Facile Fabrication of N-Slow Release Fertilizer Hydrogel Beads by Alginate-Based Composites

2021 ◽  
Vol 889 ◽  
pp. 91-97
Author(s):  
Suntree Sangjan ◽  
Wadchara Thongsamer

A novel slow-release N-fertilizer hydrogel beads were developed using sodium alginate (SA) and alginate-talcum (ST) composite as N-absorbent. In this work, the hydrogel composite were fabricated by simple method and low cost. N-fertilizer hydrogel beads were prepared two types, for SA types, which were different sodium alginate (1(SA1), 3(SA3), 5(SA5), 7(SA7), and 10(SA10) wt%). And, for ST types, sodium alginate and talcum were vary ratios to 1:0.5(S1T0.5), 1:1(S1T1), and 1:2 (S1T2). The chemical structure of hydrogel composite beads were characterized via Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The release behavior were investigate by Zero-order kinetic model, First-order kinetic model, Higuchi model and Korsmeyer-Peppas model. We have found that the N-fertilizer release constants in Korsmeyer-Peppas model were decrease with increase SA content for 1-5 wt% in SA hydrogel beads. However, SA contents were more than 5 wt% which rapidly enhanced fertilizer release. In addition, to add talcum in ST hydrogel beads significantly reduced fertilizer release rate. The N-fertilizer hydrogel beads exhibits significantly slow release behavior. These results indicates that the development of slow-release fertilizer hydrogel beads can be improve the effectiveness of N-fertilizer.

Marine Drugs ◽  
2018 ◽  
Vol 16 (12) ◽  
pp. 476 ◽  
Author(s):  
Shuxian Tang ◽  
Ying Zhao ◽  
Haitao Wang ◽  
Yuqiao Wang ◽  
Hexiang Zhu ◽  
...  

A polyampholytic superabsorbent polymer (PASAP), sodium alginate-g-(polyacrylic acid-co-allyltrimethylammonium chloride) (SA-g-(PAA-co-PTM)), was prepared by free-radical graft copolymerization and characterized. The polymer exhibited pH-dependent swelling behaviors with extremely high swelling ratios, and was saline tolerant. The dye adsorption properties of SA-g-(PAA-co-PTM) were investigated using methylene blue (MB) as a cationic dye model. It was found that its dye adsorption capacity was significantly affected by the TM content in PASAP and pH of dye solution. The dye adsorption kinetics and isotherm obey the pseudo-second-order kinetic model and the Langmuir isotherm model, respectively, and the adsorption process is chemisorption in nature. In addition, SA-g-(PAA-co-PTM) exhibited high MB adsorption capacities in a wide pH range and reusability in at least five adsorption-desorption cycles, indicating its great application potentials as the adsorbent for dye removals from effluents.


RSC Advances ◽  
2019 ◽  
Vol 9 (48) ◽  
pp. 27961-27972
Author(s):  
Dan Zheng ◽  
Bo Bai ◽  
Xiaohui Xu ◽  
Yunhua He ◽  
Shan Li ◽  
...  

Composite hydrogel beads prepared by sodium alginate with hydrophilicity and detonation nanodiamond with photothermal conversion property exhibited apparent water release behavior under illumination.


2020 ◽  
Vol 148 ◽  
pp. 02002 ◽  
Author(s):  
Rodel Guerrero ◽  
Catherine Acibar ◽  
Christine Marie Alarde ◽  
Jane Maslog ◽  
Christine Joy Pacilan

This study examined the removal of Pb2+ ions from aqueous solution with two different lead concentrations using a hydrogel-forming polymer based on hydroxypropyl cellulose (HPC) and sodium alginate (SA). The feasibility of the adsorption behavior of SA/HPC beads has been investigated with three varying ratios of 50:50, 75:25 and 100:0 under a stir condition. The adsorption experiments were done to determine the effects of contact time, lead concentration and SA-HPC ratio to the adsorption capacity of SA-HPC hydrogel beads. The results showed that the ratio 75:25 showed higher adsorption capacity compared to 100:0 and 50:50. It showcased 47.72 mg/g adsorption capacity and 95.45% adsorption percentage after three hours of contact time. The adsorption kinetic model indicated that the adsorption of Pb2+ ions onto the beads followed a pseudo-second order kinetic equation. This means that the adsorption mechanism shows a chemisorption process and its sole rate-limiting step is intraparticle diffusion.


2012 ◽  
Vol 518-523 ◽  
pp. 4745-4748
Author(s):  
Qing Wang ◽  
Sha Chen ◽  
Pei Guang Zhao ◽  
Yu Cao ◽  
Long Fei Zhu ◽  
...  

A kind of double-coated environmental friendly fertilizer was prepared by urea as a core, well-mixed keratin and oxidation starch as an inner coating, and superabsorbent polymer as the outer coating. The influence of water absorbency, water retention, and the slow-release behavior of the study fertilizer were investigated. 0.01M CaCl2 immersion extraction and Kjeldahl digestion method were used to measure the content of nitrogen. And the result showed that the nutrient release was 72wt% on the thirtieth day. This result corresponded with the standard of slow release fertilizers of the Committee of European Normalization (CEN) [1]. Keratin and oxidation starch were biodegradable polymer and nontoxic. Both the properties of the materials and the result of the slow-release behavior suggested a new kind of excellent, environmental friendly, slow-release fertilizer.


2014 ◽  
Vol 980 ◽  
pp. 18-22
Author(s):  
Nurul Ekmi Rabat ◽  
Shahrir Hashim ◽  
Rohah A. Majid

For slow release fertilizer application, oil palm empty fruit bunch-grafted-poly (acrylic acid-co-acrylamide) [OPEFB-g-P(AA-co-AAm)] hydrogel composites were synthesized via two techniques; Two Steps (T1) and in-situ (T2). Scanning electron microscopy of hydrogel composite T1 has higher surface area and holes while hydrogel T2 displays smoother and tighter surface. Water absorbency capacity of hydrogel T1 is 42.90 gram/gram (g/g) and hydrogel T2 is 39.96 g/g. WAC of hydrogel T2 has much better re-swelling ability compared to T1 after it went through five cycles of drying-swelling-drying process. Hence, T2 has produced a hydrogel composite that is reusable with great morphology properties.


2013 ◽  
Vol 743-744 ◽  
pp. 480-485
Author(s):  
Zi Ze Yang ◽  
Wang Xiao ◽  
Chun Ma ◽  
Li Hua Lv ◽  
Chun Yan Wei ◽  
...  

In this paper, the sodium alginate (SA)/poly (vinylalcohol)(PVA)/hydroxyapatite (HAp) fiber was prepared via solution spinning. The adsorption properties of SA/PVA/HAp composite fiber were studied,and the adsorption kinetics and isotherms were investigated. The experimental results showed that the adsorption process was fast, in which half-equilibrium and equilibrium was obtained in 5 and 30 minutes, respectively. The pseudo-second-order kinetic model provided a better correlation of the experimental results. Both of Langmuir isotherm and Freundlich isotherm could describe the adsorption behavior of SA/PVA/HAp composite fiber towards cadmium. The positive H° value and increased absolute value of the G° with temperature indicate that high temperature is good to the adsorption process.


Processes ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 44 ◽  
Author(s):  
Jun Zhang ◽  
Renjian Deng ◽  
Bozhi Ren ◽  
Mohammed Yaseen ◽  
Andrew Hursthouse

To remove antimony (Sb) ions from water, a novel composite adsorbent was fabricated from ferriferous oxide and waste sludge from a chemical polishing process (Fe3O4@HCO) and encapsulated in sodium alginate (SAB). The SAB adsorbent performed well with 80%–96% removal of Sb (III) ions within a concentration range of 5–60 mg/L. The adsorption mechanism of Sb (III) was revealed to be the synergy of chemisorption (ion exchange) and physisorption (diffusion reaction). The adsorption isotherms and kinetics conformed to the Langmuir isotherm and the pesudo-second-order kinetic model. Both initial pH and temperature influenced the adsorption performance with no collapse of microbeads within solution pH range 3–7. Most importantly for practical applications, these microspheres can be separated and recovered from aqueous solution by a magnetic separation technology to facilitate large-scale treatment of antimony-containing wastewater.


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