The general Europe Standards for Conditions and Definition of the grades of pollution, purification and methods of measurements in the field of small and middle waste water treatment installations are items of the DIN EN 12556-3, DIN EN 1899-1 and 1899-2 as legal framework, which is to apply in each member country of the European union.
Grade of Purification
Depending on the respectiv ecological demands in different areas as industrial-, recreation-, nature reserve ore water protection areas, water treatment installations have to perform the reduction or elimination of different organic and inorganic substanzes.
C - Carbon elimination
In areas with out special ecological demands, relating to the local requirements of local authorities
D - Denitrification
In ecologic sensitive and water protection areas with high requirements to the nitrogen content
N - Nitrification
For sensitive soil and water conditions
+H - Additional hygienic purification
When discharging into swimming waters or further technical utilisation of the cleaned waste water
+P - Additional Phosphate Elimination
In ecologic sensitive and water protection areas with the requirement of complete reduction of nutrients
In the respective national and regional requirements inform the local authorities
Important quality parameter of the waste water
COD - Chemical oxygen demand
is a measure for all in the water included organic and inorganic substances that can bee oxidized. It specifies the quantity of Oxygen in mg/l which would bee need for their oxidation
BOD - Biochemical oxygen demand
specify the quantity of oxygen in mg/l, which is necessary for the biological elimination of the organic substances (carbohydrates, greases, proteins and their chemical components) under defined conditions in a defined length of time excluding the oxygen demand of the Ammonium nitrification. Usually will bee applied the BOD5, that measure the quantity of oxygen that the micro organisms need in a water temperature of 20 °C in a period of 5 Days. In this results the quantity of the organic waste water content which is to reduce.
NH4 - Ammonium-Cation
and its compounds result from the biological degradation of proteins. By nitrification, the bacterial oxidation of ammonium, it will bee transformed gradual to nitrites (NO2) and nitrates (NO3). Thies substances are a necessary vegetable nutrients and with this a useful component in the ecologic recycling process
Inhapitant equivalence - p.e.
Define the quantity of organic waste water content produced by 1 Person in 1 day
1 p.e. corresponds
BOD5: 60 g /d
N: 11 g/d#
The water consumption, and with this, the quantity of waste water that 1 person produce in 1 day,
is a important parameter for the dimensioning of a waste water treatment installation. This value fluctuates strongly depending of the different regional and local conditions and habits.
As a basic average value in central Europe amounts 120 - 150 l/d.
To guaranty stabile waste water treatment results, the respective parameters have to bee verified in each single case of application.