The Treatment of Phenolic Wastes
HANS J. WURM,  Bauassessor
Division Director
Emschergenossenschaft
Essen, Germany
INTRODUCTION
Among the numerous contaminants of industrial wastes, phenols have particular ill effects in draining ditches and receiving waters. This is especially
true in those cases where tne water is to be used again or even to be prepared for
drinking water. In general, phenolic wastes contain -- besides phenols -- still
other substances such as ammonia, cyanides, sulfur compounds, pyridines, oils
etc. which also contribute essentially to the contamination of the receiving waters.
This paper, however, will be limited to a description of the various methods
to remove phenols from industrial wastes. Depending on the method applied,
some of the other contaminants are then eliminated, too.
The first question concerns the origin and the sources of phenolic wastes.
Even domestic wastes contain small quantities of phenols, as man excretes in his
urine about 30 mg/l phenol and p-cresol. The quantities of phenols in the industrial wastes, however, are much larger, especially in the wastewater from coal
refining plants and chemical works, i.e. gas works, coke-oven plants, lignite
low-temperature carbonization plants, benzene refining plants, hard coal pressure-gasification plants, tar distilling plants, mineral oil refineries, gas producer
plants and also the works producing synthetic phenols and cresols or processing
phenols to plastic materials, the so-called phenol plastics. The wastewaters of
all these plants and works, however, differ in quantity and type of phenols and
other contaminants as shown in Figure 1.
Among the manifold possibilities of treating phenolic wastes, I wish to describe now, as an example, the treatment of phenolic ammonia liquor from the
coke-oven plants in the Federal Republic of Germany.
The coke-oven plants and gas works of the Federal Republic of Germany produced in 1966 not less than about 65 million cu m of phenolic wastes with about
400 mg/l phenols. Most of these phenolic wastes came from the coal mining district in the Land Nordrhein-Westfalen, the region between the rivers Ruhr, Em-
scher and Lippe. In this region, Emschergenossenschaft and Lippeverband established quite a number of dephenolating plants on cokeries for the treatment of
phenolic ammonia liquor (Figure 2). In the 21 dephenolating plants of Emschergenossenschaft and Lippeverband which are today in operation, about 8000 tons of
phenols are recovered each year. This figure corresponds to about 68 per cent of
the phenols produced in the coke-oven plants in the Emscher area and to about 72
per cent of the phenols produced in the coke-oven plants of the Lippe area. (As
can be seen in Figure 3 the quantities of phenols extracted in these plants and thus
kept away from tne Rhine River are quite substantial, indeed).
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