One of the most interesting things I discovered while wandering through the multitude of exhibits at last week’s Offshore Technology Conference in Houston was that walnuts have a natural affinity for oil. The same English Black Walnuts that we routinely crack and eat can be ground up and used to safely and efficiently clean up contaminated water streams.

Walnut shell filters are simple and reliable, compared to many filtration techniques designed to remove oil contaminants and suspended solids from water. There are no chemicals, very few moving parts and the walnut shell filter media can be used over and over again. Walnut shell filters can take water with up to 100 parts per million of contaminants and reduce this level to under 5 parts per million. This is cleaner than normal drinking water.

Editor's note: John Sealander is an employee of Siemens Energy. Siemens is a sponsor of The Energy Collective.

These unique natural filters have applications in the chemical, petrochemical, metal working and power generation industries, but they are especially valuable in offshore drilling applications. The great thing about the latest generation of Walnut Shell Filters is that they are small and light enough to be installed on a ship.

Couple this with the fact that walnut shell filters can be specifically designed for offshore use to remove more than 98 percent of the contaminants passing through it, and it has an amazing large scale application. These filters can be used to treat oil field produced water, refinery wastewater, and other types of wastewater.

Compared to many of the complex energy solutions introduced at this year’s OTC conference, the walnut shell filter seemed a remarkably simple idea. I think this is part of its appeal. These filters will play a big role in helping offshore rigs meet new and more stringent water quality regulations. Best of all, a special backwash cycle can safely remove the contaminants from the walnut shell filter media, allowing the walnuts to be used again and again.

It’s nice to see a simple idea that actually works. Now if only it was this easy to find the oil in the first place…