Water remediation
The term water remediation is understood to mean the improvement of water quality and the restoration of the ecological balance of standing or flowing water. With regard to quality, pollution and oxygen content , running waters are assessed according to the saprobic system , while stagnant waters are assessed according to the trophic system .
causes
It is mostly long-term disturbances of the ecological equilibrium that lead to a deterioration in the water quality and even to the overturning of the water body. Years of discharge of insufficiently treated wastewater , but also the introduction of phosphates , nitrates , nitrogen and pesticides via the groundwater gradually lead to excessive nutrient enrichment ( eutrophication ), as a result of which organic biomass can no longer be broken down by aerobic bacteria due to a lack of oxygen . Digested sludge is created .
In stagnant waters, this problem is exacerbated by global warming : in autumn and spring there is no longer sufficient water circulation between the oxygen-rich surface water and the bottom of the water body.
Remedial measures
Many factors that have disturbed the water ecosystem have been under control for several years. Measures that should be mentioned here are, for example, the elimination of phosphates in detergents and better treatment of waste water. However, simply eliminating the cause can not necessarily bring an ecosystem that has been damaged over many years back into balance. Various additional measures are therefore undertaken to remediate damaged waters:
- Reduction of biomass
The removal of plants, leaves, algae and the mowing of aquatic and underwater plants reduce the biomass in the body of water.
- Fishing for excess stocks
The existing stocks of aquatic life due to the oversupply of food are reduced.
- Biomanipulation
The biomanipulation attempts by controlling the food chain , for example, with the trimming of top predators such as pike eutrophic to rehabilitate lakes.
- Desludging of the soil
Dead biomass, digested sludge and sediments are removed from the bottom of the water.
- Purification of the water by settling
The solid parts of the sediment are separated from the water by sedimentation, the purified water is added back to the body of water.
- Introduction of oxygen
Oxygen enrichment of the water and the introduction of oxygen into the soil to promote the self-cleaning of the water by aerobic bacteria.
Rehabilitation of Lake Constance
Ultimately, the aim of all measures is to restore the ecological balance of the water body and its ability to clean itself in the long term. Lake Constance is an outstanding example of successful water remediation, the remediation of which began in the 1970s when the lake threatened to tip over and whose complete recovery took almost 40 years.
literature
- Jürg Bloesch: Revitalization of rivers . In: Building Biology 02/2000, ISSN 1420-1895
- Oliver Grimm, Dietrich Brochardt: Water-related requirements for mixed water discharges . In: Wasser 02/2000, ISSN 1436-9095
- Measures for near-natural water stabilization . ISBN 3-89554-058-7
- Winfried Lampert : Biomanipulation - a new opportunity for lake restoration? In: Biology in Our Time . Volume 13 Number 3, 2005, pp. 79-86. Wiley-VCH Verlag , Wiesbaden, ISSN 0045-205X .
- Jürgen Mathes, Ilona Korcyynski: The rehabilitation and restoration program of the lakes in Mecklenburg-Western Pomerania . In: WLB 05/2000, ISSN 0938-8303
- Paul Seitz: Vegetation models for near-natural water purification . In: Stadt und Grün 49/2000, ISSN 0948-9770
- Peter Schmidt: Water remediation . Fraunhofer Irb, Stuttgart, ISBN 3-8167-3679-3
See also
Individual evidence
- ↑ Significance of the temperature for full circulation ( memento of the original dated September 11, 2008 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Development of river quality in Baden-Württemberg (2002) ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF)
- ↑ Lake Constance - a prime example of water remediation 3sat
