Study on SO2, NO Removal from Flue Gas Using an Aqueous NaClO2 Solution with Oxidation Reduction Potential and pH Control

2014 ◽  
Vol 955-959 ◽  
pp. 2221-2225 ◽  
Author(s):  
Ye Sun
Keyword(s):  
Removal Efficiency ◽  
Flue Gas ◽  
Feeding Rate ◽  
Ph Value ◽  
Ph Control ◽  
Sodium Chlorite ◽  
Regression Equations ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Optimized Conditions

Removal of SO2 and NO from the flue gas using an aqueous sodium chlorite solution was achieved in a bubbling reactor, ORP and pH were used as monitoring parameter. The effect of pH, NaClO2 feeding rate and SO2 concentration on simultaneous removal of SO2 and NOx efficiencies were systematical investigated. The results showed that SO2 removal efficiency was always 100% and NOx removal efficiency could achieve 65% at optimized conditions, the optimized pH value of 5-5.5 was observed. The correlation analysis among ORP, original pH, NaClO2 feeding rate and input SO2 concentration was established using multiple regression equations.

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.

scholarly journals Biological Removal NOx from Simulated Flue gas in aerobic biofilter, by Jiang R., Huang S.B. and Yang J.

2013 ◽  
Vol 10 (2) ◽  
pp. 241-248
Keyword(s):  
Gas Phase ◽  
Flue Gas ◽  
Removal Rate ◽  
Nox Removal ◽  
Biological Removal ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
O2 Concentration ◽  
Blank Experiment ◽  
Nitrate And Nitrite

A bench-scale biofiltration system was developed to evaluate the NOx removal efficiency under high oxygen concentration. The system had been running for 120 days and kept on a steady NOx removal rate above 80%. A stable NOx removal with an efficiency of more than 80% from the gas phase can be obtained by the bioreactor concept, when flue gas containing NO (400-600 ppmv) and a certain O2 concentration (0-20%). In the blank experiment, less than 35% NO was removed as oxygen increased. The tendency of the three curves about NO removal rate with various O2 concentrations was mainly similar but some differences in the highest and lowest removal rate happened in the definite O2 concentration range. Oxygen was shown to have a significant effect on NOx removal at the first two or three days when oxygen concentration increased sharply. The higher concentration NO influent gas contained, the longer time the microflora need to regain activities. Compared with humidifier, microbial regenerator which was incorporated in biofilter can improve aerobic denitrifying bacteria activity by applying alternating oxic–anoxic conditions in the presence of nitrate and nitrite. Oxidation-Reduction Potential (ORP) and Dissolved Oxygen (DO) were used to control the dose of carbon source.

scholarly journals The removal of turbid materials from AMD using bentonite clay, Fe or Al salt, MgCO3 and flocculent with varying agitations

2020 ◽  
Vol 15 (3) ◽  
pp. 580-597
Author(s):  
I. O. Ntwampe
Keyword(s):  
Removal Efficiency ◽  
Mine Drainage ◽  
Bentonite Clay ◽  
Jar Test ◽  
Oxidation Reduction ◽  
Treated Effluent ◽  
Oxidation Reduction Potential ◽  
Changing Trend ◽  
Series Of Experiments ◽  
Slow Mixing

Abstract A series of experiments was conducted using 200 mL of acid mine drainage (AMD) collected from Krugersdorp, South Africa, to determine turbid materials removal efficiency of a combination of bentonite clay, Fe or Al salt and MgCO3. The sample was poured into five 500 mL glass beakers using bentonite clay, FeCl3, AlCl3 and MgCO3 dosage respectively. The samples were treated in jar test at rapid and slow mixing, allowed to settle for 1 hour, then the pH, conductivity, total suspended solids (TSS), dissolved oxygen (DO) and oxidation reduction potential (ORP) were measured (exp A). A second and third similar sets of experiments were conducted with a combination of bentonite clay and MgCO3 (flocculent) dosage (exp B), and FeCl3 with slow mixing only (exp C). Experimental results revealed that the pH of treated effluent with bentonite clay does not exhibit significant increasing trend because of insignificant hydrolysis, whereas the pH of samples with FeCl3, AlCl3 and MgCO3 exhibit a slight decreasing trend, showing a low rate of hydrolysis. The DO and ORP of treated effluent does not show a significant changing trend compared to the untreated AMD sample. Residual TSS of the AMD samples treated with a flocculent is lower than the samples treated with bentonite clay, FeCl, AlCl3 and MgCO3. Residual turbidity of the samples with rapid mixing is identical to that of the corresponding samples with slow mixing. TSS removal efficiency of a flocculent is higher compared to other reagents. The results show that synthetic flocculent is an ideal replacement for inorganic coagulants. The scanning electron microscopy (SEM) micrographs exhibit slides with dense-sponge like flocs showing high adsorption capacity.

Adsorption of Th4+ on Waste Beer Yeast

2013 ◽  
Vol 726-731 ◽  
pp. 2111-2114
Author(s):  
Jing Wang ◽  
Yan Chen ◽  
Bo Yang ◽  
Juan Feng ◽  
Xiao Yan Lin
Keyword(s):  
Removal Efficiency ◽  
Adsorption Kinetics ◽  
Ph Value ◽  
Order Equation ◽  
Absorption Time ◽  
Radioactive Wastewater ◽  
Before And After ◽  
Pseudo Second Order ◽  
Optimized Conditions ◽  
Beer Yeast

Waste beer yeast was utilized as adsorbent to remove Th4+ from simulated radioactive wastewater. Effects of various parameters including pH value, temperature, absorbent dosage, and absorption time on adsorption of Th4+ by waste beer yeast were studied. Beer yeast before and after adsorption was characterized by IR and SEM. The results show that the removal efficiency could be reached 95% at the optimized conditions. The adsorption kinetics was described well by the pseudo second-order equation.

Removal of Sulfur Dioxide from Sintering Flue Gas with Coking Wastewater

2011 ◽  
Vol 287-290 ◽  
pp. 910-915
Author(s):  
Su Ju Hao ◽  
Wu Feng Jiang ◽  
Yu Zhu Zhang ◽  
Bing Liu
Keyword(s):  
Sulfur Dioxide ◽  
Removal Efficiency ◽  
Flue Gas ◽  
Ph Value ◽  
Coking Wastewater ◽  
Atmospheric Pollutant ◽  
Wastewater Treatment Process ◽  
Iron And Steel ◽  
On Line ◽  
Detection Instrument

Coking wastewater comprising a lot of ammonia is a good desulfurizer for recycling. Sintering flue gas is characterized by large volume, low sulfur dioxide (SO2) concentration and large variation amplitude and etc. The purpose for treating waste with waste can be carried out by treating sintering flue gas with coking wastewater. This paper uses a spray tower countercurrent device, ensures the contact between coking wastewater and sintering flue gas, and detects SO2 concentration of inlet flue gas and outlet flue gas on line by using an automatic flue gas detection instrument. This paper studies on the change regularity for the SO2 concentration at outlet flue gas during the process of treating sintering flue gas with coking wastewater, the influence of SO2 initial concentration in sintering flue gas to the removal efficiency of SO2, the influence of gas-liquid ratio between the sintering flue gas and the coking wastewater to the removal efficiency of SO2, and the change regularity for the pH value of coking wastewater after desulfurizing. The results show that the sintering flue gas which is treated can live up to the atmospheric pollutant effluent standard of iron and steel industry; the pH value of coking wastewater is reduced after treating, and the conditions for the implementation of subsequent coking wastewater treatment process are provided.

Enhanced Nitrogen Removal of Low C/N Wastewater in a Subsequent Denitrifying Reactor Fed by Endogenous Carbon Source Generated from Primary Sludge Fermentation

2011 ◽  
Vol 281 ◽  
pp. 101-105
Author(s):  
Cheng Cheng Wu ◽  
Yong Zhen Peng ◽  
Liang Zhang ◽  
Shu Ying Wang
Keyword(s):  
Carbon Source ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
High Performance ◽  
Reduction Potential ◽  
Biological Nitrogen Removal ◽  
Primary Sludge ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Biological Nitrogen

A novel post-denitrification system fed by carbon source from primary sludge (PS) was used for enhancing biological nitrogen removal (BNR) of low C/N wastewater. This system included one anoxic/oxic (AO) reactor and a special reactor for simultaneous sludge fermentation and denitrification (Sifeden). Ammonia was nitrified to nitrate in AO and then the nitrate was reduced to dinitrogen in Sifeden , into which PS was added intermittently. Results showed that this system had high performance on nitrogen removal. Total nitrogen (TN) removal efficiency was higher than 85% and the effluent TN≤10mg/L in the condition of influent C/N≤2. In Sifeden, volatile fatty acid (VFA) produced from PS fermentation provided electron donor for nitrate reduction, and PS was preliminarily stabilized simultaneously. Oxidation-Reduction Potential (ORP) had a significant correlation with the denitrification performance. TN removal efficiency could be further improved if adopting proper PS addition strategy according to the ORP profiles.

scholarly journals Combined Removal Of NOx And SO2 From Flue Gas At Low Temperature

2018 ◽  
Vol 53 ◽  
pp. 04038 ◽  
Author(s):  
Zhipeng Xue ◽  
Hao Chen ◽  
Minmin Zhao
Keyword(s):  
Removal Efficiency ◽  
Flue Gas ◽  
Gas Flow ◽  
Ph Value ◽  
National Standards ◽  
Raw Material ◽  
Nox Removal ◽  
Gas Temperature ◽  
Solution Ph ◽  
Nox Removal Efficiency

A method was proposed to remove NOx and SO2 in flue gas by using the sulfinyl functional group as a catalyst. Ozone is introduced into the flue gas to oxidize NO. Soluble NO2 and SO2 reacted with ammonia to form ammonium sulfate and ammonium nitrate, which were the raw material of the compound fertilizer. A small pilot is built in a container that can be easily transported to power plant and extracts the actual flue gas directly from the gas duct. In order to obtain the best the SO2 and NOX removal efficiency in this experiment, many parameters were changed. Such as flue gas flow, ozone / NOX ratio, liquid-gas ratio, flue gas temperature, catalyst type, catalyst concentration, solution pH value. Results indicated that SO2 was cleaned up quite efficiently and the removal efficiency was nearly 99% under all conditions. the best NOX removal efficiency can reach 88%. The NOX removal efficiency depended primarily on ozone / NOX ratio, and the temperature of flue gas also had influence on the NOX removal efficiency. The optimum pH range is 5.6-6.3. After inspection by authoritative institutions, the quality of fertilizers is superior to national standards.

Application of Bamboo Shoot Shell in Color Removal from Methylene Blue Solution

2014 ◽  
Vol 675-677 ◽  
pp. 489-492
Author(s):  
Jing Miao Zhang ◽  
Zhi Wei Zhong ◽  
Da Pan Zhu ◽  
Lin Man Lin ◽  
Qing Ju Wang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Ph Value ◽  
Color Removal ◽  
Target Color ◽  
Maximum Adsorption Capacity ◽  
Bamboo Shoot ◽  
Blue Solution ◽  
Optimized Conditions

Biosorption of dyeing wastewater is most widely used method so far. The adsorption of methylene blue (MB) with bamboo shoot shell (BSS) as biosorbent was investigated. Orthogonal test was used to optimize the adsorption process, and adsorption capacity and color removal efficiency were used to judge the adsorptivity of BSS. Results showed that maximum adsorption capacity was 225.71 mg·g-1, and color removal efficiency could achieve to 98.96% during the test. To obtain best adsorption capacity, the optimized conditions of temperature, initial concentration of dye, BSS dosage, pH value and adsorption time were 45 °C, 400 mg·L-1, 10 mg/10 mL, 9.6 and 30 min, respectively. As to another target color removal efficiency, the best parameters were 100 mg·L-1, 200 mg/10 mL, 11.5 and 120 min, respectively. The results reveal that the agricultural by-product BSS is an effective biosorbent.

Sign in / Sign up

Export Citation Format

Share Document