Removal of copper (II) by manganese-coated sand in a liquid fluidized-bed reactor

This study was performed in a fluidized-bed reactor (FBR) filled with manganese-coated sand (MCS) to treat copper-contaminated wastewater. The adsorption characteristics of MCS, the adsorption equilibrium of MCS, and the copper removal capacity by MCS in FBR were investigated. In terms of the adsorption characteristics of MCS, the surface of MCS was evaluated using a scanning electron microscope (SEM). Energy dispersive analysis (EDS) of X-rays indicated the composition of MCS, and the quantity of manganese on MCS was determined by means of acid digestion analysis. The experimental results indicated that copper was removed by both sorption (ion exchange and adsorption) and coprecipitation on the surface of MCS in FBR. Copper removal efficiency was highly dependent on the pH and increased with increasing pH from pH 2 to 8. After the copper adsorption by MCS, the pH in solution was decreased. When the MCS concentration was greater than 10 g/l, the copper adsorptivities obtained by FBR were almost the same as that from the shaker and when the MCS concentration reached 40 g/l, the copper adsorptivity in FBR was greater than that from the shaker. The adsorption sites of MCS could be used efficiently by the FBR. A Langmuir adsorption isotherm equation fit the measured adsorption data from the batch equilibrium adsorption test better than the Freundlich adsorption isotherm equation did. In addition, the adsorption rate increased when the influent wastewater was aerated.     

Equilibrium studies for the sorption of zinc and copper from aqueous solutions using sugar beet pulp and fly ash

In the present work, the abilities of native sugar beet pulp (SBP) and fly ash (FA) to remove copper (Cu(2+)) and zinc (Zn(2+)) ions from aqueous solutions were compared. The SBP and FA, an industrial by-product and solid waste of sugar industry, were used for the removal of copper and zinc from aqueous water. Batch adsorption experiments were performed in order to evaluate the removal efficiency of SBP and lignite-based FA. The effect of various operating variables, i.e. initial pH, adsorbent dose, initial metal ion concentration, and time on adsorption of copper and zinc onto the SBP and FA, has been studied. The sorption process was relatively fast and equilibrium was reached after about 60 min of contact. As much as 60-97% removal of copper and zinc for SBP and FA are possible in about 60 min, respectively, under the batch test conditions. Uptake showed a pH-dependent profile. The overall uptake for the SBP is at a maximum at pH 5.5 and gives up to 30.9 mg g(-1) for copper and at pH 6.0 and gives 35.6 mg g(-1) for zinc for SBP, which seems to be removed exclusively by ion exchange and physical sorption. Maximum adsorption of copper and zinc occurred 7.0 and 7.84 mg g(-1) at a pH value of 5.0 and 4.0 for FA, respectively. A dose of 8 g l(-1) of SBP and 8 g l(-1) FA were sufficient for the optimum removal of both the metal ions. The sorption data were represented by the Freundlich for SBP and the Langmuir and Freundlich for FA. The sorption data were better represented by the Langmuir isotherm than by the Freundlich one for FA in the adsorption of zinc ion, suggesting that the monolayer sorption, mainly due to ion exchange. The presence of low ionic strength or low concentration of Na and Cl ions does not have a significant effect on the adsorption of these metals by SBP and FA. The SBP and FA are shown to be effective metal adsorbents for these two metals.     

Removal of excess fluoride from water using waste residue from alum manufacturing process

The ability of waste residue, generated from alum manufacturing process, to remove fluoride ion from water has been investigated. Series of batch adsorption experiments were carried out to assess parameters that influence the adsorption process. The factors investigated include the effect of contact time, adsorbent dose, thermal pretreatment of the adsorbent, neutralization of the adsorbent, initial fluoride concentration, pH of the solution and effect of co-existing anions. Results showed that Adsorption of fluoride is fairly rapid in first 5min and thereafter increases slowly to reach the equilibrium in about 1h. The removal efficiency of fluoride was increased with adsorbent dosage. About 85% removal efficiency was obtained within 1h at an optimum adsorbent dose of 16g/L for initial fluoride concentration of 10mg/L. Heat treatment and surface neutralization of the adsorbent did not improve the fluoride removal capacity and efficiency. The amount of fluoride adsorbed increased with increasing initial fluoride concentration. The percentage of fluoride removal remains nearly constant within the pH range of 3-8. The adsorption data at ambient pH were well fitted to the Dubinin-Radushkevick (D-R) isotherm model with a capacity of 332.5mg/g of the adsorbent. The adsorption kinetic was found to follow a pseudo-second-order rate equation with an average rate constant of 2.25gmin(-1)mg(-1). The presence of bicarbonate at higher concentrations (100-500mg/L) decreased the fluoride removal efficiency while other anions (chloride, sulfate, phosphate and nitrate) have no significant effect within the concentration range tested. The overall result shows that the waste residue is efficient defluoridating material.     

Adsorption of Cd(II) and Cu(II) from aqueous solution by carbonate hydroxylapatite derived from eggshell waste

Carbonate hydroxylapatite (CHAP) synthesized by using eggshell waste as raw material has been investigated as metal adsorption for Cd(II) and Cu(II) from aqueous solutions. The effect of various parameters on adsorption process such as contact time, solution pH, amount of CHAP and initial concentration of metal ions was studied at room temperature to optimize the conditions for maximum adsorption. The results showed that the removal efficiency of Cd(II) and Cu(II) by CHAP could reach 94 and 93.17%, respectively, when the initial Cd(II) concentration 80 mg/L and Cu(II) 60 mg/L and the liquid/solid ratio was 2.5 g/L. The equilibrium sorption data for single metal systems at room temperature could be described by the Langmuir and Freundlich isotherm models. The highest value of Langmuir maximum uptake, (b), was found for cadmium (111.1mg/g) and copper (142.86 mg/g). Similar Freundlich empirical constants, K, were obtained for cadmium (2.224) and copper (7.925). Ion exchange and surface adsorption might be involved in the adsorption process of cadmium and copper. Desorption experiments showed that CaCl2, NaCl, acetic acid and ultrasonic were not efficient enough to desorb substantial amount of metal ions from the CHAP. The results obtained show that CHAP has a high affinity to cadmium and copper.     

Preparation of sludge-based activated carbon and its application in dye wastewater treatment

A novel activation process was adopted to produce highly porous activated carbon from cyclic activated sludge in secondary precipitator in municipal wastewater treatment plant for dye removal from colored wastewater. The physical properties of activated carbon produced with the activation of 3M KOH solution in the atmosphere of steam were investigated. Adsorption removal of a dye, Acid Brilliant Scarlet GR, from aqueous solution onto the sludge-based activated carbon was studied under varying conditions of adsorption time, initial concentration, carbon dosage and pH. Adsorption equilibrium was obtained in 15 min for the dye initial concentration of 300 mg/L. Initial pH of solution had an insignificant impact on the dye removal. Results indicated that 99.7% coloration and 99.6% total organic carbon (TOC) were removed after 15 min adsorption in the synthetic solution of Acid Brilliant Scarlet GR with initial concentration of 300 mg/L of the dye and 20 g/L activated carbon. The Langmuir and Freundlich equilibrium isotherm models fitted the adsorption data well with R(2)=0.996 and 0.912, respectively. Accordingly, it is concluded that the procedure of developing activated carbon used in this study could be effective and practical for utilizing in dye wastewater treatment.     

新型水凝胶高效吸附废水中Cd(II)的研究

以廉价的海藻酸钠、丙烯酸和三乙烯四胺作为原料,设计并制备出具有双网络互穿结构的海藻酸钠/聚丙烯酸水凝胶。通过对水凝胶的物理化学性能表征,发现该凝胶具有三维网络结构和较好的稳定性能。以Cd(II)离子作为研究对象,以水凝胶作为重金属吸附剂进行吸附实验,结果表明该水凝胶能在pH值大于2.5时具有较高的吸附率;吸附实验中由于水凝胶的三维网络结构,Cd(II)离子能在其内部进行有效扩散,在离子质量浓度为120 mg/L,水凝胶质量浓度为1g/L的条件下,整个吸附过程在60 min内达到吸附平衡;离子质量浓度低于120 mg/L时,大量暴露的活性位点使水凝胶的吸附效率达到95%以上。在选择性吸附实验中,水凝胶对Cd(II)的吸附效率最高,分配系数Kd达到84.62 L/g。海藻酸钠/聚丙烯酸水凝胶是一种具有处理重金属废水潜力的吸附材料。     

Biosorption of copper ions from aqueous solution by Codium vermilara: Optimization,kinetic, isotherm and thermodynamic studies

In this investigation, the efficiency of Codium vermilara for copper ions removal from aqueous solution was studied. Central Composite Design has been used for the Response Surface Methodology and has been found to be an effective method for investigating the influences of various variables and their interactions on the efficiency of Cu²⁺ ions removal. The interactive impacts of four variables: algal dose, pH, initial concentrations of copper and contact time on the copper removal efficiency were assessed. Algal dose 0.75 g/L, pH 5.28, contact time 70.51 min, and copper concentration 48.75 mg/L were found to be the conditions of optimum biosorption. The efficiency of copper removal was found to be 85.5% under these optimum conditions. Copper removal on the biomass of C. vermilara followed well the kinetics of pseudo-first-order, Elvoish and Intraparticle diffusion. Compared to the other models, Dubinin-Radushkevich isotherm best suited the experimental data revealing that the adsorption mechanism was physical adsorption. Thermodynamic parameters exhibited non-spontaneous, randomness and endothermic biosorption of Cu²⁺ ions. Additionally, the biosorbent characterization was estimated by scanning electron microscopy and Fourier transform infrared analysis. Thus, C. vermilara could be used as possible biosorbent for removing heavy metals and other pollutants from the environment.     

纳米二氧化锰@还原氧化石墨烯对水中Pb(Ⅱ)的吸附性能与吸附机制研究

以重金属Pb(Ⅱ)为目标污染物,制备了MnO₂@还原氧化石墨烯(MnO₂@RGO)复合吸附剂。考察了吸附剂投加量、溶液pH、初始浓度和反应温度等因素对Pb(Ⅱ)去除效果的影响。结果表明:MnO₂@RGO对废水中的Pb(Ⅱ)吸附效果显著,在Pb(Ⅱ)浓度50mg/L,MnO₂@RGO投加量0.15g/L,pH为6.0,吸附时间3h的条件下,吸附量可达到124.3mg/g,Pb(Ⅱ)去除率可达到75%。纳米MnO₂@RGO可用Langmiur等温模型和伪二级动力学方程来描述,为单分子层吸附,以化学吸附为主。在MnO₂@RGO吸附剂的X射线衍射图谱中出现了MnO₂的特征吸收峰,其附着于RGO表面,印证了MnO₂@RGO吸附剂的成功制备。     

Polyacrylamide thorium (IV) phosphate as an important lead selective fibrous ion exchanger: synthesis, characterization and removal study

The objective of the present research was to synthesize, characterize and to investigate the removal efficiency of lead (II) ion from synthetic lead solution by a hybrid fibrous ion exchanger. In the present study polyacrylamide thorium (IV) phosphate was synthesized by co-precipitation method and was characterized using SEM, XRD, FTIR and TGA-DSC. To know the practical applicability, a detailed removal study of lead ion was carried out. The removal of lead was 52.9% under neutral condition, and using 0.4 g of adsorbent in 100 mL of lead solution having initial concentration of 100 mg/L. Adsorption kinetic study revealed that the adsorption process followed first order kinetics. Adsorption data were fitted to linearly transformed Langmuir isotherm with R(2) (correlation coefficient)>0.99. Thermodynamic parameters were also calculated to study the effect of temperature on the removal process. In order to understand the adsorption type, equilibrium data were tested with Dubinin-Radushkevich isotherm. The percentage removal was found to increase gradually with increase in pH and 99% removal was achieved at pH 10. The process was rapid and equilibrium was established within first 30 min.     

Removal of copper from aqueous solution using Ulva fasciata sp.--a marine green algae

Batch adsorption experiments were carried out for the removal of copper from its aqueous solution using Ulva fasciata sp. a marine green algae as adsorbent. The adsorption of Cu(II) by Ulva fasciata sp. was investigated as a function of pH, contact time, initial Cu(II) and adsorbent concentrations and adsorbent size. About 0.1 g of Ulva fasciata sp. was found to be enough to remove 95% of 20 mg/L copper from 30 mL aqueous solution in 20 min. The optimum pH value was found to be 5. The dynamic data fitted to the pseudo-second order kinetic model. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and the isotherm constants were determined. The experimental adsorption data were fitted to the Langmuir adsorption model. The maximum adsorption capacity was 26.88 mg/g. The applicability of Lagergren kinetic model was also investigated.     

Removal of copper from aqueous solution by electrodeposition in cathode chamber of microbial fuel cell

Based on energetic analysis, a novel approach for copper electrodeposition via cathodic reduction in microbial fuel cells (MFCs) was proposed for the removal of copper and recovery of copper solids as metal copper and/or Cu(2)O in a cathode with simultaneous electricity generation with organic matter. This was examined by using dual-chamber MFCs (chamber volume, 1L) with different concentrations of CuSO(4) solution (50.3 ± 5.8, 183.3 ± 0.4, 482.4 ± 9.6, 1007.9 ± 52.0 and 6412.5 ± 26.7 mg Cu(2+)/L) as catholyte at pH 4.7, and different resistors (0, 15, 390 and 1000 Ω) as external load. With glucose as a substrate and anaerobic sludge as an inoculum, the maximum power density generated was 339 mW/m(3) at an initial 6412.5 ± 26.7 mg Cu(2+)/L concentration. High Cu(2+) removal efficiency (>99%) and final Cu(2+) concentration below the USA EPA maximum contaminant level (MCL) for drinking water (1.3mg/L) was observed at an initial 196.2 ± 0.4 mg Cu(2+)/L concentration with an external resistor of 15 Ω, or without an external resistor. X-ray diffraction analysis confirmed that Cu(2+) was reduced to cuprous oxide (Cu(2)O) and metal copper (Cu) on the cathodes. Non-reduced brochantite precipitates were observed as major copper precipitates in the MFC with a high initial Cu(2+) concentration (0.1M) but not in the others. The sustainability of high Cu(2+) removal (>96%) by MFC was further examined by fed-batch mode for eight cycles.     

Treatment of metal cyanide bearing wastewater by simultaneous adsorption and biodegradation (SAB)

This paper presents process review and comparative study of biodegradation and adsorption alone with simultaneous adsorption and biodegradation (SAB) process using Pseudomonas fluorescens. Ferrocyanide solution was used for all studies with initial CN(-) concentrations of 50, 100, 200 and 300mg/L, and initial pH of 6. Pseudomonas fluorescens used ferrocyanide as sole source of nitrogen and biodegradation efficiency was observed as 96.4, 94.1, 86.2 and 69.3%, respectively after 60h of agitation. Whereas in adsorption process with granular activated carbon (GAC) as adsorbent, CN(-) removal efficiency was found to be 85.6, 80.1, 70.2 and 50.2%, respectively. But in SAB process the removal efficiency could be more than 70% for all concentrations only at 36h of agitation and achieved removal efficiency of 99.9% for 50 and 100mgCN(-)/L. It was found that SAB process is more effective than biodegradation and adsorption alone.     

Removal of copper from industrial sludge by traditional and microwave acid extraction

This work elucidates the removal of copper from industrial sludge by traditional and microwave acid extraction. The effects of acid concentration, extraction time, sludge particle size and solid/liquid (S/L) ratio on copper removal efficiency were evaluated. Leaching with more concentrated acid yielded greater copper content from the industrial sludge. The experimental findings reveal that the most economical traditional extraction conditions were the use of 1N sulfuric or nitric acid for 60 min at an S/L ratio of 1/20; however, at an S/L ratio of 1/6, the extraction time needed to achieve the same copper removal efficiency was increased to 36 h. Increasing the microwave power and reducing the S/L ratio increased the copper extraction efficiency and the effect in the larger S/L ratio system was more significant. A comparison of the results of microwave-assisted (microwave only) and microwave-enhanced (microwave with addition of active carbon) acid extraction demonstrated that under both conditions, S/L ratio = 1/6 and 1/20; adding active carbon shortened the extraction time required to achieve 80% copper extraction efficiency from 20 to 10 min. These experimental results indicate that the most important factors that most strongly affected microwave acid extraction were the addition of a microwave absorber, the microwave power input and the S/L ratio. The sludge particle size did not significantly affect the copper extraction. The results reveal that sulfuric acid was an effective extractant and that the copper fraction in the extracted sludge shifted from being mostly bound to the Fe–Mn oxides and organic matter, to being mostly bound to organic matter and remaining as a residue during acid extraction.     

Biosorption of reactive dye using acid-treated rice husk: factorial design analysis

A factorial experimental design technique was used to investigate the biosorption of reactive red RGB (lambda(max)=521 nm) from water solution on rice husk treated with nitric acid. Biosorption is favored because of abundance of biomass, low cost, reduced sludge compared to conventional treatment techniques and better decontamination efficiency from highly diluted solutions. Factorial design of experiments is employed to study the effect of four factors pH (2 and 7), temperature (20 and 40), adsorbent dosage (5 and 50mg/L) and initial concentration of the dye (50 and 250 mg/L) at two levels low and high. The efficiency of color removal was determined after 60 min of treatment. Main effects and interaction effects of the four factors were analyzed using statistical techniques. A regression model was suggested and it was found to fit the experimental data very well. The results were analyzed statistically using the Student's t-test, analysis of variance, F-test and lack of fit to define most important process variables affecting the percentage dye removal. The most significant variable was thus found to be pH.     

Biosorption of Hg from aqueous solutions by crab carapace

Carapace from the edible crab was assessed for the biosorption of Hg from aqueous solutions. Batch adsorption studies were used to determine the effects of contact time, pH, concentration, particle size and Cu(II) as a co-ion. The removal of Hg was fast and efficient, attaining >80.0% from 500 mg/L by 60 min. Specific uptake increased from 0.1 to 13.0mg/g as initial concentration increased from 0.5 to 1000 mg/L while the removal efficiency decreased from 100.0% over the 0.5-10.0mg/L range to 65.0% at 1000 mg/L. As particle size decreases from >2.5 to <0.15 mm, the Hg uptake increased from 1.4 to 8.3mg/g. In binary metal solutions, Cu(II) reduced the Hg removal by 80.0% while the presence of Hg increased Cu(II) removal by approximately 7.0%. Crab carapace is a readily available alkaline waste and easily processed into durable granular forms. Therefore, it offers potential as a low-cost alternative to commercial adsorbents or as a complimentary polishing process for the removal of Hg from acidic solutions.     

Phosphate removal using sludge from fuller's earth production

This study assesses the phosphate removal capacity and mechanism of precipitation or adsorption from aqueous solutions in batch experiments by an industrial sludge containing gypsum (CaSO(4).2H(2)O) obtained as a by-product from a fuller's earth process. The potential capacity for phosphate removal was tested using various solution concentrations, pH values, reaction times, and amount of sludge. The maximum phosphate adsorption capacity calculated using the Langmuir equation was 2.0 g kg(-1). The pH for the maximum adsorption by the sludge was neutral to alkaline (pH 7-12). Over 99% of phosphate was removed from a phosphate solution of 30 mg L(-1) using 0.15 g of sludge in a 9-h reaction. Sulfate (SO(4)(2-)) concentration increased with increasing initial phosphate concentration, possibly because of dissolution of gypsum and adsorption of both sulfate and phosphate. At high phosphate concentration (>1000 mg L(-1)), relative constant concentration of Ca(2+) was not consistent with adsorption of the most important phosphate removal mechanism. Results suggest that precipitation of calcium phosphate is principally responsible for phosphate removal under its high concentration. Agglomerated precipitate in the reaction sludge was observed by SEM and identified as brushite (CaHPO(4).2H(2)O) by XRD, FT-IR, and DTA. Based on thermodynamic considerations, it is suggested that the brushite will readily transform to more stable phases, such as hydroxyapatite (Ca(5)(PO(4))(3).OH).     

The reuse of dried activated sludge for adsorption of reactive dye

Adsorption processes are alternative effective methods for removal of textile dyes from aqueous solutions. The adsorption ability of adsorbent affects by physico-chemical environment for this reason in this paper effect of initial pH, dye concentrations, temperature and dye hydrolyzation were determined in a batch system for removal of reactive dye by dried activated sludge. The Langmuir isotherm model was well described of adsorption reactive dye and maximum monolayer adsorption capacity (at pH 2) of activated sludge was determined as 116, 93 and 71mgg(-1) for 20 degrees , 35 degrees and 50 degrees C, respectively. Initial pH 2, 20 degrees C and 30min contact time are suitable for removal of reactive dyes from aqueous solutions. Activated sludge was characterized by FT-IR analysis and results showed that active sludge has different functional groups and functional groups of activated sludge are able to react with dye molecules in aqueous solution. The pseudo first-order, second-order and intraparticle diffusion kinetics were used to describe the kinetic data. The pseudo second-order kinetic model was fit well over the range of contact times and also an intra particle diffusion kinetic model was fit well but in the first 30min. The dye hydrolyzation was affected adsorption capacity of biomass and adsorption capacity of biomass decreased with dye hydrolyzation from 74 to 38mgg(-1).     

Physico-chemical treatments for removal of recalcitrant contaminants from landfill leachate

In this paper, the technical applicability and treatment performance of physico-chemical techniques (individual and/or combined) for landfill leachate are reviewed. A particular focus is given to coagulation-flocculation, chemical precipitation, ammonium stripping, membrane filtration and adsorption. The advantages and limitations of various techniques are evaluated. Their operating conditions such as pH, dose required, characteristics of leachate in terms of chemical oxygen demand (COD) and NH3-N concentration and treatment efficiency are compared. It is evident from the survey of 118 papers (1983-2005) that none of the individual physico-chemical techniques is universally applicable or highly effective for the removal of recalcitrant compounds from stabilized leachate. Among the treatments reviewed in this article, adsorption, membrane filtration and chemical precipitation are the most frequently applied and studied worldwide. Both activated carbon adsorption and nanofiltration are effective for over 95% COD removal with COD concentrations ranging from 5690 to 17,000 mg/L. About 98% removal of NH3-N with an initial concentration ranging from 3260 to 5618 mg/L has been achieved using struvite precipitation. A combination of physico-chemical and biological treatments has demonstrated its effectiveness for the treatment of stabilized leachate. Almost complete removal of COD and NH3-N has been accomplished by a combination of reverse osmosis (RO) and an upflow anaerobic sludge blanket (UASB) with an initial COD concentration of 35,000 mg/L and NH3-N concentration of 1600 mg/L and/or RO and activated sludge with an initial COD concentration of 6440 mg/L and NH3-N concentration of 1153 mg/L. It is important to note that the selection of the most suitable treatment method for landfill leachate depends on the characteristics of landfill leachate, technical applicability and constraints, effluent discharge alternatives, cost-effectiveness, regulatory requirements and environmental impact.     

A study on removal characteristics of copper from aqueous solution by sewage sludge and pomace ashes

In the present work, the abilities of sewage sludge and pomace ashes to remove copper (Cu(2+)) ions from aqueous solutions are compared. Batch adsorption experiments were performed in order to evaluate the removal efficiency of these materials. Effect of contact time, solution pH, ash concentration and temperature on the removal of Cu(2+) was investigated. The results of batch equilibrium studies showed that the solution pH was the key factor affecting the adsorption characteristics. In general, the amount of Cu removed increased as the solid concentration and pH increased, and then it remained constant over a wide pH region. The adsorption test of applying sewage sludge and pomace ashes into synthetic wastewater revealed that the adsorption data of these materials for copper ions were better fitted to the Langmuir isotherm since the correlation coefficients for the Langmuir isotherm were higher than that for the Freundlich isotherm. The estimated maximum capacities of copper adsorbed by sewage sludge and pomace ashes were 5.71 and 6.98 mg g(-1), respectively. Experimental results indicated that the adsorption was favorable at higher pH and higher temperature. Values of DeltaG degrees ranging from -4.64 to -5.13 kcal mol(-1) for sewage sludge ash and from -4.97 to -5.53 kcal mol(-1) for pomace ash suggest that the adsorption reaction is a physical process enhanced by the electrostatic effect. The values of DeltaH degrees and DeltaS degrees are, respectively, 4.27 kcal mol(-1) and 30.6 cal K(-1)mol(-1) for sewage sludge ash and 4.33 kcal mol(-1) and 31.3 cal K(-1)mol(-1) for pomace ash. The mechanisms of copper removal by these materials included adsorption and precipitation. The sewage sludge and pomace ashes are shown to be effective adsorbents for this metal.     

Removal turbidity and separation of heavy metals using electrocoagulation-electroflotation technique A case study

The electrocoagulation (EC) process was developed to overcome the drawbacks of conventional wastewater treatment technologies. This process is very effective in removing organic pollutants including dyestuff wastewater and allows for the reduction of sludge generation. The purposes of this study were to investigate the effects of the operating parameters, such as pH, initial concentration (C(0)), duration of treatment (t), current density (j), interelectrode distance (d) and conductivity (kappa) on a synthetic wastewater in the batch electrocoagulation-electroflotation (EF) process. The optimal operating conditions were determined and applied to a textile wastewater and separation of some heavy metals. Initially a batch-type EC-EF reactor was operated at various current densities (11.55, 18.6, 35.94, 56.64, 74.07 and 91.5mA/cm(2)) and various interelectrode distance (1, 2 and 3cm). For solutions with 300mg/L of silica gel, high turbidity removal (89.54%) was obtained without any coagulants when the current density was 11.55mA/cm(2), initial pH was 7.6, conductivity was 2.1mS/cm, duration of treatment was 10min and interelectrode distance was 1cm. The application of the optimal operating parameters on a textile wastewater showed a high removal efficiency for various items: suspended solid (SS) 86.5%, turbidity 81.56%, biological oxygen demand (BOD(5)) 83%, chemical oxygen demand (COD) 68%, and color over 92.5%. During the EC process under these conditions, we have studied the separation of some heavy metal ions such as iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), lead (Pb) and cadmium (Cd) with different initial concentrations in the range of 50-600mg/L and initial pH between 7.5 and 7.8. This allowed us to show that the kinetics of electrocoagulation-electroflotation is very quick (<15min), and the removal rate reaches 95%.