Study on Application of Water Granulated Slag in Rare-Earth Ammonia-Nitrogen Wastewater

2011 ◽  
Vol 183-185 ◽  
pp. 1178-1184
Author(s):  
Li Rong Chen ◽  
Fei Hu Jia ◽  
Xin Meng ◽  
Lian Ke Zhang
Keyword(s):  
Rare Earth ◽  
Reaction Time ◽  
Adsorption Mechanism ◽  
Removal Rate ◽  
Physical Adsorption ◽  
Ammonia Nitrogen ◽  
Chemical Adsorption ◽  
Optimum Dosage ◽  
Granulated Slag ◽  
Isothermal Equation

This paper aims to study the technological conditions and adsorption mechanism of the rare-earth ammonia-nitrogen wastewater adsorption by unmodified water granulated slag and modified water granulated slag. The results showed that the optimum adsorption reaction time is around 60min for both of unmodified and modified slag; the optimum dosage of unmodified slag is 0.015g/mL, whereas it is 0.01g/mL for modified slag, correspondingly, the removal rate of ammonia-nitrogen could attain to (59.9±2.49) % and (79.24±1.21) % associated with unmodified slag and modified slag respectively. The ammonia-nitrogen removing process conducted by unmodified water granulated slag fits the Freundlich adsorption isothermal equation, conforming to physical adsorption. By contrast, the ammonia-nitrogen removing process accomplished by modified water granulated slag fits the Temkin adsorption isothermal equation and this process should be chemical adsorption.

Pretreatment of High Strength Ammonia Removal from Rare-Earth Wastewater by Magnesium Ammonium Phosphate (MAP) Precipitation

2012 ◽  
Vol 496 ◽  
pp. 42-45 ◽  
Author(s):  
Hao Wang ◽  
Guan Wen Cheng ◽  
Xiao Wei Song ◽  
Zai Han Xu ◽  
Jin Jie Meng ◽  
...  
Keyword(s):  
Rare Earth ◽  
Reaction Time ◽  
Removal Rate ◽  
Ammonium Phosphate ◽  
High Strength ◽  
Ammonia Nitrogen ◽  
Ammonia Removal ◽  
Molar Ratio ◽  
Magnesium Ammonium Phosphate ◽  
Magnesium Ammonium

Ammonia is one of the most important contaminants affecting the quality of water environment. Magnesium ammonium phosphate (MgNH4PO4·6H2O), which is a slow releasing fertilizer, is one possible way to remove high strength ammonia from the wastewater. The wastewater is collected from the effluent of extraction of rare earth elements factory, the study investigate the influence of pH, magnesium and phosphate dosing molar ratio and reaction time for ammonia removal rate. The results show that: when the pH = 9.2, n (Mg): n (N): n (P) = 2.2:1:2, reaction time t = 20min, ammonia concentration of the wastewater from 4420mg / L down to 1440mg / L , ammonia nitrogen removal rate can reach 67%, the remaining TP = 0.9mg / L; higher Ca2 + concentration will affect the MAP precipitation for removing ammonia, but it help to reduce total phosphorus concentrations of effluent; it is not the longer reaction time the better removal rate, because the MAP-formation will destroy with longer reaction time.

The Adsorption Behavior of Modified Peanut Shells for Cr (VI)

2013 ◽  
Vol 781-784 ◽  
pp. 2189-2194
Author(s):  
Yi Hua Jiang ◽  
Xin Long Jiang
Keyword(s):  
Adsorption Mechanism ◽  
Physical Adsorption ◽  
Peanut Shell ◽  
Chemical Adsorption ◽  
Chemical Methods ◽  
Ir Spectrometry ◽  
Freundlich Isotherms ◽  
Reduction Processes ◽  
Peanut Shells ◽  
Adsorption Activation Energy

The adsorption of Cr(VI) by modified peanut shell has been investigated using chemical methods and IR spectrometry. The optimal condition for the adsorption of Cr(VI) by modified peanut shell is at 308 K and pH = 1.0, which gives a static saturated adsorption capacity of 14.15 mg·g-1, an apparent adsorption rate constant of k298 = 2.43 × 10-4 s-1, and an apparent adsorption activation energy of 10.58 kJ·mol-1. The adsorption follows the Langmuir and Freundlich isotherms and the liquid film diffusion is the controlling process of the adsorption. The adsorption thermodynamic parameters are ΔH = 125.58 kJ·mol-1, ΔS = 0.473 9 kJ·mol-1·K-1, ΔG = -17.81– -27.27 kJ·mol-1. Small amount of desorption is observed only at pH > 11. Adsorption mechanism of modified peanut shells for Cr(VI) was both physical adsorption and chemical adsorption of adsorbent "adsorption-oxidation and reduction processes".

Study on the Photocatalytic Degradation of Ammonia Nitrogen in Aquaculture Wastewater by Fe3+-Doped Nano-TiO2 under UV Irradiation

2012 ◽  
Vol 476-478 ◽  
pp. 2001-2004
Author(s):  
Xiao Cai Yu ◽  
Peng Fei Zhu ◽  
Kui Sheng Song ◽  
Dong Dong Hu ◽  
Qian Du
Keyword(s):  
Reaction Time ◽  
Photocatalytic Degradation ◽  
Uv Irradiation ◽  
Volume Fraction ◽  
Ph Value ◽  
Removal Rate ◽  
Ammonia Nitrogen ◽  
Nano Tio2 ◽  
Initial Concentration ◽  
Aquaculture Wastewater

The Fe3+-doped nano-TiO2 catalyst with various amounts of dopant Fe3+ irons was prepared by a sol-gel method. The products were characterized by XRD and SEM. The photocatalytic degradation of ammonia nitrogen in aquaculture wastewater was investigated by using Fe3+-doped nano-TiO2 under UV irradiation. In the experiment, the effect of Fe3+/TiO2 dosage, the ratio of dopant Fe3+, ammonia-N initial concentration, pH value, H2O2 volume concentration, and reaction time, respectively, on the removal of ammonia-N was investigated. The experimental results can be stated as follows: when the ratio of dopant Fe3+ was 0.25% wt, the dosage of Fe3+/TiO2 was 0.7 g/L, the initial concentration of ammonia-N was 10 mg/L, H2O2 volume fraction was 4 %, respectively, if the reaction time may last 4 h, the removal rate of ammonia-N was expected to reach 97.17 %.

Photocatalytic Degradation of Ammonia Nitrogen in Aquaculture Wastewater by Using Nano-TiO2

2011 ◽  
Vol 197-198 ◽  
pp. 774-779
Author(s):  
Peng Fei Zhu ◽  
Xiao Cai Yu ◽  
Qian Du ◽  
Kui Sheng Song ◽  
Zhong Hua He
Keyword(s):  
Reaction Time ◽  
Photocatalytic Degradation ◽  
Volume Concentration ◽  
Volume Fraction ◽  
Ph Value ◽  
Removal Rate ◽  
Sol Gel ◽  
Ammonia Nitrogen ◽  
Experimental Conditions ◽  
Aquaculture Wastewater

The nano-TiO2photocatalyst was prepared via sol-gel method, and the crystal structure and surface morphology were characterized by XRD and SEM. The photocatalytic degradation of ammonia-N in aquaculture wastewater was investigated by using nano-TiO2under UV irradiation. In the experiment, the effect of nano-TiO2dosage, ammonia-N initial concentration, pH value, H2O2volume concentration, and reaction time, respectively, on the removal of ammonia-N was investigated. On the basis of the results of these experimental data, an orthogonal array experimental design was used to select more efficient degradation condition. The optimal experimental conditions for photocatalytic degradation of ammonia-N can be stated as follows: when the concentration of ammonia-N was 20 mg/L, nano-TiO2catalyst dosage was 1.2 g/L, the pH value of solution was 5, H2O2volume fraction was 4 %, respectively, if the reaction time may last 3 h, the removal rate of ammonia-N was expected to reach 92.10 %.

Study on Removing Ammonium Nitrogen from Wastewater Using Magnesium Hydroxide

2014 ◽  
Vol 955-959 ◽  
pp. 2550-2553 ◽  
Author(s):  
Yu Qi Wang ◽  
Qi Zhang ◽  
Luo Feng Liu ◽  
Bi Jun Luo ◽  
Dan Wu ◽  
...  
Keyword(s):  
Reaction Time ◽  
Nitrogen Removal ◽  
Magnesium Hydroxide ◽  
Removal Rate ◽  
Ammonia Nitrogen ◽  
Ammonium Nitrogen ◽  
Molar Ratio ◽  
Dihydrogen Phosphate ◽  
Sodium Dihydrogen Phosphate ◽  
Sodium Dihydrogen

Magnesium ammonium phosphate (MAP) precipitation has been studied by using magnesium hydroxide and sodium dihydrogen phosphate as precipitators for treating simulation wastewater in which the concentration of ammonia nitrogen is 10.00g/L. The effect of reaction time, pH and precipitator ratio on ammonium nitrogen removal rate has been investigated. The obtained optimum treatment conditions of MAP precipitation for treating ammonia nitrogen wastewater are as follows: reaction time is 4 hours, pH is 8.0, the molar ratio of sodium dihydrogen phosphate and ammonia nitrogen in wastewater, i.e. n (P):n (N), is 1.2, the molar ratio of magnesium hydroxide and sodium dihydrogen phosphate, i.e. n (Mg):n (P), is 1.4. Under these conditions, the ammonium nitrogen removal rate, by using MAP precipitation for treating simulation ammonia nitrogen wastewater, is 90.71%.

Photocatalytic Degradation of Ammonia Nitrogen in Aquaculture Wastewater by Using Nano-ZnO

2012 ◽  
Vol 610-613 ◽  
pp. 564-568 ◽  
Author(s):  
Kui Sheng Song ◽  
Xiao Cai Yu ◽  
Dong Dong Hu ◽  
Xu Zheng ◽  
Ji Yao Guo
Keyword(s):  
Reaction Time ◽  
Photocatalytic Degradation ◽  
Volume Fraction ◽  
Ph Value ◽  
Removal Rate ◽  
Ammonia Nitrogen ◽  
Precipitation Method ◽  
Experimental Conditions ◽  
Nano Zno ◽  
Aquaculture Wastewater

Nano-ZnO photocatalyst was prepared using direct precipitation method .The crystal form, particle size and configuration characterization of the nano-ZnO prepared was characterized by XRD and SEM. The photocatalytic degradation of ammonia-N in aquaculture wastewater was investigated by using nano-ZnO under UV irradiation. The experimental results show that: nano-ZnO dosage, catalytic reaction time, initial ammonia-N concentration, H2O2volume concentration, pH value affect the efficiency of photocatalytic degradation significantly. On the basis of the results of these experimental data, the optimal experimental conditions for photocatalytic degradation of ammonia-N are tried through the orthogonal test. The optimization experimental conditions for photocatalytic degradation of ammonia-N in aquaculture wastewater are as follows, nano-ZnO catalyst dosage was 0.4 g/L, the pH value of solution was 10, H2O2volume fraction was 4 %, respectively, if the reaction time may last 1 h, the removal rate of ammonia-N was expected to reach 86.66 %.

Application of Combined Collectors in Flotation of Lepidolite

2013 ◽  
Vol 734-737 ◽  
pp. 921-924 ◽  
Author(s):  
Gui Chun He ◽  
Jin Ni Feng ◽  
Mei Xin Mao ◽  
Yi Peng Wu
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectrum ◽  
Physical Adsorption ◽  
Chemical Adsorption ◽  
Mineral Surface ◽  
Gravity Concentration ◽  
Optimum Dosage ◽  
Ore Dressing

Application of Combined Collectors in Flotation of Lepidolite were researched, and the object is the gravity concentration tailing of YiChun Tantalum&Niobium Mine. The experiments show: when LZ-00 dispensed by ourselves and mixed amine combined in two to one was used in lepidolite flotation, the flotation indexes is best,and the optimum dosage is 360g/t .The close circuit test can got the lepidolite concentrate with grade 4.12%, recovery 70.37% .It has a remarkable upgrading compared with the target of ore dressing plant . Infrared spectrum showed mineral surface existed chemical adsorption and physical adsorption and hydrogen bonding simultaneously when using LZ-00 and mixed amine to flotation lepidolite .

Study on Adsorption of Chromium in Wastewater by Diatomite

2014 ◽  
Vol 1004-1005 ◽  
pp. 983-989
Author(s):  
Kai Yong Zhang ◽  
Ling Huang
Keyword(s):  
Theoretical Basis ◽  
Adsorption Mechanism ◽  
Ph Value ◽  
Removal Rate ◽  
Physical Adsorption ◽  
Chromium Concentration ◽  
Adsorption Ability ◽  
Adsorption Time ◽  
Adsorption Removal ◽  
The Cost

Adsorption ability of chromium in wastewater by purified diatomite as the adsorbent material was studied. The influence of the diatomite dosage, adsorption time, chromium concentration, pH value and reaction temperature to chromium removal rate was got. The results show that under the condition of the diatomite dosage of 9.0g, adsorption time of 90 min, chromium concentration in wastewater of 5mg/L, wastewater pH of 6, and temperature of 30°C, diatomite adsorption removal rate to hexavalent chromium can reach 91.6%. The main adsorption mechanism is the combination of physical adsorption and chemical adsorption, and the latter is dominant. The cost of diatomite as adsorbent is low, and a good removal rate of chromium can be reached, which provides a solid theoretical basis for the removal of chromium in wastewater.

scholarly journals Preparation and Characterization of High-Efficiency Magnetic Heavy Metal Capture Flocculants

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1732
Author(s):  
Yuanyuan Yu ◽  
Yongjun Sun ◽  
Jun Zhou ◽  
Aowen Chen ◽  
Kinjal J. Shah
Keyword(s):  
Heavy Metal ◽  
Reaction Time ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Monomer Concentration ◽  
Synthesis Process ◽  
Response Surface Optimization ◽  
Metal Capture ◽  
Total Monomer Concentration

In this study, a high-efficiency magnetic heavy metal flocculant MF@AA was prepared based on carboxymethyl chitosan and magnetic Fe3O4. It was characterized by SEM, FTIR, XPS, XRD and VSM, and the Cu(II) removal rate was used as the evaluation basis for the preparation process. The effects of AMPS content, total monomer concentration, photoinitiator concentration and reaction time on the performance of MF@AA flocculation to remove Cu(II) were studied. The characterization results show that MF@AA has been successfully prepared and exhibits good magnetic induction characteristics. The synthesis results show that under the conditions of 10% AMPS content, 35% total monomer concentration, 0.04% photoinitiator concentration, and 1.5 h reaction time, the best yield of MF@AA is 77.69%. The best removal rate is 87.65%. In addition, the response surface optimization of the synthesis process of MF@AA was performed. The optimal synthesis ratio was finally determined as iron content 6.5%, CMFS: 29.5%, AM: 53.9%, AMPS: 10.1%. High-efficiency magnetic heavy metal flocculant MF@AA shows excellent flocculation performance in removing Cu(II). This research provides guidance and ideas for the development of efficient and low-cost flocculation technology to remove Cu(II) in wastewater.

Preparation of xanthated bentonite and its removal behavior for Pb(II) ions

2010 ◽  
Vol 61 (5) ◽  
pp. 1235-1243 ◽  
Author(s):  
Y. F. He ◽  
F. R. Li ◽  
R. M. Wang ◽  
F. Y. Li ◽  
Y. Wang ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Particle Size Analysis ◽  
Lead Ions ◽  
Size Analysis ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

Xanthate was successfully grafted onto bentonite by a relatively simple solution reaction. The obtained xanthated bentonite (XBent) was characterized by FT-IR spectrophotometer, thermogravimetric analysis (TG), particle size analysis, x-ray diffraction (XRD) and scanning electron microscopy (SEM). XBent acting as a type of environmentally friendly adsorbent was applied to remove lead ions from aqueous solutions. The optimum conditions were as follows: [Pb2 + ] = 500 mg L−1, [XBent] = 2 g L−1, pH = 5.0; oscillating 60 min under 200 rpm at 25°C. The removal rate of lead was up to 99.9%. It was found that the lead(II) ions—XBent adsorption isotherm model fitted well to the Freundlich isotherm. The adsorption mechanism was also investigated by SEM and XRD, which concluded that lead ions were complexed or chelated with XBent. XBent appears to have potential to be used later in water treatment as a type of inorganic polymer reagent.

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