TY  - JOUR
N1  - cited By 2
TI  - Fly ash geopolymer as a coating material for controlled-release fertilizer based on granulated urea
SN  - 20462069
IS  - 51
JF  - RSC Advances
EP  - 33199
UR  - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85143629681&doi=10.1039%2fd2ra06056f&partnerID=40&md5=815607baa97a1631cb07d24c414e8f84
N2  - Nitrogen loss from urea fertiliser due to its high solubility characteristics has led to the invention of controlled release urea (CRU). Majority of existing CRU coatings are produced from a non-biodegradable, toxic and expensive synthetic polymers. This study determines the feasibility of fly ash-based geopolymer as a coating material for urea fertilizer. The effects of fly ash particle size (15.2 μm, 12.0 μm, and 8.6 μm) and solid to liquid (S : L) ratio (3 : 1, 2.8 : 1, 2.6 : 1, 2.4 : 1 and 2.2 : 1) on the geopolymer coating, the characterization such as FTIR analysis, XRD analysis, surface area and pore size analysis, setting time analysis, coating thickness, and crushing strength, and the release kinetics of geopolymer coated urea in water and soil were determined. Lower S : L ratio was beneficial in terms of workability, but it had an adverse impact on geopolymer properties where it increased porosity and decreased mechanical strength to an undesirable level for the CRU application. Geopolymer coated urea prepared from the finest fly ash fraction and lowest S : L ratio demonstrated high mechanical strength and slower urea release profile. Complete urea release was obtained in 132 minutes in water and 15 days in soil from geopolymer-coated urea whereas for uncoated urea it took only 20 minutes in water and 3 days in soil. Thus, geopolymer can potentially be used as a coating material for urea fertilizer to replace commonly used expensive and biodegradable polymer-based coatings. © 2022 The Royal Society of Chemistry.
ID  - scholars16178
AV  - none
Y1  - 2022///
KW  - Biodegradable polymers; Fertilizers; Fly ash; Metabolism; Particle size; Particle size analysis; Plastic coatings; Pore size; Soils; Thickness measurement
KW  -  Coated ureas; Coating material; Controlled release; Controlled-release fertilizers; Geopolymer; High solubility; Nitrogen loss; Solid-to-liquid ratio; Solubility characteristics; Synthetic polymers
KW  -  Urea
A1  - Hamidi, R.M.
A1  - Siyal, A.A.
A1  - Luukkonen, T.
A1  - Shamsuddin, R.M.
A1  - Moniruzzaman, M.
SP  - 33187
PB  - Royal Society of Chemistry
VL  - 12
ER  -