42nd BImSchV for operators of open cooling water systems has been in force since September 2017. This BImSchV regulates the obligations for plant operators and defines the requirements for the construction, operation and monitoring of more than 30,000 plants. As a result, the risks from increased legionella concentrations in evaporative cooling systems, cooling towers and wet separators are legally recognised. In addition to industrial companies, hospitals, office buildings, hotels and computer centres are also affected if they have evaporative cooling systems.
The open water circulation systems and dead zones in plants offer ideal conditions for the growth of all bacteria. Aerosols containing legionella pose special dangers. Legionella are bacteria that can cause severe pneumonia in humans by inhalation, which can be severe to fatal. AWAS has been active in this market for 20 years. The problem of contamination is similar to that of cooling lubricant emulsions. AWAS has developed a concept of waste water treatment for both topics, which can treat the waste water of bacteria, Legionella etc. without biocides.
The innovative wastewater treatment technology of AWAS makes a significant contribution - with low-maintenance systems based on natural biological-physical processes.
In the EU research programme CEGRIS we have used the following combined technologies for cooling lubricant and cooling water circuits:
a) The regulation and reduction of all bacteria, as well as improved dirt sedimentation with photon transmitters in full flow
b) Phase separation with Galaxie Vortex Separator in full stream
c) Optimization by bypass (5-10 %) with separator and nano flotation
d) Enrichment of the water with oxygen by installation of a mixer - oloids in the collection basin for better mixing/avoidance of dead spaces.
The tests carried out as part of the research programme have shown that the technology used can reduce the total bacterial count by more than 99.9 %. The free light materials and light liquids are also 100% retained. Furthermore, full sedimentation of such impurities as settleable substances has been achieved. This waste water from cooling water circuits is professionally collected and purified before the water can be returned to the water circuit.
Advantages of the AWAS combination technology: