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.

Derivation of Optimum Study Factors for Samples Contaminated with Cd Using Electric/Magnetic Field and ORP

2013 ◽  
Vol 813 ◽  
pp. 519-524
Author(s):  
Sang An Ha ◽  
Jei Pil Wang
Keyword(s):  
Magnetic Field ◽  
Heavy Metals ◽  
Removal Rate ◽  
Underground Water ◽  
Liquid Electrode ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Removal Of Heavy Metals ◽  
High Removal Rate ◽  
Membrane Treatment

A purpose of the present study is to derive optimum study factors for removal of heavy metals using combined alternating current electric/magnetic field and electric membranes for the area contaminated with heavy metals in soil or underground water. ORP (Oxidation Reduction Potential) analysis was conducted to determine an intensity of tendency for oxidation or reduction of the samples contaminated with heavy metals, and electrical membrane treatment was used with adjustment of concentrations and voltages of liquid electrode (Na2SO4) to derive a high removal rate. Removal constants were analyzed to be 0.0417, 0.119, 0.1594 when the voltages were 5V, 10V, 15V, respectively, and treatment efficiency was shown to increase as the liquid electrode concentration was increased. Keywords: heavy metals, electric/magnetic field, ORP, electrical membrane

Effect of pH on Pretreatment of Sulfate-Laden Wastewater for Mixotrophic Desulfurization-Denitrification Process

2010 ◽  
Vol 113-116 ◽  
pp. 429-433
Author(s):  
Wei Li ◽  
Xiao Liang ◽  
Jian Guo Lin
Keyword(s):  
Organic Carbon ◽  
Ph Value ◽  
Removal Rate ◽  
Subsequent Treatment ◽  
Sulfate Removal ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Sulfurous Compounds ◽  
Set Up ◽  
Denitrification Process

An anaerobic attached-growth bioreactor was set up to treat wastewater rich in sulfate and organic carbon. It was the pretreatment of mixotrophic desulfurization-denitrification process. With pH decreasing from 8 to 7, the sulfate removal rate and oxidation reduction potential increased, while sulfide generating rate and effluent pH decreased. When pH value was maintained at 7.5, the removal rates of sulfate and organic carbon reached 91.5% and 90.5%, respectively. Meantime, the generating rate of sulfide reached 47.8%, which was beneficial to the subsequent treatment and to the thorough removal of sulfurous compounds. The results showed that the suitable influent pH in sulfate reduction stage for the pretreatment of desulfurization-denitrification process was 7.5.

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.

scholarly journals Effects of azo dye on simultaneous biological removal of azo dye and nutrients in wastewater

2018 ◽  
Vol 5 (8) ◽  
pp. 180795 ◽  
Author(s):  
Aihui Chen ◽  
Bairen Yang ◽  
Yuanqiang Zhou ◽  
Yuze Sun ◽  
Cheng Ding
Keyword(s):  
Removal Efficiency ◽  
Azo Dye ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Batch Reactors ◽  
Biological Removal ◽  
Oxidation Reduction ◽  
Alizarin Yellow ◽  
Oxidation Reduction Potential ◽  
Alizarin Yellow R

The potential disrupting effects of Azo dye on wastewater nutrients removal deserved more analysis. In this study, 15 days exposure experiments were conducted with alizarin yellow R (AYR) as a model dye to determine whether the dye caused adverse effects on biological removal of both the dye and nutrients in acclimated anaerobic–aerobic–anoxic sequencing batch reactors. The results showed that the AYR removal efficiency was, respectively, 85.7% and 66.8% at AYR concentrations of 50 and 200 mg l −1 , while higher AYR inlet (400 mg l −1 ) might inactivate sludge. Lower removal of AYR at 200 mg l −1 of AYR was due to the insufficient support of electron donors in the anaerobic process. However, the decolorized by-products p -phenylenediamine and 5-aminosalicylic were completely decomposed in the following aerobic stage at both 50 and 200 mg l −1 of AYR concentrations. Compared with the absence of AYR, the presence of 200 mg l −1 of AYR decreased the total nitrogen removal efficiency from 82.4 to 41.1%, and chemical oxygen demand (COD) removal efficiency initially decreased to 68.1% and then returned to around 83.4% in the long-term exposure time. It was also found that the inhibition of AYR, nitrogen and COD removal induced by a higher concentration of AYR was due to the increased intracellular reactive oxygen species production, which caused the rise of oxidation–reduction potential value and decreased ammonia monooxygenase and nitrite oxidoreductase activities.

Control of biological iron removal from drinking water using oxidation-reduction potential

1998 ◽  
Vol 38 (6) ◽  
pp. 121-128 ◽  
Author(s):  
Catherine V. Tremblay ◽  
André Beaubien ◽  
Philippe Charles ◽  
James A. Nicell
Keyword(s):  
Drinking Water ◽  
Pilot Plant ◽  
Reduction Potential ◽  
Iron Concentration ◽  
Operating Conditions ◽  
Industrial Plant ◽  
Filtration Cycle ◽  
Biological Removal ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential

Biological removal of iron to produce drinking water was established in a pilot plant treating raw water with a pH of 5.7. The objective was to evaluate the use of oxidation-reduction potential (ORP) as a control tool and determine its relationship to dissolved oxygen (DO) and residual iron concentration in filtered water from an operating biological filter. Results showed that above a low minimum value of DO, residual iron concentration and ORP were not affected by varying the DO level. A non-linear regression was established to correlate total residual iron concentration to ORP with an R2 of 0.8848. This correlation can be used to predict iron concentration when ORP is in the range 300 to 470 mV. Below this range, total residual iron is greater than or equal to 3 mg/l and above, total residual iron is less than the French regulation limit of 0.2 mg/l. Pilot plant operating conditions were implemented in the primary filter of an industrial plant in France, improving iron elimination and doubling the length of the filtration cycle.

scholarly journals Performance and mechanism of anaerobic biotrickling filter for removal of sulfite, sulfate, and hydrosulfite

2015 ◽  
Vol 5 (4) ◽  
pp. 528-534
Author(s):  
Niantao Xue ◽  
Li Wang ◽  
Tianlong Zheng ◽  
Jianhua Wang ◽  
Qunhui Wang
Keyword(s):  
Flue Gas ◽  
Sodium Acetate ◽  
Carbon Sources ◽  
Sodium Lactate ◽  
Biotrickling Filter ◽  
Regeneration Stage ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Dissolved Sulfide ◽  
The Difference

A biotrickling filter (BTF) was designed for removal of sulfite (SO32−), sulfate (SO42−), and hydrosulfite (HSO−3) produced from flue gas adsorbent during dual-alkali flue gas desulfurization. With an SO32− concentration of 0.89 g-S/(L packing), BTF could completely remove SO32− within 3 h with an elimination capacity (EC) of 296 g-S/(m3h). With an SO42− concentration of 0.60 g-S/(L packing), the removal efficiency (RE) of SO42− reached 90.3% at 5.25 h and 95% at 24 h. With an HSO−3 concentration of 0.74 g-S/(L packing), HSO−3 could not be detected in the trickling liquid at 2 h with an EC of 370 g-S/(m3h). The difference in desulfurization performance of the BTF was minor when sodium lactate and sodium acetate were used as carbon sources. Acetate was more superior when taking both the carbon/sulfur ratio (C/S) and RE into account. The total dissolved sulfide yield was over 70% with sodium acetate as the carbon source, which was 15–20% higher than that with sodium lactate. Sodium lactate was not completely degraded and acetic acid was produced. All oxidation–reduction potential values were lower than −370 mV, indicating a perfect anaerobic condition in the BTF. The BTF could efficiently treat sulfite, sulfate, and hydrosulfite and could replace the regeneration stage of the dual-alkali process.

Renovation of an Extended Aeration Plant for Simultaneous Biological Removal of Nitrogen and Phosphorus Using Oxic-Anaerobic-Oxic Process

1990 ◽  
Vol 22 (7-8) ◽  
pp. 61-68 ◽  
Author(s):  
Katsumi Moriyama ◽  
Kazuaki Sato ◽  
Yoshinobu Harada ◽  
Kazuo Washiyama ◽  
Koich Okamoto
Keyword(s):  
Control System ◽  
Treatment Plant ◽  
Optimum Level ◽  
Simultaneous Removal ◽  
Nitrogen And Phosphorus ◽  
Conventional Activated Sludge ◽  
Biological Removal ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Aeration Process

The effect of the oxidation reduction potential (i.e., ORP) control system on the simultaneous removal of nitrogen and phosphorus, utilizing the oxic-anaerobic-oxic process, was investigated. A full-scale wastewater treatment plant which was designed as an extended aeration process was modified for this process to study. The optimum ORP at the first basin for the simultaneous removal was 125 mV in this experiment. In the first oxic basin the nitrification reaction and the denitrification reaction occurred simultaneously to maintain the optimum level of the ORP value. The averaged values of the effluent of this process were 1 mg/l of total nitrogen (T-N), 0.5 mg/l of total phosphorus (T-P) and 5 mg/l of BOD respectively. It was also clearly shown by the statistic analysis that the ORP control was more effective in comparison with the control of dissolved oxygen (DO) concentration for the operating method of this process. Additionally, it was supposed that the simultaneous nitrification and denitrification using the ORP control system was a reliable nitrogen removal system for renovating the conventional activated sludge process because the hydraulic retention time of the first basin used in this study was equal to that of the conventional process.

Application of Disk Aerators to Recarbonation of Alkaline Wastewater from Wet Gasification of Carbide

1991 ◽  
Vol 24 (7) ◽  
pp. 277-284 ◽  
Author(s):  
E. Gomólka ◽  
B. Gomólka
Keyword(s):  
Carbon Dioxide ◽  
Liquid Phase ◽  
Gas Phase ◽  
Flue Gas ◽  
Carbonic Acid ◽  
Low Cost ◽  
Flue Gases ◽  
Carbon Dioxide Content ◽  
Patent Claim ◽  
Phase Dispersion

Whenever possible, neutralization of alkaline wastewater should involve low-cost acid. It is conventional to make use of carbonic acid produced via the reaction of carbon dioxide (contained in flue gases) with water according to the following equation: Carbon dioxide content in the flue gas stream varies from 10% to 15%. The flue gas stream may either be passed to the wastewater contained in the recarbonizers, or. enter the scrubbers (which are continually sprayed with wastewater) from the bottom in oountercurrent. The reactors, in which recarbonation occurs, have the ability to expand the contact surface between gaseous and liquid phase. This can be achieved by gas phase dispersion in the liquid phase (bubbling), by liquid phase dispersion in the gas phase (spraying), or by bubbling and spraying, and mixing. These concurrent operations are carried out during motion of the disk aerator (which is a patent claim). The authors describe the functioning of the disk aerator, the composition of the wastewater produced during wet gasification of carbide, the chemistry of recarbonation and decarbonation, and the concept of applying the disk aerator so as to make the wastewater fit for reuse (after suitable neutralization) as feeding water in acetylene generators.

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