Coke Oven Wastewater Research Articles

The use of polymeric and ceramic ultrafiltration in biologically treated coke oven wastewater polishing

The use of polymeric and ceramic ultrafiltration in biologically treated coke oven wastewater polishing

The use of ultrafiltration in enhancement of chemical coke oven wastewater treatment

The use of ultrafiltration in enhancement of chemical coke oven wastewater treatment

Phycoremediation of cyanide from coke–oven wastewater using cyanobacterial consortium

Owing to the presence of several toxic pollutants such as cyanide, phenol, ammonium, coke–oven wastewater is being considered as hazardous stream and needs to be treated properly. In the present study, cyanobacterial consortium of Dinophysis acuminata and Dinophysis caudata, collected from East Kolkata Wetland, was used for the treatment of both synthetic cyanide solution and real coke–oven wastewater. The growth kinetics was studied considering nitrate as substrate. Since consortium showed growth in cyanide solution, a model was proposed considering both nitrate and cyanide as substrates. The simulated data match quite well with experimental ones. Two coke–oven wastewater samples were collected—untreated one from equalization tank and another from secondary clarifier effluent and treated with consortium separately. Lipid was extracted from biomass of native cyanobacterial consortium, biomass treated with raw coke–oven wastewater and biomass treated with secondary clarifier effluents. Fatty acid methyl ester of such lipid samples was analyzed using gas chromatograph.

Treatment of coke oven wastewater using ozone with hydrogen peroxide and activated carbon

Treatment of coke oven wastewater using ozone with hydrogen peroxide and activated carbon

Anodic oxidation of coke oven wastewater: Multiparameter optimization for simultaneous removal of cyanide, COD and phenol

Anodic oxidation of industrial wastewater from a coke oven plant having cyanide including thiocyanate (280 mg L−1), chemical oxygen demand (COD – 1520 mg L−1) and phenol (900 mg L−1) was carried out using a novel PbO2 anode. From univariate optimization study, low NaCl concentration, acidic pH, high current density and temperature were found beneficial for the oxidation. Multivariate optimization was performed with cyanide including thiocyanate, COD and phenol removal efficiencies as a function of changes in initial pH, NaCl concentration and current density using Box-Behnken experimental design. Optimization was performed for maximizing the removal efficiencies of these three parameters simultaneously. The optimum condition was obtained as initial pH 3.95, NaCl as 1 g L−1 and current density of 6.7 mA cm−2, for which the predicted removal efficiencies were 99.6%, 86.7% and 99.7% for cyanide including thiocyanate, COD and phenol respectively. It was in agreement with the values obtained experimentally as 99.1%, 85.2% and 99.7% respectively for these parameters. The optimum conditions with initial pH constrained to a range of 6–8 was initial pH 6, NaCl as 1.31 g L−1 and current density as 6.7 mA cm−2. The predicted removal efficiencies were 99%, 86.7% and 99.6% for the three parameters. The efficiencies obtained experimentally were in agreement at 99%, 87.8% and 99.6% respectively. The cost of operation for degradation at optimum conditions was calculated as 21.4 USD m−3.

Modeling of phenol and cyanide removal in a full-scale coke-oven wastewater treatment plant

The BioWin general activated sludge (AS) model (EnviroSim Associates, Ltd, Canada) was extended to predict the kinetics of phenol and cyanide removal from coke-oven wastewater mixed with sewage. To apply the modeling for this type of wastewater, a different model structure and an accurate estimation of the stoichiometric and kinetic parameters are required. In this study, additional processes for the phenol and cyanide were added to the BioWin AS model. Due to the inhibitory effect phenol and cyanide have on biological processes, the Haldane equation was used rather than the Monod equation that is typically used in wastewater modeling. A sensitivity analysis was performed to select the most sensitive parameter in the extended model. The model was calibrated under steady-state conditions and validated under dynamic-flow conditions. Adjustments were made only to the most sensitive parameters of the extended model processes related to phenol and cyanide. The new calibrated parameters were compared to the existing parameters from the literature, which were based on batch lab-scale experiments with synthetic wastewater. The extended model was capable of describing COD, ammonium, phenol, and cyanide removal in a full-scale coke-oven wastewater treatment plant under dynamic conditions.

Combined biological and photocatalytic treatment of real coke oven wastewater

Wastewater generated from coke oven industries contains highly toxic organic and inorganic compounds. In the present study, biological reactors were integrated in sequence of anaerobic–aerobic–anoxic and tested with real coke oven wastewater obtained from a Steel Plant located in India. Among several pretreatment methods, coagulation of raw CWW was found to be effective. COD removal efficiency of 78.5% was achieved by the integrated bioreactor system after coagulation of CWW with 1000mg/L of alum. The effluent COD, NH4-N and TCN concentration from the integrated bioreactors was 420, 152 and 20mg/L, respectively. It was observed that 420mg/L of COD present in the effluent after integrated bio treatment was degraded in less than 4h to minimum COD concentration of 94mg/L using UV–TiO2 photocatalysis. In absence of photocatalyst (TiO2), there was no COD reduction from the bio treated effluent. Similarly, there was insignificant reduction in COD from the raw CWW using photocatalysis without biological treatment. Considerable COD reduction (78.5%) was observed only in the wastewater subjected to integrated biological system. The overall COD removal efficiency of the combined treatment system was found to be 96.2%, which resulted in an effluent COD concentration less than 94mg/L.

Treatment of coke oven wastewater in an anaerobic–anoxic–aerobic moving bed bioreactor system

In this work, sequential moving bed bioreactor (MBBR) system with mixed heterogeneous biomass was selected for the treatment of coke oven wastewater (CW). The reactors were arranged in anaerobic (R1)–anoxic (R2)–aerobic (R3) sequence. CW was collected from an industrial site which contains phenol, ammonia, sulfate, iron, oil, and grease. Few heavy metals (cadmium, lead, and cobalt) were also detected in CW at low concentrations. Raw CW was pretreated by primary settling process to remove high solid concentrations. Thereafter, CW was spiked with synthetic pollutants to make the picture of model industrial wastewater. Phenol (1,350 mg/L), ammonia-N (500 mg/L), thiocyanate (800 mg/L), pyridine (50 mg/L), m-, o-, and p-cresols (50 mg/L each) were added as synthetic pollutants in CW. The system was operated at 6 d hydraulic retention time. R1 showed only less phenol (2–5%) and chemical oxygen demand (COD) (~2%) removal. However, R2 and R3 removed significant amount of thiocyanate (>85%), cresols (~88%), and pyridine (>48%) along with the residual phenol (R2: 88%; R3: 98%) and COD (R2: 58%; R3: 79%). Also, denitrification efficiency of R2 was ~94% throughout the study. Ammonia-N removal by R3 was 64–71% comprising 75–77% of total nitrogen removal. Hence, three stage sequential MBBR could be successfully used to treat high strength CW to achieve the discharge limit of effluent.

A novel forward osmosis-nano filtration integrated system for coke-oven wastewater reclamation

A forward osmosis–nanofiltration (FO–NF) integrated new system in flat-sheet cross-flow module was designed to separate reusable water from coke-oven wastewater with reduced concentration polarization and high flux using low energy. Investigations were carried out under different sets of operating conditions of pressure, cross-flow rate, pH of the feed solution and run time for better understanding of the phenomena of concentration polarization and reverse salt diffusion in the new system. A set of polyamide composite membranes were investigated to screen out the best performing ones (NF-2 for forward osmosis and NF-1 for draw solute recovery) for the final experiments. While investigating effects of different draw solutions (DS) on the water flux and rejection of target contaminants, 1.5M NaCl was found to be the best for forward osmosis. Removal of about 96–98% of cyanide, phenols, NH4+ -N and chemical oxygen demand from real coke-oven could be achieved along with pure water flux of 46L/(m2h) in FO system under optimized conditions. Downstream nanofiltration module ensured continuous recovery and recycle of 99% of the draw solute while ensuring recovery of reusable water at the rate of 45L/(m2h).

Comparison of MBR/RO and UF/RO hybrid systems for the treatment of coke-oven effluents

The toxic industrial coke-oven effluent treatability using ultrafiltration (UF) and membrane bioreactor (MBR) technology with reverse osmosis (RO) was tested through pilot studies due to the inherent advantages of the membrane processes over conventional systems in treatment of high-strength wastewaters. The treatment was analyzed for the removal of cyanide, phenol, and chemical oxygen demand. Pre-treatment of the wastewater before RO was tested using MBR and UF. The MBR was chosen for the pre-treatment as it showed a higher treatment efficiency through aeration-enhanced biodegradation and also as the SDI was below 2.3. The final rejection of cyanide in the RO permeate was above 90%, phenol above 95%, and total suspended solids was 100%. Thus, the permeate quality was found satisfactory and the process may be adopted at full-scale for treatment of coke-oven wastewater at the industry.

Membrane-integrated physico-chemical treatment of coke-oven wastewater: transport modelling and economic evaluation.

A modelling and simulation study with economic evaluation was carried out for an advanced membrane-integrated hybrid treatment process that ensures reuse of water with recovery of ammoniacal nitrogen as struvite from coke-oven wastewater. Linearized transport model was developed based on extended Nernst-Plank and concentration polarization modulus equation. Effects of pH, transmembrane pressure and cross-flow rate of interest on membrane charge density, solute rejection and solvent flux were investigated. The membrane module was successful in yielding a pure water flux as high as 120 L m(-2) h(-1) removing more than 95 and 96% of the cyanide and phenol, respectively, while permeating more than 90% NH4 (+)-N at a transmembrane pressure of only 15 × 10(2) KPa and at a pH of 10 for a volumetric cross-flow rate of 800 L h(-1). The Fenton's reagents were used to degrade more than 99% of pollutants present in the concentrated stream. The developed model could successfully predict the plant performance as reflected in the very low relative error (0.01-0.12) and overall high correlation coefficient (R(2) > 0.96). Economic analysis indicated that such a membrane-integrated hybrid system could be quite promising in coke wastewater treatment at low cost i.e. $0.934/m(2) of wastewater.

Treatment of phenolics, aromatic hydrocarbons, and cyanide-bearing wastewater in individual and combined anaerobic, aerobic, and anoxic bioreactors.

Studies were conducted on a mixture of pollutants commonly found in coke oven wastewater (CWW) to evaluate the biodegradation of various pollutants under anaerobic, aerobic, and anoxic conditions. The removal of the pollutants was monitored during individual bioreactor operation and using a combination of bioreactors operating in anaerobic-aerobic-anoxic sequence. While studying the performance of individual reactors, it was observed that cyanide removal (83.3 %) was predominant in the aerobic bioreactor, while much of the chemical oxygen demand (COD) (69 %) was consumed in the anoxic bioreactor. With the addition of cyanide, the COD removal efficiency was affected in all the bioreactors, and several intermediates were detected. While treating synthetic CWW using the combined bioreactor system, the overall COD removal efficiency was 86.79 % at an OLR of 2.4 g COD/L/day and an HRT of 96 h. The removal efficiency of 3,5-xylenol and cyanide, with inlet concentration of 150 and 10 mg/L, was found to be 91.8 and 93.6 % respectively. It was found that the impact of xylenol on the performance of the bioreactors was less than cyanide toxicity. Molecular analysis using T-RFLP revealed the dominance of strictly aerobic, mesophilic proteobacterium, Bosea minatitlanensis, in the aerobic bioreactor. The anoxic bioreactor was dominant with Rhodococcus pyridinivorans, known for its remarkable aromatic decomposing activity, while an unclassified Myxococcales bacterium was identified as the predominant bacterial species in the anaerobic bioreactor.

Effect of cyanide on phenolics and aromatic hydrocarbons biodegradation under anaerobic and anoxic conditions

Abstract The objective of this study was to investigate the biodegradation of a mixture of pollutants commonly found in coke oven wastewater such as phenol, cresol, xylenol, quinoline, indole and cyanide under anaerobic and anoxic conditions. It was found that xylenol was highly recalcitrant under anaerobic and anoxic conditions. In presence of free cyanide (>2.5 mg/L), the organic compounds (100 mg/L) were degraded before the biodegradation of free cyanide under both the conditions. However, the biodegradation of pollutants prolonged under anaerobic conditions compared to anoxic conditions. All the organics, especially xylenol and indole, inhibited the degradation of cyanide. Experimental results highlighted the detrimental effects of the combined toxic influence of cyanide and organics on the anaerobic and anoxic microbes treating coking wastewater. The proposed mathematical model was able to simulate the biodegradation of organic compounds along with cyanide satisfactorily.

Biodegradation kinetics of Bi-substrate solution of phenol and resorcinol in an aerobic batch reactor

Phenol and resorcinol compounds are found to co-exist in real-life wastewater, especially in petrochemical, coking and coke-oven wastewater. An indigenous mixed microbial culture isolated from effluent treatment plant of a coke oven industry has been employed to investigate for its biodegradation capacity of bi-solute mixture of phenol and resorcinol under aerobic batch reactor operation. A 22 full factorial design with the two substrates at two different levels of initial concentration ranges (high and low) was explored to design the biodegradation experiments. The effect of individual substrate concentrations and their interaction on rate of phenolics biodegradation were also determined. The phenol and resorcinol as substrates were completely utilized after 22 hrs when the solutes are present at low concentrations of 100 mg/L each. But the culture has taken total 58 hrs to biodegrade completely higher initial concentrations i.e., 400 mg/L of each substrate. This study also observed that both specific growth rate of the culture and the specific substrate degradation rate have descended to lower value in presence of phenol and resorcinol as dual substrate in the solution compared to their presence as single substrate, showing the interaction and inhibition by each substrate. Sum kinetic model was used to describe the variation in the specific substrate degradation rates by the mixed culture. From the interaction parameters obtained from this model, it has been observed that resorcinol inhibits specific substrate degradation rate to a higher extent than inhibition caused by phenol (IResorcinol, Phenol = 0.5, IPhenol, Resorcinol = 0.1, RMSE = 0.04361)

A statistical approach for optimization of media components for phenol degradation by Alcaligenes faecalis using Plackett–Burman and response surface methodology

ABSTRACT In the present study, phenol degrading bacterial species was isolated from coke oven wastewater of Durgapur steel plant, India. The biochemical, morphological, and 16s rDNA study were performed to identify the isolated microbes. The studies revealed that the high concentration phenol (2,100 mg L−1) degrading isolating microbe is Alcaligenes faecalis. Optimization of media components and incubation time for phenol degradation was carried out by two-step statistical approach. Six key determinants such as phosphate, iron sulfate, calcium chloride, magnesium chloride, ammonium sulfate concentrations, and incubation time were screened using Plackett–Burman design and were further optimized by response surface methodology (RSM) using practical central composite design. The experimental results of the RSM were fitted via a second-order polynomial regression equation having the correlation coefficient (R 2) 0.9998 that indicates appropriate predictions of the above variables for significant phenol degradation. The results showed that there was 100% phenol degradation of 2100 mg/L which could be achieved at the optimized media composition as analyzed from RSM to appreciate the efficiency of the process using composition 0.42 g L−1 phosphate, 0.46 g L−1 iron sulfate, 0.08 g L−1 calcium chloride, 0.18 g L−1 magnesium chloride, and ammonium sulfate 0.25 g L−1 and 90.8 h incubation time.

Adsorptive removal of phenol from coke-oven wastewater using Gondwana shale, India: experiment, modeling and optimization

The aim of this study is to explore the effectiveness of Gondwana shale for the removal of phenol from coke-oven wastewater. The phenol concentration in coke-oven plant effluent varies from 2 mg/L to 10 mg/L depending on the extent of final treatment in the effluent treatment plant. Kinetics of the removal of phenol from industrial effluent having different initial phenol concentration using Gondwana shale has been studied in a batch contactor by varying different parameters. Morris Webber model has been found to fit the kinetic data. Langmuir isotherm model has been found to fit the equilibrium data with R2 value of 0.986 and adsorption capacity q0 of 0.0334 mg g−1. Response surface methodology has been employed to optimize the removal condition of phenol using shale. The spent shale obtained by removing phenol at optimum condition is used for recovery study. Finally, to see whether the shale is efficient with much higher concentration of phenol, it is contacted with untreated industrial wastewater coming directly from coke-oven battery in a batch contactor. 74.11% removal has been obtained after 24 h when 100 ml of industrial wastewater having phenol concentration of 476.24 mg/L was contacted with 50 g shale at pH 9.3.

Coke oven wastewater treatment by two activated sludge systems

In this study two bench scale activated sludge systems were used, a CSTR and an SBR for the treatment of coke – oven wastewater. Both reactors were inoculated with activated sludge from a municipal wastewater treatment plant. At the first stages of operation, reactors were feed by a mixture of municipal wastewater and synthetic wastewater. Full acclimatization of the microorganisms to synthetic wastewater was achieved in 60 days. The operation of the reactors was divided into three distinct periods. The first period was characterized by the treatment of high organic but non-toxic synthetic wastewater. During this period COD and BOD5 removal efficiencies reached 95 and 98% respectively, in both reactors. Nutrient removal was better in the SBR reactor rather than in the CSTR. In the second period phenol was added in concentrations up to 300 mg l-1. Degradation of phenol started about the 20th day after its introduction to the reactors. In this period no effects of phenol to nutrient removal were observed, whereas the removal efficiency of organic matter in both reactors was slightly decreased. During the third period phenol concentrations of the influent were gradually increased to 1000 mg l-1, while cyanide and thiocyanite were added to the influent composition to concentrations reaching concentrations of 20 and 250 mg l-1 respectively. The composition of the influent of this period was a full assimilation of coke oven wastewater. Introduction of increased phenol concentrations along with cyanide compounds initiated irreversible effects on the activated sludge microfauna of the CSTR causing inherent problems to the treatment process, while SBR showed greater capacity to withstand and degrade toxic compounds. The beginning of this period was characterized by decreased settleability of the suspended solids as well as decrease of organic matter and nutrient removal efficiencies. Monitoring of the effluent characteristics during this period reported over 90% for organic load, 85% of nutrient removal and over 90% of phenol and cyanide removal in SBR, while the removal efficiencies for the CSTR were 75, 65 and 80% respectively.

Sensitive and substrate-specific detection of metabolically active microorganisms in natural microbial consortia using community isotope arrays

The goal of this study was to develop and validate a novel fosmid-clone-based metagenome isotope array approach - termed the community isotope array (CIArray) - for sensitive detection and identification of microorganisms assimilating a radiolabeled substrate within complex microbial communities. More specifically, a sample-specific CIArray was used to identify anoxic phenol-degrading microorganisms in activated sludge treating synthetic coke-oven wastewater in a single-sludge predenitrification-nitrification process. Hybridization of the CIArray with DNA from the (14) C-phenol-amended sample indicated that bacteria assimilating (14) C-atoms, presumably directly from phenol, under nitrate-reducing conditions were abundant in the reactor, and taxonomic assignment of the fosmid clone end sequences suggested that they belonged to the Gammaproteobacteria. The specificity of the CIArray was validated by quantification of fosmid-clone-specific DNA in density-resolved DNA fractions from samples incubated with (13) C-phenol, which verified that all CIArray-positive probes stemmed from microorganisms that assimilated isotopically labeled carbon. This also demonstrated that the CIArray was more sensitive than DNA-SIP, as the former enabled positive detection at a phenol concentration that failed to yield a 'heavy' DNA fraction. Finally, two operational taxonomic units distantly related to marine Gammaproteobacteria were identified to account for more than half of 16S rRNA gene clones in the 'heavy' DNA library, corroborating the CIArray-based identification.

Coke Oven Wastewater Treatment Using on Immersed Membrane Biological Reactor

Coke Oven Wastewater Treatment Using on Immersed Membrane Biological Reactor

Aerobic degradation of phenolics and aromatic hydrocarbons in presence of cyanide

Present study focused on the degradation of a mixture of phenol, cresol, xylenol, quinoline, and indole along with cyanide, commonly found in coke oven wastewater, using aerobic mixed culture. It was found that xylenol and indole were difficult to degrade, when the concentrations were above 250mg/L. It was observed that free cyanide (2.5mg/L and above) has the potency to holdup the oxidation of organics (250mg/L) until the cyanide concentration drops to a minimum level. Final TOC in the mixed pollutant system was less than 4mg/L, indicating the absence of other organic byproducts. Experimental results highlight effect of free cyanide on removal of organics and the combined toxic influence of cyanide and organics on the microbes treating coking wastewater. The proposed mathematical model was able to predict the biodegradation of mixed pollutant system satisfactorily.