scholarly journals The Investigation of Some Factors Influencing to the For-mation of Monocalcium Phosphate in Aqueous Medium

2019 ◽  
Vol 57 (2) ◽  
pp. 179
Author(s):  
Duc Hong Ta ◽  
Bac Quang Nguyen
Keyword(s):  
Aqueous Solution ◽  
Phosphoric Acid ◽  
Aqueous Medium ◽  
Reaction Temperature ◽  
Initial Concentration ◽  
Monocalcium Phosphate ◽  
Reaction Duration ◽  
Factors Influencing

Some factors that influence to the formation of monocalcium phosphate in aqueous solution have been investigated in detail. The results show that reaction temperature, and initial concentration of phosphoric acid, as well as reaction duration determine the content of monocalcium phosphate in the processing mixture. The information in this report will be useful, and the basis for the design of the synthesis reactor in the monocalcium phosphate production

Parameter Screening for the Important Factors Influencing the As(V) Adsorption Using a Plackett-Burman Design

2014 ◽  
Vol 931-932 ◽  
pp. 178-182
Author(s):  
Nusavadee Pojananukij ◽  
Kitirote Wantala ◽  
Sutasinee Neramittagapong ◽  
Arthit Neramittagapong
Keyword(s):  
Aqueous Solution ◽  
Batch Reactor ◽  
Operating Parameters ◽  
Adsorption Efficiency ◽  
Initial Concentration ◽  
Factors Influencing ◽  
Adsorption Temperature ◽  
Burman Design ◽  
Plackett Burman Design ◽  
Adsorbent Dose

The adsorption efficiency of As (V) ions from an aqueous solution was investigated. The adsorption experiments were carried out in a batch reactor. The effects of operating parameters; i.e. the absorbent dose (g/L), the pH, the adsorption temperature (°C), the As (V) initial concentration (ppb), and type of adsorbents, on the adsorption efficiencies were studied. A PlackettBurman experimental design was used to screen for the important factors that influence As (V) adsorption. It has been found that the most important effect on the As (V) adsorption capacity was the type of adsorbent. The factor importance could be written in descending order as follows: the type of adsorbents, the adsorbent dose, the As (V) initial concentration, the adsorption temperature, and the pH.

Electrochemical Dechlorination of Triclosan on Palladium/Polypyrrole-Reduced Graphene Oxide/Foam Nickel Composite Electrode

2020 ◽  
Vol 12 (9) ◽  
pp. 1300-1304
Author(s):  
Junjing Li ◽  
Ziyan Qi ◽  
Leqi Fang ◽  
Cong Luan ◽  
Juan Li ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Reaction Temperature ◽  
Composite Electrode ◽  
Applied Current ◽  
Initial Concentration ◽  
Reduced Graphene ◽  
Foamed Nickel

In this study, the electrochemical dechlorination of triclosan in aqueous solution on palladium/polypyrrolereduced graphene oxide/foamed nickel composite electrode (Pd/PPy-rGO/foam-Ni electrode) was investigated. The influences of the applied current, reaction temperature and the initial concentration of triclosan solution on triclosan dechlorination efficiency were studied. The triclosan can be completely removed within 180 min under the conditions of the dechlorination current of 7 mA and dechlorination temperature of 40 °C when the initial concentration of triclosan was 50 mg · L–1 .

Photolysis of cyflufenamid in liquid media

2018 ◽  
Vol 78 (2) ◽  
pp. 424-431
Author(s):  
Zhangyu Zheng ◽  
Chunyan Zhang ◽  
Haiyan Shi ◽  
Zhiwei Liu ◽  
Jinsheng Duan ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Aqueous Solution ◽  
Ultraviolet Irradiation ◽  
Ultrapure Water ◽  
Liquid Media ◽  
Initial Concentration ◽  
First Order ◽  
Positive Effects ◽  
First Order Kinetics ◽  
Factors Influencing

Abstract The photolysis of cyflufenamid (CFA) in different organic solvents and water under ultraviolet irradiation was investigated. The photolytic rate constant and photolytic half-life were measured for the different solutions. Factors influencing the photolysis of CFA were investigated, including initial concentration, types of solvent, pH, occurrence of catalyst (TiO2), and environmental substances (Fe3+, Fe2+, NO3−, NO2−). Photolysis of CFA followed first-order kinetics in various systems, and the photolytic rate of CFA decreased with increased initial concentration. Photolytic rates of CFA in different solvents were as follows: n-hexane > methanol > acetonitrile > ultrapure water > ethyl acetate. The pH had a significant effect on the photolysis of CFA, and the photolysis rate reached its peak at pH 9.0. NO2− and TiO2 had positive effects on the photolysis of CFA, while Fe2+ had an adverse effect. NO3− in aqueous solution had no effect on the photolysis of CFA. In addition, the rates of photolysis were accelerated at lower concentrations of Fe3+ (0.5–5 mmol L−1) and decreased at higher concentrations (10 mmol L−1). Moreover, a main photolytic product of CFA was confirmed to be N-cyclopropoxy-2,3-difluoro-6-(trifluoromethyl)benzamide, and cleavage of the amido bond was proposed to be the predicted photolysis pathway in n-hexane.

scholarly journals PREPARATION OF FEED-GRADE MONOCALCIUM PHOSPHATE BY CRYSTALLIZATION IN AQUEOUS MEDIUM: CALCULATION AND EXPERIMENTS

2021 ◽  
Vol 59 (5) ◽  
Author(s):  
Ta Hong Duc
Keyword(s):  
Phosphoric Acid ◽  
Acid Solution ◽  
Aqueous Medium ◽  
Crystallization Temperature ◽  
Mother Liquor ◽  
Animal Feed ◽  
Phosphoric Acid Solution ◽  
Feed Additives ◽  
Monocalcium Phosphate ◽  
Crystallization Method

In this paper, we present the results of calculation, and experiments for the preparation of feed-grade monocalcium phosphate by crystallization method in phosphoric acid solution. Some parameters influence to the production such as the reaction and crystallization temperature, the ratio of recycle mother liquor to reactant mixture have been investigated. The results show that the crystallization method in the preparation of monocalcium phosphate will give product with higher quality, less impurities that will be suitable for animal feed additives. 

Optimization of phosphogypsum conversion into calcium carbonate and lithium sulfate monohydrate

2021 ◽  
Vol 109 (2) ◽  
pp. 202
Author(s):  
Yassine Ennaciri ◽  
Mohammed Bettach
Keyword(s):  
Calcium Carbonate ◽  
Phosphoric Acid ◽  
Environmental Risk ◽  
Lithium Sulfate ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Initial Concentration ◽  
Reaction Duration ◽  
X Ray ◽  
Influential Parameters

Phosphogypsum (PG) is an acidic by-product generated during the production of phosphoric acid. Usually this by-product is stockpiled or dumped into water bodies, which causes several environmental pollution problems. The aim of this work is to reduce this environmental risk by producing CaCO3 and Li2SO4.H2O from the conversion of PG by Li2CO3. To optimize the reaction conditions, four parameters have been investigated such as the initial concentration of the reagents, the reaction duration, the temperature and the gypsum purity. In addition, the nature of the resulting products was proved principally by X-ray diffraction technic. The obtained results show that the initial concentration of the reagents and the reaction duration are the most influential parameters, while the temperature has no significance effect on this reaction. Also, the acidity and the presence of impurities into PG induce its reactivity compared than commercial gypsum. The purity of the formed CaCO3 and Li2SO4.H2O at the optimum conversion of PG is 96.08 and 98.71% respectively.

Comparative Bio-sorption of Cadmium and Nickel Ions from Aqueous Solution onto Fibers of Date Palm using Fluidized Bed Column

2019 ◽  
Vol 70 (5) ◽  
pp. 1507-1512
Author(s):  
Baker M. Abod ◽  
Ramy Mohamed Jebir Al-Alawy ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Fluidized Bed ◽  
Removal Efficiency ◽  
Heavy Metal Ions ◽  
Date Palm ◽  
Operating Conditions ◽  
Initial Concentration ◽  
Bed Height

The aim of this study is to use the dry fibers of date palm as low-cost biosorbent for the removal of Cd(II), and Ni(II) ions from aqueous solution by fluidized bed column. The effects of many operating conditions such as superficial velocity, static bed height, and initial concentration on the removal efficiency of metal ions were investigated. FTIR analyses clarified that hydroxyl, amine and carboxyl groups could be very effective for bio-sorption of these heavy metal ions. SEM images showed that dry fibers of date palm have a high porosity and that metal ions can be trapped and sorbed into pores. The results show that a bed height of 6 cm, velocity of 1.1Umf and initial concentration for each heavy metal ions of 50 mg/L are most feasible and give high removal efficiency. The fluidized bed reactor was modeled using ideal plug flow and this model was solved numerically by utilizing the MATLAB software for fitting the measured breakthrough results. The breakthrough curves for metal ions gave the order of bio-sorption capacity as follow: Cd(II)]Ni(II).

Use of Nanopillars-TiO2 Thin Films in the Photocatalytic Degradation of Bromophenol Blue from Aqueous Solution

2018 ◽  
Vol 6 (1) ◽  
pp. 22-30
Author(s):  
C. Lalhriatpuia ◽  
◽  
Thanhming liana ◽  
K. Vanlaldinpuia
Keyword(s):  
Thin Films ◽  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Batch Reactor ◽  
Bromophenol Blue ◽  
Tio2 Thin Films ◽  
Initial Concentration ◽  
Bet Specific Surface Area ◽  
Interfering Ions

The photocatalytic activity of Nanopillars-TiO2 thin films was assessed in the degradation of Bromophenol blue (BPB) dye from aqueous solution under batch reactor operations. The thin films were characterized by the XRD, SEM and AFM analytical methods. BET specific surface area and pore sizes were also obtained. The XRD data showed anatase phase of TiO2 particles with average particle size of 25.4 and 21.9 nm, for S1 and S2 catalysts respectively. The SEM and AFM images indicated the catalyst composed with Nanosized pillars of TiO2, evenly distributed on the surface of the substrate. The average height of the pillars was found to be 180 and 40 nm respectively for the S1 and S2 catalyst. The BET specific surface area and pore sizes of S1 and S2 catalyst were found to be 5.217 and 1.420 m2/g and 7.77 and 4.16 nm respectively. The photocatalytic degradation of BPB using the UV light was studied at wide range of physico-chemical parametric studies to determine the mechanism of degradation as well as the practical applicability of the technique. The batch reactor operations were conducted at varied pH (pH 4.0 to 10.0), BPB initial concentration (1.0 to 20.0 mg/L) and presence of several interfering ions, i.e., cadmium nitrate, copper sulfate, zinc chloride, sodium chloride, sodium nitrate, sodium nitrite, glycine, oxalic acid and EDTA in the photocatalytic degradation of BPB. The maximum percent removal of BPB was observed at pH 6.0 and a low initial concentration of the pollutant highly favours the photocatalytic degradation using thin films. The presence of several interfering ions suppressed the photocatalytic activity of thin films to some extent. The time dependence photocatalytic degradation of BPB was demonstrated with the pseudo-first-order rate kinetics. Study was further extended with total organic carbon measurement using the TOC (Total Organic Carbon) analysis. This demonstrated an apparent mineralization of BPB from aqueous solutions.

scholarly journals Preliminary Study on the Use of Ozonation for the Degradation of Dithiocarbamate Residues in the Fruit Drying Process: Mancozeb Residue in Blackcurrant is the Example Used

2013 ◽  
Vol 53 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Piotr Antos ◽  
Anna Kurdziel ◽  
Stanisław Sadło ◽  
Maciej Balawejder
Keyword(s):  
Aqueous Solution ◽  
Ozone Concentration ◽  
Gaseous Phase ◽  
Plant Material ◽  
Water Solution ◽  
Ozone Treatment ◽  
Drying Process ◽  
Initial Concentration ◽  
Preliminary Study ◽  
Treatment Procedures

Abstract In order to reduce the level of dithiocarbamate fungicide mancozeb residues in blackcurrants, two different ozone treatment procedures were evaluated. The first one entailed washing the plant material with an aqueous solution of ozone. This ozone enriched water solution allowed for a 59% reduction of mancozeb residues, compared with the initial concentration. The latter method was based on the utilization of ozone in a gaseous phase combined with a drying process. In that procedure, samples of blackcurrant fruit were exposed to a 19 ppm ozone concentration, and then the blackcurrants were dried. The utilization of ozone in a gaseous phase permitted a 38% reduction of mancozeb residues, in comparison with the initial concentration. As a result of the combination of both processes; ozonation and drying, a 58% reduction of mancozeb residues was achieved.

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