Coke Plant Wastewater Research Articles

Ultrahigh-purity ammonia recovery from synthetic coke wastewater via membrane contactor: Overcoming phenolic interference and assessing cost efficiency

Ammonia recovery from industrial wastewater using membrane contactor processes is emerging as a promising method owing to the diverse applications of ammonia. This study uniquely addressed ammonia recovery from coke plant wastewater, which is challenging due to the presence of numerous toxic and volatile phenolic compounds. Experiments were conducted using a synthetic coke plant effluent to assess the effects of various pH levels and temperatures on ammonia recovery. Specifically, the aim was to achieve high-purity ammonia recovery while minimizing the permeation of phenolic compounds. The results demonstrate that ammonia recovery in the membrane contactor processes is highly efficient, even in the presence of phenolic compounds. During temperature variations at 25 °C and 40 °C, the recovery of ammonia increased from 42.36% to 52.97% at pH 11. Additionally, increasing the pH of a feed solution from 7 to 12 significantly increased the ammonia content to 58.3%. At this pH, the recovered ammonia was of exceptional purity (>99%), with phenol, p-Cresol, and 2,4-xylenol present at negligible concentrations (0.001%, 0.002%, and 0.004%, respectively). This was attributed to the ionization of phenolic compounds at higher pH levels, which prevents their permeation through the hydrophobic membrane. The estimated cost analysis revealed that the membrane contactor process at pH 12 was approximately 1.41 times more cost-effective than conventional air-stripping processes over eight years of operating period (pH-12 membrane contactor: $19.79; pH-12 air stripping: $23.75). This study provides a detailed analysis of the optimal conditions for selective ammonia recovery from complex wastewater, highlighting both effective treatment and sustainable resource recovery and offering a superior alternative to traditional methods.

Zirconium fumarate metal-organic framework: a selective adsorbent for fluoride from industrial wastewater

Abstract Many industrial processes produce high fluoride (150–450 mg/L) containing effluent. It may be recovered from the processing plants at the source. One effective technology is selective fluoride adsorption from the waste stream. Metal-organic frameworks (MOFs) are crystalline compounds with high surface area, pore volume, and tuneable pore channels and are suitable adsorbents. This study used zirconium fumarate (ZrFu) MOF to recover the fluoride from iron and steel industrial wastewater collected from blast furnaces and coke plants, respectively. In batch experiments, complete fluoride uptake from synthetic water (150 mg F/L) was obtained with 3 g ZrFu/L (qe = 49.66 mg/g), while for blast furnace (170 mg F/L) and coke plant (130 mg F/L) wastewater, 10 g ZrFu/L was required, (qe = 17 mg/g) and (qe = 13 mg/g), respectively. This difference in adsorbent dose was caused by interfering ions in industrial wastewater, which compete for the same adsorption sites as fluoride ions. Chemisorption was the rate-limiting step, and it conforms to the Langmuir isotherm and the pseudo-second-order model. Fluoride desorption was achieved in deionized water in 1 h. This suggests that the adsorption–desorption process could be scaled up to an industrial process to recover and reuse fluoride from wastewater.

Treatment of organic pollutants in coke plant wastewater by micro-nanometer catalytic ozonation, A/A/O and reverse osmosis membrane.

Coking wastewater has a complex and highly concentrated chemical composition which is toxic and does not biodegrade easily. Treating the organic pollutants in this wastewater is very challenging. The toxic substances in this wastewater make traditional biotechnological treatments inefficient. Current wastewater treatment studies are based on unit processes, and no full process studies could be found. This study used the micro-nanometer catalytic ozonation process as a pretreatment unit, and reverse osmosis membrane treatment as a depth processing unit to improve the effect of the coking wastewater degradation. The micro-nanometer catalytic ozonation pretreatment greatly improves the biodegradability of the coking wastewater and promotes the coking wastewater degradation in the anoxia/anaerobic/oxic (A/A/O) system. The integrated coagulation air flotation-micro-nanometer catalytic ozonation-A/A/O-reverse osmosis membrane system can remove 98% of the chemical oxygen demand, which meets the direct emission standard of the new national standard (China). The dominant genera in the A/A/O biochemical reactor were Thioalkalimicrobium, Proteiniphilum, Azoarcu, Bacillus, Fontibacter, and Taibaiella. This work provides a novel approach for the degradation of high-concentration organic wastewater and lays a solid foundation for the restoration of environmental water bodies.

Remediation of cyanide in biologically treated coke plant wastewater by chemical treatment method

ABSTRACT Biological treatment with a stable activated sludge process, followed by chemical treatment is one of the potential and accepted cyanide remediation processes for coke plant wastewater treatment. Biologically treated coke plant wastewater contains free cyanide above permissible limit. Presently, chemical treatment with NaOCl is being used to attenuate free cyanide below permissible limit in biologically treated water. This process increases the TDS and colour content in discharge water. Ca(OCl)2 can be used as an alternative to NaOCl for cyanide remediation in biologically treated coke plant wastewater without increasing TDS. In the present work, cyanide removal efficiency of NaOCl and Ca(OCl)2 for real coke plant wastewater after biological treatment has been studied. Optimisation of chemical dosage, treatment time and pH study has been done for Ca(OCl)2 and NaOCl treatment. It was found that up to 90% of free cyanide removal could be achieved through Ca(OCl)2 treatment without increasing the TDS value. In addition, more than 50% colour of the wastewater was removed. pH elevation step required in NaOCl treatment can be eliminated in Ca(OCl)2 treatment, thereby reducing caustic consumption. The study indicated that the use of Ca(OCl)2 is economically more viable than that of NaOCl in cyanide treatment.

Application of coke breeze for removal of colour from coke plant wastewater

Treatment of coking waste water has always been a challenge because of its complex and toxic nature. Numbers of technologies like biological treatment, advanced oxidation processes, activated carbon treatment etc. are available for removal of color and organic contaminants from wastewater. However, challenges and problems associated with application of biological, advanced oxidation methods for removal of color, chemical oxygen demand (COD), cyanides led to thrust for the development of new promising technologies. In this study, the application of coke breeze for the treatment of wastewater through adsorption has been demonstrated. A pseudo second order reaction kinetics has been observed through batch process adsorption study. Furthermore, adsorption data has found to be best fitted with the Freundlich adsorption isotherm model. Color removal efficiency of 80–90% along with COD removal efficiency of 40–50% was observed within 30 min by 120 g/L dosage of the adsorbent. The removal of phenolic and other organic compounds from coking wastewater has been measured through UV–Vis spectroscopy. The morphological changes of the adsorbent coke breeze have been captured through scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. However, because of the significant abundance in the steel plant, cost effectiveness and applicability of the post-treated coke breeze in sintered plant as fuel, turn it into a suitable adsorbent despite of having much lower specific surface area compared to commercial activated carbon (AC). Therefore, application of the coke breeze turns it into a very promising material and the technique is sustainable towards the coke quenching effluent treatment.

Remediation of phenanthrene contaminated soil through persulfate oxidation coupled microbial fortification

The technology of chemical oxidation coupled microbial remediation of polycyclic aromatic hydrocarbons contaminated soil was efficient and friendly, but the research on the compatibility of chemical oxidation and the bioremediation is insufficient. This study was to explore the compatibility of persulfate oxidation coupled microbial degradation and promote the remediation of phenanthrene contaminated soil. The results showed that the addition of persulfate with the participation of Fe2+ caused the soil environment to be acidic and the soil pH with the lower concentrations (20, 50 mmol/L) of persulfate returned to neutral after 14 days. The content of fulvic-like and humic-like increased after adding persulfate at the same time. Persulfate inhibited the activity of soil dehydrogenase and polyphenol oxidase, simultaneously, the oxidation species generated during the persulfate oxidation process and the acidic environment (pH=4.13) led the soil microbial abundance and diversity to decrease significantly. Besides, the phenanthrene degradation bacterial consortium was screened through a gradual domestication process, which derived from activated sludge in the coking plant wastewater aeration tank of Xuzhou Weitian Chemical Co., Ltd. The efficient degrading bacteria were identified as Pantoea (95%) using high-throughput sequencing, with the 84% degradation rate of phenanthrene after the 7th day. Comparing persulfate oxidation, the removal rate of phenanthrene in the soil was increased by 33% after 63 days of the combined remediation. Adding 20 mmol/L persulfate and inoculating domesticated high-efficiency degrading bacteria Pantoea was recommended in the remediation of PAHs contaminated soil.

Bioremediation of coke plant wastewater from steel industry with mixed activated sludge–microalgal consortium in lab‐scale semi‐continuous mode

AbstractBACKGROUNDRemoval of toxicities from wastewater has always demanded great attention as it has life‐threatening impacts on every living being and the environment. In the present study, bioremediation of ammonia and cyanide from coke plant wastewater (CPWW) by using bacterial consortia with activated sludge (AS) supplemented with microalgal (MA) biomass in semi‐continuous mode was performed. Parameters such as pH, total dissolved solids (TDS), dissolved oxygen (DO) and bacterial cell viability, along with any significant effect on the growth of microalgal cells in wastewater, was investigated by determining its specific growth rate (μ).RESULTSWith pH values remaining constant for the system, the ammonia removal rate with microalgae additions was approximately 38.3% lower than that with AS. Similarly, the cyanide removal rate after addition of microalgae to the system showed a difference of 43% with AS treatment. TDS levels dropped by 22.18% and the concentration of DO increased by 21.91% in comparison to the values obtained by treatment of CPWW with AS and MA to CPWW with AS alone.CONCLUSIONMicroalgae additions effectively increase the efficiency of AS treatment of CPWW and thus can be taken to field trials for developing a cost‐effective and environmentally friendly strategy of wastewater treatment. © 2021 Society of Chemical Industry

Comparative characterization of cyanide-containing steel industrial wastewater.

In the steel industry, cyanide in the wastewater is a major environmental concern. There are several chemical, physical, and biological treatment processes available for the removal of cyanide from industrial wastewater. But the efficacy of every treatment process depends on the complex elemental matrix of wastewater and the interference associated with them. Thus, water characterization plays a vital part in finding a suitable cyanide treatment process for any wastewater. Characterization data can give a clear overview of the complexity of cyanide in the wastewater, which ultimately helps in selecting the right remediation process. The present work includes comparative characterization of coke plant and blast furnace wastewater collected from an integrated steel plant. Three months of data for physico-chemical properties of the two different sources were analysed and compared. Pearson's correlation analysis of physico-chemical properties with free cyanide was also studied. The different forms of cyanide in coke plant and blast furnace water were also characterised, along with interference associated with them. It was observed that the water matrix of coke plant and blast furnace effluents are totally different. It was also evident that free cyanide concentration is much more affected in coke plant wastewater than in blast furnace water.

Meso-porous activated carbon from lignite waste and its application in methylene Blue adsorption and coke plant effluent treatment

Coke plant wastewater contains many toxic pollutants such as phenol, cyanide, and ammonia, etc., handling and disposal of which has a significant impact on the environment and human health. A novel adsorbent based on lignite extraction waste was prepared and its effect on the removal of simulated methylene blue, phenol and colour (ortho, para-benzo quinone) from real coking wastewater was investigated. Lignite waste (residue) after humic acid separation has a significant quantity of oxidized functional groups along with residual KOH, which makes it suitable for the preparation of activated carbon with high surface area. Since hydrothermal extraction breaks coal-mineral-pore aggregate, the separation efficiency of ash-bearing minerals improved, 11 % ash coal prepared from the residue with 81.6 % yield. Prepared activated carbon from low ash residue has a mesoporous surface (49.8 nm pore size), 0.554 cm3/g of total pore volume, and 980 m2/gram BET surface area. The adsorption kinetics followed pseudo-second order (R2 = 0.984) for methylene blue, pseudo-second-order (R2 = 0.978) for phenol, and pseudo-first-order (R2 = 0.935) for colour adsorption. Adsorption isotherm at equilibrium shows a maximum adsorption capacity of 120 mg/g for methylene blue, 20.49 mg/g for phenol and 588.23 PtCo/g for colour. The adsorption isotherm was in good agreement with Langmuir isotherm (R2 = 0.989−0.994) compared to Freundlich model (R2 = 0.924−0.982). The presence of negatively charged surface favours the uptake of cationic groups. Apart from phenol and colour, the adsorbent can remove total organic carbon (TOC) by 93.6 % and thiocyanide by 6.7 %. Adsorbent reutilization studies show that, the regenerated adsorbent by thermal treatment can be used for 3 cycles.

A Fast and Efficient Absorbant BYW-01 and its Applications in Coking Plant Wastewater Treatment

A Fast and Efficient Absorbant BYW-01 and its Applications in Coking Plant Wastewater Treatment

Prediction and Control of Coke Plant Wastewater Quality using Machine Learning Techniques

The present study focuses on examining the fate of coal constituents—carbon, sulphur, nitrogen and chlorine from coal blend to coke oven wastewater. Further, the impact of coal constituents and coke making process on wastewater quality has studied and analyzed the effects with plant data. Understanding helps in development of coke oven wastewater quality prediction model using machine learning techniques. A reliable model helps in minimize the operation costs and stable operation of treatment plant. The developed model is implemented and validated using plant scale data obtained for coke plant at Tata Steel Jamshedpur. The model provided accurate predictions of the effluent stream of by product plant, in terms of chemical oxygen demand (COD) and total dissolved solids (TDS) when using coal constituents and coke making process parameters as an input. Implementation strategy of model helps to control the wastewater quality within environmental limit with ease.

Tertiary treatment of coke plant effluent by indigenous material from an integrated steel plant: a sustainable approach.

Biological process is an important and integral part of the coke plant wastewater treatment. Increasing pressure to meet more stringent discharge limits has led to adopt tertiary treatment for biologically treated coke plant (BTCP) effluent which contains intense colour along with many residual toxic pollutants like phenol, cyanide, thio-cyanate and COD. A sustainable process has been developed to remove these pollutants from BTCP effluent by using an indigenous material coke breeze which is abundantly available in integrated steel plant. Based on the developed process, a full-scale (200 m3/h) treatment plant has been designed for installation. The designed data has been obtained from a continuous demo plant treating 10 m3/h BTCP effluents. The utilised coke breeze is entirely used for sinter making. The process is highly efficient for the removal of colour above 95% and other residual pollutants like phenol, cyanide and COD to a safe level for discharge or reuse. This process neither incurs any additional chemical cost nor generates any secondary pollutants or products. Moreover, the developed process is very sustainable as it has some great advantages like less investment and low maintenance cost; therefore, the method is good in economics. The treated wastewater contains very less amount of chemical residues therefore meets the standards for reuse as industrial water resource. Hence, this developed technology has significant economic, social and environmental benefits. Graphical Abstract .

Electro-Fenton with peroxi-coagulation as a feasible pre-treatment for high-strength refractory coke plant wastewater: Parameters optimization, removal behavior and kinetics analysis

Electro-Fenton (EF) with peroxi-coagulation (PC) as an emerging electro-chemical advanced oxidation method has been extensively applied to treat refractory wastewater. However, the studies on the pretreatment of the raw coke plant wastewater by EF process were still lacking. In this study, a lab-scale EF system (Fe as anode and graphite as cathode) achieved the highest COD removal of 69.2% based on the preliminary experiments. The process parameters and corresponding COD removal performance were further optimized using response surface methodology (RSM) combined with Box-Behnken experimental design (BBD). The optimal conditions were obtained as: 3.2 mA cm−2 of current density, 2 h of the reaction time and 2.6 of the initial pH value, with the COD removal reaching 70.0%. Fourier infrared (FTIR), fluorescence excitation-emmission matrix (EEM) and gas chromatography-mass spectrometry (GC-MS) also revealed the degradation behaviors of dissolved organic matters (DOMs) by characterizing their structures and compositions before and after EF pretreatment, thus greatly improving the biodegradability of the wastewater. Moreover, the EF process for COD removal well followed third-order kinetics model. These findings give helpful guidance to design, optimize and control the EF process as a favourable pretreatment for actual refractory coking wastewater in practice.

Coupled fenton-denitrification process for the removal of organic matter and total nitrogen from coke plant wastewater

This work assesses the feasibility of applying a Coupled Fenton-Denitrification (CFD) process for the treatment of wastewater from a coking plant. This highly toxic effluent is characterized by comparable carbon and nitrogen contents and it is usually released into the treatment system at well above room temperature. Recalcitrant organic matter can be easily removed in a first step using Fenton treatment. Working at 50 °C, pH0: 3, and a wastewater obtained from a coking plant, the stoichiometric amount of H2O2 relative to COD and a H2O2/Fe2+ weight ratio of 50, around 60% of carbon load was mineralized whereas H2O2 was completely depleted. However, no changes were observed in the total nitrogen content. A subsequent denitrification stage led to an additional 80% TOC (overall above 90%) and 75% Total Nitrogen removal. This was done in a batch bioreactor at room temperature over 72 h, using a 40-day pre-acclimated denitrifying biomass. These results point to the possibility of designing a combined chemical oxidation and biological treatment to deal with complex effluents containing refractory organic matter including high concentrations of nitrogen species.

Treatment of coke-plant wastewater at Bhilai Steel Plant

The existing biochemical system in the coke plant at Bhilai Steel Plant is inspected and assessed, with a view to introducing nitrification and denitrification, without reconstruction. It is shown that the existing biochemical-treatment facility will accommodate a nitrification and denitrification system capable of processing coke at a rate of 3.0–3.5 million t/yr. With reconstruction of the aeration system, the throughput may be increased to 4.8 million t/yr. That entails continuous dosing of alkaline reagent in the treated water. Recommendations are made for improved operation of the biochemical system.

Chemical oxygen demand of biochemically treated coke-plant wastewater

The factors responsible for the high chemical oxygen demand (COD) of biochemically treated coke-plant wastewater are identified. The factors responsible for overestimation of the COD in bichromate tests are also determined. Experiments show that the interference of inorganic reducing agents formed in biochemical treatment must be eliminated in determining the COD. To reduce the consumption of the reagents used to improve the results of COD tests (including the need for toxic mercury sulfate), special methods of preparing the wastewater samples are recommended.

Final purification of biochemically treated coke-plant wastewater

The final purification of coke-plant wastewater after biochemical treatment by nitrification–denitrification is considered. All the methods that reduce the chemical oxygen demand, color, and suspended substances content are complex and expensive. Only two methods reduce the salt content (dry residue) to the standard levels for water added to circulatory cooling systems: thermal distillation and membrane purification. Of these, thermal distillation is best in practice.

Improving cyanide removal from coke plant wastewaters by optimizing the operation conditions of an ammonia still tower

ABSTRACTAmmonia still tower for residual ammonia wastewater pretreatment has gained considerable application due to its high efficiencies. However, the low cyanide removal in this process is a serious environmental problem. In this paper, experiments involving full-scale studies were conducted to evaluate the stripping process for ammonia and total cyanide (TCN) removal. The optimal operating conditions of ammonia still tower were studied. Flow of alkalic solution significantly influenced the removal efficiency of cyanide. With the increase of steam flow, ammonia removal could be enhanced, but TCN removal has negligible effect. Increasing the bottom pressure of the tower proved good for improving the stripping efficiency. After combined treatment by the stripping and biological processes, the TCN concentration in the final effluent can be stable at 0.1–0.2 mg/L, which satisfies the standard.

Coke Plant Wastewater Posttreatment by Fenton and Electro-Fenton Processes

Abstract After conventional biological treatment processes, effluents of the coking industry contain high concentration of nonbiodegradable and refractory organic matters, which should be treated to satisfy the discharge water quality standards (chemical oxygen demand [COD] <150 mg/L, NH3–N < 25 mg/L). In this study, post-treatment of coke plant wastewater was treated by the direct Fenton and anodic electro-Fenton (EF-Feox) methods. COD and total organic carbon (TOC) values were selected as the target parameters. COD and TOC removal efficiency was investigated through changing some operating parameters such as initial pH, initial H2O2 concentration, and current density. Under the optimum operating conditions of each progress, COD and TOC were removed more efficiently in the EF-Feox system (90% and 84.4%) compared with that in the Fenton method (61.96% and 48.12%). Influence of H2O2 feeding on removal efficiency was also investigated in this study. Results indicated that gradual addition of H2O2 instead of...

Purification of coke-plant wastewater by means of cold plasma

Data regarding wastewater purification by means of cold plasma in the biochemical department at Nizhny Tagil Steel Works are analyzed in the light of new information regarding the chain oxidation of hydrocarbons and their products. In chain oxidation initiated by cold plasma, oxygen-bearing products that do not undergo chain reactions are formed. Therefore, the chemical oxygen demand of plasma-treated wastewater cannot be reduced below 300—400 mg O/L.