Use of Lithothamnium For Phosphorus Removal and Improvement of the Trophic Status of Water Bodies

Objective: To evaluate the efficiency of Lithothamnium calcareum as an adsorbent for the removal of phosphorus from eutrophicated water bodies. Theoretical Framework: Conventional wastewater treatment methods, such as activated sludge and biological filters, have low efficiency in removing nitrogen and phosphorus. This highlights the need for alternative strategies, such as the use of adsorbent materials, to mitigate the effects of eutrophication. Lithothamnium calcareum, also known as bioclastic granulate (BG), has been the subject of several studies indicating its potential for phosphorus removal and recovery. Methodology: Phosphorus removal was evaluated using water from Lake Açu, with Lithothamnium calcareum (particles of 0.3 to 0.6 mm) as the adsorbent. In 13 experiments, efficiency was analyzed using the Response Surface Methodology (RSM), varying the amount of BG and contact time. Results and Discussion: The study assessed phosphorus removal by Lithothamnium calcareum, achieving 48.8% efficiency with 60 g/L of BG in 180 minutes. Modeling predicted up to 55.14% removal with 68.3 g/L in 204 minutes. Concentration and time significantly influenced the results, demonstrating that conditions with higher amounts of BG and longer contact times led to greater efficiencies. Research Implications: The results suggest that Lithothamnium calcareum offers a promising solution for the treatment of eutrophicated waters, contributing to the reduction of phosphorus in water bodies and the mitigation of eutrophication. Originality/Value: The study demonstrates the applicability of a natural and sustainable material for phosphorus removal, providing innovative insights for the development of treatment technologies for eutrophicated waters, with potential for subsequent agricultural use of phosphorus-enriched BG.