Study on Advanced Pretreatment of Seawater by Electrolysis

2014 ◽  
Vol 881-883 ◽  
pp. 598-603
Author(s):  
Jing Nie ◽  
Shou Zhi Yi ◽  
Di Miao
Keyword(s):  
Water Quality ◽  
Reverse Osmosis ◽  
Organic Compounds ◽  
Removal Efficiency ◽  
Current Density ◽  
Removal Rate ◽  
Influence Factors ◽  
Operation Time ◽  
Electrode Distance

The advanced pretreatment by electrolysis of Bohai seawater in Tianjin used a diaphragm electrolyzer in the experiment. Removal efficiency and influence factors of the method were analyzed. Results show that turbidity, organic compounds, SDI and chroma of seawater were effectively decreased by electrolysis. Removal efficiency was significantly increased by current density, operation time and inter-electrode distance, and the optimum electrolytic conditions was determined as inter-electrode distance of 2 cm, current density of 15.87 mA·cm-2, operation time of 10 minutes. It was investigated that when the water quality after electrolysis was of pH 8.6, the chroma and turbidity decreasing trend slowed down, with chroma of 0.052 A, removal rate reached 88.4%; the residual turbidity reduced to 2.52 NTU, removal rate reached 90.71%. A PH of about 8.5, CODCr decreasing trend slowed down, and when CODCr < 750 mg/L, it conformed to the requirements of the reverse osmosis water.

Study on Advanced Pretreatment of Seawater by Electrolysis and Neutralization of Acidic Waste Water with By-Product Magnesium Hydroxide

2013 ◽  
Vol 821-822 ◽  
pp. 1071-1080
Author(s):  
Jing Nie ◽  
Shou Zhi Yi ◽  
Di Miao
Keyword(s):  
Removal Efficiency ◽  
Magnesium Hydroxide ◽  
Current Density ◽  
Industrial Wastewater ◽  
Removal Rate ◽  
Influence Factors ◽  
Operation Time ◽  
Wastewater Discharge ◽  
Electrode Distance

The advanced pretreatment by electrolysis of Bohai seawater in Tianjin used a diaphragm electrolyzer in the experiment. Removal efficiency and influence factors of the method were analyzed. Results show that turbidity, organic compounds, SDI and chroma of seawater were effectively decreased by electrolysis. Removal efficiency was significantly increased by current density, operation time and inter-electrode distance, and the optimum electrolytic conditions was determined as inter-electrode distance of 2 cm, current density of 15.87 mA·cm-2, operation time of 10 minutes. It was investigated that when the water quality after electrolysis was of pH 8.6, the chroma and turbidity decreasing trend slowed down, with chroma of 0.052 A, removal rate reached 88.4%; the residual turbidity reduced to 2.52 NTU, removal rate reached 90.71%. A PH of about 8.5, CODCr decreasing trend slowed down, and when CODCr < 750 mg/L, it conformed to the requirements of the reverse osmosis water. With the study on neutralization of steel pickling waste liquor by the by-product of magnesium hydroxide, it is found that the quality of treated water reached 3rd level national emissions standards (300-1000 mg/L). Magnesium hydroxide slurry of Cr (VI) removal rate reached 100%, conforming to the 1st level national industrial wastewater discharge standards (< 0.5 mg/L).

Study on De-Nitrification of Improved Step-Feed Progress

2014 ◽  
Vol 703 ◽  
pp. 171-174
Author(s):  
Bing Wang ◽  
Yi Xiao ◽  
Shou Hui Tong ◽  
Lan Fang ◽  
Da Hai You ◽  
...  
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Fluidized Bed ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Operating Conditions ◽  
Removal Mechanism ◽  
Aerobic Zone

Improved step-feed de-nitrification progress combined with biological fluidized bed was introduced in this study. The progress had good performance and capacity of de-nitrification and organic matter. The experiment result showed that the de-nitrification efficiency of the improved biological fluidized bed with step-feed process was higher than the fluidized bed A/O process under the same water quality and the operating conditions. When the influent proportion of each segment was equal, the system showed good nitrogen removal efficiency with the change of influent C/N ratio, HRT and sludge return ratio. The removal rate of TN reached up to 88.2%. It showed that the simultaneous nitrification and de-nitrification phenomenon happened in the aerobic zone. The nitrogen removal mechanism was also studied.

Electrochemical Removal Cyanide in Wastewater by Ti/RuO2-Pt Electrodes

2014 ◽  
Vol 955-959 ◽  
pp. 2290-2293
Author(s):  
Chang Hang Wu
Keyword(s):  
Removal Efficiency ◽  
Current Density ◽  
Chloride Ion ◽  
High Energy ◽  
Electrolytic Cell ◽  
Direct Oxidation ◽  
High Concentration ◽  
Electrode Distance ◽  
Pt Electrodes ◽  
Operating Current

A laboratory-scale electrolytic cell with a Ti/RuO2-Pt anode and a Ti cathode was developed to treat high concentration cyanide-contained wastewater. The effects of the different electrode distances, concentration of chlorine anion and current densities, on the CN- removal were investigated. The results shown the too short and long electrode distance resulted in high energy consumption and low current, the appropriate electrode distance was essential. The CN- removal was very significant at the electrode distance was 9 cm, and the removal efficiency reached 99.2%. The removal CN- electrochemical oxidation was mainly attributed the success to in direct oxidation effect of chlorine /hypo-chlorite produced during the electrochemical reaction process. The CN- removal efficiency increased with increasing the concentration of chloride ion and operating current density. The optimum experimental condition was set at the electrode distance of 9 cm, NaCl dosage of 0.5 g/L, the current density of 10 mA/cm2, and pH of 12. At the optimum experimental condition, the CN- concentration in the solution decreased from 150.33 mg/L to 1.20 mg/L, and the CN- removal efficiency reached 99.2%.

Study on Influence Factors in Flocculation Conditions of Bioflocculant

2012 ◽  
Vol 581-582 ◽  
pp. 242-245
Author(s):  
Li Xin Li ◽  
Yan Jun Liu ◽  
Gang Ren ◽  
Zhi Wei Song ◽  
Xiu Min Yang ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Removal Rate ◽  
Influence Factors ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Minimal Impact ◽  
Jar Test ◽  
Effective Performance ◽  
Flocculation Effect

0.5g/L of kaolin suspension was took as the sample for coagulation. The jar test was adopted to examine the effects of the Compound Bioflocculant (CBF) dosage, hydrogen ion concentration (pH) and the CaCl2 dosage as coagulation aid on the removal efficiency of turbidity. The experimental results showed that CBF had an effective performance with dosage of 4-5mg/L in the alkalescence environment. The optimal conditions for the removal efficiency of turbidity by CBF were the dosage of 4ml/L and pH of 7.5. CBF added coagulation aid(CaCl2) could play effect of flocculation. Adding 1.0ml / L of 10% concentration solution of CaCl2 could achieve the best flocculation effect. Temperature had minimal impact on the removal efficiency of turbidity , it indicated that the removal rate of turbidity at low temperatures was not obviously influenced.

The Operation Time Influence on the Sauce Wastewater Treatment

2011 ◽  
Vol 183-185 ◽  
pp. 278-281
Author(s):  
Zhi Xiao Liu ◽  
Jin Long Zuo
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Food Industry ◽  
Rapid Development ◽  
Water Environment ◽  
Operation Time ◽  
Ammonia Nitrogen ◽  
Aeration Time

With rapid development of food industry, the production of soybean sauce is increasing in recent years. The sauce wastewater is doing greater and greater harm to the water environment. In order to tackle this problem, the operation time on the sauce wastewater treatment were investigated. The results showed that the process has a better effect for ammonia nitrogen, the orthophosphate and COD removal. The effluent ammonia nitrogen was less than 5mg/L and the ammonia nitrogen removal efficiency could reach about 90% with the aeration time 2 h-3.5 h. The orthophosphate increased during the anoxic stage while decreased during the aerobic stage. At the end of the aerobic stage, the orthophosphate concentration and the COD could reach about 1mg/L and 21 mg/L respectively when aeration time was 2 h-3.5 h. The better operation time (the aeration time) was at 2 h-3.5 h and the system could get a good water quality for sauce wastewater treatment.

Study on Removal of Iron and Manganese from Mine Water by Method of Medicament

2012 ◽  
Vol 217-219 ◽  
pp. 843-848
Author(s):  
Lei Lei Hou ◽  
Yu Qi Wang ◽  
Tie Gao ◽  
Jia Jing Jiang
Keyword(s):  
Water Quality ◽  
Reaction Time ◽  
Removal Efficiency ◽  
Mine Water ◽  
Room Temperature ◽  
Removal Rate ◽  
Quality Characteristics ◽  
Efficient Removal ◽  
Iron And Manganese

Use single and coexistence of simulated mine water contains Fe2+ and Mn2+ as processing object, the new NWMO medicament on Fe2+ and Mn2+’s removal efficiency, NWMO dosage, pH, reaction time and temperature on NWMO’s removal efficiency were investigated. When treated mine water only contains Fe2+, the appropriate conditions of the factors are that NWMO dosage/Fe2+ content=19:1, pH=5, room temperature, the reaction time is 10min, and the removal rate of Fe2+ is more than 80%; When treated mine water only contains Mn2+, the appropriate conditions of the factors are that NWMO dosage/Mn2+ content=22:1, pH=6, 35°C, the reaction time is 10min, the removal rate of Mn2+ is more than 60%; When the processing of Fe2+ and Mn2+ coexistence of mine water, the appropriate conditions of the factors are that NWMO dosage/Fe2+content=19:1, Fe2+ content/Mn2+ content=5:1, pH=6, 35°C, the reaction time is 10min, the removal rate of Fe2+ can be as high as 100%, and the highest Mn2+ removal rate can amount to 75%. In view of the current mine water quality characteristics that contains Fe2+ and Mn2+, the NWMO medicament is very suitable, and can achieve quick and efficient removal of iron and manganese.

The Study of Phosphorus Removal by Electrocoagulation with Iron-Anodes

2011 ◽  
Vol 183-185 ◽  
pp. 417-421
Author(s):  
Yong Bo Lin ◽  
Yang Yang ◽  
Shuai Wang
Keyword(s):  
Reaction Time ◽  
Total Phosphorus ◽  
Current Density ◽  
Phosphorus Removal ◽  
Removal Rate ◽  
Electrolysis Time ◽  
Optimal Conditions ◽  
Reaction Conditions ◽  
Electrode Distance ◽  
Initial Ph

Determined to adopt iron as anodes, and Ti-base board with coating as cathodes. To optimize the reaction conditions of phosphorus removal by electrocoagulation (EC), testing the effect of current density, electrode distance, initial pH and electrolysis time on the phosphorus removal. According to the results, the optimal conditions for the phosphorus removal in the EC treatment were obtained, i.e., 20 mA/cm2 of current density, 2cm of distance and 10min of reaction time were optimum. Under these conditions, phosphorus removal by electrocoagulation reached to 95.07%, 10min later the change of total phosphorus (TP) removal rate is not obvious. By the end of this test, phosphorus removal by electrocoagulation reached to 99.68%.

scholarly journals Electrochemical Degradation of Tetracycline Using a Ti/Ta2O5-IrO2 Anode: Performance, Kinetics, and Degradation Mechanism

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4325
Author(s):  
Hao Dong ◽  
Wanqiang Chi ◽  
Ang Gao ◽  
Tianyu Xie ◽  
Bo Gao
Keyword(s):  
Current Density ◽  
High Performance ◽  
Removal Rate ◽  
Degradation Mechanism ◽  
Influence Factors ◽  
High Volume ◽  
Electrode Spacing ◽  
Electrochemical Degradation ◽  
Solution Ph ◽  
Experimental Conditions

Tetracycline (TC) is widely used in production and in life. The high volume of its use and the difficulty of its disposal have become the most important causes of environmental pollution. A suitable method needs to be found to solve this problem. In this study, the Ti/Ta2O5-IrO2 electrode was characterized for its surface morphology and crystal composition. The electrochemical catalytic ability of the Ti/Ta2O5-IrO2 electrode was investigated using LSV and CV tests. The electrochemical degradation of tetracycline (TC) in water with a Ti/Ta2O5-IrO2 anode was investigated. The main influence factors, such as current density (2.5–10 mA/cm2), electrode spacing (20–40 mm), initial TC concentration (20–80 mg/L) and initial solution pH (4.74–9.48) were analyzed in detail and their influences on reaction kinetics was summed up. The removal rate increased along with the increasing current density, decreasing initial TC concentration and decreasing of electrode distance under the experimental conditions. The optimum pH was 4.74. UV–vis, total organic carbon (TOC) and high-performance liquid chromatography-mass spectrometry (HPLC-MS) analyses were used to reveal the mechanism of TC degradation. Nine main intermediates were identified, and the degradation pathways were proposed. A new insight has been postulated for the safe and efficient degradation of TC using the Ti/Ta2O5-IrO2 electrode.

Treatment of Car-Washing Wastewater by Electrocoagulation-Ultrasound Technique for Reuse

2012 ◽  
Vol 433-440 ◽  
pp. 227-232 ◽  
Author(s):  
Jin Yu Chu ◽  
Yu Rong Li ◽  
Ning Li ◽  
Wei Hong Huang
Keyword(s):  
Removal Efficiency ◽  
Water Consumption ◽  
Treatment Time ◽  
Removal Rate ◽  
Treated Wastewater ◽  
Reaction Cell ◽  
Ultrasound Technique ◽  
Electrode Distance ◽  
Washing Wastewater ◽  
Combined Technique

To reduce the water consumption and pollution in car-washing, a combined technique, i.e., electrocoagulation coupled with ultrasound, was proposed to treat the car-washing water for reuse. The effects of parameters (such as current intensity (I), initial pH, electrode distance (d), treatment time (t), and so on) on the removal efficiency of COD and turbidity in the wastewater were studied. The results indicate that the removal efficiency of COD and turbidity is maximum (68.77% and 96.27%, respectively) when I=1.2 A, pH=6.0, d=1.5 cm, and t=20 min. The quality of treated wastewater could meet the COD and turbidity requirements in Water Quality Standard for Urban Water Consumption. Meanwhile, the character of the reaction cell was studied, and it shows that the cell voltage is a linear function of the electrode distance when the current is constant. Compared with the removal rate of pollutants from car-washing wastewater by the single electrocoagulation method, a higher rate could be achieved by this combined technique.

Membrane Fouling Mechanism and its Control in the Treatment of Brackish Water with Reverse Osmosis Process

2013 ◽  
Vol 788 ◽  
pp. 268-274 ◽  
Author(s):  
Jian Bing Wang ◽  
Jun Yang Cheng ◽  
Ting Shi ◽  
Qing Huang ◽  
Xu Wen He
Keyword(s):  
Water Quality ◽  
Reverse Osmosis ◽  
Organic Compounds ◽  
Brackish Water ◽  
Membrane Fouling ◽  
Control Method ◽  
Membrane Surface ◽  
Development Stage ◽  
Fouling Mechanism

Brackish water was treated with reverse osmosis process. The fouling mechanism of RO and its control method was studied. In the treatment of brackish water, the salt removal efficiency was above 95% and the effluent quality was up to the standard for drinking water quality (GB5749-2006). The SDI of the influent of RO was less than 5 after the raw water was pretreated by the combination of coagulation and sedimentation process and filtration process, which met the demand of the water quality of the RO influent. If ultrafiltration was added, the water quality of the pre-treatment was better. Coagulation and precipitation was not very effective for the removal of dissolved organic compounds, especially for the removal of organic compounds with molecular amount ranging from 1000 to 10000. The formation of RO membrane fouling can be divided into five stages, which is membrane surface coarseness stage by inorganic substrate, organic compounds adsorption stage, organism adhesion stage, microbial film development stage, and irreversible membrane block stage. The membrane fouling was effectively alleviated by the strategy of first alkali solution cleaning and then acid solution cleaning.

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