Removal of hard COD from biological effluent of coking wastewater using synchronized oxidation-adsorption technology: Performance, mechanism, and full-scale application

Sun, Guangming; Zhang, Yu; Gao, Yingxin; Han, Xiaogang; Yang, Min

doi:10.1016/j.watres.2020.115517

Cited by 64 publications

(16 citation statements)

References 53 publications

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“…Previously developed homogeneous Fenton systems and typical bioelectro-Fenton ,, consume high amounts of pH-adjustment reagents to dissolve Fe(III), separate Fenton sludge from the effluent, and produce H 2 O 2 . In our reagentless bioelectrode system, the acid–base buffering of the main reactions (eqs – and ) could essentially waive the need for pH adjustment.…”

Section: Resultsmentioning

confidence: 99%

“…Alkalinity was essentially self-buffering within the bioelectrode system, thereby avoiding the high consumption of pH-adjustment reagents found in conventional Fenton systems. Compared with the previous (electro-)Fenton-like systems, , the reagentless bioelectrode system therefore has the advantages of negligible chemical consumption, no accumulation of Fenton sludge, low energy consumption, and no catalyst leaching risk. The operation cost of the reagentless bioelectrode system was only 1.4% of classic Fenton.…”

Section: Discussionmentioning

confidence: 99%

“…The biodegradable organics in these complex wastewaters can be efficiently removed by biological treatment systems. , However, removal performance for the more recalcitrant organics has so far been unsatisfactory. , Homogeneous Fenton systems, which are based on a combination of dissolved Fe(II) and H 2 O 2 to produce · OH, have shown diverse recalcitrant organic removal, low interference of aqueous matrices, and no energy consumption. , However, the high operating costs caused by high reagent consumption and secondary pollution remain a scientific challenge . Fenton-like systems − (such as the addition of iron reducing reagents and/or iron complexing reagents or the use of UV to activate H 2 O 2 ) can reduce the dosage of part of Fenton’s reagent but require additional reagents or high energy input.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Sustainable and Reagentless Fenton Treatment of Complex Wastewater

Wang

Tang

Hambly

et al. 2022

Environ. Sci. Technol.

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Conventional Fenton treatment is fundamentally impractical for large-scale applications, as the consumption of Fe(II), H2O2, and pH regulators and the accumulation of iron hydroxide sludge are very costly. This paper describes a new method for Fenton treatment of complex wastewater without additional dosing of Fe(II) and H2O2, without iron-sludge accumulation, and with less consumption of pH regulators, using a novel bioelectrode system. Our new system includes a novel three-chamber microbial electrolysis unit and Fenton reaction unit, where Fenton reagents are generated by biotic and abiotic cathodes, while the bioanode simultaneously degrades biodegradable organics from the wastewater. The system’s self-alkalinity buffering also waives the need for pH regulators. Dissolved organic carbon and 22 specific recalcitrant organics were removed by 99% and between 78 and 100%, respectively. The bioelectrode system generated 13 ± 3 mg/L dissolved Fe(II) and 5 ± 0.4 mg/L H2O2 for the Fenton reaction unit. The closed iron cycle avoided iron loss and iron sludge accumulation during operation. The pH regulator dosage and operating costs were just 9.7 and 1.4%, respectively, of what is required by classic Fenton. The low operating cost and reduction in chemical usage make it an efficient, sustainable alternative to the conventional treatment processes currently used for complex wastewater.

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Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Sustainable and Reagentless Fenton Treatment of Complex Wastewater

Wang

Tang

Hambly

et al. 2022

Environ. Sci. Technol.

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“…It contains a variety of contaminants such as phenols, indoles, quinoline pyridines, polycyclic aromatic hydrocarbons (PAHs), sulfides (S 2– ), thiocyanide (SCN – ), and cyanides (CN – ) . The main challenge for coking wastewater treatment is the effective removal of toxic pollutants that inhibit biological activity. , The A/A/O process requires relatively consistent influent wastewater conditions (i.e., low shock resistance) and is susceptible to toxic pollutants. The toxicity of the coking wastewater inhibits the sludge activity in the anaerobic and anoxic tanks, resulting in high organic loading rate (OLR) and low nitrification rate in the subsequent oxic tanks in the A/A/O process.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Carbon and Nitrogen Removal Performance of the Oxic-Hydrolytic and Denitrification-Oxic Process in Coking Wastewater Treatment

Wei

Pan

et al. 2022

ACS EST Water

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The novel oxic-hydrolytic and denitrification-oxic (O/H/O) process has attracted intensive attention from the industry and academia and has been applied in coking wastewater treatment practice in recent years. However, there has yet been a mechanism model that can systematically guide the design and operation of the O/H/O process in optimization. In this study, a two-step nitrification−denitrification activated sludge model no. 3 for coking wastewater (TCW-ASM3) model was established. The addition of new components and processes enables TCW-ASM3 to accurately simulate the biological reaction processes in the O/ H/O system. The simulation results show that the increase in the step feeding ratio (R1) will lead to the increase in biological effluent chemical oxygen demand (COD) and total nitrogen (TN). To meet the TN effluent target (TN < 50 mg/L), R2 > 320% was needed. The energy consumption under this effluent constraint (COD < 200 mg/L, TN < 50 mg/L) was 4.873−5.752 kWh/m 3 . The foregoing results showed that the O/H/O process could be adjusted in different modes according to the pollutant characteristics and effluent targets. This study is the first report of the O/H/O process model, which is capable of providing strategies of multiple targets for the pollutant removal from industrial wastewaters with high toxicity and high C/N ratio.

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“…The discharge of the bio-treated coking wastewater (BCW) without effective further treatment could result in serious environmental problems. Thus, efforts on advanced treatment processes for coking wastewater to remove the organic matters present in the BCW, especially refractory and toxic compounds, are necessary to guarantee the safety of the water environment [3,4].…”

Section: Introductionmentioning

confidence: 99%

Treatment of Bio-Treated Coking Wastewater by Catalytic Ozonation with Semi-Batch and Continuous Flow Reactors

Wang

et al. 2020

Water

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In this work, the treatment of bio-treated coking wastewater (BCW) by catalytic ozonation was conducted in semi-batch and continuous flow reactors. The kinetics of chemical oxygen demand (COD) removal were analyzed using BCWs from five coking plants. An integral reactor with catalytic ozonation stacked by ozone absorption (IR) was developed, and its efficiency was studied. The catalyst of MnxCe1-xO2/γ-Al2O3 was efficient in the catalytic ozonation process for the treatment of various BCWs. The chemical oxygen demand (COD) removal efficiencies after 120 min reaction were 64–74%. The overall apparent reaction rate constants were 0.0101–0.0117 min−1, which has no obvious relationship with the initial COD of BCW and pre-treatment biological process. The IR demonstrated the highest efficiency due to the enhancement of mass transfer and the utilization efficiency of ozone. Bypass internal circulation can further improve the reactor efficiency. The optimal results were obtained with the ozone absorption section accounting for 19% of the valid water depth in the reactor and 250% of circulation flow ratio. The long-term and full-scale application of the novel reactor in a continuous mode indicated stable removal of COD and polycyclic aromatic hydrocarbons (PAHs). The results showed that the system of IR is a promising reactor type for tertiary treatment of coking wastewater by catalytic ozonation.

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Removal of hard COD from biological effluent of coking wastewater using synchronized oxidation-adsorption technology: Performance, mechanism, and full-scale application

Cited by 64 publications

References 53 publications

Sustainable and Reagentless Fenton Treatment of Complex Wastewater

Sustainable and Reagentless Fenton Treatment of Complex Wastewater

Evaluation of Carbon and Nitrogen Removal Performance of the Oxic-Hydrolytic and Denitrification-Oxic Process in Coking Wastewater Treatment

Treatment of Bio-Treated Coking Wastewater by Catalytic Ozonation with Semi-Batch and Continuous Flow Reactors

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