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Newsletter and Technical Publications
<Planning and Management of Lakes and Reservoirs:
An Integrated Approach to Eutrophication
Abridged Version- A Student's Guide>
Selection of a Proper Solution to Defined Wastewater Problems
The selection of the best solution to the municipal wastewater problem
requires quantitative estimation of the relationship between the quality of the
wastewater and the receiving water. The pertinent question is how much
phosphorus, nitrogen, and BOD5 can be permitted in the treated wastewater to
ensure acceptable water quality for the receiving water body. Figure 1 and 2
present two decision trees that may facilitate the selection of a proper
solution.
| Table 2. Treatment processes for the removal
of phosphorus by cost-moderate methods |
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| Method |
Epected efficiency |
|
| Precipitation in WSPs |
50-75% |
| Harvest of wetlands (2-4 times/year) |
40-180kg P/ha |
| Application of soil with high adsorption capacity for
phosphorus |
100-300kg P/ha |
| Direct precipitation in conjunction with mechanical-biological
treatment |
75-95% |
|
| Table 3. Treatment processes for the removal
of nitrogen by cost-moderate methods |
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| Method |
Expected efficiency |
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| Denitrification in a constructed wetland |
1,000-2,500 kg N/ha* |
| Harvest of wetlands (2-4 times/year) |
250-1,200 kg N/ha ** |
| Nitrification and denitrification |
75-90% |
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* based mostly on experience from temperate climate
(summer conditions).
** based on the concentration of nitrogen in the common wetland plants; number
of harvests is dependent on climate |
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