Decontamination of synthetic textile wastewater by electrochemical processes: energetic and toxicological evaluation

2012 ◽  
Vol 66 (12) ◽  
pp. 2586-2596 ◽  
Author(s):  
Y. Mountassir ◽  
A. Benyaich ◽  
M. Rezrazi ◽  
P. Berçot ◽  
L. Gebrati
Keyword(s):  
Current Density ◽  
Organic Contaminants ◽  
Operating Time ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Toxicological Evaluation ◽  
Textile Materials ◽  
Titanium Electrode ◽  
Electrochemical Processes ◽  
Influence Of Ph

The treatment of a synthetic textile wastewater, prepared with several compounds used in the finishing of textile materials, was comparatively studied by electrochemical methods such as electrooxidation (EO) (titanium electrode) and electrocoagulation (EC) (with aluminum and iron electrodes). The influence of pH, current density and operating time on the treatment was assessed by the parameters used to measure the level of organic contaminants in the wastewater; i.e. color, toxicity and chemical oxygen demand (COD). The experimental results showed that an effective electrochemical oxidation was achieved in which the wastewater was decolorized and 92% of COD was completely eliminated. In particular, the mineralization took place by indirect oxidation, mediated by active chlorine, and the treatment efficiency was enhanced by the addition of NaCl to the wastewater and by increasing the applied current density. The toxicity, still higher than the toxicity of the raw effluent, indicated a presence of toxic products after EO. Good results were obtained with the Al and Fe electrodes, mainly with respect to the removal of color and toxicity. EC is more economical than EO and the toxicity evaluation with the Daphnia magna test shows a significant reduction after EC.

scholarly journals Treatment of textile wastewater using a novel electrocoagulation reactor design

2018 ◽  
Vol 20 (3) ◽  
pp. 449-457
Keyword(s):  
Wastewater Treatment ◽  
Rotation Speed ◽  
Removal Rate ◽  
Operating Time ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Total Suspended Solid ◽  
Operating Conditions ◽  
Conventional Model ◽  
Textile Wastewater Treatment

<p>This study explored the best-operating conditions for a novel electrocoagulation (EC) reactor with the rotating anode for textile wastewater treatment. The influence of operating parameters like inter-electrode distance (IED), current density (CD), temperature, pH, operating time (RT), and rotation speed on the removal efficiency of the contaminant was studied. A comparative study was done using conventional model with static electrodes in two phases under same textile wastewater The findings revealed that the optimal conditions for textile wastewater treatment were attained at RT = 10 min, CD = 4 mA/cm2, rotation speed = 150 rpm, temperature = 25oC, IED = 1cm, and pH = 4.57. The removal efficiencies of colour, biological oxygen demand (BOD), turbidity, chemical oxygen demand (COD), and total suspended solid (TSS) were 98.50%, 95.55%, 96%, 98% and 97.10% within the first 10 min of the reaction. The results of the experiment reveal that the newly designed reactor incorporated with cathode rings and rotated anode impellers provide a superior treatment efficiency within a short reaction time. The novel EC reactor with a rotating anode significantly enhanced textile wastewater treatment compared to the conventional model. The values of adsorption and passivation resistance validated the pollutants removal rate.</p>

scholarly journals Combined electrocoagulation and electro-oxidation of industrial textile wastewater treatment in a continuous multi-stage reactor

2017 ◽  
Vol 76 (9) ◽  
pp. 2515-2525 ◽  
Author(s):  
Edison GilPavas ◽  
Paula Arbeláez-Castaño ◽  
José Medina ◽  
Diego A. Acosta
Keyword(s):  
Wastewater Treatment ◽  
Current Density ◽  
Design Of Experiment ◽  
Operating Cost ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Fractional Factorial ◽  
Multi Stage ◽  
Electro Oxidation ◽  
Textile Wastewater Treatment

Abstract A combined electrocoagulation (EC) and electrochemical oxidation (EO) industrial textile wastewater treatment potential is evaluated in this work. A fractional factorial design of experiment showed that EC current density, followed by pH, were the most significant factors. Conductivity and number of electrooxidation cells did not affect chemical oxygen demand degradation (DCOD). Aluminum and iron anodes performed similarly as sacrificial anodes. Current density, pH and conductivity were chosen for a Box–Behnken design of experiment to determine optimal conditions to achieve a high DCOD minimizing operating cost (OC). The optimum to achieve a 70% DCOD with an OC of USD 1.47/m3 was: pH of 4, a conductivity of 3.7 mS/cm and a current density of 4.1 mA/cm2. This study also shows the applicability of a combined EC/EO treatment process of a real complex industrial wastewater.

Electrochemical treatment and operating cost analysis of textile wastewater using sacrificial iron electrodes

2009 ◽  
Vol 60 (9) ◽  
pp. 2261-2270 ◽  
Author(s):  
M. Kobya ◽  
E. Demirbas ◽  
A. Akyol
Keyword(s):  
Current Density ◽  
Batch Reactor ◽  
Operating Cost ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Iron Electrode ◽  
Treated Wastewater ◽  
Experimental Conditions ◽  
Potential Measurement ◽  
Initial Ph

Electrocoagulation (EC) method with iron electrode was used to treat the textile wastewater in a batch reactor. Iron electrode material was used as a sacrificial electrode in monopolar parallel mode in this study. The removal efficiencies of the wastewater by EC were affected by initial pH of the solution, current density, conductivity and time of electrolysis. Under the optimal experimental conditions (initial pH 6.9, current density of 10 mA/cm2, conductivity of 3,990 μS/cm, and electrolysis time of 10 min), the treatment of textile wastewater by the EC process led to a removal capacity of 78% of chemical oxygen demand (COD) and 92% of turbidity. The energy and electrode consumptions at the optimum conditions were calculated to be 0.7 kWh/kg COD (1.7 kWh/m3) and 0.2 kgFe/kg COD (0.5 kgFe/m3), respectively. Moreover, the operating cost was calculated as 0.2 €/kg removed COD or 0.5 €/m3 treated wastewater. Zeta potential measurement was used to determine the charge of particle formed during the EC which revealed that Fe(OH)3 might be responsible for the EC process.

scholarly journals Treatment of Textile Wastewater by Coagulation Precipitation Method

2012 ◽  
Vol 4 (3) ◽  
pp. 623-633 ◽  
Author(s):  
M. A. Sabur ◽  
A. A. Khan ◽  
S. Safiullah
Keyword(s):  
Large Scale ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Quality Parameters ◽  
Precipitation Method ◽  
Alkaline Ph ◽  
Effluent Quality ◽  
The Individual ◽  
Influence Of Ph

Treatment of textile effluent, collected from Sattar Textile located at Chandra under Gazipur district, Bangladesh was carried out by chemical coagulation and precipitation method. The highly alkaline (pH=12.0) reddish orange colored effluent was characterized by chemical oxygen demand (COD) 1638 mg O2/L; total suspended solids (TSS) 9.76 g/L; total dissolved solids (TDS) 6.62 g/L and turbidly 31.24 FTU. In the present study, polyaluminium chloride (PAC) and SAFI (described in the results and discussions part) solutions were used as coagulants both individually and as their mixture at various ratios. As coagulation precipitation is highly pH sensitive, influence of pH was noted in each case. It was seen that the combined effect of both the coagulants is more effective than the individual effect of coagulants at a particular proportion at pH 6 for the removal of pollutional load from the effluent. The minimum dosages for the coagulants were worked out also from the initial beaker experiments. Finally, the effluent obtained from the large scale treatment was characterized for some effluent quality parameters and 90.17, 74.09 and 93.47% removal COD, TDS and turbidity were observed, respectively.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i3.10777 J. Sci. Res. 4 (3), 623-633 (2012)

Biodegradability of industrial textile wastewater – batch tests

2016 ◽  
Vol 74 (5) ◽  
pp. 1079-1087 ◽  
Author(s):  
Katarzyna Paździor ◽  
Anna Klepacz-Smółka ◽  
Julita Wrębiak ◽  
Ewa Liwarska-Bizukojć ◽  
Stanisław Ledakowicz
Keyword(s):  
Activated Sludge ◽  
Kinetic Parameters ◽  
Organic Contaminants ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Batch Tests ◽  
Half Saturation Constant ◽  
Batch Bioreactors ◽  
Parameter Values

Following new trends we applied oxygen uptake rate (OUR) tests as well as long-term tests (in two batch bioreactors systems) in order to assess the biodegradability of textile wastewater. Effluents coming from a dyeing factory were divided into two streams which differed in inorganic and organic contaminants loads. Usefulness of the stream division was proved. Biodegradation of the low-loaded stream led to over 97% reduction of biochemical oxygen demand (BOD5) together with 80% reduction of chemical oxygen demand (COD) and total organic carbon (TOC). Most of the controlled parameter values were below the levels allowed by legislation for influents to surface water, whereas the high-loaded stream was so contaminated with recalcitrant organic compounds that despite the reduction of BOD5 by over 95%, COD, TOC, total nitrogen and total phosphorus levels exceeded permissible values. OUR tests were aimed at determination of the following kinetic parameters: maximum specific growth rate (μMax), half-saturation constant, hydrolysis constant and decay coefficient for activated sludge biomass for both types of textile wastewater studied. The values of kinetic parameters will be applied in activated sludge models used for prediction and optimisation of biological treatment of textile wastewater.

scholarly journals Integrated electrochemical processes for textile industry wastewater treatment: system performances and sludge settling characteristics

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Hanane Afanga ◽  
Hicham Zazou ◽  
Fatima Ezzahra Titchou ◽  
Youness Rakhila ◽  
Rachid Ait Akbour ◽  
...  
Keyword(s):  
Textile Industry ◽  
Organic Dyes ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Metal Species ◽  
Metallic Ions ◽  
One Pot ◽  
Efficient Treatment ◽  
Electrochemical Processes

AbstractTextile wastewater containing toxic dyes needs efficient treatment before being released into the environment. Certain dyes are known or presumed to have carcinogenic potential for humans. In this work, hybrid electrochemical processes including electrocoagulation (EC) alone and combined with electro Fenton (EF), anodic oxidation (AO) and peroxi-coagulation (PC) were tested to treat real textile wastewater using a batch reactor. A sequential EC and EF (EC-EF) process was found to be more effective. The experimental results indicated that the effectiveness of the treatment decreases in the following order: EC-EF > EC-AO > EC-PC > EC. EC-EF results showed a decrease in chemical oxygen demand (COD, 97%), total organic carbon (98%), total suspended solids (98%), and the concentration of metal species; showing that the treatment of such wastewater type can be achieved by combined EC-EF process in a one-pot bench-scale reactor. The electrical energy consumption, the iron dissolution, and the biological oxygen demand/COD ratios of EC and EC-EF processes were evaluated. Characterization of the sludge generated during EC treatment at current density of 20 mA cm− 2 was carried out. Precipitation, adsorption, and electrochemical oxidation/reduction of organic dyes and metallic ions occurred during the treatment. This investigation shows the efficiency of combined EC-EF to treat textile wastewater.

scholarly journals Optimization of guava juice wastewater electrochemical treatment

2021 ◽  
Vol 10 (2) ◽  
pp. e41910212474
Author(s):  
Gilmar dos Santos ◽  
Joel Marques da Silva ◽  
Javier Alonso Villegas-Aragón ◽  
Silvanio Silvério Lopes da Costa ◽  
Joel Alonso Palomino-Romero
Keyword(s):  
Current Density ◽  
Aluminum Sulfate ◽  
Treatment Time ◽  
Electricity Consumption ◽  
Oxygen Demand ◽  
Electrochemical Treatment ◽  
Cod Removal ◽  
Electrochemical Processes ◽  
Initial Ph ◽  
Consumption Rates

Wastewater from guava juice production was treated by two electrochemical processes: Electroflotation (EF) and Electrocoagulation (EC). Using Box-Behnken experimental design, these processes were optimized in order to find the values of treatment time, initial pH and current density that lead to the maximum chemical oxygen demand (COD) removal efficiencies. Aluminum electrodes were used in EC treatment and an iron cathode and a ruthenium dioxide / titanium dioxide anode were applied in EF treatment. EC treatment resulted in maximum COD removal of 60%, when treating the wastewater for 40 minutes, with initial pH 4.5 and current density of 35 A/m2. On the other hand, EF only removed 25% of the wastewater COD (treatment time 40 minutes, initial pH 7.0 and current density 45 A/m2). Aluminum sulfate addition improved the wastewater conductivity, lowering electricity consumption rates. Moreover, the treatment combining EF and this chemical coagulant lead to better results than the ones found when using EF alone.

Kinetic study of slaughterhouse wastewater treatment by electrocoagulation using Fe electrodes

2012 ◽  
Vol 66 (4) ◽  
pp. 754-760 ◽  
Author(s):  
Mohammad Ahmadian ◽  
Nader Yousefi ◽  
Steven W. Van Ginkel ◽  
Mohammad Reza Zare ◽  
Sajad Rahimi ◽  
...  
Keyword(s):  
Current Density ◽  
Contact Time ◽  
Operating Time ◽  
Oxygen Demand ◽  
Total Suspended Solid ◽  
Pollutant Removal ◽  
Order Kinetic ◽  
Slaughterhouse Wastewater ◽  
Removal Efficiencies ◽  
A Current

In this study, treatment of slaughterhouse wastewater by electrocoagulation was investigated in batch system using Fe electrodes. The effect of various variables such as electrode number, current density and operating time was tested. Pollutant removal efficiency increased with increasing electrode number and operating time. The biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solid (TSS), and total nitrogen (TN) removal efficiencies using eight electrodes at a contact time of 50 min and a current density of 10 A/m2 were 66, 62, 60, and 56%, respectively. Higher electrode numbers will allow shorter operating times to achieve certain removal efficiencies. Also, removal efficiencies increased by increasing the current density; the highest removal efficiencies of BOD5, COD, TSS, and TN at a contact time of 50 min and a current density of 25 A/m2 were 97, 93, 81, and 84%, respectively. The results also show that the reactor pH varies directly with the current density; at 25 A/m2, the reactor pH increased from an initial value of 7.1 to 7.7 after 50 min. The experimental results showed that the kinetics of BOD5, COD, TSS and TN removal could be fitted adequately using a first order kinetic model (higher R2).

scholarly journals Efficiency of turbidity and BOD removal from secondarily treated sewage by electrochemical treatment

2012 ◽  
Vol 4 (2) ◽  
pp. 304-309 ◽  
Author(s):  
A. K. Chopra ◽  
Arun Kumar Sharma
Keyword(s):  
Removal Efficiency ◽  
Current Density ◽  
Supporting Electrolyte ◽  
Operating Time ◽  
Oxygen Demand ◽  
Electrochemical Treatment ◽  
Electrochemical Process ◽  
Effective Removal ◽  
Treated Sewage ◽  
Study Results

The present investigation observed the effect of operating time, current density, pH and supporting electrolyte on the removal efficiency of Turbidity (TD) and Biochemical oxygen demand (BOD) of secondarily treated sewage (STS) using electrochemical process. A glass chamber of 2 litre volume was used for the experiment with two electrode plates of aluminum, each having an area of 125 cm2 and 2 cm distance apart from each other. The treatment showed that the removal efficiency of TD and BOD increased to 87.41 and 81.38 % respectively with theincrease of current density (1.82 -7.52 mA/cm2), time (5 - 40 mins.) and different pH (4-8) of the STS. The most effective removal efficiency was observed around the pH 7. Further, 0.5 g/l NaCl as a supporting electrolyte for electrochemical treatment of STS was found to be more efficient for an increase to 95.56 % and 86.99 % for the removal of TD and BOD at 7.52 mA/cm2 current density in 40 mins. respectively. The electrode and energy consumption was found to vary from 2.52 x10-2 to 10.51 x10-2 kg Al/m3 and 2.76 kwh/m3 to 45.12 kWh/m3 depending on the operating conditions.The kinetic study results revealed that reaction rate (k) increased from 0.0174 to 0.03 min-1 for TD and 0.0169 to 0.024 min-1 for BOD with increase in current density from 1.82 to 7.52 mA/cm2.

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