scholarly journals Solubility Characteristics and Slow-Release Mechanism of Nitrogen from Organic-Inorganic Compound Coated Urea

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Hongtao Zou ◽  
Yao Ling ◽  
Xiuli Dang ◽  
Na Yu ◽  
YuLing Zhang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Slow Release ◽  
Membrane Surface ◽  
Inorganic Compound ◽  
Release Mechanism ◽  
Sem Images ◽  
Coated Urea ◽  
Membrane Microstructure ◽  
Nutrient Solubility ◽  
Incubation Method

A soil incubation method was used to investigate the solubility characteristics and slow-release mechanism of organic-inorganic compound coated urea at temperature of 10, 20, and 30°C. The membrane microstructure with and without incubation was tested via scanning electron microscopy (SEM). Slow release of nitrogen (N) from different inorganic minerals was analysed by the activation energy from the nutrient solubility system. The rate of nitrogen solubility increased with temperature increasing. The first-order reaction kinetic equation described the solubility process of coated urea. The rate constantkalso increased with temperature increasing. Moreover, the SEM images showed that the microstructure of the coating layer changed into a flocculent structure and the number of tiny pores and holes on the membrane surface increased significantly with temperature increasing, which increased N solubility rate. The Arrhenius equation indicated that activation energy was closely related tokduring the solubility process; the activation energy was reduced withkrising, which resulted in N solubility rate increasing. Overall, the N solubility rate of coated urea was affected by temperature.

Attributes of natural and synthetic materials pertaining to slow-release urea coating industry

2017 ◽  
Vol 33 (3) ◽  
Author(s):  
Muhammad Yasin Naz ◽  
Shaharin Anwar Sulaiman
Keyword(s):  
Slow Release ◽  
Economic Losses ◽  
Release Mechanism ◽  
Coating Materials ◽  
Synthetic Materials ◽  
Wide Range ◽  
Slow Release Fertilizers ◽  
Coated Urea ◽  
Slow Release Urea ◽  
Natural And Synthetic

AbstractUrea is one of the spirited input materials for plant growth. However, more than half of conventional urea applied to the soil may not reach the plants and be washed off by rain and irrigation water. The high lost proportion results not only in economic losses but also in environmental pollution. Alleviation in cost and nitrogen pollution is possible by mitigating the nitrogen release rate and synchronizing it with the plant’s need. A wide range of synthetic and natural materials are being tested for production of slow-release fertilizers. Each one of these materials has its own merits, with accompanying disadvantages. This study critically reviews the most featured natural and synthetic materials pertaining to the slow-release urea industry. The focused review was aimed at elaborating the benefits and limitations of polymeric and nonpolymeric coating materials, release mechanism of conventional and coated urea, methods to characterize the coated urea, slow-release characteristics imparted by a coating to the coated urea, and release patterns of conventional and coated urea. This discussion was further extended to commercially available coatings and slow-release potential of superabsorbent, urethane, and starch-based coatings.

The Development of Pemetrexed Diacid-Loaded Gelatin-Cloisite 30B (MMT) Nanocomposite for Improved Oral Efficacy Against Cancer: Characterization, In-Vitro and Ex-Vivo Assessment

2020 ◽  
Vol 17 (3) ◽  
pp. 246-256
Author(s):  
Kriti Soni ◽  
Ali Mujtaba ◽  
Md. Habban Akhter ◽  
Kanchan Kohli
Keyword(s):  
Drug Release ◽  
Oral Delivery ◽  
Ex Vivo ◽  
Confocal Laser ◽  
Release Mechanism ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Cloisite 30B ◽  
Ft Ir

Aim: The intention of this investigation was to develop Pemetrexed Diacid (PTX)-loaded gelatine-cloisite 30B (MMT) nanocomposite for the potential oral delivery of PTX and the in vitro, and ex vivo assessment. Background: Gelatin/Cloisite 30 B (MMT) nanocomposites were prepared by blending gelatin with MMT in aqueous solution. Methods: PTX was incorporated into the nanocomposite preparation. The nanocomposites were investigated by Fourier Transmission Infra Red Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), Scanning Electron Microscope (SEM) X-Ray Diffraction (XRD) and Confocal Laser Microscopy (CLSM). FT-IR of nanocomposite showed the disappearance of all major peaks which corroborated the formation of nanocomposites. The nanocomposites were found to have a particle size of 121.9 ± 1.85 nm and zeta potential -12.1 ± 0.63 mV. DSC thermogram of drug loaded nanocomposites indicated peak at 117.165 oC and 205.816 oC, which clearly revealed that the drug has been incorporated into the nanocomposite because of cross-linking of cloisite 30 B and gelatin in the presence of glutaraldehyde. Results: SEM images of gelatin show a network like structure which disappears in the nanocomposite. The kinetics of the drug release was studied in order to ascertain the type of release mechanism. The drug release from nanocomposites was in a controlled manner, followed by first-order kinetics and the drug release mechanism was found to be of Fickian type. Conclusion: Ex vivo gut permeation studies revealed 4 times enhancement in the permeation of drug present in the nanocomposite as compared to plain drug solution and were further affirmed by CLSM. Thus, gelatin/(MMT) nanocomposite could be promising for the oral delivery of PTX in cancer therapy and future prospects for the industrial pharmacy.

Evaluation of neem bark coated urea for slow release of nitrogen

2014 ◽  
Vol 34 (1) ◽  
pp. 26
Author(s):  
Chelvi Ramessh ◽  
A.R. Ramesh ◽  
Kokila ◽  
N.S. Venkataraman
Keyword(s):  
Slow Release ◽  
Coated Urea

scholarly journals Molecular Dynamic Simulation Analysis on the Inclusion Complexation of Plumbagin with β-Cyclodextrin Derivatives in Aqueous Solution

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6784
Author(s):  
Kulpavee Jitapunkul ◽  
Pisanu Toochinda ◽  
Luckhana Lawtrakul
Keyword(s):  
Aqueous Solution ◽  
Slow Release ◽  
Storage Temperature ◽  
Simulation Analysis ◽  
Inclusion Complexation ◽  
Storage Life ◽  
Release Mechanism ◽  
Guest Binding ◽  
Binding Cavity ◽  
Dynamics Simulations

Stable encapsulation of medically active compounds can lead to longer storage life and facilitate the slow-release mechanism. In this work, the dynamic and molecular interactions between plumbagin molecule with β-cyclodextrin (BCD) and its two derivatives, which are dimethyl-β-cyclodextrin (MBCD), and 2-O-monohydroxypropyl-β-cyclodextrin (HPBCD) were investigated. Molecular dynamics simulations (MD) with GLYCAM-06 and AMBER force fields were used to simulate the inclusion complex systems under storage temperature (4 °C) in an aqueous solution. The simulation results suggested that HPBCD is the best encapsulation agent to produce stable host–guest binding with plumbagin. Moreover, the observation of the plumbagin dynamic inside the binding cavity revealed that it tends to orient the methyl group toward the wider rim of HPBCD. Therefore, HPBCD is a decent candidate for the preservation of plumbagin with a promising longer storage life and presents the opportunity to facilitate the slow-release mechanism.

scholarly journals Biofouling Characteristics of Graphene Oxide Membrane in a Protein-rich Environment

2021 ◽  
Author(s):  
Richard P Rode ◽  
Saeed Moghaddam
Keyword(s):  
Graphene Oxide ◽  
Self Assembly ◽  
Membrane Surface ◽  
Water Flux ◽  
Polymer Membrane ◽  
Blood Protein ◽  
Separation Processes ◽  
Sem Images ◽  
Membrane Flux ◽  
Protein Rich

Membrane biofouling has inhibited permselective separation processes for decades, requiring frequent membrane backwash treatment or replacement to maintain efficacy. However, frequent treatment is not viable for devices with a continuous blood flow such as a wearable or implantable dialyzer. In this study, the biofouling characteristics of a highly hemocompatible graphene oxide (GO) membrane developed through a novel self-assembly process is studied in a protein-rich environment and compared with performance of a state-of-the-art commercial polymer membrane dialyzer. The studies are conducted in phosphate-buffered saline (PBS) environment using human serum albumin (HSA), which represents 60% of the blood protein, at the nominal blood protein concentration of 1 g L-1. Protein aggregation on the membrane surface is evaluated by monitoring the change in the membrane flux and SEM imaging. The GO membrane water flux declined only ~10% over a week-long test whereas the polymer membrane flux declined by 50% during the same period. The SEM images show that HSA primarily aggerates over the graphitic regions of nanoplatelets, away from the charged hydrophilic edges. This phenomenon leaves the open areas of the membrane formed between the nanoplatelets edges, through which the species pass, relatively intact. In contrast, HSA completely plugs the polymer membrane pores resulting in a steady decline in membrane permeability.

Effect of solution chemistry and operating conditions on the nanofiltration of acid dyes by a nanocomposite membrane

2011 ◽  
Vol 64 (12) ◽  
pp. 2404-2409 ◽  
Author(s):  
A. Akbari ◽  
M. Homayoonfal ◽  
V. Jabbari
Keyword(s):  
Uv Irradiation ◽  
Separation Efficiency ◽  
Irradiation Time ◽  
Membrane Surface ◽  
Operating Conditions ◽  
Solution Chemistry ◽  
Polymerization Process ◽  
Inversion Method ◽  
Sem Images ◽  
Polysulfone Membrane

A composite nanofiltration membrane was developed by a poly(acrylic acid) in situ ultraviolet (UV) graft polymerization process using an ultrafiltration polysulfone membrane as a porous support, by a phase inversion method. SEM images showed that the PSf membranes had numerous finger-like pores. Atomic force microscopy (AFM) showed that the roughness of the surface was reduced by an increase in UV irradiation times. The rejections of sodium chloride and sodium sulfate were moderate and declined with the increase of concentration. We observed that by increasing UV irradiation time and nanofiltration pressure applied, retention of dyes was enhanced and in the most irradiated membrane (M-4 membrane) at 4 bars, color removal with a high rejection of about 99.80% was achieved. It was found that the separation efficiency of dyes in the mixture of salt and dyes decreased with the salt concentration due to a decrease in the Donnan effect. It was also found that by varying the pH, the membrane surface and the dyes' charges are changed, which meant that the membrane surface and dyes had different interactions at various pHs.

scholarly journals Performance and Characterization for Blend Membrane of PES with Manganese(III) Acetylacetonate as Metalorganic Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
H. Abdallah ◽  
M. S. Shalaby ◽  
A. M. H. Shaban
Keyword(s):  
Membrane Surface ◽  
Lower Surface ◽  
Permeate Flux ◽  
Asymmetric Membrane ◽  
Sem Images ◽  
Blend Membrane ◽  
Membrane Morphology ◽  
Evaluation Of Performance ◽  
Angle Measurements ◽  
And Performance

This study describes the preparation, characterization, and evaluation of performance of blend Polyethersulfone (PES) with manganese(III) acetylacetonate Mn(acac)3to produce reverse osmosis blend membrane. The manganese(III) acetylacetonate nanoparticles were prepared by a simple and environmentally benign route based on hydrolysis of KMnO4followed by reaction with acetylacetone in rapid stirring rate. The prepared nanoparticle powder was dissolved in polymer solution mixture to produce RO PES/Mn(acac)3blend membrane, without any treatment of Polyethersulfone membrane surface. The membrane morphology, mechanical properties, and performance were presented. The scanning electron microscopy (SEM) images have displayed a typical asymmetric membrane structure with a dense top layer due to the migration of Mn(acac)3nanoparticles to membrane surface during the phase inversion process. Contact angle measurements have indicated that the hydrophilicity of the membrane was improved by adding Mn(acac)3. AFM images have proved excellent pores size distribution of blend membrane and lower surface roughness compared with bare PES. The desalination test was applied to blend membrane, where the blend membrane provided good performance; particularly, permeate flux was 24.2 Kg/m2·h and salt rejection was 99.5%.

Investigation of membrane fouling in ultrafiltration using model organic compounds

2005 ◽  
Vol 51 (6-7) ◽  
pp. 101-106 ◽  
Author(s):  
J.H. Kweon ◽  
D.F. Lawler
Keyword(s):  
Organic Compounds ◽  
Membrane Fouling ◽  
Alginic Acid ◽  
Membrane Surface ◽  
Sem Images ◽  
Membrane Processes ◽  
Xps Spectra ◽  
Relative Composition ◽  
Flux Decline ◽  
The City

Natural organic matter (NOM) is known to be the worst foulant in the membrane processes, but the complexities of NOM make it difficult to determine its effects on membrane fouling. Therefore, simple organic compounds (surrogates for NOM) were used in this research to investigate the fouling mechanisms in ultrafiltration. Previous research on NOM components in membrane processes indicated that polysaccharides formed an important part of the fouling cake. Three polysaccharides (dextran, alginic acid, and polygalacturonic acid) and a smaller carbohydrate (tannic acid) were evaluated for their removal in softening (the treatment process in the City of Austin). Two polysaccharides (dextran and alginic acid) were selected and further investigated for their effects on membrane fouling. The two raw organic waters (4 mg/L C) showed quite different patterns of flux decline indicating different fouling mechanisms. Softening pretreatment was effective to reduce flux decline of both waters. The SEM images of the fouled membrane clearly showed the shapes of deposited foulants. The high resolution results of the XPS spectra showed substantially different spectra of carbon, C(1s), in the membrane fouled by two raw organic waters. The XPS was beneficial in determining the relative composition of each fouling material on the membrane surface.

Tropical jute with coated and uncoated urea

1987 ◽  
Vol 109 (1) ◽  
pp. 187-188
Author(s):  
Apurba Sarkar ◽  
P. C. Mitra ◽  
A. R. Roy ◽  
G. C. Biswas
Keyword(s):  
Growth Response ◽  
Slow Release ◽  
Nitrification Inhibitor ◽  
Residual Effect ◽  
Exchange Capacity ◽  
Corchorus Capsularis ◽  
Coated Urea ◽  
The Tropics ◽  
Urea Granules ◽  
Better Than

Jute (Corchorus capsularis L.) is grown in the tropics. It is next only to cotton in importance as a fibre crop. Adequate supplies of plant nutrients, especially N, are essential for its vegetative growth. Response to applied N varies from region to region. In a light-textured soil with low cation exchange capacity (CEC), part of the applied N is generally lost mostly under rainfall (Engelsted & Russel, 1975) and the rest is manifested in the form of residual effect (McEwen, 1970). Such losses can be reduced by using slow-release N fertilizers or by coating the urea granules by paraffin wax, resin, gum, lac, or with a nitrification inhibitor (Prasad, Raj ale & Lakhdive, 1971). There is little information on the use of these products on jute. Mondal, Dohary & Pal (1977) reported that coated urea is better than uncoated ones. The current programme was designed to give a better picture.

scholarly journals Formulating and Optimizing a Novel Biochar-Based Fertilizer for Simultaneous Slow-Release of Nitrogen and Immobilization of Cadmium

2018 ◽  
Vol 10 (8) ◽  
pp. 2740 ◽  
Author(s):  
Lu Chen ◽  
Qincheng Chen ◽  
Pinhua Rao ◽  
Lili Yan ◽  
Alghashm Shakib ◽  
...  
Keyword(s):  
Release Rate ◽  
Slow Release ◽  
Porous Structures ◽  
Nitrogen Release ◽  
Sem Images ◽  
Elementary Analysis ◽  
Monolayer Adsorption ◽  
Urea Hydrogen Peroxide ◽  
Rice Husk Biochar ◽  
Optimized Conditions

This study aimed to develop and optimize a novel biochar-based fertilizer composed of rice husk biochar and urea–hydrogen peroxide (UHP), which can simultaneously slowly release nitrogen and immobilize cadmium (Cd). Response surface methodology (RSM) was adopted to optimize the fertilizer formulation with the lowest nitrogen release rate. Under the optimized conditions, the cumulative nitrogen release rate of the biochar-based fertilizer was 17.63%, which was significantly lower than that of ordinary fertilizer. Elementary analysis, scanning electron microscopy (SEM) images, and Fourier transform infrared (FTIR) spectroscopy proved that UHP attached to the porous structures of the biochar. The adsorption test showed that the adsorption of Cd onto biochar-based fertilizer quickly reached equilibrium with an equilibrium adsorbing quantity (Qe) of 6.3279 mg·g−1 with an initial concentration of 10 mg·L−1. Compared to original biochar, the Cd immobilization ability of biochar-based fertilizer was significantly better. The adsorption of Cd on biochar-based fertilizer is mainly based on a monolayer adsorption behavior. Finally, improved crop growth was demonstrated by pot experiments, which showed a significant increase in the biomass of cabbage. The concept and findings presented in this study may be used as references in developing a novel biochar-based fertilizer for simultaneously enhancing crop yield and reducing environmental risk.

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