiaries of the research would be the environment and the general public. These would benefit from the avoidance of hazardous chemical pollution (micropollutants) that is known to affect wildlife and with unknown but suspected health effects in humans. In contrast to alternative solutions, this research would provide a cost-effective solution for micropollutant removal and allow people to continue reaping the benefits of pharmaceuticals and other chemicals to improve their health and well-being. This would be done without significant changes to their life-styles or regulations that might impinge on, or add costs to, those benefits.