Advanced Treatment of Coking Wastewater by Coagulation with PAC

2010 ◽  
Vol 159 ◽  
pp. 499-504 ◽  
Author(s):  
Yi Zheng ◽  
Zhuo Zhang ◽  
Hong Tao Hu ◽  
Xia Liang Wei
Keyword(s):  
Reaction Time ◽  
Optimal Condition ◽  
High Speed ◽  
Dynamic Condition ◽  
Advanced Treatment ◽  
Coking Wastewater ◽  
Efficient Removal ◽  
Low Speed ◽  
Integrated Technique

An integrated technique was investigated, aiming to provide an effective method for the treatment of biologically treated coking wastewater and to reduce pollutants to concentration values below the limits imposed by the legislation. Coking wastewater containing 270 mg/L COD and 202 times color was treated by coagulation using PAC as well as PAC +PAM, respectively. The application of coagulation using PAC+PAM resulted to a much more efficient removal of color, COD and SS in comparison with single coagulation without PAC. The optimal condition for coagulation with PAC was pH 8, dosage 75 mg/L and dynamic condition 1-minute high speed stirring followed by 15-minute low speed stirring. The optimal condition for coagulation with PAC and PAM was: PAM dosage of 6 mg/L, PAC dosage of 70 mg/L, pH of 8 and reaction time of 20 minutes. Both processes of coagulation were found to be efficient for removal of COD from coking wastewater, but ineffective in reducing color.

Experimental Research on the Advanced Treatment of Coking Wastewater by Patented Wastewater Treatment Equipment

2012 ◽  
Vol 599 ◽  
pp. 313-317
Author(s):  
Juan Wang ◽  
Ling Fei Fan ◽  
Di Fan
Keyword(s):  
Wastewater Treatment ◽  
Reaction Time ◽  
Treatment Plant ◽  
Volume Ratio ◽  
National Standard ◽  
Municipal Sewage ◽  
Advanced Treatment ◽  
Optimum Process ◽  
Coking Wastewater ◽  
Treatment Equipment

In this study, we presented an approach to coking wastewater advanced treatment process with a patented wastewater treatment equipment. The samples were collected from the effluents of the biological treatment tank in a coking wastewater treatment plant. With the experiments of four static single factors and the continuing dynamic process, the discussions about the effects of pH value, influent loading, reaction time, and volume ratio on chromaticity, COD and NH3-N respectively were conducted. The experimental results identified that the optimum process parameters were pH of 3, influent load of 1m3/m2•h, reaction time of 4h and volume ratio of 2:1 respectively. When influents of chromaticity, COD and NH3-N were 210 times, 249.4mg/L, and 31.7mg/L respectively , the effluent of chromaticity, COD and NH3-N were 16 times, 49.7mg/L, and 9.5mg/L respectively, these values could meet the National standard of Recycling and Miscellaneous usages of Municipal Sewage on chromaticity, COD and NH3-N requirements.

Advanced Treatment of Stabilized Leachate by Sodium Hypochlorite Composite Chemicals

2011 ◽  
Vol 474-476 ◽  
pp. 1272-1276 ◽  
Author(s):  
Hai Ying Zhang ◽  
Hong Tao Hu ◽  
Yi Zheng ◽  
Dong Hui Chen
Keyword(s):  
Reaction Time ◽  
Optimal Condition ◽  
Sodium Hypochlorite ◽  
Biological Treatment ◽  
Advanced Treatment ◽  
Sodium Hypochlorite Solution ◽  
Optimal Conditions ◽  
Wastewater Discharge ◽  
Hypochlorite Solution ◽  
Effluent Quality

In this work, advanced treatment of leachate after biological treatment was performed using sodium hypochlorite solution (NaClO) + ferric chloride (FeCl3) + polyacrylamide (PAM) and NaClO + aluminum poly-chloride (PAC) + PAM, respectively, to determine the optimal condition for removal of COD and color. It was found that the optimal condition was: PAM 5 mg/L, FeCl3 420 mg/L, NaClO 6 mL/L, reaction time 15 min for treatment using FeCl3 + NaClO + PAM, and PAM 5 mg/L, PAC 800 mg/L, NaClO 6 mL/L, reaction time 15 min for PAC + NaClO + PAM. After being treated at the optimal conditions, the effluent quality met requirements of the tertiary grade described in “Integrated wastewater discharge standard”.

Advanced Treatment of Biochemical Treated Coking Wastewater by Ozonation Process

2013 ◽  
Vol 726-731 ◽  
pp. 2515-2520 ◽  
Author(s):  
De Min Yang ◽  
Jian Mei Yuan
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Ozone Concentration ◽  
Ph Value ◽  
Removal Rate ◽  
Color Removal ◽  
Advanced Treatment ◽  
Coking Wastewater ◽  
Initial Ph ◽  
Ozonation Process

Advanced treatment of biochemical treated coking wastewater was studied experimentally with ozonation process. The effects of initial pH value, ozone concentration, reaction temperature, and reaction time on the COD and color removal rate were investigated. The results showed that ozonation was an effective method for advanced treatment of biochemical treated coking wastewater. The increasing of initial pH value, ozone concentration, reaction temperature, and reaction time has enhanced the removal rate of COD and color. Meanwhile, the results also revealed that the maximal COD and color removal rate of 69.65% and 92.27% could be reached under the optimal conditions of the initial pH value is 10.5, ozone concentration is 150 mg/L, reaction temperature is 298 K, and reaction time is 30 min.

Advanced Treatment of Coking Wastewater by Electro-Coagulation

2014 ◽  
Vol 700 ◽  
pp. 426-430 ◽  
Author(s):  
Hai Tang ◽  
Jun Peng Sha ◽  
Yang Long Ou ◽  
Xiang Zhao
Keyword(s):  
Reaction Time ◽  
Current Density ◽  
Color Removal ◽  
Advanced Treatment ◽  
Coking Wastewater ◽  
Degradation Behavior ◽  
Optimal Conditions ◽  
Initial Ph ◽  
Electro Coagulation

The degradation behavior and mechanism of biologically pretreated coking wastewater (BPCW) were investigated by means of a lab-scale electro-coagulation (EC) in static methods. The results showed that the percent COD and color removal can reach 80.5 % and 95.4 % respectively under the optimal conditions (initial pH of 8.0; reaction time of 30 min; current density of 14.0 mA/cm2 and NaCl dosage 1.6 g/L).

Do You Name Speedy Objects Faster Than Slow Objects: SPEEDED NAMING OR NAMING SPEED? THE AUTOMATIC EFFECT OF OBJECT SPEED ON PERFORMANCE

2018 ◽  
Author(s):  
Moshe Shay Ben-Haim ◽  
Eran Chajut ◽  
Ran Hassin ◽  
Daniel Algom
Keyword(s):  
High Speed ◽  
Mental Representations ◽  
Reading Aloud ◽  
Naming Task ◽  
Naming Speed ◽  
Low Speed ◽  
Everyday Objects ◽  
Pictures And Words

we test the hypothesis that naming an object depicted in a picture, and reading aloud an object’s name, are affected by the object’s speed. We contend that the mental representations of everyday objects and situations include their speed, and that the latter influences behavior in instantaneous and systematic ways. An important corollary is that high-speed objects are named faster than low-speed objects despite the fact that object speed is irrelevant to the naming task at hand. The results of a series of 7 studies with pictures and words support these predictions.

Advanced Treatment of Coking Wastewater by Oxidation Process Using Pyrite and Hydrogen Peroxide

2013 ◽  
Vol 726-731 ◽  
pp. 2521-2525
Author(s):  
Zhi Yong Zhang ◽  
De Li Wu
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidation Process ◽  
Low Cost ◽  
Oxygen Demand ◽  
Utilization Efficiency ◽  
Advanced Treatment ◽  
Coking Wastewater ◽  
Second Stage ◽  
Potential Alternative ◽  
High Utilization

Coking wastewater is a kind of recalcitrant wastewater including complicate compositions. Advanced treatment of coking wastewater by Fenton-Like reaction using pyrite as catalyst was investigated in this paper. The results show that the chemical oxygen demand (COD) of coking wastewater decreased significantly by method of coagulation combined with two-stage oxidation reaction. COD of wastewater can decrease from 250mg/l to 45mg/l after treatment, when 2g/L pyrite was used in each stage oxidation and the dosage of hydrogen peroxide (H2O2) is 0.2ml/l for first stage treatment, 0.1ml/l for second stage treatment respectively. The pyrite is effective to promote Fenton-Like reaction with low cost due to high utilization efficiency of H2O2, moreover, catalyst could be easily recovered and reused. The Fenton-Like reaction might be used as a potential alternative to advanced treatment of recalcitrant wastewater.

scholarly journals Splatters and Aerosols Contamination in Dental Aerosol Generating Procedures

2021 ◽  
Vol 11 (4) ◽  
pp. 1914
Author(s):  
Pingping Han ◽  
Honghui Li ◽  
Laurence J. Walsh ◽  
Sašo Ivanovski
Keyword(s):  
Particle Size ◽  
Disease Transmission ◽  
High Speed ◽  
Low Speed ◽  
Dental Procedures ◽  
Dental Equipment ◽  
Produce Contamination ◽  
Fluorescein Dye ◽  
Filter Papers ◽  
Airborne Disease

Dental aerosol-generating procedures produce a large amount of splatters and aerosols that create a major concern for airborne disease transmission, such as COVID-19. This study established a method to visualise splatter and aerosol contamination by common dental instrumentation, namely ultrasonic scaling, air-water spray, high-speed and low-speed handpieces. Mock dental procedures were performed on a mannequin model, containing teeth in a typodont and a phantom head, using irrigation water containing fluorescein dye as a tracer. Filter papers were placed in 10 different locations to collect splatters and aerosols, at distances ranging from 20 to 120 cm from the source. All four types of dental equipment produced contamination from splatters and aerosols. At 120 cm away from the source, the high-speed handpiece generated the greatest amount and size (656 ± 551 μm) of splatter particles, while the triplex syringe generated the largest amount of aerosols (particle size: 1.73 ± 2.23 μm). Of note, the low-speed handpiece produced the least amount and size (260 ± 142 μm) of splatter particles and the least amount of aerosols (particle size: 4.47 ± 5.92 μm) at 120 cm. All four dental AGPs produce contamination from droplets and aerosols, with different patterns of distribution. This simple model provides a method to test various preventive strategies to reduce risks from splatter and aerosols.

Nonlinear transport of rarefied Couette flows from low speed to high speed

2020 ◽  
Vol 32 (11) ◽  
pp. 112021
Author(s):  
Jihui Ou ◽  
Jie Chen
Keyword(s):  
High Speed ◽  
Nonlinear Transport ◽  
Low Speed

scholarly journals Energy Absorption Characteristics of PVC Coarse Aggregate Concrete under Impact Load

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Shi Hu ◽  
Huaming Tang ◽  
Shenyao Han
Keyword(s):  
Compressive Strength ◽  
Energy Absorption ◽  
High Speed ◽  
Coarse Aggregate ◽  
Specific Energy Absorption ◽  
Low Speed ◽  
High Speed Impact ◽  
Aggregate Content ◽  
Dynamic Compressive Strength ◽  
Absorption Characteristics

AbstractIn this paper, polyvinyl chloride (PVC) coarse aggregate with different mixing contents is used to solve the problems of plastic pollution, low energy absorption capacity and poor damage integrity, which provides an important reference for PVC plastic concrete used in the initial support structures of highway tunnels and coal mine roadway. At the same time, the energy absorption characteristics and their relationship under different impact loads are studied, which provides an important reference for predicting the energy absorption characteristics of concrete under other PVC aggregate content or higher impact speed. This study replaced natural coarse aggregate in concrete with different contents and equal volume of well-graded flaky PVC particles obtained by crushing PVC soft board. Also, slump, compression, and splitting strength tests, a free falling low-speed impact test of steel balls and a high-speed impact compression test of split Hopkinson pressure bar (SHPB) were carried out. Results demonstrate that the static and dynamic compressive strength decreases substantially, and the elastic modulus and slump decrease slowly with the increase of the mixing amount of PVC aggregate (0–30%). However, the energy absorption rate under low-speed impact and the specific energy absorption per MPa under high-speed impact increase obviously, indicating that the energy absorption capacity is significantly enhanced. Regardless of the mixing amount of PVC aggregate, greater strain rate can significantly enhance the dynamic compressive strength and the specific energy absorption per MPa. After the uniaxial compression test or the SHPB impact test, the relative integrity of the specimen is positively correlated with the mixing amount of PVC aggregate. In addition, the specimens are seriously damaged with the increase of the impact strain rate. When the PVC aggregate content is 20%, the compressive strength and splitting strength of concrete are 33.8 MPa and 3.26 MPa, respectively, the slump is 165 mm, the energy absorption rate under low-speed impact is 89.5%, the dynamic compressive strength under 0.65 Mpa impact air pressure is 58.77 mpa, and the specific energy absorption value per MPa is 13.33, which meets the requirements of shotcrete used in tunnel, roadway support and other impact loads. There is a linear relationship between the energy absorption characteristics under low-speed impact and high-speed impact. The greater the impact pressure, the larger the slope of the fitting straight line. The slope and intercept of the fitting line also show a good linear relationship with the increase of impact pressure. The conclusions can be used to predict the energy absorption characteristics under different PVC aggregate content or higher-speed impact pressure, which can provide important reference for safer, more economical, and environmental protection engineering structure design.

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