Bacteria will turn drains into clean water and electricity

Daria Zagorskaya, Vesti

Humanity has long been sufficiently aware of its responsibility for the environment. We produce and consume a lot and, of course, pollute the air, water and soil – everything without which life on Earth itself would be impossible, at least as we know it. In particular, many wastewater treatment technologies have been developed and put into operation at the moment. But progress is inexorable and requires improvement in everything.

One of the newest and most promising wastewater treatment technologies is based on the use of the so-called microbial fuel cell (MTE). It is a biotechnological device in which bacteria in the course of their life consume organic substances and "produce" protons and electrons. In this case, electrons are collected at the anode, and protons are sent through a special membrane to the cathode. As a result, a voltage arises between the electrodes, which leads to the generation of an electric current by the cell.

The main advantage of using MTE in wastewater treatment is the compensation of energy costs. This is a big problem for widely used methods, including those using a variety of bacteria, since their implementation takes an average of 1.5 kilowatt-hour for each kilogram of pollutants removed. In the US alone, this represents 3 percent of total energy consumption and $25 billion per year.

The Boston-based company Cambrian Innovation is one of the leaders in the promotion of MTE technology. Its specialists joined forces with the US Navy Naval Surface Warfare Center in Maryland and launched the BioVolt project (Cambrian Innovation Pilots Self-Powered Water Treatment System with U.S. Army – VM).

According to quite realistic forecasts, this installation will be able to produce about 2,250 liters of clean water every day, which will ensure the daily needs of at least 15 people. At the same time, it will provide itself with energy for wastewater treatment and even with a small margin.

BioVolt uses a proprietary blend of strains of anaerobic iron bacteria of the genus Geobacter and bacteria of the species Shewanella oneidensis. This mixture has one important advantage – the microorganisms included in it do not show too rapid growth. The fact is that there should be no bacteria in the water at the outlet, and the fewer they are initially, the easier it is to get rid of them in the end.

Now the first tests of the installation are successfully passing in test mode. And the CEO of Cambrian Innovation, Matt Silver, is already thinking about creating an installation that will be able to clean 20 thousand liters of wastewater per day.

In addition to Cambrian Innovation, other research teams have also made significant progress in the development of MTE. Many of them pay special attention to the working mixture of microorganisms.

For example, Orianna Bretschger from the Craig Venter Institute in San Diego and her colleagues have launched a plant that processes 630 liters of pig farm waste per day. In addition, this team is developing its first large-scale project. They plan to launch a large pilot system in Tijuana (Mexico) and hope to enter the market within the next 3-5 years.

Brechger technology even surpasses BioVolt's achievements in some positions. Its system removes more pharmaceuticals from the water, in particular, synthetic estrogens. Now they are working to add painkillers to this list. For obvious reasons, the presence of all these substances in tap water or in a natural reservoir harms both people and animals.

In addition to large-scale cleaning projects, MTE may well take its place in the home of the mass consumer. The developers are confident that if the microbial fuel cell technology develops in accordance with forecasts, then over time it will be as easy to install such a system as installing a solar panel on the roof of your house.

Portal "Eternal youth" http://vechnayamolodost.ru 23.08.2016