Work

Spent coffee ground biochar for phosphate adsorption in water: Influence of pyrolysis temperature and iron-coating activation method

Year: 2024

Type: article

Abstract: A substantial portion of the phosphorus utilized in crop and food production is dispersed into soil and water, posing a challenge to the management of eutrophication and sustainable nutrient recovery. This research focuses on the reclamation of phosphate from polluted water through affinitive adsorption on biochar derived from spent coffee grounds (SCG). SCG were subjected to pyrolysis within a N 2 -purged vertical furnace across a temperature range of 300–550 °C, with a 1-h holding time. The adsorption capability of SCG biochar was systematically investigated and experimental data were interpreted using Langmuir and Freundlich isotherm models. Notably, the biochar pyrolyzed at 450 °C and activated with a Fe/biochar mass ratio of 2:1 demonstrated the highest adsorption capacity (0.87 mg P/g biochar) when exposed to the highest initial phosphate concentration in the solution (15 mg P/L). Comparative analyses revealed that the removal efficiency of non-activated SCG biochar was considerably lower (5.7%) compared to the corresponding activated biochar (up to 17.3%). This highlights the significant increase in adsorption capacity facilitated by the introduction of ferric chloride. Furthermore, phosphate desorption experiments were conducted to assess the biochar's phosphorus release characteristics and stability. The results demonstrate the positive outcomes of upcycling SCG waste material as a pollutant sorbent and the potential to diminish reliance on chemical fertilizers through the recovery of Fe-phosphate-enriched SCG biochar. • Adsorption behavior of spent coffee ground biochar favorable for phosphate removal • Rising pyrolysis temperature results in higher carbon content and aromaticity • Upward trend of adsorption capacity when the pyrolysis temperature increases • Functional groups of biochar can be functionalized to accommodate iron salts • Enhanced adsorption capacity of phosphorus by iron-activated biochar

Source: Cleaner Engineering and Technology

DOI: 10.1016/j.clet.2024.100839

Authors: Alessia Torboli, Paola Foladori, Mingming Lu, Stefano Gialanella, Lorena Maines

Institutions: University of Trento, University of Cincinnati

Language: English

Topic: Phosphorus and nutrient management

Subfield: Waste Management and Disposal

Field: Environmental Science

Domain: Physical Sciences

SDGs: Clean water and sanitation, Responsible consumption and production, Climate action

Open Access status: gold

Estimated APC paid: $1,470