Application of a bio-electrochemical reactor process to direct treatment of metal pickling wastewater containing heavy metals and high strength nitrate

2004 ◽  
Vol 50 (8) ◽  
pp. 111-118 ◽  
Author(s):  
T. Watanabe ◽  
H.W. Jin ◽  
K.J. Cho ◽  
M. Kuroda
Keyword(s):  
Heavy Metals ◽  
Electric Current ◽  
Ph Value ◽  
Electrochemical Reactor ◽  
Hydrogen Gas ◽  
Operating Conditions ◽  
Synthetic Wastewater ◽  
Carbon Anode ◽  
Lead Removal ◽  
Direct Treatment

The fundamental performance of a bio-electrochemical reactor for the direct treatment of metal ickling wastewater was investigated experimentally. In the reactor, carbon anode and cathode were installed. On the cathode, denitrifying microorganisms were immobilized. Continuous experiments were carried out by feeding a synthetic wastewater containing nitrate and binary heavy metal ions, copper and lead, under different operating conditions. Acetate as well as the electric current was supplied at the minimum amount for stoichiometry of the dissimilatory denitrification reaction. The results indicated that the dissolved copper and lead removal, denitrification and neutralization could be achieved simultaneously in a single bio-electrochemical reactor. The dissolved heavy metals were removed by electrochemical deposition on cathode and by the other phenomena such as the formation of insoluble suspensions and the sorption on suspended bacterial sludge. Denitrification proceeded effectively with the utilization of both added acetate and hydrogen gas generated by electrolysis of water. The pH value increased up to around neutral due to the occurrence of denitrification in the reactor, although the influent pH was less than 3. The removal efficiencies of heavy metals and nitrate increased with increasing the current density. The applied electric current was indispensable for sustaining the stable treatment in the reactor.

Simultaneous COD removal and denitrification of wastewater by bio-electro reactors

1997 ◽  
Vol 35 (8) ◽  
pp. 161-168 ◽  
Author(s):  
M. Kuroda ◽  
T. Watanabe ◽  
Y. Umedu
Keyword(s):  
Organic Matter ◽  
Electric Current ◽  
Denitrifying Bacteria ◽  
Hydrogen Gas ◽  
Cod Removal ◽  
Hydrogen Donor ◽  
Continuous Treatment ◽  
Synthetic Wastewater ◽  
Internal Source ◽  
Nitrogen Gas

Application of a bio-electro reactor process for the treatment of wastewater containing nitrate and internal source of hydrogen donor as organic matter was experimentally investigated. The bio-electro reactor consisted of immobilized denitrifying bacteria electrode as cathode and carbon electrode as anode. Hydrogen gas was produced on the cathode surface by the electrolysis of water when electric current was applied, and immediately utilized to reduce biologically nitrate to nitrogen gas by the cathodic immobilized denitrifying bacteria. Consumption characteristics of organic matter and utilization of hydrogen gas derived from the electrolysis of water for denitrification was studied by batch experiments. Continuous treatment experiments using a synthetic wastewater containing nitrate and organic matter were carried out to investigate the denitrification and organic matter removal performances. Denitrification occurred with simultaneous utilization of organic matter existed as internal source of hydrogen donor in the wastewater and hydrogen gas by electrolysis of water. Hydrogen gas was utilized efficiently for denitrification even if excess amount of organic hydrogen donor existed in wastewater. In this bio-electro reactor system, it was confirmed that COD as well as nitrate was removed simultaneously by applied electric current in continuous experiment, though further investigation are necessary to analyze the COD removal by applied electric current in detail.

Effectiveness of anaerobic biomass in adsorbing heavy metals

2001 ◽  
Vol 44 (10) ◽  
pp. 245-252 ◽  
Author(s):  
B. Haytogiu ◽  
G.N. Demirer ◽  
U. Yetis
Keyword(s):  
Heavy Metals ◽  
Ph Value ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Synthetic Wastewater ◽  
Isotherm Models ◽  
Adsorptive Capacity ◽  
Initial Ph ◽  
Anaerobic Biomass ◽  
Langmuir And Freundlich Models

This study focuses on the effectiveness of waste anaerobic dead biomass (ADB) in adsorbing heavy metals, namely Pb(II), Cr(VI), Cu(II), Ni(II) and Zn(II). The metal uptake capacity of ADB was investigated and compared with the values for various biomass types from the literature. The biomass, which was grown under laboratory conditions using a synthetic wastewater, was used throughout the study after sterilization. The maximum metal adsorptive capacities were evaluated by running isotherm tests at 25°C and initial pH of 4. It was observed that Pb(II) was adsorbed with the highest capacity. The maximum adsorptive capacity of ADB for Pb(II), Zn(II), Cu(II), Ni(II) and Cr(VI) was determined as 1250, 625, 357, 227 and 384 mg/g dry biomass, respectively. These values were significantly higher than the corresponding capacities reported in the literature for other types of biomass. In describing the adsorption equilibrium, both the Langmuir and Freundlich isotherm models were examined. The experimental data for Pb(II), Zn(II), Cr(VI), and Ni(II) fitted both the Langmuir and Freundlich models with correlation coefficients of 0.80-0.99 while Cu(II) only fitted the Langmuir model with a correlation coefficient of 0.99. Therefore, different and distinct aspects of the interactions between the cell surfaces and the metal ions might have occurred for Cu(II) and the rest of the metals. The equilibrium pH values attained were all higher than the initial pH value of 4.0, and this indicated that both the type and the initial concentration of the metal influenced the equilibrium pH. Furthermore, there was a decrease in equilibrium pH with increasing initial metal concentration at varying levels.

scholarly journals Application of electrokinetic in controlling heavy metals migration in sand: A feasibility study

2014 ◽  
Vol 5 (2) ◽  
pp. 8-15
Author(s):  
Cindy Liew ◽  
Leonard L. P. Lim
Keyword(s):  
Heavy Metals ◽  
Environmental Quality ◽  
Human Activities ◽  
Water Velocity ◽  
Operating Conditions ◽  
Carbon Anode ◽  
Initial Concentration ◽  
Electrical Gradient ◽  
Potential Use ◽  
Land Filling

 Uncontrolled migration of heavy metals from human activities in the subsurface can lead to the degradation of environmental quality and potential use of soil and groundwater. This paper studies the feasibility of using electrokinetics in controlling the migration of heavy metals in sand. Copper and iron (initial concentration of 100 mgL-1) are the target heavy metals in this study as they are the most commonly found heavy metals from human activities such as mining and land filling. The performance of electrokinetic in controlling the migration of these heavy metals is tested in a sand tank at combination of water velocity and electrical gradient of 1.3 cm h-1, 0.5 V cm-1 and 0.88 cm h-1, 1 V cm-1, respectively. The formation of gas at electrodes, scouring on carbon anode and corrosion of crocodile clips during experiment (0.88 cm h-1, 1 V cm-1) showed the occurrence of electrokinetics. Further studies need to be conducted to optimize the operating conditions for effective application of electrokinetic in controlling heavy metals migration in sand.

scholarly journals Polynomial Regression Analysis for Removal of Heavy Metal Mixtures in Coagulation/Flocculation of Electroplating Wastewater

2020 ◽  
Vol 21 (1) ◽  
pp. 46
Author(s):  
Siti Wahidah Puasa ◽  
Kamariah Noor Ismail ◽  
Muhammad Amarul Aliff Bin Mahadi ◽  
Nur Ain Zainuddin ◽  
Mohd Nazmi Mohd Mukelas
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Polynomial Regression ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Final Concentration ◽  
Operating Conditions ◽  
Synthetic Wastewater ◽  
Metal Mixtures ◽  
Metals Removal

Wastewater produced from the electroplating industry generally consists of heavy metals mixture and organic materials that need to be treated before it can be discharged to the environment. Thus, the present investigation was focused on the selectivity removal of heavy metal mixtures consists of Copper (Cu), Cadmium (Cd), and Zinc (Zn). Several operating conditions, including the effect of pH and coagulant (FeCl3) dosage, were varied to find the best performance of heavy metal removal. Results show the efficiency of heavy metals removal for both wastewater characteristics were approximately 99%. The experimental data on the treatment of synthetic wastewater was plotted using polynomial regression (PR) via Excel software. The value of adjusted R2 obtained for the final concentration of Cu, Zn, and Cd after treatment were 0.6884, 0.9676, and 0.9283, respectively, which shows data were acceptably fitted for Cu and very well fitted for Zn and Cd. The coagulation/flocculation process performed on actual wastewater shows that the lowest final concentration of Cu, Zn, and Cd after treatment were 0.487, 1.232, and 0 mg/L respectively at pH of 12.

Cadmium and lead removal from aqueous synthetic wastes utilizing Chemelec electrochemical reactor: Study of the operating conditions

2012 ◽  
Vol 88 ◽  
pp. 107-115 ◽  
Author(s):  
José E.D.V. Segundo ◽  
Giancarlo R. Salazar-Banda ◽  
Aércio C.O. Feitoza ◽  
Eudésio O. Vilar ◽  
Eliane B. Cavalcanti
Keyword(s):  
Electrochemical Reactor ◽  
Operating Conditions ◽  
Lead Removal ◽  
Cadmium And Lead

scholarly journals Removal of Cadmium from Simulated Wastewaters Using a Fixed Bed Bio-electrochemical Reactor

2020 ◽  
Vol 26 (12) ◽  
pp. 110-130
Author(s):  
Duaa R. Saad ◽  
Ziad T. Alismaeel ◽  
Ali H. Abbar
Keyword(s):  
Energy Consumption ◽  
Current Efficiency ◽  
Removal Efficiency ◽  
Applied Voltage ◽  
Ph Value ◽  
Fixed Bed ◽  
Cell Voltage ◽  
Packed Bed ◽  
Electrochemical Reactor ◽  
Operating Conditions

In this research, the removal of cadmium (Cd) from simulated wastewater was investigated by using a fixed bed bio-electrochemical reactor. The effects of the main controlling factors on the performance of the removal process such as applied cell voltage, initial Cd concentration, pH of the catholyte, and the mesh number of the cathode were investigated. The results showed that the applied cell voltage had the main impact on the removal efficiency of cadmium where increasing the applied voltage led to higher removal efficiency. Meanwhile increasing the applied voltage was found to be given lower current efficiency and higher energy consumption.  No significant effect of initial Cd concentration on the removal efficiency of cadmium but increasing the initial concentration would be given higher current efficiency and lower energy consumption. The results established that using a pH value lower than three results in a sharp decrease in the removal efficiency as well as  using a pH value higher than seven results in decreasing the removal efficiency. Using a mesh number higher than 30 gave a lower removal efficiency. The best operating conditions were found to be an applied potential of 1.8 V, an initial Cd concentration of 125 ppm, and a pH of 7. Under these operating conditions with the using a stack of stainless with mesh number 30 as a packed bed cathode, a complete removal efficiency of Cd(100%)  was obtained at a current efficiency of 83.57% and energy consumption of 0.57 kWh/kg Cd.

Excess nitrogen accumulation in activated sludge in sequencing batch reactor with a single-stage oxic process

2009 ◽  
Vol 59 (3) ◽  
pp. 573-582 ◽  
Author(s):  
Xiao-ming Li ◽  
Dong-bo Wang ◽  
Qi Yang ◽  
Wei Zheng ◽  
Jian-bin Cao ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Sequencing Batch Reactor ◽  
Ph Value ◽  
Batch Reactor ◽  
Nitrogen Loss ◽  
Single Stage ◽  
Synthetic Wastewater ◽  
Nitrogen Accumulation ◽  
Excess Nitrogen

It was occasionally found that a significant nitrogen loss in solution under neutral pH value in a sequencing batch reactor with a single-stage oxic process using synthetic wastewater, and then further studies were to verify the phenomenon of nitrogen loss and to investigate the pathway of nitrogen removal. The result showed that good performance of nitrogen removal was obtained in system. 0–7.28 mg L−1 ammonia, 0.08–0.38 mg L−1 nitrite and 0.94–2.12 mg L−1 nitrate were determined in effluent, respectively, when 29.85–35.65 mg L−1 ammonia was feeding as the sole nitrogen source in influent. Furthermore, a substantial nitrogen loss in solution (95% of nitrogen influent) coupled with a little gaseous nitrogen increase in off-gas (7% of nitrogen influent) was determined during a typical aerobic phase. In addition, about 322 mg nitrogen accumulation (84% of nitrogen influent) was detected in activated sludge. Based on nitrogen mass balance calculation, the unaccounted nitrogen fraction and the ratio of nitrogen accumulation in sludge/nitrogen loss in solution were 14.6 mg (3.7% of nitrogen influent) and 0.89, respectively. The facts indicated that the essential pathway of nitrogen loss in solution in this study was excess nitrogen accumulation in activated sludge.

scholarly journals Comparison between Different Keratin-composed Biosorbents for the Removal of Heavy Metal Ions from Aqueous Solutions

2002 ◽  
Vol 20 (4) ◽  
pp. 393-416 ◽  
Author(s):  
Fawzi Banat ◽  
Sameer Al-Asheh ◽  
Dheaya‘ Al-Rousan
Keyword(s):  
Aqueous Solutions ◽  
Human Hair ◽  
Metal Ion ◽  
Ph Value ◽  
Freundlich Isotherm ◽  
Operating Conditions ◽  
Ion Uptake ◽  
Chicken Feathers ◽  
Initial Ph ◽  
Metal Ion Uptake

This study examined and compared the ability of chicken feathers, human hair and animal horns, as keratin-composed biosorbents, for the removal of Zn2+ and Cu2+ ions from single metal ion aqueous solutions under different operating conditions. The three biosorbents investigated in this study were all capable of adsorbing Zn2+ and Cu2+ ions from aqueous solutions. The biosorbent showing the highest uptake of Zn2+ and Cu2+ ions was animal horns. Chicken feathers showed a higher Cu2+ ion uptake and a lower Zn2+ ion compared to human hair. Increasing the initial concentration of Zn2+ or Cu2+ ions, or increasing the initial pH value, increased the metal ion uptake. Such uptake decreased when the temperature was raised from 25°C to 50°C for all adsorbent/metal ion combinations except for Zn2+ ion/human hair where the uptake increased with temperature. It was demonstrated that the addition of NaCl salt to the metal ion solution depressed the metal ion uptake. The Freundlich isotherm model was found to be applicable to the adsorption data for Cu2+ and Zn2+ ions.

Removal of heavy metal ion from synthetic wastewater using spent tea waste powder

2021 ◽  
pp. 24-38
Author(s):  
Devyanshu Sachdev ◽  
Shyam Sunder Mishra ◽  
Srinivas Tadepalli
Keyword(s):  
Metal Ion ◽  
Traditional Approach ◽  
Operating Conditions ◽  
Ion Concentration ◽  
Metal Particles ◽  
Synthetic Wastewater ◽  
Batch Adsorption ◽  
Toxic Heavy Metals ◽  
Copper Solution ◽  
Tea Waste

The current work centres around on the expulsion of toxic heavy metals from mechanical effluents through the cycle of adsorption. This traditional approach is expensive, henceforth the utilization of ease, bountiful naturally neighbourly bio sorbents must be utilized. Adsorption conduct of copper and lead from waste water has been researched in this paper utilizing adsorbent like used tea powder waste. Copper and lead are profoundly harmful metal particles and considered as the need contamination delivered from different chemical ventures electroplating, blending exercises, smelting, battery manufacture etc. The effluents have been unnecessarily delivered into the climate because of expeditious industrialization and have made a worldwide concern. Hence, they should be taken out before release. In current paper, the trial results did in batch adsorption measure utilizing the treated waste tea powder with engineered test arranged in the test center were tried and introduced. The different boundaries, for example, solution’s pH, initial metal ion concentration, temperature and adsorbent dosage on the adsorption of Cu and Pb were considered. The greatest evacuation of Copper was above (at pH 5) 90% was observed using used tea waste powder at 100 ppm Copper solution. The removal of lead was above 85% (at pH 5) was respectively observed at the same operating conditions.

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