Kobus Cilliers | On 09, Feb 2020

Darrell Mann

Some months are better than others. Some weeks are better than others. The first week of September saw a swarm of below-average patents. The second week, on the other hand gave us several candidates for this Patent of the Month feature. A shout-out to US10,412,819 (Plasma heating) and US10,407, 320 (killing water-borne mosquito larvae using ultrasound), both very TRIZ-like in their elegance and simplicity. In the end, however, we decided that US10,406,572 was going to be our winner. Despite its mouthful of a title. And rather crude write-up.

The patent was granted to a trio of inventors at the University of Colorado (that said, the lead inventor, Jin Song, appears to have done the majority of his noble work on remediation of polluted ground while at the University of Wyoming, so it feels like at least some of the credit should head in that direction).

The problem to be solved is really simple. To describe at least. When ground becomes polluted, there are multiple ways of restoring things to their former natural glory. One way is excavating the polluting chemicals. This is the hard work option. Another way is ‘Monitored Natural Attentuation’ (MNA) which, as the name suggests, is the lazy-polluters strategy of letting time take its course. Then there is bioremediation, which is all about adding appropriate microorganisms naturally existing in the groundwater sediments to degrade or transform chemical pollutants into non-toxic forms. This is the closest the world currently has to what we might think of as a TRIZ-like solution to the problem. In crude terms bioremediation is getting nature to repair itself. The only problem being that, although it is generally faster than MNA, it is usually not nearly fast enough. Which gives us this very simple contradiction:

So, how have the Colorado scientists solved the problem? Well, sticking with the idea of TRIZ-like – and, I guess there’s a clue in the title of the patent – how about using a field (Principle 28)?

It turns out that adding a suitable flow of electrons is a great way of encouraging the microorganisms to work faster. Add a field. Simple.

Well, of course, nothing is ever quite that simple. From an academic perspective, bioelectrochemical (BEC) systems have been hypothesized and tested at lab scale for a number of years now. So maybe the real importance of the patent is all about turning the theory into a practical, deployable device to create the required electron flow. Something like this maybe?