Coking Wastewater Research Articles

Factors controlling adsorption of recalcitrant organic contaminant from bio‐treated coking wastewater using lignite activated coke and coal tar‐derived activated carbon

AbstractBACKGROUNDLow‐cost coal‐based carbonaceous material has attracted special attention for removal of organics from industrial wastewaters. In this study, coal tar‐derived activated carbon (AC1) and lignite activated coke (AC2) were employed to identify the fundamental factors that facilitate the selection of suitable adsorbents for removing recalcitrant organic contaminant (ROC) from bio‐treated coking wastewater (BTCW).RESULTSResults show that AC2 exhibited superior ROC adsorption efficiency (57.9%), which was apparently higher than that of AC1 (45.2%), in spite of its lower specific surface area (238.05 m2 g−1) and pore volume (0.21 cm3 g−1). FTIR and XPS characterization indicated that AC2 possessed a distinctive configuration of functional groups, of which the basic oxygenic groups (60%) provided more hydrophobic adsorption sites for ROC. 3D‐EEM spectra suggested more aromatics and fluorescent materials were removed by AC2 compared with AC1. GC‐MS further confirmed that AC2 had stronger affinity with the ROC in BTCW, especially for PAHs and heterocyclic compounds.CONCLUSIONSurface chemistry is vital to the adsorption of ROC from coking wastewater, of which basic oxygenic functional groups have specific interactions with PAHs and heterocyclic compounds. The mechanism that best explains ROC adsorption is π–π dispersion between carbon materials and the pollutants, as well as the hydrogen‐bonding interactions. This study provides an encouraging and practical guide to ROC adsorption from BTCW in future operations. © 2017 Society of Chemical Industry

Biocathode denitrification of coke wastewater effluent from an industrial aeration tank: Effect of long-term adaptation

Despite recent advances in the development of autotrophic denitrification, wherein the electrode is used directly as the electron donor (known as biocathode denitrification), very little attention has been given to this approach for removal of nitrate in real industrial wastewater. This study shows that a bioelectrochemical reactor poised at −0.50V (vs. a saturated calomel electrode (SCE)) achieved successful nitrate removal from coke wastewater effluent (CWE) sampled from an industrial aeration tank. The results show that direct exposure to CWE initially led to dramatic inhibitory effects, as evidenced by the observed lack of apparent cathodic current and small variations in the concentration of NO3−–N. However, long-term adaptation of the biocathode to the CWE remarkably increased the rate of dinitrification, from 2.35 (Cycle 1) to 4.93 (Cycle 3), 14.4 (Cycle 7) and 16.5mg NO3−–N L−1 d−1 (Cycle 10). Both confocal laser scanning microscopy (CLSM) and electrochemical impedance spectrometry (EIS) characterizations provided evidence that long-term adaptation can induce recovery of active cells and promote electron transfer between the bacteria and the cathode. Analysis of bacterial structures suggests that cathode-driven autotrophic denitrifiers represented by Thiobacillus play an important role in nitrate reduction.

Biotransformation of nitrogen- and sulfur-containing pollutants during coking wastewater treatment: Correspondence of performance to microbial community functional structure

Although coking wastewater is generally considered to contain high concentration of nitrogen- and sulfur-containing pollutants, the biotransformation processes of these compounds have not been well understood. Herein, a high throughput functional gene array (GeoChip 5.0) in combination with Illumina MiSeq sequencing of the 16S rRNA gene were used to identify microbial functional traits and their role in biotransformation of nitrogen- and sulfur-containing compounds in a bench-scale aerobic coking wastewater treatment system operated for 488 days. Biotransformation of nitrogen and sulfur-containing pollutants deteriorated when pH of the bioreactor was increased to >8.0, and the microbial community functional structure was significantly associated with pH (Mantels test, P < 0.05). The release of ammonia nitrogen and sulfate was correlated with both the taxonomic and functional microbial community structure (P < 0.05). Considering the abundance and correlation with the release of ammonia nitrogen and sulfate, aromatic dioxygenases (e.g. xylXY, nagG), nitrilases (e.g. nhh, nitrilase), dibenzothiophene oxidase (DbtAc), and thiocyanate hydrolase (scnABC) were important functional genes for biotransformation of nitrogen- and sulfur-containing pollutants. Functional characterization of taxa and network analysis suggested that Burkholderiales, Actinomycetales, Rhizobiales, Pseudomonadales, and Hydrogenophiliales (Thiobacillus) were key functional taxa. Variance partitioning analysis showed that pH and influent ammonia nitrogen jointly explained 25.9% and 35.5% of variation in organic pollutant degrading genes and microbial community structure, respectively. This study revealed a linkage between microbial community functional structure and the likely biotransformation of nitrogen- and sulfur-containing pollutants, along with a suitable range of pH (7.0–7.5) for stability of the biological system treating coking wastewater.

Evaluation of the detoxification efficiencies of coking wastewater treated by combined anaerobic-anoxic-oxic (A2O) and advanced oxidation process

Coking wastewater contains many types of toxic and hazardous pollutants that have serious toxic effects on human beings as well as aquatic organisms. However, few studies have evaluated the detoxification efficiencies of the treatment processes that are extensively performed in operational coking wastewater treatment plants (WWTPs). This study investigates the detoxification efficiencies of a combined anaerobic-anoxic-oxic (A2O)-ozonation and A2O-Fenton oxidation process in two coking WWTPs using an acute immobilization test for Daphnia magna, acute toxicity test for adult zebrafish, embryo toxicity test for zebrafish and the comet assay. The raw coking wastewaters displayed high acute daphnia and fish toxicity, zebrafish embryo toxicity and genotoxicity. The A2O processing unit effectively removed acute and embryo toxicity, but not genotoxicity. In addition, the A2O effluent quality did not meet the integrated wastewater discharge standard in China (GB18918-2002). The ozonation and Fenton oxidation units used as post-treatments in these two plants not only treated the coking wastewater to the discharge standard but also reduced the genotoxicity. However, the final effluents still showed potential genotoxicity after high dilution. The results suggest that the discharge of treated coking wastewater probably poses potential risks to human health and the environment even if it met regulatory standards.

Dissolved organic matter (DOM) removal from bio-treated coking wastewater using a new polymeric adsorbent modified with dimethylamino groups

In the current study a new recyclable aminated hyper-cross-linked polymeric adsorbent (A-HPA) was prepared for effective removal of DOM from BTCW. Possibly benefited from its unique structure of polystyrene matrix, sufficient aminated groups and high specific surface area, A-HPA could remove DOM from BTCW through the synergetic effect of π-π interactions, acid-base interactions and micropore filling, and exhibited the highest removal efficiency than the other adsorbents. Moreover, the exhausted A-HPA was amenable to effective regeneration by using acid and alkaline solution, allowing for repeated use with a constant removal efficiency. Field application of continuous 3-year fixed-bed runs demonstrated that A-HPA is capable of effectively removing DOM from BTCW with no significant capacity loss, and the treated effluent can be partially used as recycled water in production. All the above results demonstrated that A-HPA adsoption could serve as a good choice for the advanced treatment of bio-treated sewage effluent.

Aerobic Degradation Characteristics of the Quinoline-Degrading strain Ochrobactrum sp. and Its Bioaugmentation in Coking Wastewater

Quinoline is one of the common refractory organic pollutants in coking wastewater. An aerobic bacterial strain KDQ3 capable of utilizing quinoline as the sole source of carbon, nitrogen and energy was isolated from activated sludge of a coking wastewater treatment plant. The morphological properties and the 16S rDNA sequence identified KDQ3 as Ochrobactrum sp.. The optimized temperature and initial pH for quinoline degradation were 37℃ and 7.0-8.0, and the degradation kinetics fit with Haldane's model. KDQ3 could degrade 200 mg·L-1 quinoline in the presence of 10.4 mg·L-1 hexavalent chromium. In addition, KDQ3 was able to degrade quinoline in real coking wastewater of aerobic tank and improve the removal of COD, indicating that KDQ3 had the potential of bioaugmentation for removal of quinoline from coking wastewater.

Bio-refractory organics removal and floc characteristics of poly-silicic-cation coagulants in tertiary-treatment of coking wastewater

Poly-silicic-cation coagulants are increasingly being used to remove the bio-refractory organic compounds from industrial wastewaters, yet the research on the interactions between the coagulants and organics remains limited. In this study, three composite coagulant poly-aluminum-silicate-chloride (PASiC), poly-ferric-silicate-chloride (PFSiC) and poly-aluminum-ferric-silicate-chloride (PAFSiC) were prepared and examined as tertiary-treatment coagulants for coking wastewater. Excitation-emission fluorescence (EEM) spectra and gas chromatograph/mass spectroscopy (GC/MS) were applied to characterize composition of the organics, and the floc characteristics were monitored using a laser diffraction particle size analyzer and a particle vision system. The results show that a board range of organics including microbial metabolites, fulvic acid and humic acid-like fluorophores and polymeric aromatic hydrocarbons, can be removed by PAFSiC. This is attributed to the synergetic removal of organic compounds by aluminum and iron based poly-silicic salts. Compared with PASiC and PFSiC, the resultant flocs of PAFSiC have the moderate size and porous inner structure, with more branch-like units but less agglomeration. The structure is favorable for capture, adsorption and enmeshment of the bio-refractory organic compounds from the bio-treated coking wastewater. This study indicates that the organic removal is closely related to floc characteristics and PAFSiC can be used as an effective and promising coagulant for tertiary-treatment of coking wastewater.

Synergic Adsorption-Biodegradation by an Advanced Carrier for Enhanced Removal of High-Strength Nitrogen and Refractory Organics.

Coking wastewater contains not only high-strength nitrogen but also toxic biorefractory organics. This study presents simultaneous removal of high-strength quinoline, carbon, and ammonium in coking wastewater by immobilized bacterial communities composed of a heterotrophic strain Pseudomonas sp. QG6 (hereafter referred as QG6), ammonia-oxidizing bacteria (AOB), and anaerobic ammonium oxidation bacteria (anammox). The bacterial immobilization was implemented with the help of a self-designed porous cubic carrier that created structured microenvironments including an inner layer adapted for anaerobic bacteria, a middle layer suitable for coaggregation of certain aerobic and anaerobic bacteria, and an outer layer for heterotrophic bacteria. By coating functional polyurethane foam (FPUF) with iron oxide nanoparticles (IONPs), the biocarrier (IONPs-FPUF) could provide a good outer-layer barrier for absorption and selective treatment of aromatic compounds by QG6, offer a conducive environment for anammox in the inner layer, and provide a mutualistic environment for AOB in the middle layer. Consequently, simultaneous nitrification and denitrification were reached with the significant removal of up to 322 mg L-1 (98%) NH4, 311 mg L-1 (99%) NO2, and 633 mg L-1 (97%) total nitrogen (8 mg L-1 averaged NO3 concentration was recorded in the effluent), accompanied by an efficient removal of chemical oxygen demand by 3286 mg L-1 (98%) and 350 mg L-1 (100%) quinoline. This study provides an alternative way to promote synergic adsorption and biodegradation with the help of a modified biocarrier that has great potential for treatment of wastewater containing high-strength carbon, toxic organic pollutants, and nitrogen.

Advanced Decomposition of Coking Wastewater in Relation to Total Organic Carbon Using an Electrochemical System

Advanced Decomposition of Coking Wastewater in Relation to Total Organic Carbon Using an Electrochemical System

Enhancing the removal of hazardous pollutants from coke‐making wastewater by dosing activated carbon to a pilot‐scale activated sludge process

AbstractBACKGROUNDPowdered activated carbon (PAC) was investigated for its ability to remove six polycyclic aromatic hydrocarbons (Σ6PAHs) (fluoranthene, benzo[b + J]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3‐cd]pyrene, benzo[g,h,i]perylene), trace metals and colour from coke‐making wastewater when dosed to a pilot‐plant activated sludge process (ASP). The ASP had a volume of 0.68 m3 and was operated to simulate the full‐scale ASP treating coke wastewater from a steel works. Operational conditions included a flow rate of 0.78 m3 day−1, a hydraulic retention time of 21 h, a sludge retention time of 38 days and a temperature of 27 °C. The ASP was operated for a control period before PAC was dosed directly into the aeration cell at a dose of 400 mg L−1.RESULTSPowdered activated carbon addition resulted in a 20% increase in removal efficiency of the Σ6PAHs. Removal efficiency of trace metals was variable, but increased for nickel, chromium and cadmium by 22.6%, 20.5% and 12.4%, respectively. Improvement in colour removal efficiency was marginal at 5%.CONCLUSIONPAC addition allowed the improvement of treatment efficiencies in the ASP process at relatively low capital and operational costs, which may assist in reaching tighter effluent emission limits set for the industry. © 2017 Society of Chemical Industry

Analysis of organic compounds’ degradation and electricity generation in anaerobic fluidized bed microbial fuel cell for coking wastewater treatment

ABSTRACTA single-chambered packing-type anaerobic fluidized microbial fuel cell (AFBMFC) with coking wastewater (CWW) as fuel was built to treat CWW, which not only has high treating efficiency, but also can convert organic matter in wastewater into electricity. AFBMFC was constructed by using anaerobic sludge that was domesticated as inoculation sludge, which was used to biochemically treat CWW. The organic compounds in CWW were extracted by liquid–liquid extraction step by step every day. The extraction phase was concentrated by a rotary evaporator and a nitrogen sweeping device and was analyzed by GC–MS. And the electricity-generation performances of AFBMFC were investigated. The results show that the composition of CWW was complicated, which mainly contains hydrocarbons, phenols, nitrogenous organic compounds, alcohols and aldehydes, esters and acids and so on. After a cycle of anaerobic biochemical treatment, the content of organic compounds in the effluent decreased significantly. After the treatment of AFBMFC, 99.9% phenols, 98.4% alcohol and aldehydes and 95.3% nitrogenous compounds were biodegraded. In the effluent, some new compounds (such as tricosane and dibutyl phthalate) were produced. The chemical oxygen demand (COD) of CWW decreased from 3372 to 559 mg/L in the closed-circuit microbial fuel cell, and the COD removal was 83.4 ± 1.0%. The maximum power density of AFBMFC was 2.13 ± 0.01 mW m−2.

Characterization of a microbial consortium capable of heterotrophic nitrifying under wide C/N range and its potential application in phenolic and coking wastewater

Nitrogen pollution has been a serious problem in environmental water particularly in industrial wastewater. A microbial consortium named FG-06 was found to exhibit efficient heterotrophic nitrification and aerobic denitrification ability, with the maximum NH4+-N, NO2−-N and NO3−-N removal rate of 7.33, 6.53 and 4.53mg/L/h, respectively. High-throughput sequencing analysis showed that it was mainly made up of Acinetobacter spp. (54.37%) and Pseudomonas spp. (26.52%). The consortium could grow under a wide range of C/N ratio and the NH4+-N removal efficiencies at C/N ratio 4 and 32 were 90.40% and 93.84% separately. Furthermore, simultaneous biodegradation of NH4+-N and COD were achieved by inoculation with enriched consortium in synthetic phenolic wastewater and real coking wastewater samples. Results demonstrated that the consortium had high potential for further practical applications.

The Resilience of Microbial Community Involved in Coking Wastewater Treatment System

Biological treatment processes are the most important step for removing various nutrient matters due to their high removal efficiency and low operational cost. The activated sludge technology was used extensively in coking wastewater biological treatment processes where a complex prokaryotic microbial consortium played an important role in the processes of oxygen-depleting organics, toxics and nutrients removal and preventing discharge of pathogens. Thus, a thorough knowledge of the ecology of the coking wastewater activated sludge communities is required to improve system operation and stability. Therefore, there is necessary to reveal the resilience of microbial community involved in coking wastewater treatment system.

Four-stage biofilm anaerobic–anoxic–oxic–oxic system for strengthening the biological treatment of coking wastewater: COD removal behaviors and biokinetic modeling

Biokinetic models of high-strength coking wastewater with a high chemical oxygen demand (COD) was efficiently treated by a novel pilot-scale four-stage biofilm anaerobic–anoxic–oxic–oxic (FB-A2/O2) system.

Analysis of the Metabolites of Indole Degraded by an Isolated Acinetobacter pittii L1.

Indole and its derivatives are typical nitrogen heterocyclic compounds and have been of immense concern since they are known for the risk of their toxic, recalcitrant, and carcinogenic properties for human and ecological environment. In this study, a Gram-negative bacterial strain of eliminating indole was isolated from a coking wastewater. The strain was confirmed as Acinetobacter pittii L1 based on the physiological and biochemical characterization and 16S ribosomal DNA (rDNA) gene sequence homology. 400 mg/L indole could be completely removed within 48 h by the strain on the optimum condition of 37°C, pH 7.4, and 150 rpm. The organic nitrogen was converted to NH3-N and then to NO3− and the organic carbon was partially transferred to CO2 during the indole biodegradation. The metabolic pathways were proposed to explain the indole degradation based on the liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis of indigo, 4-(3-Hydroxy-1H-pyrrol-2-yl)-2-oxo-but-3-enoic acid, and isatin. The toxicity of the biodegradation products was evaluated using the Microtox test, which revealed that the metabolites were more toxic than indole. Our research holds promise for the potential application of Acinetobacter pittii L1 for NHCs degradation, production of indigoids, and soil remediation as well as treatment of indole containing wastewater.

Denitrification with glucose as an external carbon source and investigation of microbial communities in a sequencing batch reactor treating reverse osmosis concentrate produced by a coking wastewater treatment plant

Denitrification with glucose as an external carbon source and investigation of microbial communities in a sequencing batch reactor treating reverse osmosis concentrate produced by a coking wastewater treatment plant

Fraction Of Heavy Metals In Sludges From Typical Coking Wastewater Treatment Plants By Modified Bcr Sequential Extraction Procedure

Fraction Of Heavy Metals In Sludges From Typical Coking Wastewater Treatment Plants By Modified Bcr Sequential Extraction Procedure

Comparison of parameters co-fermentation process of municipal sewage sludge with excess sewage sludge from treated coking wastewater

Porownanie parametrow procesu kofermentacji mieszaniny osadow komunalnych z nadmiernymi osadami z oczyszczania ściekow koksowniczych

Removal of recalcitrant organic pollutants from bio-treated coking wastewater using coal-based carbonaceous materials

Removal of recalcitrant organic pollutants from bio-treated coking wastewater using coal-based carbonaceous materials

Nitrified coke wastewater sludge flocs: an attractive precursor for N,S dual-doped graphene-like carbon with ultrahigh capacitance and oxygen reduction performance

N,S dual-doped graphene-like carbons synthesized from coke wastewater sludge flocs exhibit ultrahigh capacitance and outstanding oxygen reduction performance.