kong-modifiedironphosphate-2018.pdf (1.08 MB)
Modified iron phosphate/polyvinyl alcohol composite film for controlled-release fertilisers
journal contribution
posted on 2018-01-01, 00:00 authored by Yi Zhang, Zhifeng YiZhifeng Yi, L Wei, Lingxue KongLingxue Kong, L WangTraditional soluble phosphorous (P) fertilisers can be easily leached to pollute water systems, resulting in water eutrophication, a major environmental problem from the oversupply of unused nutrients. One innovative solution is to control the release of P upon demands of the plants. This study established a new concept of controlled-release P fertiliser via incorporation of ferric phosphate (FePO4) as a P source in polyvinyl alcohol (PVA) films, which can immobilise the FePO4particles and stimuli-responsively accelerate their release rate in the presence of citric acid. More importantly, FePO4used in this work originated from steelmaking slag as a potential waste reuse. Due to the low solubility of FePO4, diethylamine was introduced to modify FePO4particles to facilitate the release of P before incorporating with PVA. The effects of diethylamine modification and the properties of FePO4/PVA films were systematically investigated through microscopic and spectroscopic methods. The release of P from particles and films was examined in both deionised water and citric acid solution for 30 days. The results showed a tenfold increase of the release rate of modified FePO4/PVA in citric acid solution compared with that in deionised water, and also a doubled release rate of the modified FePO4/PVA compared to that of FePO4/PVA in citric acid. The improved performance suggests that PVA can maintain the phosphorous content with exposure to water and expedite release in citric acid upon the demand of plants. This composite film offers a new opportunity for the application of insoluble phosphate as a phosphorous fertiliser.
History
Journal
RSC advancesVolume
8Issue
32Pagination
18146 - 18152Publisher
Royal Society of ChemistryLocation
Cambridge, Eng.Publisher DOI
Link to full text
eISSN
2046-2069Language
engPublication classification
C1 Refereed article in a scholarly journalCopyright notice
2018, The Royal Society of ChemistryUsage metrics
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iron phosphatepolyvinyl alcoholcontrolled-release fertilisersphosphorous (P)water eutrophicationenvironmental problemfertiliserferric phosphate (FePO4)polyvinyl alcohol (PVA)Science & TechnologyPhysical SciencesChemistry, MultidisciplinaryChemistryPOLY(VINYL ALCOHOL)CITRIC-ACIDPHOSPHORUSCELLULOSENITROGENWHEATCHINAPVA
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