Release Kinetics of Phosphorus in Sediments from Baihua Lake

2012 ◽  
Vol 599 ◽  
pp. 91-95 ◽  
Author(s):  
Jin Mei ◽  
Ji Wei Hu ◽  
Xian Fei Huang ◽  
Li Ya Fu ◽  
Jin Luo ◽  
...  
Keyword(s):  
Organic Phosphorus ◽  
Release Kinetics ◽  
Phosphorus Release ◽  
Release Kinetic ◽  
Iron Aluminum ◽  
P Content ◽  
Elovich Equation ◽  
Release Data ◽  
The Relationship ◽  
Kinetics Of

Release kinetics of phosphorus in 17 sediments samples collected from Baihua Lake were determined, and the relationship between the phosphorus release kinetic parameters and the sediment composition was also investigated. The results showed that both the Elovich equation and power function equation were valid models for describing the phosphorus release data in the 17 sediments. Within the beginning 12 h, the rate of phosphorus release was high, and then decreased. Our correlation analysis demonstrates that there were no significant correlations between the maximum capacity of phosphorus release (Qmax) and the content of total nitrogen (TN), organic matter (OM), calcium-bound phosphorus (Ca-P), and organic phosphorus (OP). But the correlation between Qmax and iron/aluminum-bound phosphorus (Fe/Al-P) content was positive (R2 = 0.6064, P < 0.01), suggesting that Fe/Al-P might be the main contributor to the released phosphorus in the sediments.

scholarly journals Preparation and Assessment of Some Characteristics of Nanoparticles Based on Sodium Alginate, Chitosan, and Camellia chrysantha Polyphenols

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Phu Hoang Luong ◽  
Thuy Chinh Nguyen ◽  
The Dan Pham ◽  
Do Mai Trang Tran ◽  
Thi Ngoc Lien Ly ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Release Kinetics ◽  
Release Kinetic ◽  
Ionic Gelation ◽  
Visible Spectroscopy ◽  
Polyphenol Content ◽  
Release Process ◽  
Kinetics Of ◽  
Scanning Electron

This paper presents the characteristics, morphology, and properties of alginate/chitosan/polyphenol nanoparticles, in which polyphenols were extracted from Camellia chrysantha leaves collected in Tam Dao district, Vinh Phuc province (Vietnam). The alginate/chitosan/polyphenol nanoparticles were prepared by ionic gelation method at different polyphenol content. The characteristics and morphology of these nanoparticles were investigated using infrared spectroscopy (IR), ultraviolet-visible spectroscopy (UV-Vis), and scanning electron microscopy (SEM). Release kinetic of polyphenols from the alginate/chitosan/polyphenol nanoparticles was conducted in simulated human body fluids. The release kinetics of polyphenols from the above nanoparticles were also evaluated and discussed. The experimental results showed that the release process of polyphenols from the nanoparticles was dependent on three factors: time, pH of solution, and amount of polyphenols.

scholarly journals Characteristics and Kinetics of Phosphorus Release from Formulated Fertilizer in Clay Loam Soil

KIMIKA ◽  
2019 ◽  
Vol 30 (2) ◽  
pp. 1-4
Author(s):  
Vernadette J. Soriano ◽  
Veronica P. Migo ◽  
Monet Concepcion Maguyon-Detras ◽  
Catalino G. Alfafara
Keyword(s):  
Light Scattering ◽  
Kinetic Model ◽  
Dynamic Light Scattering ◽  
Release Kinetics ◽  
Phosphorus Release ◽  
Particle Dynamic ◽  
Clay Loam ◽  
Clay Loam Soil ◽  
Loam Soil ◽  
Kinetics Of

A kinetic study for the phosphorus release of a formulated CaHAP-Z fertilizer was done to observe its behavior when applied to clay loam soil. The study of release kinetics of CaHAP-Z was done along with CaHAP and the control fertilizer Solophos™ to determine whether the formulated fertilizer can be an alternative for the conventional fertilizer. Results showed that the formulated fertilizer CAHAP-Z contains 3.73% phosphorus with 513.10 nm particle (Dynamic Light Scattering) indicating that the formulated fertilizer can be classified as a nanofertilizer. The formulated CaHAP-Z fertilizer showed the slowest release kinetics compared to the controls. In addition, this study showed that the simple Elovich kinetic model is the general equation that best fits to describe the phosphorus release of fertilizers.

scholarly journals Phosphorus Fractions and Release Factors in Surface Sediments of a Tailwater River in Xinmi City, a Case Study

2021 ◽  
Vol 13 (10) ◽  
pp. 5417
Author(s):  
Shanheng Huang ◽  
Hongbin Xu ◽  
Dan Shang ◽  
Junzhao Liu ◽  
Qiuju Tang ◽  
...  
Keyword(s):  
Total Phosphorus ◽  
Elevated Temperatures ◽  
Organic Phosphorus ◽  
Paper Industry ◽  
Phosphorus Release ◽  
Overlying Water ◽  
Sewage Plant ◽  
P Content ◽  
Hydrodynamic Disturbance ◽  
Alkaline Conditions

The Shuangji River in Xinmi City is a tailwater-type river. Its main water sources are the effluent from the domestic sewage plant, the effluent from the paper industry sewage plant and the coal well. The construction of wastewater treatment facilities in Xinmi city has significantly reduced the amount of total phosphorus (TP) discharged into Shuangji River. However, phosphorus control in rivers where the overlying waters are predominantly tailwaters is still a challenge, especially as the sediment–water interface’s phosphorus exchange mechanism needs to be investigated in detail. In this study, the content and proportion of each phosphorus fraction in the sediment of a tailwater-type river, the Shuangji River, were determined. It was found that the organic phosphorus (OP) and iron-bound phosphorus (Fe-P) content and proportion were high, and the risk of release was relatively high in the section of the river where the overlying water was the tailwater of a sewage plant. Temperature, pH, dissolved oxygen, and hydraulic disturbance were also found to control phosphorus forms’ transformation and release in the sediment. Elevated temperatures mainly stimulated the release of OP and Fe-P from the sediments. The dissolution of calcium-bound phosphorus (Ca-P) is the main pathway for phosphorus release under acidic conditions, whereas, under alkaline conditions, phosphorus release is mainly controlled by ion exchange between OH− and Fe-P and metal oxide-bound phosphorus (Al-P). Aerobic versus anaerobic conditions cause changes in Fe-P content in the sediment mainly by changing Fe ions’ chemical valence. Hydrodynamic disturbance accelerates labile-P release, but once the hydrodynamic disturbance stops, the overlying water dissolved total phosphorus (DTP) concentration rapidly decreases to a similar concentration as before.

THE DISTRIBUTION OF ORGANIC PHOSPHORUS IN BRITISH COLUMBIA SOILS AND ITS RELATIONSHIP TO SOIL CHARACTERISTICS

1965 ◽  
Vol 45 (1) ◽  
pp. 87-95 ◽  
Author(s):  
M. K. John ◽  
P. N. Sprout ◽  
C. C. Kelley
Keyword(s):  
Organic Phosphorus ◽  
Chemical Properties ◽  
The Other ◽  
Organic P ◽  
Significant Relationships ◽  
P Content ◽  
Wide Range ◽  
Relationship Of ◽  
The Relationship ◽  
Total P

The relationship of organic phosphorus content to a number of chemical properties was studied in the surface horizons of 38 soils of six different soil orders in British Columbia.The concentration of organic P ranged from 1.8 to 77.7% of the total P with amounts varying from 21 to 802 p.p.m. The forested soils of the Podzolic and Brunisolic Orders contained the least organic P. However, the wide range in organic P content within some soil orders indicated that its distribution was not entirely characteristic of the soil order.Simple correlation studies between organic P and nitrogen, carbon, pH, per cent base saturation, total P, and free iron in all soils before assigning them to groups indicated that only nitrogen and carbon were significantly related to organic P. Significant relationships between the other variables and organic P were restricted to specific soil orders. The organic P content has been found to be primarily dependent on nitrogen and pH, since the inclusion of the other independent variables in the multiple regression did not significantly change the coefficient of determination.The range of C/organic P and N/organic P ratios for the 38 samples was between 46 and 648 and 5.5 to 57.6 respectively. Soil pH was the only variable studied which could account for the wide variation of these ratios.

scholarly journals In Vitro Release Kinetic Study of Ciprofloxacin HCl from Methocel K15M CR, Methocel K4M CR and Methocel K4M Premium Matrix Tablets

1970 ◽  
Vol 2 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Muhammad Shahidul Islam ◽  
Tasnuva Haque ◽  
Rumana Jahangir ◽  
Kanij Fatema ◽  
Mynol Islam Vhuiyan ◽  
...  
Keyword(s):  
Release Rate ◽  
Release Kinetics ◽  
Hydroxypropyl Methylcellulose ◽  
In Vitro Release ◽  
Matrix Tablets ◽  
Release Kinetic ◽  
Matrix Tablet ◽  
Direct Compression ◽  
Kinetic Order ◽  
Kinetics Of

In the present study Ciprofloxacin HCl sustained release matrix tablet was prepared by utilizing different grades of hydroxypropyl methylcellulose (HPMC) polymers such as Methocel K4M CR, Methocel K4M Premium & Methocel K15M CR by direct compression method. Different amount of Methocel K15M CR was used to develop matrix builder in the three proposed formulations (F1-F3) for the study of release rate retardant effect at 5%, 6%, and 7% of total weight of tablet matrix respectively. The dissolution study of Methocel K15M CR based tablet matrices of those proposed formulations were carried out in the simulated gastric medium (pH 1.3) for 8 hours using USP dissolution apparatus II. Similarly Methocel K4M premium was used to develop matrix builder in another three proposed formulations (F4-F6). It was found that formulations F-4 (15%), F-5 (17%) and F-6 (18.3%) met the desired release rate of Ciprofloxacin HCl for 8hrs period. The release kinetics of formulation F-4, F-5 and F-6 followed Higuchi kinetic order. Again Methocel K4M premium was used for another three proposed formulations (F7-F9). It was found that formulations F-7 (6.7%), F-8 (12.3%) and F-9 (15.6%) met the desired release rate of Ciprofloxacin HCl for 8hrs period. The release kinetics of formulation F-7, F-8 and F-9 followed Higuchi kinetic order. Among these three polymers, Methocel K4M Premium showed better release retardant effect than Methocel K4M CR and Methocel K15M CR. Key Words: Ciprofloxacin HCl; Direct compression; Controlled release; Methocel K15M CR; Methocel K4M CR; Methocel K4M premium.DOI: 10.3329/sjps.v2i1.5814Stamford Journal of Pharmaceutical Sciences Vol.2(1) 2009: 37-43

Heavy Metals (Cu and Zn) Release Kinetics in a Sediment Sample from the Inlet of Baihua Lake, China

2012 ◽  
Vol 599 ◽  
pp. 81-85
Author(s):  
Ji Ping Zhang ◽  
Ji Wei Hu ◽  
Xian Fei Huang ◽  
Jin Mei ◽  
Wei Shen ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Sediment Sample ◽  
Ph Value ◽  
Release Kinetics ◽  
Relationship Of ◽  
The Relationship ◽  
Kinetics Of ◽  
Best Fit ◽  
Metals Release ◽  
Cu And Zn

Release kinetics of two selected heavy metals (Cu and Zn) in a sediment sample collected from the inlet of Baihua Lake was determined. The results show that the double-constant equation was considered as the best-fit equations describing the relationship of Cu and Zn release and time in the sediment from the inlet of the lake (R2 = 0.9759, 0.9226, P<0.01). The effects of temperature, acidity, salinity, and the water/soil ratio on the releasing of heavy metals in sediment sample were also investigated. The heavy metals release would increase as the temperature increased. A low pH value could promote the heavy metals release. The heavy metals in the sediment tended to be released under a relatively high salinity condition. The amount of the heavy metals released from the sediment decreased with the increase of the water/soil ratio.

Models for potassium release kinetics of four Humic Gleysols high in clay by electro-ultrafiltration

2001 ◽  
Vol 81 (5) ◽  
pp. 603-611 ◽  
Author(s):  
N. Ziadi ◽  
R. R. Simard ◽  
T. S. Tran
Keyword(s):  
Solid Phase ◽  
Release Kinetics ◽  
Order Equation ◽  
K Uptake ◽  
First Order ◽  
Incremental Model ◽  
Release Data ◽  
First Time ◽  
Kinetics Of ◽  
K Release

The rate of K release from the soil solid phase to its solution, especially from its rapidly and slowly exchangeable forms, can affect plant K uptake. The electro-ultrafiltration (EUF) technique was used to kinetically characterize the K release from four soils (Humic Gleysols) from Abitibi-Temiscaming, Quebec, Canada. Potassium was desorbed from soils that received over 166 kg K ha-1 yr-1 from 1994 to 1996. The desorption was carried out for 58 min (4, 4, and every 5 min thereafter for a total of 12 desorptions) at 400 V and 80°C. The amount of K desorbed was between 199 and 342 mg kg-1. Cumulative K desorption was described by the following six equations: power function, simplified Elovich, extended Elovich, parabolic diffusion, zero-order, and first-order. An incremental first-order equation was also tested. The studied soils have large K supplying capacities as suggested by forage K-uptake and total soil K desorption by EUF. In general, all tested equations adequately described the K release by EUF from the four soils. The incremental first-order equation, used for the first time, described well the soil K release data. The k rate constant from this model was significantly related to forage K uptake (R2 = 0.58). Results from this study indicate that the investigated soils have large K reserves and that the incremental first-order equation and most of the cumulative ones are suitable for describing the kinetics of the large K release from these fine-textured Gleysols. Key Words: Potassium, desorption, cumulative model, incremental model

scholarly journals FORMULA OPTIMIZATION AND IN VITRO RELEASE KINETIC STUDIES OF DILTIAZEM HYDROCHLORIDE MUCOADHESIVE BILAYER BUCCAL FILM

2021 ◽  
pp. 7-12
Author(s):  
LINA WINARTI ◽  
AFALAH ZULFA LAILY ◽  
LUSIA OKTORA RUMA KUMALA SARI ◽  
EKA DEDDY IRAWAN ◽  
DWI NURRAHMANTO ◽  
...  
Keyword(s):  
Release Kinetics ◽  
Hydroxypropyl Methylcellulose ◽  
In Vitro Release ◽  
Kinetic Studies ◽  
Release Kinetic ◽  
Diltiazem Hydrochloride ◽  
Optimum Formula ◽  
Kinetics Of ◽  
Vitro Release

Objective: This research aims to determine the amount of hydroxypropyl methylcellulose (HPMC) and chitosan, which can produce the optimum buccal film formula and to determine the release kinetics of diltiazem hydrochloride in vitro. Methods: The film was prepared by the solvent casting method. The formula's optimization was carried out using factorial design, which was processed using Design Expert 11.0.0 software, while the release kinetics was analyzed using the DDSolver program. Results: The optimization results show that HPMC and chitosan (30 mg: 10 mg) is the amount of polymer that can produce the optimum formula. The buccal film formula has a swelling index of 2.92, a mucoadhesive strength of 64.40 gF, and a mucoadhesive residence time of 464 min. In vitro release study showed 97.64% release of Diltiazem hydrochloride after 480 min. The release kinetic’s of diltiazem hydrochloride follow the Korsmeyer Peppas model. Conclusion: Thus, it can be concluded that the prepared formulation of the buccal mucoadhesive film can be a delivery system for diltiazem hydrochloride.

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