scholarly journals Treatment of Tannery Wastewater by Electrocoagulation using Aluminium and Iron Electrodes

2019 ◽  
Vol 8 (4) ◽  
pp. 12572-12580

This Tannery industry is one of oldest industry the effluent is highly complex and characterized by high Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), suspended solids, dissolved solids, total solids, and color. Untreated Tannery wastewater when discharged directly into the water bodies or into open lands cause irreversible damage to environment. Electrocoagulation is one of the most important electrochemical treatment employed for industrial wastewater treatment to treat highly polluted industrial effluents which have high suspended and colloidal materials, BOD, COD in wastewater. Electrocoagulation treatment is used in this study to study the removal efficiency of BOD, COD, Chromium (Cr) Total Dissolved Solids (TDS) and the effect of pH of tannery wastewater. The experiments were conducted using aluminum and iron as plane and punched electrodes. When aluminum Plane and punched electrodes were used the optimum removal efficiency for plain electrodes was found to be BOD-89.66%, COD-96.21%, Cr-96.05% and TDS-95.77% for punched electrodes BOD-90.86%, COD-98.62%, Cr-96.94% and TDS96.92% and for iron plane electrodes BOD-87.57%, COD94.77%, Cr-93.42% and TDS-93.08% for iron punched electrodes BOD-89.01%, 96.59%, Cr-94.66% and TDS-95.0% at pH of 9, Voltage 20V, for electrode distance of 1cm and 90 minutes electrolysis duration. The Electrocoagulation treatment has proved to be economical and efficient method for the treatment of tannery wastewater rather than chemical coagulation.

The Common Effluent Treatment Plants (CETP) minimizes the pollution from industrial effluents. This plant monitors the reduction of physical and biochemical parameters such as total suspended solids (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), heavy metals etc. The Sequential Batch Reactor (SBR), a variation of the ASP, combines all the treatment steps and processes into a single basin. An improved SBR process is Attached Growth Batch Reactor (AGBR) technology that provisions for microbial growth on the settled media/bed to treat the industrial wastewater using enzymes. This technology, when used to treat polluted river water, achieved about 90% of reduction of wastewater parameters. Hence the same is envisioned for the treatment of industrial effluent. In all the above methods the sludge settlement occurs. It contains biodegradable carbon content which could be used as feed for Biogas Digesters to produce Methane. The present study aims at examining the benefits of combining AGBR and Biogas Digester to implement the 3Rs (Reduce, Recycle, Reuse) [1]


Author(s):  
P Ravi Kumar ◽  
Liza Britta Pinto ◽  
RK Somashekar

Bangalore city hosts two Urban Wastewater Treatment Plants (UWTPs) towards the periphery of Vrishabhavathi valley, located in Nellakedaranahalli village of Nagasandra and Mailasandra Village, Karnataka, India. These plants are designed and constructed with an aim to manage wastewater so as to minimize and/or remove organic matter, solids, nutrients, disease-causing organisms and other pollutants, before it reenters a water body. It was revealed from the performance study that efficiency of the two treatment plants was poor with respect to removal of total dissolved solids in contrast to the removal/reduction in other parameters like total suspended solids, BOD and COD. In Mailasandra STP, TDS, TSS, BOD, and COD removal efficiency was 20.01, 94.51, 94.98 and 76.26 % and respectively, while in Nagasandra STP, TDS, TSS, BOD, and COD removal efficiency was 28.45, 99.0, 97.6 and 91.60 % respectively. The order of reduction efficiency was TDS < COD < TSS < BOD and TDS < COD < BOD < TSS respectively in Mailasandra and Nagasandra STPs. Additionally, the problems associated with the operation and maintenance of wastewater treatment plants is discussed. Keywords: Total dissolved solids; Chemical oxygen demand; Biochemical oxygen demand; Aeration tank; Mixed liquor suspended solids; Sludge volume index DOI: 10.3126/kuset.v6i2.4020Kathmandu University Journal of Science, Engineering and Technology Vol.6. No II, November, 2010, pp.115-125


2017 ◽  
Vol 77 (4) ◽  
pp. 988-998 ◽  
Author(s):  
Tadesse Alemu ◽  
Andualem Mekonnen ◽  
Seyoum Leta

Abstract In the present study, a pilot scale horizontal subsurface flow constructed wetland (CW) system planted with Phragmites karka; longitudinal profile was studied. The wetland was fed with tannery wastewater, pretreated in a two-stage anaerobic digester followed by a sequence batch reactor. Samples from each CW were taken and analyzed using standard methods. The removal efficiency of the CW system in terms of biological oxygen demand (BOD), chemical oxygen demand (COD), Cr and total coliforms were 91.3%, 90%, 97.3% and 99%, respectively. The removal efficiency for TN, NO3− and NH4+-N were 77.7%, 66.3% and 67.7%, respectively. Similarly, the removal efficiency of SO42−, S2− and total suspended solids (TSS) were 71.8%, 88.7% and 81.2%, respectively. The concentration of COD, BOD, TN, NO3−N, NH4+-N, SO42 and S2− in the final treated effluent were 113.2 ± 52, 56 ± 18, 49.3 ± 13, 22.75 ± 20, 17.1 ± 6.75, 88 ± 120 and 0.4 ± 0.44 mg/L, respectively. Pollutants removal was decreased in the first 12 m and increased along the CW cells. P. karka development in the first cell of CW was poor, small in size and experiencing chlorosis, but clogging was higher in this area due to high organic matter settling, causing a partial surface flow. The performance of the pilot CW as a tertiary treatment showed that the effluent meets the permissible discharge standards.


Author(s):  
R. Sandhiya ◽  
K. Sumaiya Begum ◽  
D. Charumathi

<p><strong>Objective: </strong>The objectives of the present study were a) to isolate and screen bacteria for dye removal from synthetic solution b) to optimize various variables such as pH, static/shaking and initial dye concentration on degradation of triphenyl methane dyes namely basic violet 3 and basic green 4 by isolated <em>Staphylococcus aureus</em> c) to analyse enzymes involved in the biodegradation of triphenylmethane dyes d) to treat real leather dyeing wastewater with newly isolated strain of <em>Staphylococcus aureus </em>e) to characterize untreated and treated leather dyeing wastewater f) to study the effects of real and treated effluent on plants and <em>Rhizobium</em>.<strong></strong></p><p><strong>Methods: </strong>Isolation of bacteria from sludge was carried out by spread plate method and the bacteria was identified by morphological and biochemical characterization. The isolated bacterium was screened for dye decolorization potential of triphenylmethane dyes basic violet 3 and basic green 4 The effects of parameters were studied by varying pH (from 3 to 9), temperature (from 15-45 °C), and initial dye concentration (from 10-500 mg/l). The enzyme involved in biodegradation was studied in intracellular extract. Real leather dyeing wastewater was treated with the bacteria and characterized. The treated wastewater was tested on plants and <em>Rhizobium </em>for toxicity. <strong></strong></p><p><strong>Results: </strong>Dye decolorization potential of bacteria <em>Staphylococcus aureus</em> isolated from wastewater for leather dyes basic violet 3 and basic green 4 were evaluated. Dye decolorization using bacteria was found to be dependent on physicochemical parameters (shaking, pH and initial dye concentration). Enzymes NADH-DCIP reductase and MG reductase were found to play dominant role during biodegradation of synthetic dyes. Application oriented studies using growing bacteria in pure cultures were carried out with leather dyeing wastewater collected from DKS prime tanners. Analysis of raw leather dyeing wastewater showed high pollution load in terms of color, Total solids, Total suspended solids, Total dissolved solids and Biological oxygen demand whereas the leather dyeing wastewater treated with pure culture of <em>Staphylococcus aureus</em> showed considerable decrease in Total solids, Total suspended solids, Total dissolved solids and Biological oxygen demand values which were within the permissible limits. Phytotoxicity and microbial toxicity studies confirmed the non-toxic nature of treated leather dyeing wastewater. <strong></strong></p><p><strong>Conclusion: </strong>Our study proved that <em>Staphylococcus aureus</em> can serve as a potential remediation agent for the treatment of leather dyeing wastewater.</p>


2019 ◽  
Vol 6 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Veymar G. Tacias-Pascacio ◽  
Abumalé Cruz-Salomón ◽  
José H. Castañón-González ◽  
Beatriz Torrestiana-Sanchez

Background: Wet coffee processing consists of the removal of the pulp and mucilage of the coffee cherry. This process generates a large amount of acidic wastewater which is very aggressive to the environment because of its high content of recalcitrant organic matter. Therefore, treatment is necessary before discharge to water bodies. Because of this reason, this study aimed to evaluate the organic matter removal efficiency in an Anaerobic Baffled Bioreactor (ABR) coupled to a Microfiltration Membrane (MF) system as a new eco-friendly option in the treatment of wet Coffee Processing Wastewater (CPWW). Methods: Two systems (S1 and S2) were evaluated at Hydraulic Retention Times (HRT) of 59 h and 83 h, respectively. Both systems were operated at mesophilic conditions, at a Transmembrane Pressure (TMP) of 50 kPa during 1800 h. Results: The S2 generated higher organic matter removal efficiency, reaching removal values of turbidity of 98.7%, Chemical Oxygen Demand (COD) of 81%, Total Solids (TS) of 72.6%, Total Suspended Solids (TSS) of 100%, and Total Dissolved Solids (TDS) of 61%, compared with the S1. Conclusion: The S2 represents a new eco-friendly alternative to treat CPWW and reduce its pollutant effect.


Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3784 ◽  
Author(s):  
Violetta Kozik ◽  
Krzysztof Barbusinski ◽  
Maciej Thomas ◽  
Agnieszka Sroda ◽  
Josef Jampilek ◽  
...  

The potential implementation of Envifer®, a commercial product containing potassium ferrate (40.1% K2FeO4), for the purification of highly contaminated tannery wastewater from leather dyeing processes was proposed. The employment of the Taguchi method for optimization of experiments allowed the discoloration (98.4%), chemical oxygen demand (77.2%), total organic carbon (75.7%), and suspended solids (96.9%) values to be lowered using 1.200 g/L K2FeO4 at pH 3 within 9 min. The application of the central composite design (CCD) and the response surface methodology (RSM) with the use of 1.400 g/L K2FeO4 at pH 4.5 diminished the discoloration, the chemical oxygen demand, the total organic carbon, and suspended solids within 9 min. The Taguchi method is suitable for the initial implementation, while the RSM is superior for the extended optimization of wastewater treatment processes.


2019 ◽  
Vol 80 (3) ◽  
pp. 458-465 ◽  
Author(s):  
Ahmed Samir Naje ◽  
Mohammed A. Ajeel ◽  
Isam Mohamad Ali ◽  
Hussein A. M. Al-Zubaidi ◽  
Peter Adeniyi Alaba

Abstract In this work, landfill leachate treatment by electrocoagulation process with a novel rotating anode reactor was studied. The influence of rotating anode speed on the removal efficiency of chemical oxygen demand (COD), total dissolved solids (TDS), and total suspended solids (TSS) of raw landfill leachate was investigated. The influence of operating parameters like leachate pH, leachate temperature, current, and inter-distance between the cathode rings and anode impellers on the electrocoagulation performance were also investigated. The results revealed the optimum rotating speed is 150 rpm and increasing the rotating speed above this value led to reducing process performance. The leachate electrocoagulation treatment process favors the neutral medium and the treatment performance increases with increasing current intensity. Furthermore, the electrocoagulation treatment performance improves with increasing leachate temperature. However, the performance reduces with increasing inter-electrode distance.


2018 ◽  
Vol 78 (9) ◽  
pp. 1879-1892 ◽  
Author(s):  
Md Khalekuzzaman ◽  
Muhammed Alamgir ◽  
Mehedi Hasan ◽  
Md Nahid Hasan

Abstract In this research, a hybrid anaerobic baffled reactor (HABR) configuration was proposed consisting of a front sedimentation chamber and four regular baffled chambers followed by two floated filter media chambers for the treatment of domestic wastewater. Performance comparison of uninsulated and insulated HABRs was carried out operating at warm temperature (18.6–37.6 °C) under variable HRTs (30 h and 20 h). The study suggests that almost similar chemical oxygen demand (91% vs 88%), total suspended solids (90% vs 95%), turbidity (98% vs 97%), and volatile suspended solids (90% vs 93%) removal efficiencies were obtained for uninsulated and insulated HABRs. Higher removal of total nitrogen (TN) of 41%, NH4+-N of 44%, and NO3−-N of 91% were achieved by the insulated HABR compared to TN of 37%, NH4+-N of 36%, and NO3−-N of 84% by the uninsulated HABR, whereas lower PO43− removal efficiency of 17% was found in the insulated HABR compared to 24% in the uninsulated HABR. This indicated insulation increased nitrogen removal efficiencies by 4% for TN, 8% for NH4+-N and 7% for NO3−-N, but decreased PO43−removal efficiency by 7%.


1984 ◽  
Vol 16 (5-7) ◽  
pp. 95-125 ◽  
Author(s):  
A Azkona ◽  
S H Jenkins ◽  
H M G Roberts

This paper describes part of a comprehensive multidisciplinary study of the pollution of the estuary of the River Nervion, Bilbao, Spain. The objectives of the study were to determine the sources and loads of pollution from domestic sewage and industrial wastewater; provide information on the extent of pollution; formulate hydrodynamic and predictive models capable of forecasting the effects on the estuary of the anticipated growth of population and industry; determine the amount of polluting matter that would have to be removed in order to reach defined estuary water quality standards; arrive at suitable technical methods able to attain these standards at minimum cost; determine the treatability of wastewater discharges and recommend methods for controlling industrial wastewater. These objectives necessitated a survey of the pollution loads from domestic sources and industry which were discharged to the fresh water and tidal reaches of four major tributaries in addition to the main river Nervion; the results of this part of the survey are described in this paper. The presence of iron in discharges from iron ore mining and metal processing was found to aid flocculation of organic matter and the consequent deposition of sludge in the estuary. This action and the rate of oxygen uptake during the decomposition of such deposits are also described. The domestic sewage of the study area receives treatment in septic tanks before discharging to rivers or the estuary. In spite of free hydrogen sulphide and high concentrations being present in the septic tank effluents, odour nuisance does not occur, because, as is shown in the paper, of the formation of ferrous sulphide. The hydrogen sulphide concentration in the atmosphere at a pumping station was found to be above the safety level. The industrial load of impurity was estimated to be approximately 15% higher than the domestic load, but it is extremly difficult to find a rational basis on which comparisons may be made between domestic sewage and a mixture of industrial effluents containing substances inimical to biological activity. The industrial effluent was contained in a very large volume of water, much of it taken from the estuary for cooling or process water. It is calculated that if the industrial pollutants had been contained only in the fresh water used by industry the COD of the mixture would have been 1317 mg/l; the suspended solids 2143 mg/l; the ammonia nitrogen 191 mg/l; iron 1037 mg/l; other heavy metals 118 mg/l; fluoride as F 14.5 mg/l; cyanide as CN 8.1 mg/l; oil 196 mg/l; phenols 8.1 mg/l; mercury 0.13 mg/l; and the mixture would have had an excess of acidity of 5188 mg/l. An estimate of the load of substances having an oxygen demand indicated that of the total oxygen demand discharged to the system of rivers and estuary approximately 50% entered the estuary from the main tributaries, the remainder being discharged directly to the estuary. An outline is given of the methods that would be used to determine the treatability of industrial effluents which were rendered acceptable for discharge into public sewers.


2008 ◽  
Vol 58 (5) ◽  
pp. 1071-1077
Author(s):  
Bidhan C. Bag ◽  
Makireddi Sai ◽  
Mahavir P. Kaushik ◽  
Krishnamurthy Sekhar ◽  
Chiranjib Bahttacharya

Coagulation is one of the most important physicochemical treatment steps in industrial wastewater to reduce the suspended and colloidal materials responsible for colour and turbidity of the wastewater. The manufacturing plant of N,N′-Dichloro bis (2,4,6-trichlorophenyl) urea (CC2) produces wastewater containing pyridine, acetic acid and diphenyl urea (DPU). The wastewater also contains lot of suspended solids like CC2 and various poly-aromatic compounds. In our present investigation, our basic aim was to find an effective coagulation process for the pretreatment of wastewater discharged from the CC2 plant. Studies were conducted to find out a suitable and effective coagulant for pretreatment of this wastewater. Various coagulating agents such as alum, ferric chloride, sodium carboxymethyl cellulose (Na-CMC) were used. Alum was found to be the most effective coagulant. Coagulation of the wastewater resulted in the total suspended solids (TSS) removal in the range of 92–94% and chemical oxygen demand (COD) removal in the range of 59 to 65% at a dose of 500 mg L−1 of alum at a pH ≥ 7.0. After coagulation the concentration of pyridine in wastewater was found to be reduced by 10.0% and that of DPU 40–45% with a dosage of 500 mg L−1 alum.


Sign in / Sign up

Export Citation Format

Share Document