Bacteria Purifying Our Contaminated Water Supply

A large number of personal care products, from coconut shampoos and hydrating body washes to expensive face serums, end up in the sewer system. Wastewater treatment facilities, however, were not built to handle these so-called micropollutants. In the early days of wastewater treatment, the primary aim was to prevent the spread of infectious diseases, not to deal with these micropollutants.

Contemporary wastewater treatment plants often combine wastewater and air to produce activated sludge; this process aids bacteria in breaking down pollutants. Initially, this system was designed to eliminate nitrogen, phosphates, and organic matter, not pharmaceuticals. The instances where bacteria metabolize medicines such as metformin are more of fortunate coincidences than intended outcomes.

There are some technologies that utilize bacteria to effectively eradicate these small pollutants. Membrane biological reactors, for example, merge activated sludge with microfiltration, and biofilm reactors depend on bacteria grown on membrane surfaces. Additionally, anaerobic “sludge blankets” are used, where microbes change pollutants into biogas in an oxygen-deficient setting. Nevertheless, these technologies are costly and there are no regulations mandating treatment plants to ensure the removal of these pollutants from treated water, at least in the US.

The European Commission is planning to implement new regulations by 2045 that will require larger wastewater treatment facilities to remove numerous micropollutants. In this scenario, the polluters which are pharmaceutical and cosmetics companies will be responsible for 80% of the costs. Unsurprisingly, this idea is not popular within the pharmaceutical industry. Industry trade groups claim these regulations will probably result in medication scarcities.

In the US, the federal government is still deliberating on how to manage these pollutants. One challenge is the uncertainty surrounding the effects of small amounts of pharmaceuticals in water on the environment and human health. The risk can also fluctuate based on the specific drug involved. Oral contraceptives, for instance, have been associated with fertility issues and gender transitioning in fish.

A possible solution might come from bacteria. Over 100 types of microbes capable of degrading estrogen have been identified. The key is figuring out how to effectively utilize these bacteria.

For more insight, check out these previous articles: one explores the concept of the exposome, encompassing all the chemicals we consume and encounter, and another discusses the pervasive issue of microplastics, which are ubiquitously present but poorly understood in terms of their impact on humans.