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The present investigation focused on End-of-pipe treatment of secondary treated coke-oven wastewater to remove cyanide, phenol, ammoniacal-N, nitrate and fluoride using earthen tea pot (ETP), a local market waste. The effect of parameters like adsorption time (0–10 h), particle size (1–3 mm) and adsorbent dose (10–30 gL−1) was tested for removal of pollutants from synthetic BOD treated coke-oven wastewater (SBTCW) and maximum removal was obtained as cyanide (95.46 ± 0.004%), phenol (99.70 ± 0.005%), ammoniacal-N (47.88 ± 6.31%), nitrate (61.03 ± 2.12%), and fluoride (92.35 ± 0.09%) at adsorption time 10 h, particle size 1 mm and adsorbent dose 10 gL−1. Kinetic study showed that the fluoride removal data fit satisfactorily to the Pseudo 2nd order kinetic model, whereas the Pseudo 1st order model was found to be fitted well to the kinetic data of all other pollutants. Adsorption isotherm study portrayed that the Freundlich isotherm model holds good to represent equilibrium data for the removal of pollutants. Response Surface Methodology (RSM) was used to optimize the removal efficiencies of all five pollutants. The optimum removal condition as shown by RSM study was contact time: 7.3 h, and initial concentrations (ICs) of cyanide, phenol, ammoniacal-N, nitrate and fluoride are 0.71, 10, 400, 100 and 10.1 mgL−1, respectively, and the removal of five pollutants (cyanide, phenol, ammoniacal-N, nitrate and fluoride) were predicted as 40.58%, 90.00%, 41.63%, 96.00% and 45.29%, respectively. Artificial Neural Network model was developed based on experimental points which indicated that the model can calculate abatement of five different pollutants for various operating conditions with reasonably high accuracy. Genetic Algorithm was then used to optimize the removal process of the five pollutants. Regeneration study was conducted to assess the efficacy of the regenerated adsorbent in next cycle of the End-of-pipe treatment of SBTCW. Finally, real secondary treated coke-oven wastewater was collected and treated with the present adsorbent. • End-of-pipe treatment of secondary treated coke-oven wastewater was studied. • Earthen tea pot was used for simultaneous removal of five pollutants. • Response Surface Methodology was used to optimize the removal process. • Artificial Neural Network was used to model the adsorptive removal. • Genetic Algorithm was used to optimize the removal of all five pollutants. [ABSTRACT FROM AUTHOR]

Coke-oven wastewater is usually treated with the activated sludge process, which requires large amounts of electrical energy for aeration and sludge disposal. A more sustainable treatment is strongly required. Recently, microbial fuel cells (MFCs) are focused as a technology for the production of electricity from wastewaters with simultaneous removal of organic matter. However, no MFC has been reported that can remove phenol, thiosulfate and thiocyanate simultaneously without aeration. Phenol can generally be removed well, whereas thiocyanate is relatively difficult to degrade. In this study, a dual-chamber MFC (D-MFC) was designed and equipped with a thiocyanate-degrading biofilm enriched on an air cathode. The D-MFC degraded phenol and thiosulfate in the anode chamber at the rate of 104 and 331 mg/L/day, respectively and subsequently degraded thiocyanate in the cathode chamber at the rate of 250 mg/L/day. The D-MFC showed high thiocyanate degradation rate. This suggests that pre-enrichment could accelerate thiocyanate degradation in MFC. In addition, thiocyanate degradation was not inhibited by phenol as thiocyanate was removed in the cathode chamber after phenol was removed in the anode chamber. This study demonstrated the feasibility of treating coke-oven wastewater by a D-MFC with a thiocyanate-degrading biofilm enriched at the air cathode. HIGHLIGHTS A dual-chamber microbial fuel cell achieved simultaneous phenol, thiosulfate and thiocyanate degradation without active aeration.; Pre-enrichment on an air cathode could accelerate thiocyanate degradation in MFC.; The membrane is essential to avoid inhibition of thiocyanate degradation by phenol.;

This article focuses on the phycoremediation of pollutants from secondary treated coke-oven effluent through a green and economical route. A microalgal sample was collected and identified as a consortium of Chlorella sp. and Synechococcus sp. The culture cost was reduced by using poultry litter extract as supplementary material to BG-11 medium. Since the major pollutants present in real secondary treated coke-oven wastewater are phenol, ammoniacal-N (NH4+) and cyanide, several matrices were designed with these three major pollutants by varying their initial concentrations such as phenol (2–10 mg/L), cyanide (0.3–1 mg/L) and NH4+ (100–200 mg/L), termed as simulated secondary treated coke-oven wastewater. Maximum removal was observed with individual solutions of phenol (4 mg/L), cyanide (0.6 mg/L) and NH4+ (175 mg/L), while maximum removal in simulated secondary treated coke-oven wastewater was observed at higher concentrations of phenol (8 mg/L) and cyanide (0.8 mg/L) and the same concentration of NH4+ (175 mg/L). A consortium was found effective to meet statutory limits of pollutants. Kinetic model was developed for predicting growth of consortium and observed that the poultry litter extract-enriched BG-11 medium showed higher values of maximum specific growth rate (0.56 per day) and carrying capacity (1,330 mg/L) than that in BG-11 medium only. HIGHLIGHTS A consortium was identified for tertiary treatment of coke-oven wastewater.; Poultry litter extract was found effective as a growth medium for consortium.; Phycoremediation of NH4+, phenol and cyanide was examined with the present consortium.; Biomass and biomolecules were extracted and estimated.; A consortium was found effective for real wastewater treatment.;

Coke-oven wastewater is generally characterized by having an array of pollutants such as cyanide, phenol, and ammoniacal-N. The present study focuses on the simultaneous removal of such pollutants from synthetic coke-oven wastewater using a bacterial isolate, Bacillus sp. NITD 19, collected from the contaminated site. Growth of bacterial sample was studied in Luria–Bertani (LB) medium. The tolerance limit of each pollutant was studied with the bacterial strain. One variable at a time (OVAT) approach was followed to see the individual effect of operating factors on the removal of each pollutant. Effective conditions like pH (8); inoculum size (IS) (4%); and initial concentrations of phenol (100 mg/L), cyanide (40 mg/L), and ammoniacal-N (400 mg/L) were ascertained after OVAT analysis. Synthetic coke-oven wastewater (SCW) was prepared by mixing these three pollutants at their most effective initial concentrations. The time variation for removal of pollutants from individual aqueous solutions and SCW was studied at the most effective condition with the bacterial strain. Maximum removal of phenol (79.88%±1.3% , 72.84%±1.21%), ammoniacal-N (82.83%±1.23% , 80.25%±1.49%), and cyanide (89.51%±1.44% , 79.78%±0.95%) were obtained from individual aqueous solution and SCW, respectively. Biomass extracted from the SCW solution was less than that obtained after the treatment of individual pollutants. Fourier-transform infrared spectrophotometry (FTIR) study and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis were performed for native and treated bacterial strain. [ABSTRACT FROM AUTHOR]

Although the time for operating mines and coking plants in many countries is coming to an end due to climate change, we must still ensure that the pollution generated by this source of the economy is minimized. Despite the several stages of treatment of the coke-oven effluent, completed with nitrification and denitrification processes preceding final sedimentation, the stream obtained does not meet the requirements of water for coke quenching. That is why the stream after biodegradation and sedimentation was treated on membrane units to ensure water reusing in the coking plant. As the subjected stream contained both solid and dissolved pollutants, a two-stage system was proposed: low- and high-pressure membrane filtration. Industrial modules were tested on pilot units operating under industrial plant conditions. In the case of the ultrafiltration process, all the tested ultrafiltration modules fulfilled the primary task. All of them separated almost completely the turbidities present in the stream, which would have disturbed the operation of the high-pressure plant. Considering the decrease in permeate flux and the possibility of cleaning, a PCI membrane made of PVDF tubes with a diameter of 12.5 mm and pore size of 20 μm was selected. Regarding the high-pressure membrane filtration, the reverse osmosis membrane was significantly better in the removal efficiency of both organic and inorganic dissolved substances. An operating pressure of 3 MPa was chosen for the system. Hence, membrane processes, which are not used as stand-alone treatment units for coke-oven effluents, function well as a final treatment stage.

In this study, steelmaking slag is selected as an adsorption material to treat coke-oven wastewater. The study shows the use of solid waste to treat liquid waste of the same industry. The full effect of adsorption on steel slag with coke-oven wastewater has been analysed using SEM, XFR, XRD, FTIR and GC-MS. The adsorption pattern for steel slag at high temperatures, i.e. up to 1100C was studied. It is observed that adsorption of pollutants does not favour higher temperature. Leaching studies showed increase in traces of heavy metals. However, only arsenic was found to be leaching beyond permissible limits. GC-MS studies showed no disorption of organic compounds from the treated slag. Compressive strength slightly weakened for the slag after adsorption, but lime saturation factor as well as soundness favoured the use of treated slag as an adsorbent. Overall analysis suggests that steel slag can be used for adsorption of coke-oven wastewater pollutant at lower temperatures. Thus steelmaking slag is found to be an efficient, readily available and economical adsorbent for removal of toxins from the coke-oven wastewater at lower temperatures. [ABSTRACT FROM AUTHOR]

The robustness of an anaerobic ammonium oxidation (anammox) process under individual and combined thiocyanate (SCN − ) and hydraulic shocks was investigated. The nitrogen removal performance and stability of a process subjected to transient SCN − (300, 600 and 900 mg L −1 ), hydraulic shock (2-fold increase in flow rate) and the combined effects of SCN − and hydraulic shock were evaluated. The sensitivity index (SI) was used to characterize the impact of the SCN − , and the SI exhibited a rising trend with increases in shock strength. The higher SI of effluent was reached after exposure to SCN − shocks (900 mg L −1 ) for 3 h, and the reactor performance was stable at a relatively lower SCN − concentration (300 mg L −1 ) after exposure to SCN − shocks for 1.5 and 3 h. The shock effect was mainly related to the SCN − concentration rather than the shock time. The similar phenomenon also was found in the test of combined SCN − and hydraulic shocks. The reactor performance in hydraulic shock tests was robust, and the relative low SAA loss ratios (9.2% and 4.0%) were observed. The specific anammox activity and heme c in the shock period were adversely affected, with maximum loss rates of 42.6% and 22.7%, respectively. However, the extracellular polymeric substance content during the shock period increased in varying degrees and antagonized exogenous disturbances. The results for these different shocks suggested that instabilities in the anammox process were dependent on both time and the concentration intensity. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM PUBLISHER]

A Visual Basic simulation software (WATTPPA) has been developed to analyse the performance of an advanced wastewater treatment plant. This user-friendly and menu-driven software is based on the dynamic mathematical model for an industrial wastewater treatment scheme that integrates chemical, biological and membrane-based unit operations. The software-predicted results corroborate very well with the experimental findings as indicated in the overall correlation coefficient of the order of 0.99. The software permits pre-analysis and manipulation of input data, helps in optimization and exhibits performance of an integrated plant visually on a graphical platform. It allows quick performance analysis of the whole system as well as the individual units. The software first of its kind in its domain and in the well-known Microsoft Excel environment is likely to be very useful in successful design, optimization and operation of an advanced hybrid treatment plant for hazardous wastewater. [ABSTRACT FROM AUTHOR]

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 14C-phenol-amended sample indicated that bacteria assimilating 14C-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 13C-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 r RNA gene clones in the 'heavy' DNA library, corroborating the CIArray-based identification. [ABSTRACT FROM AUTHOR]

Although the time for operating mines and coking plants in many countries is coming to an end due to climate change, we must still ensure that the pollution generated by this source of the economy is minimized. Despite the several stages of treatment of the coke-oven effluent, completed with nitrification and denitrification processes preceding final sedimentation, the stream obtained does not meet the requirements of water for coke quenching. That is why the stream after biodegradation and sedimentation was treated on membrane units to ensure water reusing in the coking plant. As the subjected stream contained both solid and dissolved pollutants, a two-stage system was proposed: low- and high-pressure membrane filtration. Industrial modules were tested on pilot units operating under industrial plant conditions. In the case of the ultrafiltration process, all the tested ultrafiltration modules fulfilled the primary task. All of them separated almost completely the turbidities present in the stream, which would have disturbed the operation of the high-pressure plant. Considering the decrease in permeate flux and the possibility of cleaning, a PCI membrane made of PVDF tubes with a diameter of 12.5 mm and pore size of 20 μm was selected. Regarding the high-pressure membrane filtration, the reverse osmosis membrane was significantly better in the removal efficiency of both organic and inorganic dissolved substances. An operating pressure of 3 MPa was chosen for the system. Hence, membrane processes, which are not used as stand-alone treatment units for coke-oven effluents, function well as a final treatment stage. [ABSTRACT FROM AUTHOR]

A recent investigation into the application of pulsed corona discharge process, in which simultaneous SO2 removal from simulated flue gas and coke-oven wastewater degradation, was conducted at Wuhan Integrated Steel Plant. The outcome indicates that coke-oven wastewater has good desulfurization ability and pulsed corona discharge enhances the removal efficiency of SO2; up to 85% SO2 is removed from gas through absorption, neutralization and radical reactions. Coke-oven wastewater can also be degraded by pulsed corona discharge, and injection SO2 is helpful to the degradation process; up to 99.98% cyanide and 66.8% phenols can be decomposed and this is of important value in solving the inactivation problem of aerobic bacteria in biological treatment of coke-oven wastewater. The ratio of biochemical oxygen demand content to chemical oxygen demand content increases greatly for the co-effect of SO2 and pulsed corona discharge, which indicates the improvement of complete degradation of coke-oven wastewater by biological treatment. The experimental result suggests the possibility of the simultaneous processing of desulfurization and decontamination of coke-oven wastewater. This research may provide a new technology for desulfurization and coke-oven wastewater treatment in integrated steel plants. [Copyright &y& Elsevier]

Biological and chemical oxidation characteristics of two kinds of coke-oven wastewaters, A and B, discharged from a conventional batch coke-oven and a newly developed continuous coke-oven, respectively, were studied for selecting effective treatment processes of the wastewaters. Pollutants contained in Wastewater-A could be removed by biological process with a sufficient effluent quality, while those which existed in Wastewater-B could not be satisfactorily removed. Microbial community structure investigation using the respiratory quinone profile clarified that Pseudomonas putida (dominant quinone: ubiquinone-9) was a dominant species in the biological treatment system. The refractory organic pollutants, existed in Wastewater-B, were mineralized more effectively by Fenton's reagent than by ozone. A wastewater treatment process, in which Fenton's oxidation is followed by a biological treatment, was proposed for the treatment of Wastewater-B based on the experimental results. [ABSTRACT FROM AUTHOR]

The treatment performance and microbial population of two biofilters treating seawater-diluted and freshwater-diluted coke-oven wastewaters, respectively, was compared in this study. The treatment performance did not differ between the two biofilters. The DOC removal efficiency of coke-oven wastewater was as low as 50% at a DOC volumetric loading of 0.7 kg-C m−3 per day, while the fractional BOD removal was as high as 90%. This fact indicated that some less-biodegradable, i.e. refractory, organic matters remained in the effluent of the biological treatment process without degradation. The microbial population in the biofilter treating seawater-diluted wastewater differed from that in the biofilter treating freshwater–diluted wastewater. The quinone profiles of the microorganisms in the biofilters showed that Pseudomonas putida, (dominant quinone ubiquinone-9), actively contributed to the biological degradation of phenolic compounds contained in coke-oven wastewater. The microbial diversities of the biofilters treating seawater-diluted and freshwater-diluted coke-oven wastewater calculated based on the composition of all quinones were 5.2–9.4 and 5.8–6.2, respectively. [Copyright &y& Elsevier]

Nitrogen and heavy metals can co-occur in various industrial wastewaters such as coke-oven wastewater. Removal of these contaminants is important, but cost-efficient removal technology is limited. In this study, we examined the usefulness of nitrate-dependent ferrous iron oxidation (NDFO) for the simultaneous removal of nitrate and heavy metals (iron and zinc), by using an NDFO strain Pseudogulbenkiania sp. NH8B. Based on the batch culture assays, nitrate, Fe, and Zn were successfully removed from a basal medium as well as coke-oven wastewater containing 5 mM nitrate, 10 mM Fe(II), and 10 mg/L Zn. Zinc in the water was most likely co-precipitated with Fe(III) oxides produced during the NDFO reaction. Simultaneous removal of nitrate, Fe, and Zn was also achieved in a continuous-flow reactor fed with a basal medium containing 10 mM nitrate, 5 mM Fe(II), 4 mM acetate, and 10 mg/L Zn. However, when the reactor is fed with coke-oven wastewater supplemented with 10 mM nitrate, 5 mM Fe(II), 4 mM acetate, and 10 mg/L ZnCl 2 , the reactor performance significantly decreased, most likely due to the inhibition of bacterial growth by thiocyanate or organic contaminants present in the coke-oven wastewater. Use of mixed culture of NDFO bacteria and thiocyanate/organic-degrading denitrifiers should help improve the reactor performance. Image 1 • Nitrate-dependent Fe(II) oxidation (NDFO) was used to remove nitrate and metals. • Batch culture assays and a continuous-flow reactor was used to analyze NDFO. • Nitrate, Fe, and Zn were simultaneously removed in the NDFO reactor. • The NDFO reactor was applied to treat coke-oven wastewater. • Thiocyanate/organic contaminants likely lowered the NDFO reactor performance. [ABSTRACT FROM AUTHOR]

Bioremediation of wastewater is gaining popularity over chemical treatment due to the greener aspect. The volume of literature containing algal biodegradation is small. Especially, removal of toxic materials like phenol from coke-oven wastewater using fast-growing cyanobacteria was not tried. The current study, therefore, targeted at bioremediation of phenol from wastewater using Leptolyngbya sp., a cyanobacterial strain, as a finishing step. Furthermore, the growth of the strain was studied under different conditions, varying phenol concentration 50-150 mg/L, pH 5-11, inoculum size 2-10% to assess its ability to produce lipid. The strain was initially grown in BG-11 as a reference medium and later in phenolic solution. The strain was found to sustain 150 mg/L concentration of phenol. SEM study had shown the clear difference in the structure of cyanobacterial strain when grown in pure BG-11 medium and phenolic solution. Maximum removal of phenol (98.5 ± 0.14%) was achieved with an initial concentration 100 mg/L, 5% inoculum size at pH 11, while the maximum amount of dry biomass (0.38 ± 0.02 g/L) was obtained at pH 7, initial phenol concentration of 50 mg/L, and 5% inoculum size. Highest lipid yield was achieved at pH 11, initial phenol concentration of 100 mg/L, and 5% inoculum size. Coke-oven wastewater collected from secondary clarifier of effluent treatment plant was also treated with the said strain and the removal of different pollutants was observed. The study suggests the utilization of such potential cyanobacterial strain in treating industrial effluent containing phenol. [ABSTRACT FROM AUTHOR]

Coke-oven wastewater discharged from the steel-manufacturing process is phenol and thiocyanate (SCN)-rich wastewater, which inhibits microbial activities in biological wastewater treatment processes. In the present study, synergistic inhibition of anaerobic ammonium oxidation (anammox) activity by phenol and SCN was examined by batch incubation and continuous operation of an anammox reactor. The comparison of anammox activities determined in the batch incubation, in which the anammox biomass was anoxically incubated with 10-250 mg L -1 of i) phenol, ii) SCN, or iii) both phenol and SCN, showed that synergistic inhibition by phenol and SCN was greater than the inhibitions by phenol or SCN alone. The synergistic inhibition by phenol and SCN was further investigated by operating an up-flow column anammox reactor for 262 d. The removal efficiencies of NH 4 + and NO 2 - deteriorated when phenol and SCN concentrations in the influent increased to 16 and 32 mg L -1 , respectively, and the inhibition of anammox activity was further investigated by a 15 NO 2 - tracer experiment. Addition of phenol and SCN resulted in a population shift of anammox bacteria, and the dominant species changed from "Candidatus Kuenenia stuttgartiensis" to "Ca. Brocadia sinica". The relative abundance of Azoarcus and Thiobacillus 16S rRNA gene reads increased during the operation, suggesting that they were responsible for the anaerobic phenol and SCN degradation. The present study is the first to document the synergistic inhibition of anammox activity by phenol and SCN and the microbial consortia involved in the nitrogen removal as well as the phenol and SCN degradations., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

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 2mg/L to 10mg/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 0.0334mgg-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. [ABSTRACT FROM AUTHOR]