scholarly journals Controlled preparation of a MCC-g-AM/EDA/PA loaded Fe(iii) adsorbent by the pre-radiation grafting method and its application for the adsorption removal of phosphate

RSC Advances ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 6173-6181
Author(s):  
Yuan Zhao ◽  
Jin-Yu Yang ◽  
Ting-Ting Li ◽  
Guo Liu ◽  
Ya-Yang Wang ◽  
...  
Keyword(s):  
Chemical Modification ◽  
Microcrystalline Cellulose ◽  
Phthalic Anhydride ◽  
Removal Rate ◽  
Phosphate Removal ◽  
Radiation Grafting ◽  
Adsorption Removal ◽  
Modification Method ◽  
Controlled Preparation ◽  
High Phosphate

A new spherical cellulose-based adsorbent and high phosphate removal rate microcrystalline cellulose-g-acrylamide/ethylenediamine/phthalic anhydride (MCC-g-AM/EDA/PA) loaded Fe(iii) adsorbent was prepared by a pre-radiation grafting and chemical modification method.

scholarly journals Phosphate Removal Using Polyethylenimine Functionalized Silica-Based Materials

2021 ◽  
Vol 13 (3) ◽  
pp. 1502
Author(s):  
Maria Xanthopoulou ◽  
Dimitrios Giliopoulos ◽  
Nikolaos Tzollas ◽  
Konstantinos S. Triantafyllidis ◽  
Margaritis Kostoglou ◽  
...  
Keyword(s):  
Sorption Capacity ◽  
Removal Rate ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Equilibrium Studies ◽  
Maximum Sorption Capacity ◽  
Algae Blooms ◽  
Maximum Sorption ◽  
Phosphate Anions ◽  
Adsorbent Dose

In water and wastewater, phosphate anions are considered critical contaminants because they cause algae blooms and eutrophication. The present work aims at studying the removal of phosphate anions from aqueous solutions using silica particles functionalized with polyethylenimine. The parameters affecting the adsorption process such as pH, initial concentration, adsorbent dose, and the presence of competitive anions, such as carbonate, nitrate, sulfate and chromate ions, were studied. Equilibrium studies were carried out to determine their sorption capacity and the rate of phosphate ions uptake. The adsorption isotherm data fitted well with the Langmuir and Sips model. The maximum sorption capacity was 41.1 mg/g at pH 5, which decreased slightly at pH 7. The efficiency of phosphate removal adsorption increased at lower pH values and by increasing the adsorbent dose. The maximum phosphate removal was 80% for pH 5 and decreased to 75% for pH 6, to 73% for pH 7 and to 70% for pH 8, for initial phosphate concentration at about 1 mg/L and for a dose of adsorbent 100 mg/L. The removal rate was increased with the increase of the adsorbent dose. For example, for initial phosphate concentration of 4 mg/L the removal rate increased from 40% to 80% by increasing the dose from 0.1 to 2.0 g/L at pH 7. The competitive anions adversely affected phosphate removal. Though they were also found to be removed to a certain extent. Their co-removal provided an adsorbent which might be very useful for treating waters with low-level multiple contaminant occurrence in natural or engineered aquatic systems.

Evaluation and thermodynamic calculation of ureolytic magnesium ammonium phosphate precipitation from UASB effluent at pilot scale

2012 ◽  
Vol 65 (11) ◽  
pp. 1954-1962 ◽  
Author(s):  
E. Desmidt ◽  
K. Ghyselbrecht ◽  
A. Monballiu ◽  
W. Verstraete ◽  
B. D. Meesschaert
Keyword(s):  
Removal Efficiency ◽  
Pilot Plant ◽  
Saturation Index ◽  
Ammonium Phosphate ◽  
Phosphate Removal ◽  
Operational Cost ◽  
Magnesium Ammonium Phosphate ◽  
Magnesium Ammonium ◽  
Ph Increase ◽  
High Phosphate

The removal of phosphate as magnesium ammonium phosphate (MAP, struvite) has gained a lot of attention. A novel approach using ureolytic MAP crystallization (pH increase by means of bacterial ureases) has been tested on the anaerobic effluent of a potato processing company in a pilot plant and compared with NuReSys® technology (pH increase by means of NaOH). The pilot plant showed a high phosphate removal efficiency of 83 ± 7%, resulting in a final effluent concentration of 13 ± 7 mg · L−1 PO4-P. Calculating the evolution of the saturation index (SI) as a function of the remaining concentrations of Mg2+, PO4-P and NH4+ during precipitation in a batch reactor, resulted in a good estimation of the effluent PO4-P concentration of the pilot plant, operating under continuous mode. X-ray diffraction (XRD) analyses confirmed the presence of struvite in the small single crystals observed during experiments. The operational cost for the ureolytic MAP crystallization treating high phosphate concentrations (e.g. 100 mg · L−1 PO4-P) was calculated as 3.9 € kg−1 Premoved. This work shows that the ureolytic MAP crystallization, in combination with an autotrophic nitrogen removal process, is competitive with the NuReSys® technology in terms of operational cost and removal efficiency but further research is necessary to obtain larger crystals.

scholarly journals Room-temperature dissolution and chemical modification of cellulose in aqueous tetraethylammonium hydroxide–carbamide solutions

Cellulose ◽  
2019 ◽  
Vol 27 (4) ◽  
pp. 1933-1950 ◽  
Author(s):  
Juho Antti Sirviö ◽  
Juha P. Heiskanen
Keyword(s):  
Chemical Modification ◽  
Charge Density ◽  
Microcrystalline Cellulose ◽  
Room Temperature ◽  
Molar Ratio ◽  
Cellulose Modification ◽  
Tetraethylammonium Hydroxide ◽  
Cellulose Concentration

AbstractThe room-temperature dissolution of cellulose in aqueous tetraethylammonium hydroxide (TEAOH) in the presence of carbamides (ureas) was investigated. Without carbamide, 35 wt% TEAOH was able to dissolve cellulose (microcrystalline cellulose) up to 3 wt%, whereas carbamides—such as urea, N-methylurea, N-ethylurea, 1,3-dimethylurea, and imidazolidone—were able to improve the dissolution of cellulose. At 5 wt% cellulose concentration, the highest carbamide contents in the solvent still able to dissolve cellulose within 1 h were 56 and 55 wt% of 1,3-dimethylurea and N-methylurea, respectively. When using urea, up to 15% of cellulose could be dissolved in a solution containing 22 wt% of urea. To demonstrate the possibility of the use of a carbamide-based solvent in cellulose modification, cationic cellulose was produced using glycidyltrimethylammonium chloride (GTAC). At a molar ratio of 1:3 of cellulose and GTAC, all the studied TEAOH–carbamide solvents produce cationic cellulose with higher charge density compared to the reference NaOH–urea solvent.

Effect of Environment Factors on Phosphorus Removal Efficiency of Phosphate Reduction System

2011 ◽  
Vol 255-260 ◽  
pp. 2797-2801
Author(s):  
Chen Yao ◽  
Chun Juan Gan ◽  
Jian Zhou
Keyword(s):  
Removal Efficiency ◽  
Phosphorus Removal ◽  
Ph Value ◽  
Removal Rate ◽  
Mass Rearing ◽  
Phosphate Removal ◽  
Environment Factors ◽  
Reduction System ◽  
Initial Ph ◽  
The Impact

Effect of environment factors such as initial pH value, dissolved oxygen (DO) and temperature on phosphorus removal efficiency of phosphate reduction system was discussed in treating pickled mustard tube wastewater. Results indicate that environment factors have significant influence on dephosphorization efficiency. And, the impact of DO on phosphate reduction is mainly by affecting the distribution of micro-environment inner biofilm, manifest as phosphate removal rate decreased with a fall in DO concentration, while overhigh DO can lead to detachment of biofilm, thus causing the increase of effluent COD concentration, and so DO need to be controlled in the range of 6 mg/L. Moreover, a higher temperature is more beneficial to phosphorus removal by PRB. Unfortunately, exorbitant temperature can result in mass rearing of Leuconostoc characterized with poor flocculability in reactor, and that cause turbidity in effluent appeared as a rise in COD of effluent. Hence, the optimal temperature is found to be about 30°C.

NONTRADITIONAL METHOD OF CHEMICAL MODIFICATION OF THE SURFACE OF POROUS SILICA

2020 ◽  
Vol 54 (1 (251)) ◽  
pp. 33-37
Author(s):  
T.O. Kamalyan
Keyword(s):  
Chemical Modification ◽  
Porous Silica ◽  
Chemical Transport Reaction ◽  
Transport Reaction ◽  
Texture Parameters ◽  
Nontraditional Method ◽  
Modification Method ◽  
Gaseous Intermediate ◽  
Proposed Modification ◽  
Modification Of The Surface

The main results obtained in the study of the possibility of low-temperature chemical modification of porous silica, applying various nanodispersed substances to their surface are given. It has been shown that the use of the chemical transport reaction (CTR) $ \mathrm{H_{2}O_{2}/ZnO} $ for this purpose with the participation of $ \mathrm{H_{2}O_{2}} $ vapors at room temperature makes it possible to apply a number of oxides, sulfides and metal halides to the surface of various sorbents. An important advantage of the proposed modification method is that changes in the original texture parameters of the substrate are minimized. Using the example of modifying the behavior of highly pure $ \mathrm{SiO_{2}} $ with zinc oxide, it was shown that the decomposition of gaseous intermediate products of CTR $ \mathrm{H_{2}O_{2}/ZnO} $ occurs mainly in pores with a diameter of more than $ 6~nm $.

The Aeration Time Influence on the Brewery Wastewater Treatment in SBR

2011 ◽  
Vol 183-185 ◽  
pp. 1200-1203
Author(s):  
Jun Sheng Li ◽  
Zhi Wei Zhao ◽  
Jin Long Zuo
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Removal Rate ◽  
Phosphate Removal ◽  
Experimental Result ◽  
Brewery Wastewater ◽  
Aeration Time

The effect s of aeration time on the treatment of brewery wastewater in SBR reactor were investigated by using synthetic brewery wastewater. The experimental result indicates that under the condition of influent COD is 300～650mg/L, the temperature is 25°C, continual aerations is 2.5 h and sludge density is 2000～3000 mg/L, the reactor has a good degeneration ability of COD and NH4+-N in simulation brewery wastewater，removal rate can reached 90 % or more，phosphate removal efficiency was above 70%. so the SBR technology is feasible．

Optimization of Crystallization of Magnesium Ammonium Phosphate: Initial Phosphate Concentration, PH and Reactants Molar Ratio

2013 ◽  
Vol 295-298 ◽  
pp. 1289-1292 ◽  
Author(s):  
Kai Huang ◽  
Li Ping Qiu ◽  
Jin Feng Meng ◽  
Dong Wang
Keyword(s):  
Ph Value ◽  
Removal Rate ◽  
Ammonium Phosphate ◽  
Xrd Analysis ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Molar Ratio ◽  
Septic Tank ◽  
Magnesium Ammonium Phosphate ◽  
Magnesium Ammonium

By- products are widespread in the crystallization of magnesium ammonia phosphate (MAP) as the differences in reactive conditions which effects the forms and habits of crystals. The study focused on the supernatant from septic tank in order to achieve in-situ treatment. Based on the effluent, the optimization research of initial phosphate concentration and pH was investigated by using single factor analysis. The crystal products with different reaction condition were also characteristiced through the XRD analysis. The experimental results showed that the optimum reactants molar ratio of n(NH4+):n(Mg2+):n(PO43-) were 90:25:1, 4:1.6:1 and 3:1.4:1 when pH value was 9.5 with initial phosphate concentration 8mg/L, 50mg/L and 100mg/L, respectively. It was also observed that the phosphate removal rate increased with increasing the initial phosphate concentration or pH value. As the aging time increased, the removal rate was in parabolic curve with 30 minute at the highest point. The XRD analysis revealed that the best MAP crystal could be produced with initial phosphate concentration 50mg/L and pH 9.0.

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-.

Influencing Factors of the In Situ Formed Iron Hydroxide (FeOxHy) on the Removal of Phosphate by Coagulation and Adsorption

2013 ◽  
Vol 864-867 ◽  
pp. 1772-1778 ◽  
Author(s):  
Li Hua Sun ◽  
Tian Min Yu ◽  
Xue Ru Chen ◽  
Xiao Lu Qi ◽  
Ya Jun Zhang
Keyword(s):  
Ph Value ◽  
Removal Rate ◽  
Iron Hydroxide ◽  
Phosphate Removal ◽  
Chemical Action ◽  
Mass Unit ◽  
Molar Ratios ◽  
Hydroxyl Ion ◽  
Water Ph

This study prepared the in situ formed iron hydroxide (in situ FeOxHy) by the interactions between Fe3+ and OH- at different molar ratios of 1:0, 1:1, 1:2 and 1:3. The influences of molar ratios and pH on the removal of phosphate were investigated and the surface of in situ FeOxHy before and after adsorption was analyzed. The phosphate removal rate with mass unit iron hydroxide is greater at the molar ratios of 1:3 between Fe3+ and OH-. The phosphate removal rate is maximum at the pH 6~7. The compatibility of iron hydroxide towards raw water pH value is better when the proportion of hydroxyl ion is greater. The disposal effect is good at the pH 4~9. The iron hydroxide formed at different molar ratios is not definitive shape and it can remove phosphate by the chemical action of adsorption and sedimentation.

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