Fertilization with Municipal Wastewater Phosphorus Adsorbed to Alginate Beads: Results from a Pot Experiment with Italian Ryegrass

• Published in: Agronomy (Basel) Vol. 11; no. 11; p. 2142
• Main Authors: Pawelec, Krzysztof, Siwek, Hanna, Kitczak, Teodor, Włodarczyk, Małgorzata
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.11.2021
• Subjects: Adsorbents; Adsorption; alginate adsorbents; Alginates; Alginic acid; Beads; Binding sites; Competitiveness; Copper; Crop yield; Depletion; Experiments; Fertilization; fertilizer formulation; Fertilizers; Food; Hydrogels; Iron; Lolium perenne; Membrane separation; Metal concentrations; Metal industry wastewaters; Mineral fertilizers; multivalent metals; Municipal wastewater; Nutrition; Phosphorus; phosphorus removal; Seeds; Sewage treatment plants; Sludge; Sorbents; Thermal stability; Wastewater
• ISSN: 2073-4395; 2073-4395
• DOI: 10.3390/agronomy11112142

The global increase in the demand for fertilizers and thus phosphorus (P) contributes to the depletion of P reserves and the need to recycle this element. This paper presents the results of a pilot-scale experiment on the possibility of using a fertilizer preparation containing alginate, Fe and P (AFP) obtained in the process of P adsorption from sludge water on a hydrogel alginate adsorbent cross-linked with iron (III) ions. The influence of AFP on the growth of a model plant of the Italian ryegrass (Lolium perenne cv. Turtetra) was examined in comparison with differentiated mineral fertilization (MF) under the conditions of a pot experiment. The two fertilizers produced similar crop yields of the tested plant and had similar plant and soil macro- and micro-elements, except for the content of Fe and Cu in ryegrass, which was significantly higher with AFP fertilization. Further research on the use of the proposed sorbent for large-scale P recycling in an uncontrolled field environment should include acceptable limits for multivalent metal concentrations in wastewater, the mechanical/thermal stability, and the effectiveness of AFP under field conditions and a cost competitiveness. AFP has the potential to compete with mineral fertilizers for P fertilization, and this technology is in line with the EU circular economy vision.