Quantification of carbon dioxide sequestration by duckweed: promoting circular economy in tilapia aquaculture

The global demand for fish is predicted to double by 2050. Tilapia is a commonly farmed species because of its nature, which produces high yields. However, high-density farming can lead to increased greenhouse gas emissions due to respiration and poor water quality. Introducing a circular economy in the farming line can greatly reduce emissions, contributing to a more sustainable aqua environment. CO2 can be sequestered using biological methods such as photosynthesis by macrophytes like duckweed, which are fast-growing plants. Duckweed, with its leaf-stem structure and roots, can take up more CO2 than other plants. Ambient conditions between 20°C to 30°C are ideal for their growth. Our study focuses on investigating the effectiveness of Lemna minor duckweed, which is used to treat tilapia water in sequestering CO2 from the atmosphere. A laboratory-scale duckweed pond was built using a 55 L basin. The CO2 flux was measured using the static chamber method. A transparent chamber was placed in the middle of the basin. CO2 concentration in the chamber was collected periodically under constant luminosity and temperature.