scholarly journals Model for Predicting the Initial Solution pH at Pre-Assumed Final pH and Concentration of Dissolved Zinc during Leaching of Galena in Butanoic Acid Solution

2009 ◽  
Vol 08 (08) ◽  
pp. 621-633
Author(s):  
C. I. Nwoye
Keyword(s):  
Acid Solution ◽  
Initial Solution ◽  
Butanoic Acid ◽  
Solution Ph

Thermodynamic Simulation of Sulphide Mineral Leaching

2009 ◽  
Vol 71-73 ◽  
pp. 437-440
Author(s):  
Lasse Ahonen ◽  
Pauliina Nurmi ◽  
Olli H. Tuovinen
Keyword(s):  
Acid Solution ◽  
Ferric Iron ◽  
Geochemical Modeling ◽  
Thermodynamic Simulation ◽  
Sulphide Mineral ◽  
Solution Ph ◽  
Dissolved Iron ◽  
Iron Precipitation ◽  
Oxidative Leaching ◽  
Mineral Leaching

Geochemical modeling program PHREEQC was used to simulate generic bioleaching processes. Carbonate minerals (e.g., calcite) dissolve in acid solution, increasing the solution pH and Ca concentration while the concentration of CO2 may be controlled by the equilibrium with the atmospheric CO2. Non-oxidative dissolution of Fe-monosulphides was demonstrated to release H2S and increase the pH. In the absence of ferric iron precipitation (goethite), the oxidation of pyrite decreased the solution pH from 2 to ~1.4, while the oxidation of Fe-monosulphide and chalcopyrite increased the solution pH to ~3.2-3.4. Assuming equilibrium precipitation of goethite, oxidative leaching decreased the solution pH for all three minerals from pH ~2 to ~0.9-1.2. Adjustment of the solution pH to 1.8 or 2.0 with KOH with concurrent equilibrium precipitation of K-jarosite resulted in low dissolved iron concentrations.

Enhanced red upconversion emission and its mechanism in Yb3+–Er3+ codoped α-NaLuF4 nanoparticles

2017 ◽  
Vol 41 (3) ◽  
pp. 1193-1201 ◽  
Author(s):  
Hao Lin ◽  
Dekang Xu ◽  
Anming Li ◽  
Zhiren Qiu ◽  
Shenghong Yang ◽  
...  
Keyword(s):  
Upconversion Luminescence ◽  
Upconversion Emission ◽  
Initial Solution ◽  
Solution Ph

Red upconversion luminescence is greatly enhanced through manipulation of the initial solution pH.

Effects of organic acids and initial solution pH on photocatalytic degradation of bisphenol A (BPA) in a photo-Fenton-like process using goethite (α-FeOOH)

2016 ◽  
Vol 15 (8) ◽  
pp. 1046-1053 ◽  
Author(s):  
Guangshan Zhang ◽  
Qiao Wang ◽  
Wen Zhang ◽  
Tian Li ◽  
Yixing Yuan ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Bisphenol A ◽  
Organic Acids ◽  
Photocatalytic Degradation ◽  
Initial Solution ◽  
Solution Ph ◽  
System P

Proposed reaction mechanism of BPA photodegradation in an α-FeOOH-oxalate synergistic system.

Metal Adsorbent Prepared from Coir Pith as Agricultural Waste: Adsorption of Zn(II) and Pb(II) from Aqueous Solution

2013 ◽  
Vol 545 ◽  
pp. 101-108 ◽  
Author(s):  
Kitirote Wantala ◽  
Nusavadee Pojananukij ◽  
Pongsert Sriprom ◽  
Tinnakorn Kumsaen ◽  
Arthit Neramittagapong ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Calcination Temperature ◽  
Ph Value ◽  
Agricultural Waste ◽  
Initial Solution ◽  
Order Kinetic ◽  
Solution Ph ◽  
Freundlich Isotherms ◽  
Coir Pith

Adsorption of Zn(II) and Pb(II) from aqueous solution were studied by using modified coir pith as an adsorbent. The extended adsorption conditions were investigated as a function of calcination temperature, contact time, adsorbent size, initial pH of solution and initial Zn(II) and Pb(II) concentrations. The adsorption capacity increased rapidly in first 5 minute and reached equilibrium in 120 minutes for Zn(II) and 10 minutes for Pb(II). In case of Zn(II); the results showed that the calcination temperature of modified coir pith above 600oC gave the higher adsorption capacity. The sizes of modified coir pith have no effect on the adsorption capacity. The adsorption capacity increased with increasing initial solution pH value. In case of Pb(II); the calcination temperature of modified coir pith showed no effect on the adsorption capacity. The sizes of modified coir pith showed a little effect on the adsorption capacity. The adsorption capacity increased with increasing of initial solution pH value up to pH of 3 and then stable. The results also corresponded with the Langmuir and Freundlich isotherms and pseudo second order kinetic adsorption models. The modified coir pith gave a higher Zn(II) and Pb(II) adsorption capacity of 29.33 mg Zn(II)/g adsorbent and 36.50 mg Pb(II)/g adsorbent, respectively.

Dependence of Stability of Sr5(AsO4)3OH on pH Value

2014 ◽  
Vol 692 ◽  
pp. 229-233
Author(s):  
Yan Hua Huang ◽  
Zong Ning Li ◽  
Hui Qin ◽  
Zong Qiang Zhu ◽  
Yi Nian Zhu ◽  
...  
Keyword(s):  
Solid Solution ◽  
Ph Value ◽  
Reaction System ◽  
Initial Solution ◽  
Alkaline Solutions ◽  
Solution Ph ◽  
Batch Dissolution ◽  
Initial Ph

The object of this work was to determine the solubility and stability of the synthetic Sr5(AsO4)3OH solid solution at 25°C and the different initial pHs (pH at 2, 6 and 9) by batch dissolution experiments. The results indicated that with the initial pH value of 2, 6 and 9, the reaction system reached equilibrium after 2880h, and by that time the pH value of the solution reached, 7.90, 8.74 and 8.27 respectively. The concentration of strontium and arsenic in the initial solution pH at 2 are higher than that of solutions pH at 6 and 9. While the concentration of strontium in neutral or alkaline solutions is low and stays unchanged.

scholarly journals Simultaneous Adsorption of Chromium and Acidic Dye from Leather Tannery Model Wastewater Using a Novel Modified Nanoclay

2021 ◽  
Author(s):  
Mahsa Golghasemi Sorkhabi ◽  
Hassan Aghdasinia ◽  
Fatemeh Notghi Oskui ◽  
Afzal Karimi ◽  
Mortaza Golizadeh
Keyword(s):  
Contact Time ◽  
Zero Point ◽  
Initial Solution ◽  
Isotherm Models ◽  
Solution Ph ◽  
Binary Solutions ◽  
Adsorbent Dosage ◽  
X Ray ◽  
Simultaneous Adsorption ◽  
Bet Analysis

Abstract Simultaneous removal of Cr^3+ and acidic dye from model tannery wastewater was investigated using local nano clay modified by 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC) surfactant. X-ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), carbon, hydrogen, nitrogen and sulfur analysis (CHNS), Brunauer-Emmet-Teller (BET) analysis and pH of zero point charge (pH_ZPC) analyses were carried out for characterization of the adsorbent, and adsorptive properties of the modified clay were investigated by batch experiments. The effects of essential parameters, such as adsorbent dosage, initial solution pH, initial solution concentration, contact time, and temperature, were studied. Maximum adsorption values (99.74% for Cr^3+ and 83.26% for dye) were obtained in the following conditions: pH of 4, initial concentration of 100 mg/L, adsorbent dosage of 15000 mg/L, contact time of 30 min. The effect of contaminants’ concentration was also investigated through response surface methodology (RSM), central composite face-centered (CCF) design and an empirical model was presented. The results of kinetic models’ studies demonstrated that simultaneous adsorption of contaminants follows the pseudo-second-order model, and the adsorption data of single and binary solutions fitted nonlinearly to isotherm models showed that the adsorption of Cr (III) from binary and single solutions follow Langmuir and Dubinin-Radushkevitch (D-R) isotherms, respectively. Adsorption of dye from both single and binary solutions follows Redlich- Peterson (R-PT) isotherm. Maximum adsorption capacities were obtained to be 193.1390 mg/g and 144.1782 mg/g for Cr^3+ and dye, respectively. Synergistic and antagonistic adsorptions were observed in binary solutions.

scholarly journals New Water Treatment Chemical PFZSS Preparation and Application

2015 ◽  
Vol 9 (1) ◽  
pp. 121-124
Author(s):  
Qilin Liu
Keyword(s):  
Water Pollution ◽  
Acid Solution ◽  
Water Purification ◽  
Ph Value ◽  
Absorption Capacity ◽  
Iron Sulfate ◽  
Mixed Solution ◽  
Solution Ph ◽  
Purification Method ◽  
Catering Industry

Nowadays global water quality pollution has become extremely serious, and solving water pollution has been extremely urgent, so researches on water pollution solutions have become even urgent. And flocculating method is the most traditional water purification method, research and create new high performance flocculating agent is one of flocculating method inherent problems. The paper mainly describes adding iron, zinc two kinds of metal captions together in polysyllabic acid, well controlling all aspects requirements in technology, researching and creating new water purification substance—poly iron and zinc silicate sulfate flocculants (PFZSS). PFZSS making method is weighting proper amount sodium silicate into container, and meanwhile putting it into water to dissolve, then utilizing dilute euphoric acid and sodium hydroxide to adjust silicic acid solution pH value and arrive at regulated scope, letting it to activate and arrive at certain time, slowly importing activated proper silica acid solution into moderate iron sulfate and zinc sulfate on the condition of fully blending, and finally putting and curing for a while. And implement experiment research on how mixed solution metal cations matching; making method, pH value, and silicon dioxide concentration these factors affect PFZSS overall performance. PFZSS application mainly takes catering industry sewage solution as an example to get PFZSS has very strong absorption capacity, owns good cleaning effects on extremely turbid catering industry treatment sewage COD and turbidity acquiring, its reaction formed flock density is great, sedimentation rate is very fast, so PFZSS will have great application prospects in the aspect of treating urban sewage.

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