HygienisationHygienisation of wastewater has become a central role of wastewater treatment, since nutrient removal has been mastered in most treatment plants. Especially areas where treated wastewater is released into natural bathing areas, the pathogen removal is of high importance.
Instead of the costly methods of precipitation and filtration, constructed wetlands are an effective alternative. The natural pathogen removal process is mainly achieved by adsorption and breakdown by protozoa and other organisms.
Very effective natural hygienisation has lately been achieved by vertical constructed wetlands with sand as substrate and a height of 1m.
Water is the source of all life. We need it
to drink, to prepare food, for washing and cleaning, but also
for industrial and food production. Water is, in short,
irreplaceable. Yet clean water is becoming an increasingly
rare resource in many parts of the world.
The largest consumer of water is agriculture. Around 70 % of the water used by humans – in some developing countries as high as 90 % - is used for irrigation, with fatal consequences in some cases. Faced with a lack of alternatives, farmers often use waste water for irrigation, which leads to health risks, in particular diarrhoea.
In the course of laboratory research and tests under practical conditions carried out over several years in collaboration with partners from science and industry, UFZ scientists have succeeded in demonstrating that waste water can be made hygienic for irrigation purposes using simple technology. This means that it is possible to reap the benefits of waste water recycling whilst meeting hygiene requirements.
After a general introduction, the following sequences provide (with text, but no sound) about various aspects of constructed wetlands: What effect do wetland hydraulics have on removal efficiencies? What is the difference between horizontal and vertical flow filters? What type of plant is suitable for treating waste water and what fundamental soil processes do constructed wetlands use to purify waste water?
CAST creativ-fernseh GmbH & Co. KG, Dresden
Conceptual design and editorial work:
Dr. Oliver Bederski | Umwelt- und Biotechnologisches Zentrum, UFZ
Dr. Peter Kuschk | Department Bioremediation, UFZ
Doris Böhme und Andreas Staak | Public Relations, UFZ
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