Page 904

904 MINERALS YEARBOOK, 1972 
processes used in the experiments were physical and chemical as well as biological
in nature, and the major emphasis was placed upon the removal of phosphorus,
which has become a major pollutant in recent years. The studies also showed
that various types of peat can be used in such filter systems and that the
systems are not only efficient, but they can be operated at relatively high
application rates. 
 Additional research work on peat at the University of Sherbrooke,4 evaluated
the use of peat as an absorbing agent for the removal of coloring matter
from the effluent of a dye house at a textile plant. Many of the dyes used
by the textile industry are nonbiodegradable, and their removal in an economic
manner remains a problem. Adsorption of these dyes with activated carbon
is one of the most promisi-ag of the processes -proposed or used, but activated
carbon is a relatively expensive material for this use. The study concluded
that sphagnum peat moss of the blond type has good absorption capacity for
basic dyes, but this capacity decreases for dyes that are acidic. Also, with
an actual effluent from a dye house, competitive adsorption with other polluting
material decreased the efficiency of peat moss in reducing the concentration
of dyestuff. 
 Laboratory tests,5 confirmed partly on a pilot and technical scale, in Raciborz,
Poland, show that peat can be used effectively as a basic raw -material to
obtain a 
number of activated carbons with good physical, chemical, and adsorption
properties. Such carbons may be produced, both by gas activation in which
peat is treated with steam, carbon dioxide, or air at 700° to 1,000°C,
or by chemical activation, based upon the impregnation of peat with chemical
compounds. The chemical activation method uses chemicals such as zinc chloride
or -phosphoric acid to impregnate the peat, after which it is carbonized
and activated at 600° to 700°C. Activated carbons with a high proportion
of micropores are generally used for gas and vapor adsorption, carbons with
medium-sized pores are used for catalytic and special applications, and macroporous
carbons serve as decolorizing and medicinal agents. Peat has been used for
the production of all of the aforementioned types of activated carbon as
a replacement raw material for wood charcoal, which -is more costly and,
in Poland, becoming increasingly less available because of a timber deficit.
Baltic-type peat from the Szczencin and Lebork regions of Poland, which is
characteristically low in ash content, is especially amenable to activated
carbon production. 
 4Dufort, Jean, and Maurice Ruel. Peat Moss As An Adsorbing Agent for the
Removal of coloring Matter. Proc. 4th Internat. Peat Cong., Otaniemi, Finland,
June 25—30, 1972, v. 4, pp. 
299—310. 
 ' Fica, Jozef. Investigations on Peat Utilization for the Production of
Activated Carbon. Proc. 4th Internat. Peat Cong., Otaniemi, Finland, June
25—30, 1972, v. 4, pp. 185—196.