1 Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt 1 REMOVAL OF HEAVY METALS FROM INDUSTRIAL WATER USING ELECTRO-COAGULATION TECHNIQUE Riyad H. Al Anbari A, Jabar Albaidani B, Suuad Mahdi Alfatlawi B, and Thikra Aissa Al-Hamdani C A B C Department of Building and Construction Engineering, University of Technology- Baghdad, Iraq / Academic Visitor 27 /University of Monash, VIC, Australia Department of Civil engineering, Babylon University, Babylon, Iraq Directorate of Health /Babylon Governorate, Iraq ABSTRACT Heavy metal removal by electrocoagulation using iron electrodes material was investigated in this paper. Several working parameters, such as ph, current density and heavy metal ions concentration were studied in an attempt to achieve a higher removal capacity. A simple and efficient treatment process for removal of heavy metals is essentially necessary. The continuous flow electrocoagulation system, with reactor consists of a ladder series of twelve electrolytic cells, each cell containing stainless steel cathode and iron anode. The treatment of synthetic solutions containing Zn 2+, Cu 2+, Ni 2+, Cr 3+, Cd 2+ and Co 2+ has been investigated. Results obtained with synthetic wastewater revealed the following: - The most effective removal capacities of studied metals could be achieved when the ph was kept at ~7. - Charge loading was found to be the only variable that affected the removal efficiency significantly. - An increase of charge loading is observed for all metals ions, when current density was varied in the range ma/cm 2. - The removal efficiencies of all studied ions increased with charge loading (Qe). - The removal rate has decreased upon increasing initial concentration. - The amount of iron delivered per unit of pollutant removed is not affected by the initial concentration. - Longer electrolysis times are necessary for chromium, cadmium and cobalt removal. - Lower efficient removal of chromium compared to zinc, copper and nickel and the less efficient removal of cadmium and cobalt. - Result show that iron is very effective as sacrificial electrode material for heavy metals removal efficiency and cost points.
2 2 Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt 1. INTRODUCTION Heavy metals are strictly regulated and must be treated before being discharged in the environment. One of the most techniques has been employed for the treatment of heavy metals, is electrocoagulation. Electrocoagulation is an emerging water treatment technology that has been applied successfully to treat various wastewaters. It has been applied for treatment of potable water (Vik et al., 1984; Holt et al., 22), urban wastewater (Pouet and Grasmick, 1995), heavy metal laden wastewater (Mills, 2), restaurant wastewater (Chen et al., 2), and colored water (Jiang et al., 22). Further, electrocoagulation offers possibility of anodic oxidation and in situ generation of adsorbents (such as hydrous ferric oxides, hydroxides of aluminum). One of the most widely used electrode materials in electrocoagulation process is iron. When iron is used as anodes, upon oxidation in an electrolytic system, it produces iron hydroxide, Fe(OH)n where n = 2 or 3. Two mechanisms for the production of the metal hydroxide have been proposed (Daneshvar, 23). The aims of this paper were to investigate the effect of initial ph, initial metal ion concentrations, current density, and treatment time on the removal efficiency of zinc, copper, nickel, chromium, cadmium and cobalt using iron anodes. The Kinetic models for heavy metals removal were studied also. 2. EXPERIMENTAL WORK Synthetic solutions were prepared from reagent grade chemical without any further purification. All glassware were cleaned with water and 1 N H 2 SO 4 and then rinsed with distilled water, while, the working solutions containing heavy metals were prepared by dissolving appropriate amount of each heavy metal in tap water. Moreover, tap water was tested for the ph and alkalinity.the ph of the tap water varied from , bicarbonate alkalinity was approximately 75-8 mg/l as CaCo 3.
3 Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt 3 A continuous flow electrocoagulation process was built in lab having a device containing twelve electrolytic cells. The device consists of a ladder series of electrolytic cells containing (carbon steel) anodes and stainless-steel cathodes. Fig. (1) Photo of the experimental apparatus. Electrolytic cells iron anodes (low carbon steel, LCS) (99.5%), each of them is constructed to achieve a narrow concentric gap of about 2 mm between the central anode and the surrounding cathode as shown in figure (2). The volume of the electrolytic cells basin alone was approximately (4.5 liters). The active surface for each (27.3 cm) anode surface area is approximately (154 cm 2 ). Fig. (2) Electrolytic cell Each (27.3 cm) carries a DC current of (1. 5.5) amp and a current densities of ( ) ma/cm 2. The over all electrolytic cell pack has dimension of (3 cm) width, (43.5 cm) height and (3.5 cm) in its thickness. All the terminals of electrodes are attached to a power source by using copper strip which acts as a single anode of electrolytic cell assembly, while the outer stainless steel strip which connects the stainless-steel perforated pipe assembly acts as a cathode. The electrolytic cell assembly was operated with flow rates up to1.9 m 3 /hr. By the end of each run, the power supply was switched off and the electrolytic solution was transferred to the settling container. Without polymer addition, about (12 hours) retention time is desirable. The clarified effluent was filtered and analyzed for the
4 4 Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt improvement of its quality to specify the electrocoagulation process efficiency for each heavy metal effluents treatment. 3. RESULT AND DISCUSSION Electrode assembly is the heart of the present treatment facility. Therefore the appropriate selection of its materials is very important. The most common electrode materials for electrocoagulation are iron and aluminum. However it is usually to use iron for wastewater treatment and aluminum for water treatment because iron is relatively cheaper (Chen, 24). 3.1 Effect of ph It has been established that the initial ph (Chen et al., 2 and Do et al., 1994) is an important factor and has a considerable influence on the performance of electrocoagulation process. Generally, the ph of the medium changes during the process, as observed by other investigator (Vic et al., 1984).this change depends on the type of electrode and on initial ph. To evaluate the ph effect, a series of experiments were performed, using solutions containing each of the six heavy metals (Zn 2+, Cu 2+, Cr (VI), Ni 2+, Co 2+, Cd 2+ ) of 5 mg/l each with initial ph varying in the range (2-1). The solutions of these metals were adjusted to the desired ph for each experiment using sodium hydroxide or hydrochloric acid. As illustrated in Figure (3), the removal efficiency of zinc, copper, Cr (VI) and nickel, reached value as high as 99%, when ph is 7 and seem to be not affected by ph for zinc, copper and nickel, as long as this kept in the range between 7 and 12, in contrast a slightly decrease of the removal efficiency of chromium is observed, when the initial ph is increased above 7. The removal efficiency of cadmium and cobalt reaches a maximum of about 83% and 8% respectively when initial ph is 7 as it seems from the same figure. However as the same as chromium, when the initial ph is increased above 7, a slightly decrease of the removal efficiency of cadmium and cobalt is observed. Furthermore, it can be seen that the removal efficiency of all studied ions decreased significantly upon decreasing initial ph and there is maximum removal efficiency at the ph of 7, which is almost neutral. Therefore, it can be concluded that when ph is 7, the majority of iron complexes (coagulants) are formed and it s the optimum ph for carrying out the electrocoagulation. From the Pourbaix diagram (Pourbaix, 1974), it can be deduced that the major complexes formed at this ph are Fe (OH) 2 + and Fe(OH) 2+.
5 Final ph Removal efficincy(%) Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt Zn Cu Ni Cr Cd Co Initial ph Fig. (3) Effect of initial ph on metal ions removal by using iron anodes material. Initial concentration of Zn, Cu, Ni, Cr, Cd, Co = 5mg/l each, current density 1.35 ma/cm 2, anode surface = 1848 cm 2, time of electrolysis = 22.2 min. Using solutions of containing mixture of the six heavy metals of 5 mg /l each, Figure (4) shows that the final ph is always higher than initial ph. This may be explained by the excess of hydroxyl ions produced at the cathode in sufficiently acidic conditions (Chen et al., 2).The difference between initial and final ph values diminishes for initial ph > 7. As a result of previous discussion of the effect of ph on the removal efficiency, the initial ph was adjusted to 7 for all subsequent studies Initial ph Fig. (4) ph variation after electrocoagulation. Initial concentrations of Cu 2+, Zn 2+, Cr 3+, Co 2+, Ni 2 +, Cd 2+ = 5 mg/l each, current density = 1.35 ma/cm 2, anode surface = 1848 cm 2, time of electrolysis = 22.2 min.
6 6 Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt 3.2 Effect of current density The current density not only determines the coagulant dosage rate, but also the bubble production rate and size (Kobia et al., 23 and Holt et al., 22).Thus, this parameter should have a significant impact on pollutants removal efficiencies. A large current means a small electrocoagulation unit. However, when too large current is used, there is a high chance of wasting electrical energy in heating up water. To investigate the effect of current density on the removal efficiency, a series of experiments were carried out on solutions containing a constant pollutants loading with current density being varied from.27 ma/cm 2 to 1.35 ma/cm 2. Figures (5) to (1) show the concentrations profiles of the studied metal ions for typical electrocoagulation runs, where the initial ph was fixed at 7.The removal rate of all studied metal ions increased upon increasing current density. The highest current (1.35 ma/cm 2 ) produced the quickest removal rate, with a 99%,concentrations reduction occurring just after 6.4 min for zinc, copper and chromium and after 9 min for nickel. While the removal rate with 87% and 8% concentration reduction occurring just after 3 min for cadmium and cobalt respectively. This is ascribed to the fact that at high current, the amount of iron oxidized increased, resulting in a greater amount of precipitate for the removal of pollutants. In addition, it was demonstrated that bubbles density increases with increasing current density (Holt et al., 22), resulting in more efficient and faster removal. Moreover, it was previously shown (Khosla et al., 1991) that the bubble size decreases with increasing current density, which is beneficial to the separation process. Indeed, the amounts of iron and hydroxide ions generated at a given time, within the electrocoagulation cell are related to the current flow, using Faraday's law: m = I t M / z F (1) where I is the current intensity, t is the time, M is the molecular weight of iron or hydroxide ion (g/mol), z is the number of electrons transferred in the reaction and F is the Faraday's constant (96486 C/mol). As the current decreased, the time needed to achieve similar efficiencies increased. This expected behavior is explained by the fact that the treatment efficiency was mainly affected by charge loading (Q = I * t), as reported by Chen et al. (2). As the time progresses, the amount of oxidized iron and the required charge loading increase. However, these parameters should be kept at low level to achieve a low-cost treatment.
7 Residual concentration (mg/l) Residual concentration (mg/l) Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt ma/cm2.54 ma/cm2 1.8 ma/cm ma/cm Q(m 3 /h) Fig. (5) Effect of current density on the removal rate of Zn 2+ ions. Initial concentrations of ions = 5 mg/l, anode surface = 1848 cm ma/cm2.54 ma/cm2 1.8 ma/cm ma/cm Q(m 3 /h) Fig. (6) Effect of current density on the removal rate of Cu 2+ ions. Initial concentrations of ions = 5 mg/l, anode surface = 1848 cm 2.
8 Residual concentration (mg/l) Residual concentration (mg/l) 8 Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt ma/cm2.54 ma/cm2 1.8 ma/cm ma/cm Q(m 3 /h) Fig. (7) Effect of current density on the removal rate of Cr 3+ ions. Initial concentrations of ions = 5 mg/l, anode surface = 1848 cm ma/cm2.54 ma/cm2 1.8 ma/cm ma/cm Q(m 3 /h) Fig. (8) Effect of current density on the removal rate of Ni 3+ ions. Initial concentrations of ions = 5 mg/l, anode surface = 1848 cm 2.
9 Residual concentration (mg/l) Residual concentration (mg/l) Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt ma/cm2.54 ma/cm2 1.8 ma/cm ma/cm Q(m3/h) Fig. (9) Effect of current density on the removal rate of Cd 2+ ions. Initial concentrations of ions = 5 mg/l, anode surface = 1848 cm ma/cm2.54 ma/cm2 1.8 ma/cm ma/cm Q(m 3 /h) Fig. (1) Effect of current density on the removal rate of Co 2+ ions. Initial concentrations of ions = 5 mg/l, anode surface = 1848 cm 2. To optimize the treatment efficiency, optimum charge loading required to achieve high removal yields (residual concentration under 2 mg/l for each metal ions except cadmium and cobalt) for each metals ion, were calculated at different current densities. The results shown in Figure (11), point out that the removal rate of zinc and copper is almost three times faster than that of chromium and nickel. Indeed, the volumetric
10 Charge loading (coloumb/l) 11 Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt electrical charges ensuring 96% removal of zinc and copper were coulomb/l, while that needed to achieve the same removal efficiency of chromium and nickel was coulomb/l. For cadmium and cobalt, the optimum charge loading required to achieve 7% removal yields were calculated at different current densities. Furthermore more, as observed by other investigators(adhoum et al., 24 and Holt et al., 22), an increase of charge loading is observed for all metals ions, when current density was varied in the range ma/cm 2. At high current density, the bubble density and upwards flux increased and resulted in a faster removal of the coagulant by floatation. Hence, there is a reduction in the probability of collision between the coagulant and pollutants. The lowest current should be selected to obtain the best removal rate without increasing of cost. The removal efficiencies of all studied ions increased with charge loading (Qe). According to Faradays law, the concentration of Fe 2+ ions released from anodes can be calculated by: [Fe 2+ ] = Qe / ZF, Z = 2 for Fe 2+ (2) The Fe 2+ ions form iron hydroxide flocs to remove heavy metal ions. However, there is a critical charge loading required. Once the charge loading reaches the critical value, the effluent quality does not show significant improvement for further current increase (Chen et al., 2). Figure (12) illustrates the effect of the charge loading on removal efficiency when the current density is the lowest (.27 ma/cm 2 ). Sharp increase of removal efficiencies are clearly shown initially. The optimum charge loading should be at the end of the sharp increase stage. In this case, they are 31.6, 37 and 44.4 coulomb/l for zinc, copper and nickel respectively and it is 55.5 coulomb/l for each of chromium, cadmium and cobalt Zn2+ Cu2+ Cr3+ Ni2+ Cd2+ Co Current density (ma/cm2) Fig. (11) Effect of current density on charge loading. Initial concentration of metals ions = 5mg/l each, anode surface = 1848 cm 2.
11 Removal efficincy (%) Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt Zn2+ Cu2+ Cr3+ Ni2+ Cd2+ Co Charge loading(coulomb/l) Fig. (12) Effect of charge loading on removal efficiency. Current density =.27 ma/cm Effect of metal ion concentration In order to examine the effect of metal ion concentration on the removal rate, several solutions containing increased concentrations (5-4 mg/l) of all six heavy metals were prepared and treated.the residual concentrations of ions were measured at different times. Figures (13) to (18) show the change in the removal rate of zinc, copper, chromium, Nickel, cadmium and cobalt with initial concentration. They all showed the same trends. As expected, it appears that the removal rate has decreased upon increasing initial concentration. This induced a significant increase of charge loading required to reach residual metal concentrations below the levels admissible for effluents discharge into the sewage system (2 mg/l) for zinc, copper, chromium and nickel and which is required to reach residual concentration of (3 mg/l) for cadmium and cobalt as shown in Fig. (19). It can be observed that charge loading undergo an increase with initial concentration. This result proves that the amount of iron delivered per unit of pollutant removed is not affected by the initial concentration. In addition, the charge loading required to remove chromium to the admissible level, is higher than that required for zinc, copper and nickel. Moreover the charge loading required to reach residual concentration of (3 mg/l) of cadmium and cobalt is much more than the other. This confirmed lower efficient removal of chromium compared to zinc, copper and nickel and the less
12 Residual concentration (mg/l) Residual concentration (mg/l) 12 Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt efficient removal of cadmium and cobalt which indicated that longer electrolysis times are necessary for chromium, cadmium and cobalt removal mg/l 1 mg/l 2 mg/l 4 mg/l Time (min.) Fig. (13) Effect of initial concentration on the removal efficiency of Zn 2+ ions. Current density = 1.35 ma/cm 2, anode surface = 1848 cm mg/l 1 mg/l 2 mg/l 4 mg/l Time (min.) Fig. (14) Effect of initial concentration on the removal efficiency of Cu 2+ ions. Current density = 1.35 ma/cm 2, anode surface = 1848 cm 2.
13 Residual concentration (mg/l) Residual concentration (mg/l) Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt mg/l 1 mg/l 2 mg/l 4 mg/l Time (min.) Fig. (15) Effect of initial concentration on the removal efficiency of Ni 2+ ions. Current density = 1.35 ma/cm 2, anode surface = 1848 cm mg/l 1 mg/l 2 mg/l 4 mg/l Time (min.) Fig. (16) Effect of initial concentration on the removal efficiency of Cr 3+ ions. Current density = 1.35 ma/cm 2, surface = 1848 cm 2.
14 Rwsidual concentration (mg/l) Residual concentration (mg/l) 14 Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt mg/l 1 mg/l 2 mg/l 4 mg/l Time (min.) Fig. (17) Effect of initial concentration on the removal efficiency of Cd 2+ ions. Current density = 1.35 ma/cm 2.anode surface = 1848 cm mg/l 1 mg/l 2 mg/l 4 mg/l Time (min.) Fig. (18) Effect of initial concentration on the removal efficiency of Co 2+ ions. Current density = 1.35 ma/cm 2, surface = 1848 cm 2.
15 Charge loading (coulomb/l) Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt Zn2+ Cu2+ Ni2+ Cr3+ Cd2+ Co Initial concentration (mg/l) Fig. (19) Effect of initial concentration on the charge loadings required for an effective removal of metals,current density = 1.35 ma/cm 2, anode surface = 1848 cm 2 residual concentration for Zn, Cu, Ni, Cr < 2mg/l and for Cd, Co < 3 mg/l. 4. CONCLUSIONS This study investigate the performance of a new continuous-flow, perforated tube electrocoagulation system for treating synthetic solutions containing zinc, copper, nickel, trivalent chromium, cadmium and cobalt using iron anodes materials. The results show the following: The removal efficiency of all studied ions decreased significantly upon decreasing initial ph and maximum removal efficiency at the ph of 7. At initial ph of 7, the removal efficiency reached value as high as 99% for zinc, copper, Cr (VI) and nickel, while it is about 83% and 8% for cadmium and cobalt. The final ph is always higher than initial ph. The removal rate of all studied metal ions increased upon increasing current density. The highest current (1.35 ma/cm 2 ) produced the quickest removal rate, with a 99%,concentrations reduction occurring after 6.4 min for zinc, copper and chromium and after 9 min for nickel. While the removal rate with 87% and 8% concentration reduction occurring just after 3 min for cadmium and cobalt respectively.
16 16 Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt The removal rate of zinc and copper is three times faster than that of chromium and nickel. The volumetric electrical charges ensuring 96% removal of zinc and copper were 37, coulomb/l respectively; while to achieve the same removal efficiency for chromium and nickel was 148.1coulomb/l. For cadmium and cobalt, the charge loading to achieve 7% removal yields were 111 coulomb/l. An increase of charge loading is observed for all metals ions, when current density was varied in the range ma/cm 2. At lowest current density (.27 ma/cm 2 ), The optimum charge loading are 31.6, 37 and 44.4 coulomb/l for zinc, copper and nickel respectively and it is 55.5 coulomb /l for each of chromium, cadmium and cobalt. The removal efficiencies of all studied ions increased with charge loading (Qe). The removal rate has decreased upon increasing initial concentration. The amount of iron delivered per unit of pollutant removed is not affected by the initial concentration. Longer electrolysis times are necessary for chromium, cadmium and cobalt. REFERENCES Adhoum, N., Monser, L., Decolourization and removal of phenolic compounds from olive mill wastewater by electrocoagulation, Chemical Engineering and Processing 43 (24) Adhoum, N., Monser, L., N. Bellakhal, J. Belgaied, Treatment of electroplating wastewater containing Cu 2+, Zn 2+ and Cr(VI) by electrocoagulation, Journal of Hazardous Materials, B 112 (24) Al-Baiani, J. H., The efficiency of electrocoagulation in the treatment of water and industrial wastewater, (23), PhD thesis, University of Technology. Chen, X., Chen, G., Yue, P.L., 2. Separation of pollutants from restaurant wastewater by electrocoagulation. SepUse of the IT facilities at Monash is governed by the following policies which can be found at: Chen, X., Chen, G., Yue, P.L., Electrocoagulation and electroflotation of restaurant wastewater, J. Environ. Eng. 126 (2) Chen, X., Chen, G., Yue, P.L., 22. Investigation on the electrolysis voltage of electrocoagulation. Chemical Engineering Science 57,
17 Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt 17 Chen, G., Electrochemical technologies in wastewater treatment, Sep. Purif. Technol. 38 (24) Chen, X., Chen, G., Separation of pollutants from restaurant wastewater by electrocoagulation, Sep. Purif. Technol., 19(2) Dabrowski, A., M. Curie-Sklodowska, Adsorption and its Application in Industry and Environmental Protection, Elsevier, Daneshvar, N., H. Ashassi-Sorkhabi, A. Tizpar, Decolorization of orangeii by electrocoagulation method, Sep. Purif. Technol. 31 (23) Do, J.S., Chen, M. L., Decolourization of dye-containing solutions by electrocoagulation,j.appl.electrochem. 24 (1994) Holt, P.K., G.W. Barton, C.A. Mitchell, A step forward to understanding electrocoagulation, characterization of pollutant s fate, Sixth Congress of Chemical Engineering, Melbourne, 21. Holt, P.K., G.W. Barton, C.A. Mitchell, Mathematical analysis of a batch electrcoagulation reactor, Water Science and Technology: Water Supply, Vol. 2, No. 5-6, pp , 22. Holt, P.K., Barton, G.W., M. Wark, A.A. Mitchell, A quantitative comparison between chemical dosing and elecrtocoagulation, Colloids Surf. A Physicochem. Eng. Aspects 211 (22) Holt, P.K., Geoffrey W. Barton and Cynthia A. Mitchell, The future for electrocoagulation as a localized water treatment technology, Chemosphere, Volume 59, Issue 3, April 25, Pages 355-Khosla, N. K., S. Venkachalam, P. Sonrasundaram, Pulsed electrogeneration of bubbles for electroflotation, J. Appl. Electrochem. 21(1991) Kobya, M., Elif Senturk, Treatment of poultry slaughterhouse wastewaters by electrocoagulation, Journal of Hazardous Materials (25). Kobya, M., Can, O.T., M. Bayramoglu, Treatment of textile wastewaters by electrocoagulation using iron and aluminum electrodes, J. Hazard. Mater. B 1 (23) Mills, D., 2. A new process for electrocoagulation. J. Am. Water Works Assoc. 92 (6), Pouet, M.F., Grasmick, A., Urban wastewater treatment by electrocoagulation and flotation. Water Sci. Technol. 31, Qasim, S.R., Wastewater Treatment Plants. Planning, Design and Operation, Technomic Publishing Company Inc., Lancaster-Basel, Ratna, P. Kumar, Sanjeev Chaudhari, Removal of arsenic from water by electrocoagulation, Chemosphere 55 (24) Rajeshwar, K., J.G. Ibanez, Environmental Electrochemistry, Academic Press, UK, 1997.
18 18 Twelfth International Water Technology Conference, IWTC12 28 Alexandria, Egypt Vic, E.A., Carlson, D.A., Electrocoagulation of potable water, Water Res. 18(1984)
International Journal of Engineering and Technical Research (IJETR) ISSN: 2321-0869, Volume-2, Issue-4, April 2014 Domestic Wastewater Treatment Using Fe-Al Electrodes Dayananda H S, Madhukar M, Apoorva
Removing Heavy Metals from Wastewater Engineering Research Center Report David M. Ayres Allen P. Davis Paul M. Gietka August 1994 1 2 Removing Heavy Metals From Wastewater Introduction This manual provides
HEXAVALENT CHROMIUM REMOVAL FROM INDUSTRIAL WATSEWATER BY CHEMICAL PRECIPITATION METHOD Dr. C.R.Ramakrishnaiah P.G-Environmental Engineering Dept of Civil Engineering, B.M.S. College of Engineering Bull
Dr.Ehssan Nassef Petrochemical Department Faculty of Engineering Pharos University exandria, Egypt. IRCST Engineering Science and Technology: n International Journal (ESTIJ), ISSN: 5-498, Vol., No., June
BCSIR Available online at www.banglajol.info Bangladesh J. Sci. Ind. Res. 47(1), 77-82, 2012 Electrocoagulation (EC) for Reduction of Chemical Oxygen Demand (COD) of Surface Water BANGLADESH JOURNAL OF
Advances in Environmental Biology, 6(7): 1897-1901, 2012 ISSN 1995-0756 1897 This is a refereed journal and all articles are professionally screened and reviewed ORIGINAL ARTICLE Treatment of Dairy Industry
Treating Metal Finishing Wastewater Sultan I. Amer, Ph.D. AQUACHEM INC. Environmental Technology March/April 1998 Wastewater from metal finishing industries contains high concentrations of contaminants
ELECTROCHEMISTRY (All questions may be completed without the use of a calculator. All answers given were generated without the use of a calculator.) 1) Balance each skeleton reaction, calculate ε cell,
REMOVAL AND ANALYSES HEAVY METALS AND THEIR SOURCES The most commonly encountered toxic heavy metals in wastewater: Arsenic, Lead, Mercury, Cadmium Less common: Chromium, Copper, Nickel, Zinc Sources Industrial
Coagulation-Flocculation-Jar Test Assoc. Prof. Kozet YAPSAKLI Turbidity Turbidity particles (sand, silt, clay, bacteria, viruses) in the initial source water that need to be removed to improve treatment.
Single and Double Displacement Reactions Objectives To perform and observe a variety of single and double displacement reactions To record observations in detail To identify the products formed in each
Nickel DOC316.53.01065 Dimethylglyoxime Method Method 10220 0.1 to 6.0 mg/l Ni TNTplus 856 Scope and application: For water and wastewater. Test preparation Instrument-specific information Table 1 shows
Chapter 4 Forms of corrosion Uniform corrosion In such type of corrosion there is a uniform decrease in the volume of the metal due to direct contact with the surrounding environment. Examples Dissolvation
1. Which process occurs in an operating voltaic cell? A) Electrical energy is converted to chemical energy. B) Chemical energy is converted to electrical energy. C) Oxidation takes place at the cathode.
Lecture 11 Mixed Potentials Concepts and Basics Keywords: Mixed Potential, Charge Conservation, Corrosion Potential Principle of charge conservation: Total rate of oxidation must be equal to total rate
Chemistry 12 UNIT 5 OXIDATION AND REDUCTION PACKAGE #2 HOW TO PREDICT WHETHER A REDOX REACTION WILL BE SPONTANEOUS: Looking at the table in the data booklet on page 8, INCREASING TENDENCY TO REDUCE = INCREASING
Chemistry at Work How Chemistry is used in the Water Service WATER TREATMENT Everyday, more than 100 water treatment works in Northern Ireland put approximately 680 million litres of water into the supply
INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCES Volume 1, No 5, 2011 Copyright 2010 All rights reserved Integrated Publishing Association Research article ISSN 0976 4402 Removal of nickel, copper, zinc
Simplified Removal of Chelated Metals Sultan I. Amer, AQUACHEM INC. Metal Finishing, April 2004, Vol. 102 No. 4 Chelating agents are used in large quantities in industrial applications involving dissolved
Name: Thursday, May 08, 2008 Redox and Electrochemistry 1. A diagram of a chemical cell and an equation are shown below. When the switch is closed, electrons will flow from 1. the Pb(s) to the Cu(s) 2+
Name Electrochemical Cells Practice Exam Date: 1. Which energy change occurs in an operating voltaic cell? 1) chemical to electrical 2) electrical to chemical 3) chemical to nuclear 4) nuclear to chemical
Chemistry of Voltaic Cells An electrochemical cell consists of two parts, called half-cells, in which the separate oxidation and reduction reactions take place. Each half cell contains a metal electrode
Desalination, 62 (1987) 251-257 Elsevier Science Publishers B.V., Amsterdam - Printed in The Netherlands The Treatment of Cupric Chloride Solution after the Etching Process by Ion Exchange Membrane Electrodialysis*
Redox and Electrochemistry This section should be fresh in your minds because we just did this section in the text. Closely related to electrochemistry is redox chemistry. Count on at least one question
International Journal of Engineering Inventions ISSN: 2278-7461, www.ijeijournal.com Volume 1, Issue 7 (October2012) PP: 44-50 REMOVAL OF PHOSPHATE FROM WASTEWATER USING LOW-COST ADSORBENTS Dr. C.R.Ramakrishnaiah
Experiment 3 The Electrical Control of Chemical Reactions E3-1 E3-2 The Task In this experiment you will explore the processes of oxidation and reduction, in which electrons flow between materials, and
Operating Experience on the Treatment on FGD Scrubber Blowdown From Existing Generating Stations Michael L. Pudvay Infilco Degremont, Richmond, VA IWC 05 XX Keywords: FGD wastewater treatment, Chemical
Polish J. of Environ. Stud. Vol., No. 1 (11), 17-179 Original Research Operating Cost Analysis and Treatment of Domestic Wastewater by Electrocoagulation Using Aluminum Electrodes Fuat Ozyonar*, Bunyamin
Postfach 169 CH-9545 Wängi TG 26.08.2009 RIAG Zn 270 Acid bright zinc plating process for high temperature application Properties Excellent for barrel plating with high temperature stability Can be operated
14 Development of Advanced Wastewater Treatment and Reclamation System TAKESHI TERAZAKI *1 HOZUMI OTOZAI *2 KOSUKE SHIGIISHI *2 HIDEO SUZUKI *3 HIROSHI NAKASHOJI *4 HIROYUKI KAWAMOTO *5 Recycling and the
Question Bank Electrolysis 1. (a) What do you understand by the terms (i) electrolytes (ii) non-electrolytes? (b) Arrange electrolytes and non-electrolytes from the following substances (i) sugar solution
LACR Method for Alkalinity and TOC Control Marvin Gnagy, P.E., President PMG Consulting, Inc. OTCO Water Workshop March 5, 014 Agenda LACR Defined Applicability of LACR in Treatment Development of LACR
1 SIDE BY SIDE COMPARISON TABLE FOR THE DETERMINATION OF CYANIDE BY UV DIGESTION AND AMPEROMETRIC DETECTION FIA METHOD - 10-204-00-5-D (ASTM D7511-09 e ) TOPIC Method ASTM D7511-09e LACHAT METHOD NUMBER
Electrolytic Cells Voltaic cells are driven by a spontaneous chemical reaction that produces an electric current through an outside circuit. These cells are important because they are the basis for the
Ch 20 Electrochemistry: the study of the relationships between electricity and chemical reactions. In electrochemical reactions, electrons are transferred from one species to another. Learning goals and
EXPERIMENT #9 CORROSION OF METALS Objective The objective of this experiment is to measure the corrosion rate of two different metals and to show the effectiveness of the use of inhibitors to protect metals
Electrochemistry Voltaic Cells Many chemical reactions can be classified as oxidation-reduction or redox reactions. In these reactions one species loses electrons or is oxidized while another species gains
Chapter 5 Toxic Substances in Anaerobic Digestion Toxicity in AD A variety of inorganic and organic wastes can cause toxicity in anaerobic digesters. Many toxic wastes are removed in primary clarifiers
1 EXTRACTION OF METALS Occurrence ores of some metals are very common (iron, aluminium) others occur only in limited quantities in selected areas ores need to be purified before being reduced to the metal
Solving Corrosion Problems On Cast Iron & Ductile Iron Water Mains Presented by: ADITYA SHANKAR GAURAV Regd. No.: 0501223221 Roll No.: ML-21 Dept. Of Mechanical Engg. Krupajal Engineering College Under
Lime Softening Chemical precipitation is one of the more common methods used to soften water. Chemicals normally used are lime (calcium hydroxide, Ca(OH) 2 ) and soda ash (sodium carbonate, Na 2 CO 3 ).
ENE 806, Project Report 3 CHEMICAL PRECIPITATION: WATER SOFTENING Grégoire Seyrig Wenqian Shan College of Engineering, Michigan State University Spring 2007 ABSTRACT The groundwater with high level initial
1 OXIDATION NUMBERS (Section 4.4) Oxidation number is the charge of an atom in a molecule if all the bonding is considered ionic. Oxidation number is different from formal charge. Using oxidation numbers
Characterizing Beauty Salon Wastewater for the Purpose of Regulating Onsite Disposal Systems Fred Bowers 1,2, Ph.D. New Jersey Department of Environmental Protection Division of Water Quality August 14,
1. Using the Activity Series on the Useful Information pages of the exam write the chemical formula(s) of the product(s) and balance the following reactions. Identify all products phases as either (g)as,
1. According to Reference Table J, which metal will react spontaneously with Ag + ions, but not with Zn 2+ ions? 1) Cu 3) Al 2) Au 4) Mg 2. Which will oxidize Zn(s) to Zn 2+, but will not oxidize Pb(s)
Chapter 18-1 1. Assign oxidation numbers to each atom in: Ni Nickel ion charge would be +2, so oxidation number is +2 Chloride ion charge would be 1, so each chlorine has an ox # of -1 Mg 2 Ti 4 Magnesium
Conductors Metals and graphite are the only solids which conduct electricity, but no chemical change is involved. Liquid (melted) metals also conduct, but again there is no chemical change. Electrolytes
1 ELECTROCHEMISTRY REDOX Reduction gain of electrons Cu + 2e > Cu(s) Oxidation removal of electrons Zn(s) > Zn + 2e HALF CELLS these are systems involving oxidation or reduction there are several types
Dr. Ali Abadi Chapter 5: Chemical Effect Materials Properties (Corrosion) Introduction 1 By the end of this tutorial, you should have an understanding of: relative susceptibility of different metals to
Global NEST Journal, Vol 13, No 4, pp 412-418, 2011 Copyright 2011 Global NEST Printed in Greece. All rights reserved REMOVAL OF HEXAVALENT CHROMIUM FROM ELECTROPLATING WASTEWATER BY ELECTROCOAGULATION
IJRRAS 13 (1) October 212 www.arpapress.com/volumes/vol13issue1/ijrras_13_1_25.pdf COAGULATION TREATMENT OF WASTEWATER IN PETROLEUM INDUSTRY USING POLY ALUMINUM CHLORIDE AND FERRIC CHLORIDE Hamidreza Farajnezhad
SIDE DISPLAY Power to Go Visitors observe an electrochemical cell constructed from a small jar containing zinc and copper strips immersed in separate solutions. The strips are connected to a motor that
vii TABLE OF CONTENTS CHAPTER TITLE PAGE DECLARATION ii DEDICATION iii ACKNOWLEDGEMENTS iv ABSTRACT v ABSTRAK vi TABLE OF CONTENTS vii LIST OF TABLES x LIST OF FIGURES xi LIST OF SYMBOLS xiv LIST OF APPENDICES
Chapter 20 Electrochemistry Electrochemistry deals with the relationships between electricity and chemical reactions. Oxidation-reduction (redox) reactions were introduced in Chapter 4 Can be simple displacement
May 09 Investigation on the factors that affect the amount of metal coated in an electroplating process Name of Candidate: Ayşe Melis Aygar Number of Candidate: D1129053 Name of Supervisor: Mustafa Üstünışık
Definitions acid-an ionic compound that releases or reacts with water to form hydrogen ion (H + ) in aqueous solution. They taste sour and turn litmus red. Acids react with certain metals such as zinc,
Int. J. Electrochem. Sci., 9 (2014) 6103-6112 International Journal of ELECTROCHEMICAL SCIENCE www.electrochemsci.org Short Communication Electrocoagulation Process Coupled with Advance Oxidation Techniques
Al-Khwarizmi Engineering Journal, Vol. 5, No. 3, PP 72-76 (29) Al-Khwarizmi Engineering Journal Removal of Sulfate from Waste Water by Activated Carbon Mohammed Sadeq Salman Computer Centre/ University
WATER TREATMENT PROCESSES Effluent Primary treatment Secondary Treatment runoff Tertiary treatment Water Treatment Processes PRIMARY TREATMENT to prepare the wastewater for biological treatment Purpose
DETERMINING THE MASS OF A COPPER ATOM LAB ADV.31 From Vernier Software & Technology, 2004 STANDARDS ADDRESSED 3.4.10 A Explains concepts about the structure and properties of matter. 3.4.12 A Apply concepts
Pollution Prevention and Abatement Handbook WORLD BANK GROUP Effective July 1998 Electroplating Industry Description and Practices Electroplating involves the deposition of a thin protective layer (usually
1 Learning Outcomes EXPERIMENT A5: TYPES OF REACTIONS Upon completion of this lab, the student will be able to: 1) Examine different types of chemical reactions. 2) Express chemical equations in molecular,
Name Chemistry 132 Lab 09 Lab Section Chemical Reactions Part II Prelaboratory Exercise Write out the answers on a separate sheet of paper and turn in the paper at the start of lab. 1. Define the terms
Presented at 12 th IWA ASPAC Regional Conference and Exhibition, Water Beyond 2000, 5 9 November 2000, Chiangmai, THAILAND Ratana Kanluen and Sultan I. Amer AQUACHEM INC. Canton, Michigan, U.S.A. ABSTRACT
Two Types of Chemical Rxns Oxidation/Reduction Chapter 20 1. Exchange of Ions no change in charge/oxidation numbers Acid/Base Rxns NaOH + HCl Two Types of Chemical Rxns Precipitation Rxns Pb(NO 3 ) 2 (aq)
The original manufacturer of Titanium Anodes COMPANY Introduction Profile MAGNETO special anodes B.V. is a technology driven, customer orientated company. The majority of our products consist of tailor
Discovering Electrochemical Cells Part I Electrolytic Cells Many important industrial processes PGCC CHM 102 Cell Construction e e power conductive medium What chemical species would be present in a vessel
Scientific Research and Essays Vol. 6(2), pp. 4264-4272, 19 September, 211 Available online at http://www.academicjournals.org/sre DOI: 1.5897/SRE11.777 ISSN 1992-2248 211 Academic Journals Full Length
Electrochemical cells Introduction: Sudha Madhugiri D.Chem. Collin College Department of Chemistry Have you used a battery before for some purpose? I bet you have. The type of chemistry that is used in
Q. (a) The figure below represents the reaction of sulfur dioxide with oxygen. Oxygen Sulfur dioxide Sulfur trioxide (i) Complete the word equation for the reaction of sulfur dioxide with oxygen. sulfur
Oxidation-Reduction Reactions What is an Oxidation-Reduction, or Redox, reaction? Oxidation-reduction reactions, or redox reactions, are technically defined as any chemical reaction in which the oxidation
ELECTROCHEMICAL PROCESSING OF REGENERATION SOLUTIONS FROM ION- EXCHANGE TREATMENT OF WATER WITH PRODUCTION OF ACIDS AND ALKALIS T. Shabliy, E. Goltvianytskaya, N. Gomelya Department of Ecology and Plant
Chemistry 1C-Dr. Larson Chapter 20 Review Questions MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) is reduced in the following reaction: Cr2O7
CORROSION CONTROL OF ELECTROLYZER, ANOLYTE TANK AND DECHLORINATION TOWER TANK OF A CHLOR-ALKALI PLANT BY AN INNOVATIVE METHOD Sazal Kumar Kundu* Global Heavy Chemicals Limited (GHCL), Dhaka, Bangladesh
21 st Century Chemistry Structured Question in Topic 5 Chemical Cells and Electrolysis Unit 18-21 1. (a) Both zinc-carbon cell and silver oxide cell are primary cells. (i) Why are they classified as primary
BOD / CBOD FROM A TO Z Amy Starkey Stark County Sanitary Engineers What is BOD???? What is BOD? It is a measure of the amount of oxygen consumed by bacteria during the decomposition of organic materials.
THE EUROPEAN PORTABLE BATTERY ASSOCIATION Product Information Primary and Rechargeable Batteries Introduction The following document provides product information on portable primary and rechargeable batteries.
Coagulation and Flocculation Groundwater and surface water contain both dissolved and suspended particles. Coagulation and flocculation are used to separate the suspended solids portion from the water.
Cautions Heavy metals, such as lead, and solutions of heavy metals may be toxic and an irritant. Purpose To determine the cell potential (E cell ) for various voltaic cells and compare the data with the