Seasonal variability and kinetics of phosphate removal in a Phragmites-based engineered wetland

2021 ◽  
Author(s):  
Harsh Pipil ◽  
A. K. Haritash ◽  
Krishna R. Reddy
Keyword(s):  
Seasonal Variability ◽  
Phosphate Removal ◽  
Engineered Wetland ◽  
Kinetics Of

Effect of Operating Conditions on the Chemical Phosphate Removal Using during Ferrous Iron Oxidation

2013 ◽  
Vol 807-809 ◽  
pp. 478-485 ◽  
Author(s):  
Ting Li ◽  
Wen Yi Dong ◽  
Hong Jie Wang ◽  
Jin Nan Lin ◽  
Feng Ouyang ◽  
...  
Keyword(s):  
Ferrous Iron ◽  
Removal Rate ◽  
Iron Oxidation ◽  
Operating Conditions ◽  
Phosphate Removal ◽  
Order Kinetic ◽  
Ferrous Iron Oxidation ◽  
Order Kinetic Model ◽  
Time Required ◽  
Kinetics Of

In this study, the effect of operating parameters and the co-existing ions on the phosphate removal during the ferrous iron oxidation was investigated. Results showed that with the increase of DO and [Fe (II)]0, the final phosphate removal rate both increased. But with increasing of pH, the final phosphate removal rate firstly increased and then decreased when the pH was higher than 8.0. The co-existing ions affected the final removal rate significantly, and the kinetics of phosphate removal followed the pseudo-first-order kinetic model. The corresponding kobs trends for the cation followed the order of Cu2+>Mn2+>Zn2+>NH4+-N. The presence of Cu2+ promoted the phosphate removal significantly. Compared with the control, , the time required to achieve 40 % phosphate removal rate, at the condition of 0.5 mg/L Cu2+, reduced from 60 min to 10 s. However, the selective anions inhibited the phosphate removal, due to the formation of Fe-anions complexes. The effect of selective anions on the phosphate removal rate constant decreased in the order of SO42->Cl-> NO3-.

Kinetics of Simultaneous Ammonium and Phosphate Recovery by Natural Zeolite

2021 ◽  
Vol 5 (4) ◽  
pp. 68
Author(s):  
Sandro Pesendorfer ◽  
Markus Ellersdorfer
Keyword(s):  
Ion Exchange ◽  
Natural Zeolite ◽  
Large Scale ◽  
Ph Value ◽  
Exchange Process ◽  
Phosphate Removal ◽  
Synthetic Wastewater ◽  
Nutrient Recovery ◽  
Phosphate Recovery ◽  
Kinetics Of

Nowadays, fertilizers containing nitrogen and phosphorus are indispensable for medium and large-scale industrial agriculture. To meet the growing demand of nutrients and reduce the accompanied ecological footprint of primary fertilizer production, processes and technologies for nutrient recovery are necessary and have to be developed. This study represents the basis of an extension of the ion-exchange-loop-stripping process (ILS), which is a combined stripping and ion exchange process using natural zeolite for nitrogen recovery. In batch experiments with a special zeolite filled stirrer, the mechanism and kinetics of simultaneous ammonium and phosphate recovery by natural zeolite were determined. Zeolite loadings of 6.78 mg PO43− g−1 were reached and after regeneration, phosphate recovery rates up to 75% of the initial concentration were achieved. The speed of phosphate precipitation is mostly controlled by the pH value of synthetic wastewater. Phosphate removal in simultaneous experiments does not affect ammonium sorption onto zeolite. These findings and the different removal mechanisms of ammonium and phosphate lead to versatile applications in wastewater treatment and reveal great potential of natural zeolite in simultaneous nutrient recovery processes.

Seasonal variability in the kinetics of Cu, Pb, Cd and Hg accumulation by macroalgae

2001 ◽  
Vol 74 (1) ◽  
pp. 65-85 ◽  
Author(s):  
M.Teresa S.D Vasconcelos ◽  
M.Fernanda C Leal
Keyword(s):  
Seasonal Variability ◽  
Kinetics Of ◽  
Hg Accumulation

Disappearance kinetics of 2,4- and 3,4-dichlorophenol in a fluvial system

1984 ◽  
Vol 62 (8) ◽  
pp. 971-975 ◽  
Author(s):  
J. H. Carey ◽  
M. E. Fox ◽  
B. G. Brownlee ◽  
J. L. Metcalfe ◽  
R. F. Platford
Keyword(s):  
Rate Constants ◽  
Seasonal Variability ◽  
Controlling Factor ◽  
Fluvial System ◽  
Small Stream ◽  
Ecological Zones ◽  
First Order ◽  
First Order Kinetics ◽  
Kinetics Of ◽  
Disappearance Kinetics

The disappearance rates of 2,4- and 3,4-dichlorophenol in a small stream were studied and were shown to be first order with respect to either distance or time of flow. Both chlorophenols disappeared at approximately the same rate with average half-lives in the stream of about 4 h. The absence of seasonal variability in the rate constants along with the observance of first order kinetics over several ecological zones of the stream led to the conclusion that the rate controlling factor was not biological. It is suggested that the disappearance was due to degradation within the biofilm covering the stream bed and that the rate is controlled by diffusion of the chlorophenols across the water–biofilm interface.

Urea, Creatinine and Phosphate Kinetic Modeling during Dialysis: Application to Pediatric Hemodialysis

1995 ◽  
Vol 18 (3) ◽  
pp. 122-129 ◽  
Author(s):  
M. Maasrani ◽  
M.Y. Jaffrin ◽  
M. Fischbach ◽  
B. Boudailliez
Keyword(s):  
Mass Transfer ◽  
Pediatric Patients ◽  
Large Time ◽  
Phosphate Removal ◽  
Transfer Coefficients ◽  
Pediatric Hemodialysis ◽  
Fluid Shifts ◽  
Pool Model ◽  
Kinetics Of ◽  
Phosphate Influx

The kinetics of urea, creatinine and phosphate removal during dialysis were investigated in pediatric patients using a two-pool model taking into account fluid shifts and mass transfer between the two compartments. It is found that even urea must be described by a two-pool model since it presents a post dialysis rebound due to equilibration between the two compartments. Phosphate plasma concentration drops very sharply during the first hour of dialysis and rises rapidly during the rebound period. This pattern cannot be accounted for by the classical two-pool model with constant generation rate and mass transfer coefficients, but corresponds to a large time-dependent phosphate influx from the intracellular compartment in which phosphate is generated by biochemical reactions or liberated from the bones. This influx was calculated for four patients representing 8 dialysis sessions and was found to reach a plateau after 90 minutes of dialysis, dropping rapidly during the rebound period.

Adsorption of Phosphate on Mg/Fe Layered Double Hydroxides with Different Anions Intercalation

2015 ◽  
Vol 737 ◽  
pp. 524-527
Author(s):  
Yan Wei Guo ◽  
Hua Zhang ◽  
Zhi Liang Zhu
Keyword(s):  
Layered Double Hydroxides ◽  
Phosphate Removal ◽  
Order Kinetic ◽  
Solution Ph ◽  
Adsorption Ability ◽  
Freundlich Adsorption Isotherm ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Double Hydroxides ◽  
Kinetics Of

Three kinds of Mg/Fe layered double hydroxides (LDHs) with different intercalation anions (NO3-, Cl- and CO32-) were synthesized and used as adsorbents for the removal of phosphate in aqueous solutions. Results showed that the phosphate removal decreased with the increase of solution pH from 3.0 to 11.0. The adsorption behavior of phosphate followed the Freundlich adsorption isotherm. LDHs-NO3- had the highest adsorption ability for phosphate, the followed order was LDHs-Cl- and LDHs-CO32-. The adsorption kinetics of phosphate onto the three kinds of LDHs fit the pseudo-second-order kinetic model.

Preparation of Mesoporous Gamma Alumina Derived from Waste Can for Nutrient Recovery Process

2020 ◽  
Vol 20 (7) ◽  
pp. 4267-4270
Author(s):  
Seong Gyu Seo ◽  
Kyung-Jun Hwang ◽  
Ho-Hyun Ahn ◽  
Wang Geun Shim ◽  
Min-Jin Hwang
Keyword(s):  
Low Temperature ◽  
Pore Size ◽  
Hydrothermal Method ◽  
Recovery Process ◽  
Phosphate Removal ◽  
Nutrient Recovery ◽  
Precipitation Process ◽  
Gamma Alumina ◽  
Adsorption Isotherms And Kinetics ◽  
Kinetics Of

Mesoporous gamma alumina (MGA) was synthesized using aluminum trash containers by a low temperature hydrothermal method for effectively removing phosphate from wastewater. The effects of precursor concentrations in gel precipitation process over the pore size and surface area of MGA were investigated in detail. The phosphate removal by prepared MGAs were rigorously investigated through adsorption isotherms and kinetics of phosphate.

Direct observations of radiation-enhanced transformations in glass

1983 ◽  
Vol 41 ◽  
pp. 354-355
Author(s):  
J. F. DeNatale ◽  
D. G. Howitt
Keyword(s):  
Glass Matrix ◽  
Diffusion Mechanism ◽  
Bubble Formation ◽  
Silicate Glasses ◽  
Phase Decomposition ◽  
Direct Observations ◽  
Thin Foils ◽  
Oxygen Bubble ◽  
Electron Energy Loss ◽  
Kinetics Of

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

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