Application of Flocculation Process in Dressing Wastewater from Antimony Mine

2012 ◽  
Vol 518-523 ◽  
pp. 2370-2375
Author(s):  
Jing Zhu ◽  
Tian Xiang Li
Keyword(s):  
Removal Efficiency ◽  
Ferrous Sulfate ◽  
Ph Value ◽  
Optimal Choice ◽  
Settling Time ◽  
Treated Wastewater ◽  
Sulfate Heptahydrate ◽  
Carcinogenic Property ◽  
Ferrous Sulfate Heptahydrate ◽  
Flocculation Process

Antimony (Sb) has received increasing environmental concerns due to its potential toxicity and carcinogenic property. In the present work, the flocculation process had used to treat dressing wastewater (DW) from some antimony mine, and the mechanism of removing Sb was investigated. The study focused on the effect of experimental parameters on the Sb removal efficiency, such as dosage of flocculant, pH value and the settling time. Several flocculants were evaluated and the results suggested that ferrous sulfate heptahydrate (FeSO4•7H2O) was the optimal choice. When the dosage of ferrous sulfate heptahydrate (FeSO4•7H2O) was 0.075:100, pH value was 7 and the settling time was 180 min, removal efficiency of Sb in the DW reached 99.86% and concentration of Sb in the treated wastewater was below 0.04mg/L, which meets the emission standards established by State Department of Environmental Protection and State Administration for Quality Supervision and Inspection and Quarantine.

scholarly journals Effect of Praestol as a Coagulant-Aid to Improve Coagulation-Flocculation in Dye containing Wastewaters

2015 ◽  
Vol 18 (1) ◽  
pp. 38-46 ◽  
Keyword(s):  
Ionic Strength ◽  
Aqueous Solutions ◽  
Removal Efficiency ◽  
Dye Removal ◽  
Settling Time ◽  
Solution Ph ◽  
Polyaluminum Chloride ◽  
Flocculation Process ◽  
Flocculation Time

<div> <p>This study was conducted to investigate the effect of praestol, as a coagulant-aid, to improve coagulation-flocculation process in the removal of disperse red 60 from aqueous solutions. The effect of various parameters including coagulants dose (10-1000 mg l<sup>-1</sup>), praestol dose (0-1000 mg l<sup>-1</sup>), solution pH (3-11), initial dye concentration (100-500 mg l<sup>-1</sup>), flocculation speed (30-60 rpm), flocculation time (15-30 min), settling time (5-60 min) and ionic strength (0-6 mg l<sup>-1</sup>) was evaluated on the dye removal. The dye removal efficiency was substantially increased by using praestol in the concentration of 80 mg l<sup>-1 </sup>and 400 mg l<sup>-1 </sup>for coagulation with alum and polyaluminum chloride (PACl), respectively. The maximum dye removal by alum coupled with praestol (Al-P) and PACl coupled with praestol (PA-P) was found to be 97.8% and 98.7%, respectively that were occurred at pH 7. The results showed that the application of PA-P or Al-P can be effectively used to remove disperse red 60 (DR 60) in aqueous solutions.</p> </div> <p>&nbsp;</p>

Evaluation of NOX Removal from Simulated Flue Gas by "Absorption-Oxidation-Reduction" Method

2014 ◽  
Vol 884-885 ◽  
pp. 261-265
Author(s):  
Bao Lin Li ◽  
Ming Yu Li ◽  
Hai Hao Liu ◽  
Gang Cao ◽  
Gang Ren ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Flue Gas ◽  
Ferrous Sulfate ◽  
Gas Flow ◽  
Reduction Method ◽  
Ph Value ◽  
Sulfate Solution ◽  
Gas Flow Rate ◽  
Oxidation Reduction

This paper presented a new method of absorption-oxidation-reduction which used ferrous sulfate solution as absorbent, oxygen as oxidizer and urea as reducer to remove NOX from flue gas based on the properties of Fe2+, NO, [Fe (NO)]2+ and urea. These properties included that Fe2+ and NO could produce [Fe (NO)]2+, furthermore [Fe (NO)]2+ was easy to be oxidized by O2, as well as urea can reduce HNO2 and HNO3 in the absorption liquid. This research was to discuss its absorption and removal mechanism with the influence of the initial urea concentration, pH value, initial NOX concentration and gas flow rate on the NOX removal efficiency. The results showed that the removal efficiency of NOX would increase when the initial concentration of urea and NOX increased, while the pH value and gas flow rate decreased.

Optimization of Coagulation Process for Disperse Navy Blue Dye Wastewater Treatment Using Response Surface Methodology

2014 ◽  
Vol 977 ◽  
pp. 270-273
Author(s):  
Ming Li ◽  
Yan Zhen Yu ◽  
Guang Yong Yan
Keyword(s):  
Response Surface Methodology ◽  
Wastewater Treatment ◽  
Response Surface ◽  
Removal Efficiency ◽  
Ph Value ◽  
Settling Time ◽  
Blue Dye ◽  
Dye Wastewater ◽  
Coagulation Process ◽  
Coagulant Dosage

A response surface methodology (RSM) was used for the determination of optimum coagulation process conditions for disperse navy blue dye wastewater treatment. The experimental design was Box-Behnken design (BBD) with three operational variables: coagulant dosage, pH value and settling time. The influence of these three independent variables on the chroma removal was evaluated using a second-order polynomial multiple regression model. Quadratic model was predicted for the response variable and the maximum model-predicted chroma removal efficiency was 95%. Based on surface and contour plots, the optimum conditions were obtained to be coagulant dosage of 70.98 mg/L, pH value of 7.46, and settling time of 15.80 min with the actual chroma removal efficiency as 93%.

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