When peat is excavated from bogs, it must be purified
by separating it from other components. One major
component is cotton grass fibre (Fig. 1). Sheathed cotton
sedge, cotton grass (Eriophorum vaginatum) is a
common plant in peat bogs. Cotton grass fibre is formed
when the plant dies and partly degrades detaching the plant fibres in a slatted form. Due to the acidic and
anaerobic nature of the bog, the stem and root of the
plant do not decompose totally, but deteriorate into fibre.
This fibre is a by-product of peat-excavation operations.
The fibre is normally separated from piled peat
using a rotary screen. A small portion of this separated
fibre is used in the textile industry, but most goes waste.
We compared its oil- and water-absorption capacities
with a synthetic, commercial sorbent designed to absorb
oil.
We tested several types of cotton grass fibres and
mats. We measured their absorption capacities and rates
and selected two sorbents for further testing. We measured
the sorbents ability to absorb oil from the surface
of water, the amount of saturation, and how much oil
was left on the surface of the water. We determined
the contact angle between the fabric and a drop of oil
or water, as well as the fabrics ability to absorb heavy
fuel oil from stones, representing a cleaning operation
in a case when oil has reached a shore after a spill at sea.