Diatoms and Diatomaceous Earth: Beer Filtration for What Ales You

      Diatomite is a generally light-colored sedimentary rock that is  composed mostly of the siliceous skeletons of diatoms. It is an extremely porous rock with a fine particle size and a low specific gravity. These properties make it useful as a filter media, especially for beer and wine. It is also used as an absorbent, and as a lightweight filler for paint and plastics. When diatomite is crushed into a very fine powder, it is called diatomaceous earth.

      Diatoms are members of a large, diverse group of algae that drift in the waters of both oceans and lakes. A few types of diatoms live on the bottom of these water bodies and in soils. Most diatoms are microscopic, although a few species are up to two (2) mm in length. As a group, diatoms are unique because they are single-celled organisms that produce an external cell wall composed of silica, called a frustule. These frustules are very thin and have a delicate structure.

      Most diatoms are photosynthetic and live in water less than thirty (30) feet deep, where sunlight can penetrate. Diatoms are prolific and are responsible for producing nearly half of the organic mass in the world’s oceans. Their abundance and tiny size places them at the base of the marine food chain. We have discussed the strength and Fibonacci ordering of diatoms before here at PEOTS.

     After diatoms die ("die, atoms, die!"-- sorry, I couldn't resist) their siliceous frustules sink. In some areas, the frustules are not incorporated into the bottom sediment because they dissolve as they sink or dissolve while on the sediment surface. If the sediment is composed of over 30% diatom frustules by weight, it is called diatomaceous ooze or siliceous ooze.

      Of course, all this ooze discussion leads to a talk of diatomaceous ooze filtering your booze. Freshwater ooze or earth must be used unless you like your booze salty (yuck for me!).    Diatomite from saltwater sources can contain salts that can produce objectionable or toxic effects. Although some beer crafters are, indeed, using salt in the brewing process. Enjoy the beer, skip the pretzels? Have a little diatomaceous ooze with your booze? Woe is mead?

 

     The four main uses of diatomite in the United States during 2019 were filtration (50%), light aggregate (30%), fillers (15%), and absorbents (5%).

      Diatomaceous earth is used as a lightweight, inert filler in some manufactured products. It is added to paint as a whitening agent and extender. Diatomite is added to plastics as a lightweight filler. 

     If dry diatomaceous earth is placed on a liquid spill, it can absorb and hold an amount of liquid equivalent to its own weight. This absorption facilitates containment, cleanup, and removal. Capillary action of liquids into diatomaceous earth is enhanced by its small particle size, high surface area, and its high porosity.

       These same properties make diatomaceous earth able to absorb skin oils when used in cosmetics and facial masks. Diatomaceous earth is an absorbent ingredient of some kitty litters. It is also used as a soil treatment to absorb and hold water.

     Diatomaceous earth is used as a mild abrasive in some toothpastes, facial scrubs, and metal polishes. Its silica particles are small, friable, have a high surface area, and are angular in shape. These are properties that help it perform well as a mild abrasive.

     Diatomaceous earth is used as a growing medium in hydroponic gardens. It is inert, holds water, and has a porosity that allows the soil to breathe. To help grain and other seeds from sticking together and remain dry, they are dusted with diatomaceous earth.

     The cost of diatomite depends on its quality, how it will be used, and the preparation effort that has been invested by the supplier. The cost of diatomite straight from the mine without processing for use in concrete starts at about $7/ton. Diatomite from high-grade deposits that has been crushed, sized, and sieved for use in cosmetics, art supplies, & DNA extraction markets can cost more than $400/ton.

     The extraordinary intricacy of diatoms in Scanning Electron Micrographs shown throughout this post is astounding. Do you have a favorite?

Hoping you are all well in this weirdest of times,

Steph

P.S. Begone, M a r c h, oh longest of months this year.

The Universe Truly IS in a Grain of Sand

          You may have noticed I've been a bit sand-obsessed since my trip to Great Sand Dunes National Park in Colorado in October. Discovering these individual sand grain images magnified 250 times has blown in a fresh look at sand. The sea urchin spines in the right part of the image are particularly striking in this calcium carbonate-rich sand:

      The three-pronged sponge spicule in this image from a Maui beach is but one sand grain; "sand" is defined as a size of sedimentary particle ranging from 1/16 to 2 mm, rather than composition (I.e., quartz).

     Sand grains may also be glacially deposited as these grains of garnet, agate, epidote, quartz, magnetite, and hematite, in Lake Winnibigoshish, WI.

      Sand grains of gypsum from the White Sands area in New Mexico, are some of the most uniform in color, though they are quite soft (hardness of 2 on Moh's Hardness Scale):

      And the hydraulic fracturing sands in western and southern Wisconsin are quite uniform, hard (hardness of 7 on Moh's Hardness Scale) quartz grains:

      "Puffy stars," calcium carbonate forams on Okinawa beaches are quite uniform in size and have a distinctive shape:

     Note the rounded, smooth shells, foraminifera, piece of coral, and the volcanic fragment (in the lower right.)

     Check out these colorful, luminescent, rounded bits of foraminifera, shells, and quartz in this sand mix.

And, to tie things back to where we started this week, here are rounded, smoothed, sea urchin sand fragments from Hawai'ian sand; these are essentially cross sections of the long, green spines seen in the first image.

Take this all with a grain of calcium car- bonate or quartz or gypsum salt or. . .

Steph

There are GLOSTA lovers in Colorado!