| Treatment Wetlands | |||
|---|---|---|---|
| Overview | How Treatment Wetlands Work | ||
| Effectiveness and Problems | Glossary, Links, and References | ||
What are the Treatment Wetlands?
The Treatment Wetlands (Figure 1) are fully overgrown marsh cells consisting of mainly Cattails and Hardstem Bulrush. The dense canopy and biological processes aid in the overall treatment of the water flowing in from the oxidation ponds. The system requires a lower capital investment, energy demands, and labor requirements compared to other wastewater treatment processes (Gearheart, Wilbur, Williams, Hull, 1982).
Figure 1. Arcata's Treatment Wetlands
What is the purpose of the Treatment Marsh?
- As a part of Secondary Treatment, the purpose of the treatment marsh is to
remove:
- Algae, a suspended solid, from the oxidation pond effluent before it is pumped to the chlorine contact basin (Couch, 2008).
- Biological Oxygen Demand (BOD) (Gearheart, Williams, Hollbrook, Ives, 1986)
- Non-Filterable Residue (NFR)
- Ammonia
- Total and fecal coliform
- Nutrients such as nitrogen and phosphorus
A number of biological and physical processes contribute to how the Treatment Wetlands work.