Potential integration of wastewater treatment and natural pigment production by Phaeodactylum tricornutum: microalgal growth, nutrient removal, and fucoxanthin accumulation

The use of microalgae cultured in wastewater to produce high-value products has gained considerable attention. We studied the ability of the diatom Phaeodactylum tricornutum to remove nutrients from diluted swine wastewater (SW) and simultaneously produce fucoxanthin. The alga had the strongest capability to remove nutrients from the SW when the dilution ratio of SW to water was 1:1. Under this condition the removal efficiencies of total phosphorus (TP), total nitrogen (TN), and ammonia nitrogen (NH3-N) were 97.17 ± 0.14%, 92.02 ± 0.02%, and 98.42 ± 0.06%, respectively. The highest fucoxanthin concentration was 28.41 ± 2.41 mg L−1, which was comparable to previously reported levels. This study demonstrates that P. tricornutum has great potential in swine wastewater treatment integrated with fucoxanthin production. It provides an environmentally friendly approach for natural pigment production and resource recycling.