Abstract
Inexpensive and sustainable methods are needed to reclaim nutrients from agricultural waste solutions for use as a fertilizer while decreasing nutrient runoff. Fe(III)-polysaccharide hydrogels are able to flocculate solids and absorb nutrients in liquid animal waste from Confined Animal Feeding Operations (CAFOs). Fe(III)-alginate beads absorbed 0.05 mg g-1 NH4+ and NO3- from 100 ppm solutions at pH = 7, with > 80% phosphate uptake and ∼30% uptake of ammonium and nitrate. Ammonium uptake from a raw manure solution (1420 ppm NH4+) showed a significant 0.7 mg g-1 uptake. Tomato plant trials carried out with Fe(III)-alginate hydrogel beads in greenhouse conditions showed controlled nutrient delivery for the plants compared to fertilizer solution with the same nutrient content. Plants showed an uptake of Fe from the gel beads, and Fe(III)-alginate hydrogel beads promoted root growth of the plants. The plants treated with nutrient-loaded Fe(III)-alginate hydrogels yielded comparable tomato harvest to plants treated with the conventional fertilizer solution.
Original language | English |
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Pages (from-to) | 23009-23020 |
Number of pages | 12 |
Journal | ACS Omega |
Volume | 5 |
Issue number | 36 |
DOIs | |
State | Published - Sep 15 2020 |
Funding
We acknowledge the Herman Frasch Foundation for Chemical Research in Agricultural Chemistry (811-HF17) for funding to support this project. We are grateful for funding of grants #6883 and 7177 from the Ohio Water Development Authority, for funding of grant R/HAB-17-ODHE from the Ohio Department of Higher Education’s Harmful Algal Bloom Research Initiative, and for funding of grant SG 538–2018 of the Lake Erie Protection Fund. KMB acknowledges the BGSU’s Center for Undergraduate Research for a summer undergraduate research grant.