How Wetlands Can Help Clean Water in Small Towns
The Challenge
Wetlands offer a cheap and easy method to clean water in small towns. However, most studies overlook how these wetlands perform when water flow varies throughout the day. This is crucial because water usage in small towns isn't constant.
The Study
In a recent study, three types of wetlands were tested, each filled with different materials:
- Zeolite and woodchips
- Gravel and woodchips
- Just woodchips
The study evaluated how well these wetlands cleaned water when different amounts of water were added at different times of the day.
Key Findings
- Organic Matter and Tiny Solid Particles: The wetlands effectively removed these from the water.
- Nitrogen Removal: The amount of nitrogen removed depended on the type of wetland and the size of the water dose.
- Zeolite-Woodchip Wetlands: Removed the most nitrogen, regardless of dose size.
Other Two Types: Removed less nitrogen as the dose size increased.
Wetland Setup: The design, which included both free-draining and saturated layers, aided in nitrogen removal.
- Woodchip-Only Wetlands: The smallest dose size led to the most nitrogen removal.
- Zeolite-Woodchip Wetlands: The largest dose size still removed a significant amount of nitrogen.
Potential Drawbacks
Larger doses led to an increase in bacteria and phosphorus in the water. This occurred because the water moved through the wetlands too quickly.
