Nutrient Recovery from Columns Filled with Zeolite and Biochar: The Case Study of Marineo (ITALY) Wastewater Treatment Plant

Rapid population and economic growth have nourished an increasing demand for finite resources, leading to their depletion and adverse environmental impacts. In the agricultural sector, fertiliser production heavily relies on energy-intensive processes and non-renewable mineral resources, exacerbating greenhouse gas emissions and resource depletion. Nitrogen and phosphorus, key components of fertilisers, contribute significantly to eutrophication through soil runoff. Recovering these nutrients from wastewater using adsorption techniques offers a promising solution. Previous studies demonstrated the adsorption capabilities of materials like biochar and zeolite for phosphorus and ammonium. Biochar, derived from biomass pyrolysis, exhibits high porosity and carbon content, while zeolite’s aluminosilicate structure enables efficient cation exchange. Moreover, these materials can serve as soil amendments, acting as slow-release fertilizers within a circular economy framework. This study aims to assess the adsorption capacities of biochar and zeolite using column tests with treated wastewater from the Marineo wastewater treatment plant. Despite some issues related to the real effluent used during the test, the tested materials showed good adsorption capacities towards phosphorus and ammonia.