What is one benefit of duckweed in a facultative lagoon?

Duckweed is a floating aquatic plant that plays a vital role in the biological processes of facultative lagoons, which are engineered systems for wastewater treatment. One of the principal benefits of duckweed in these environments is its capacity to absorb nutrients, particularly phosphorus and nitrogen.

As duckweed thrives on these nutrients, it effectively reduces their concentration in the water. This is beneficial not only for maintaining water quality but also for controlling algal blooms that can result from high nutrient levels. The uptake of nitrogen and phosphorus by duckweed helps to prevent eutrophication, which can lead to deteriorated water conditions and the growth of harmful algae.

In addition to nutrient removal, species like duckweed contribute to the overall health of the lagoon by providing a source of organic matter when they die and decompose, further aiding in nutrient cycling. Their growth can also improve dissolved oxygen levels in the water, supporting other aquatic life.

Other options in the question present different aspects related to aquatic ecosystems, but the most significant contribution of duckweed in a facultative lagoon setting is its ability to remove nitrogen and phosphorus, thereby enhancing the efficiency of the wastewater treatment process.