Page 247 - Industrial Wastewater Treatment, Recycling and Reuse

Novel Technologies for the Elimination of Pollutants 221

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70
COD Well degradable 0.75
25
COD and BOD 5 concentration −[g/L] 20 50 −[mg/L] AOX concentration AOX BOD 0.5 BOD Biodegradability COD
60

COD
40
15
30
10
20
5
10
BOD 5 Hardly degradable 0.25
0 0 0
30 100 150 200
Temperature (°C)
Figure 5.7 Typical behavior of pollutants in the LOPROX process.

The LOPROX process has proven ideal for breaking down organic hal-
ogen compounds adsorbable organically bound halogens (AOX). In most
cases, the oxidation of toxic wastewater also results in a decrease of fish,
daphnia, and bacteria toxicity.
Aliphatic compounds, which are poorly biodegradable and have to be
removed from wastewater, include amino compounds. Wet oxidation usu-
ally only splits off the amino groups, which in itself results in a considerable
improvement in the biodegradability of the wastewater.
It is particularly clear at this point that the catalytic wet oxidation process
developed by Bayer is especially suitable for treating effluent streams before
they enter a biological treatment plant.
The question about what degradation rates can be achieved in individual
cases using a combination of the LOPROX process and biological treatment
processes will have to be answered in a laboratory and pilot plant trial.

5.2.1 Examples of the Use of the Loprox Process
(Holzer et al., 1992)
The new wastewater treatment process has already proven successful in prac-
tical operation. At Bayer’s Leverkusen factory, four plants are in operation to
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pretreat effluent streams of 6–60 m /h. Since 1982 Bayer has been gathering
considerable expertise in this process.