On parle de biotechnologies dès lors que l’on utilise des micro-organismes pour intervenir dans le processus de transformation de la matière. Notre métier : les biotechnologies appliquées à l’environnement. Depuis 1988, HTS BIO conçoit et fabrique en France des produits et solutions écologiques à la pointe de l’innovation pour le nettoyage et l’entretien, la bioremédiation (dépollution biologique), l’agriculture, l’aquaculture, le traitement des eaux et les plans d’eau.
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pH tells us about the acidity of a solution. But is that all?


What is pH?

Meaning “potential of hydrogen,” pH explicitly expresses the concentration of hydrogen ions, H3O+ in a solution. Basically, the lower a pH value is, the higher the H3O+ concentration. The value indicates the acidity of an aqueous solution on a scale from 0 to 14 by measuring the ratio of H3O+ ions (what renders a solution acidic) to HO- ions (what renders a solution basic).

–          0 represents the most acidic solution

–          14 represents the most basic solution

–          7 is defined as neutral: the concentration of H3O+ (what renders a solution acidic) and HO- ions (what renders a solution basic) is equal in pure water.

Every day, we encounter items of pH values between 4 and 9: but handling extreme pH solutions requires special equipment. We often find them in agriculture and industrial fields, but we avoid them (and leave them up to the pros in lab-coats!)

Super-concentrated, both acids and basics have destructive powers. Quicklime, for example: A superbase (a solution with a pH value over 12) is used in aquaculture to sanitize the bottoms of tanks between cycles because it radically eliminates germs.

Good to know: solutions with pH values below 5 and above 9 require so-called extreme environments to live, existing in such environments as your stomach for example (which is, if we remember from previous publications, home to billions of our “bacteria friends”) and underwater hot springs also known as “black smokers”.



pH is measured in moles (you will see, it’s easy!)

What is a mole? We are not talking about furry kind…

You know that:

–          in a ream of paper, we can count 500 sheets, regardless of the quality, thickness, or size (US letter, ledger, etc.)

–          on a handball team, we can count 7 players, regardless of their weight or size,

–          in a quartet, we can count 4 musicians, regardless of their instrument, gender, or looks.

Much in the same way, in one mole, we can count 6,022 × 1023 chemical entities (atoms, molecules, etc.) regardless of their nature: big or small, simple or complex.

Numerically (astronomically) speaking: 1 mole = 6 022 000 000 000 000 000 000 000 atoms or molecules! (1)

A mole is then one universal unit of measurement for atoms and molecules, but we can certainly use this to count whatever else: stars, grains of sand, all the while never minding their physical makeup, (size, density, etc.).

Easy, right?



The pH scale is logarithmic (no, don’t leave yet, we are going to explain!)

On this scale:

–          1 point lower on the pH scale = a concentration 10 x higher in H3O+ ions (making a solution more acidic),

–          2 points = 100 x lower,

–          3 points = 1000 x lower,

–          Etc.

And vice-versa.

pH value has a power of negative 10. It is the number of times by which a mole of H3O+ ions has been divided by 10 to reach a certain level of concentration:

–          If a solution has a pH of 2, it has a concentration of 1/100th (or 10-2) of H3O+ ionic moles per liter. Here, the mole is divided 2 times by 10.

–          If a solution has a pH of 3, it has a concentration of 1/1000th (or 10-3) of H3O+ ionic moles per liter. In this case, the mole is divided 3 times by 10 and the solution is less acidic.

We can clearly see the difference: the solution with a pH of 2 has an H3O+ ionic concentration 10 times higher than the solution with a pH of 3, and is therefore more acidic.



How does this relate to real life?

Let us come back down to earth and take on hydrangeas for example. Ah, how poetical of science: the color of a flowers depends on the soil’s pH value! More acidic soil grows bluer flowers, and more basic soil brings pinks out.

Another example — without going into all the chemical details —: the (oxygen-charged) blood running through our arteries has a higher pH (less acidic) than the blood in our veins (more acidic) that are loaded in CO2.

If you have ever owned a swimming pool or aquarium, you know the importance of maintaining a neutral pH level. To measure it, you would use a digital pH meter or colorimetric test: thus ensues a chain of chemical reactions that result in colors changes which indicate a pool’s level of acidity.

Gardening and horticulture fanatics already know: all soil is not created equal. Different plants require different soil. Particular plants like rhododendrons or camellias thrive in acidic soil, and others like scrubs are better off in basic (chalky) soil. Depending on your setup, you can regulate a soil’s pH value, correcting it with additives such as fertilizer, peat moss, compost, etc.



pH in the ECOWAY® range

Some select products in the ECOWAY® range claim to have the descaling powers. For that to be so, a product must have highly-concentrated acidity (a low pH). Let’s have a look:

–          pH of 2.5 in NAT’SAN, lime scale remover, bathroom cleaner,

–          pH of 2.2 in 4D-SCALE, descaling, disinfecting and deodorizing gel,

–          Etc.

Whereas degreasing cleaners have a higher pH value (more basic):

–          pH of 8,5 in MULTI’ORGINAL, multipurpose degreasing cleaner,

–          pH of 9 in ALIWAY, Food contact surface degreaser and cleaner,

–          Etc.

Additionally, if we compare the pH values of 2 window and smooth surface cleaners, we’ll see:

–          WINWAY has a pH of 4 (low, so acidic): this product claims to have anti-lime scale properties and is not recommended for use on screens. Why? Strong acidity can damage fragile surfaces. Hence the importance of following product protocols.

–          NAT’SURF has a pH of 8 (higher, so basic): it’s not strong enough to have descaling powers and is safe for use on all surfaces.

Crystal clear, right?



pH in aquaculture and agricultural biotreatments

pH plays an important role in our Biotreatment product ranges for agriculture and aquaculture, VIVA® and HYGEFAC®: by slightly raising and stabilizing pH on a microbial scale, we create an environment that makes it easier for micro-organisms to breakdown matter.


(1) Why is the mole defined as being equal to the the number of atoms in 12g of carbon 12 (and therefore one mole of carbon 12 = 12g? Well, that’s a topic for another post…


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