1. Biochar Properties Water Absorption Micropore Sponge
Immense internal capacity
Soil porosity & permeability
Gradual release
Keeps soil wetter
Keeps microbiology active in drought
Tar & Resin Residues
Black specks, shiny in sunlight
Oily hydrocarbons
Initially hydrophobic
VOC and PAH: multi-ring carbons
Carbon-ring candy: feast for microbes
Soil Water Filtration
Absorption, followed by adsorption
Water quality in watersheds
Role of microbes in filtration and Soil Food Web
Sand Biofilter
+ Biochar

2. charcoal will adsorb gases
Biochar Properties
Ion Adsorption
Adsorb
Adsorb  (verb)  Physical Chemistry to gather on a surface in a condensed layer
Adsorb: d
(gas, liquid, or dissolved solid)
charcoal will adsorb gases
Adhesion of atoms, ions or molecules
from a gas, liquid or dissolved solid
to create a film on a surface of the adsorbent.
This differs from Absorption,
where a fluid permeates or is dissolved by or into a solid,
such as: water is absorbed by a sponge.
Adsorption is a surface process.
Absorption involves the whole volume of material.
Sorption applies to both processes.
Desorption is the reverse of adsorption,
and is thus a surface phenomenon.

3. H2O + + Biochar Properties Ion Adsorption water − −
Adsorb  (verb)  Physical Chemistry to gather on a surface in a condensed layer:
Typically, Adsorption is an electric attraction between atoms and molecules
quite different from Absorption
Ion is an atom with an electric charge
Cations
Cations are made when atoms give up one or more electrons
and thus have a positive (+) charge
H2O
Anions
Anions form when atoms gain one or more electrons
and thus have a negative (−) charge
water
Each element has different attraction for electrons
molecule
Hydrogen has a weak attraction for electrons
Oxygen has a strong attraction for electrons
In a water molecule, Hydrogen yields its electron
Oxygen attracts two electrons
Thus, a water molecule has an electric polarity, + +
Hydrogens each have a slight positive (+) charge − −
Oxygen becomes a mild negative (−) charge
Cations (+)
Anions (−)
Sodium, Potassium, Calcium, Magnesium
Phosphorus, Sulfur, Chlorine
most Trace Elements
Nitrogen, Boron, Iodine

4. H2O + + + DNA + Biochar Properties Ion Adsorption = = water − − − −
Adsorb  (verb)  Physical Chemistry to gather on a surface in a condensed layer:
Typically, Adsorption is an electric attraction between atoms and molecules
Ion is an atom with an electric charge
An H2O water molecule is not an Ion,
because it has no net electric charge +
H2O
protons + =
− electrons =
balance
But water molecules do have electric polarity,
water
and attract ions and other polarized molecules
molecule −
with opposite electric charge,
hydrogen
bond
including other water molecules. − + + − −
A useful example of attraction between polarized molecules
is the “hydrogen bond” between adjacent water molecules.
Amino
Acid
Amino
Acid
Hydrogen bonds make water “wet” and stick to itself.
DNA +
This slight electric attraction makes water a great solvent,
and gives water structure as a “liquid crystal.”
DeoxyriboNucleic Acid
Cations (+)
Three Hydrogen “bonds”
between Amino Acids on opposite sides
of DNA’s twin spirals
hold this complex molecule together
Anions (−)
Sodium, Potassium, Calcium, Magnesium
Phosphorus, Sulfur, Chlorine
most Trace Elements
Nitrogen, Boron, Iodine

5. + + + + + + + Biochar Properties Ion Adsorption − − − − − − − − − − −
Adsorb  (verb)  Physical Chemistry to gather on a surface in a condensed layer:
Typically, Adsorption is an electric attraction between atoms and molecules
This attraction quickly gets much more complex with biocarbon molecules
Humus and biochar molecules − − −
consist of tens, hundreds, − − −
even thousands of carbons. − − − − −
These are very large molecules − − −
with multiple carbon rings, + − − + − −
Nitrogens
and Oxygens, − −
and embedded mineral Ions.
Each ring, Nitrogen, Oxygen, and +
mineral Ion is an electric charge +
Humic substance + −
Humic substance
on the surface of the molecule.
C27O20Hx −
C72O33N4Hx+ 2R +
Each charge site will attract and
very low molecular weight +
low molecular weight
adsorb Ions of opposite polarity.
Cations (+)
Anions (−)
Sodium, Potassium, Calcium, Magnesium
Phosphorus, Sulfur, Chlorine
most Trace Elements
Nitrogen, Boron, Iodine

6. + + + + + + + Biochar Properties Ion Adsorption − − − − − − − − − − −
Adsorb  (verb)  Physical Chemistry to gather on a surface in a condensed layer:
Typically, Adsorption is an electric attraction between atoms and molecules
This attraction quickly gets much more complex with biocarbon molecules
Biochar micropores provide a huge −
internal Ion adsorption capacity, − − − −
hundreds, even thousands times − − −
greater than other soil substances. − − − − −
Thus, charcoal is an ideal media + −
to filter and purify water. − − + − − − −
Biochar’s advantage is to adsorb
both Cations (+)
and Anions (−),
Including Nitrogen & Phosphorus.
Nitrogen
Phosphorus + +
Simple mineral ions + −
Humic substance −
C72O33N4Hx+ 2R +
Complex organic ions +
low molecular weight
Cations (+)
Anions (−)
Sodium, Potassium, Calcium, Magnesium
Phosphorus, Sulfur, Chlorine
Phosphorus, Sulfur, Chlorine
most Trace Elements
Nitrogen, Boron, Iodine
Nitrogen, Boron, Iodine

7. Cation Exchange Capacity Anion Exchange Capacity
Biochar Properties
Ion Adsorption
Adsorb  (verb)  Physical Chemistry to gather on a surface in a condensed layer:
Ions in the circulating solution are adsorbed by char particles
Charcoal
Cations & Anions are attracted to electric charges on char particles
and gradually removed from the soil-water solution.
This electric attraction is like water’s hydrogen bond +
Adsorped ions are loosely held, not bonded
adsorped
pump
Nutrients
Ions are slowly caught and held by char's electric charges
Slowly, the ion concentration in solution will drop
Charcoal adsorption removes and neutralizes toxic chemicals
Water
Adsorption also holds nutrient ions safely in soil
Miracle
Gro
fertilizer
Hydrometer
Ion exchanges with microbes & roots:
H+ traded for nutrient ions
concentrated
weak
Nutrient
Solution
Pure water run thru all day barely affects ion concentrations,
because ions are adsorped onto and into char particles, and held.
Microbes can free elements chemically bound in soil and rocks
by an active digestive process different from exchanging ions.
Cation Exchange Capacity
Cations (+)
Anions (−)
Anion Exchange Capacity
Sodium, Potassium, Calcium, Magnesium
Phosphorus, Sulfur, Chlorine
most Trace Elements
Nitrogen, Boron, Iodine