Differential control of anode/cathode potentials of paired electrolysis for simultaneous removal of chemical oxygen demand and total nitrogen

Yao, Jiachao; Pan, Bingjun; Shen, Ruxue; Yuan, Tongbin; Wang, Jiade

doi:10.1016/j.scitotenv.2019.06.106

Cited by 36 publications

(7 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mechanisms of electrochemical oxidation of ammonia are divided into direct and indirect anodic oxidation. The detail mechanism of direct oxidation on the Ti/PbO 2 electrode has been fully described in our previous research [37]. Briefly, in direct electrolysis, pollutants are oxidized after transferred to the anode surface, without involvement of any substances other than the electron, which is a clean reagent (Equation (17)) [38].…”

Section: Resultsmentioning

confidence: 99%

Process Optimization of Electrochemical Oxidation of Ammonia to Nitrogen for Actual Dyeing Wastewater Treatment

Yao

Xia

et al. 2019

IJERPH

Self Cite

View full text Add to dashboard Cite

To mitigate the potential environmental risks caused by nitrogen compounds from industrial wastewater, residual ammonia after conventional wastewater treatment should be further eliminated. In this work, an electrochemical oxidation process for converting ammonia to nitrogen in actual dyeing wastewater was investigated. The effects of the main operating parameters, including initial pH value, applied current density, NaCl concentration, and flow, were investigated on ammonia removal and products distribution. Experimental results indicated that, under optimal conditions of an initial pH value of 8.3, applied current density of 20 mA cm−2, NaCl concentration of 1.0 g L−1, and flow of 300 mL min−1, the ammonia could be completely removed with N2 selectivity of 88.3% in 60 min electrolysis. A kinetics investigation using a pseudo-first-order model provided a precise description of ammonia removal during the electro-oxidation process. Experimental functions for describing the relationships between kinetic constants of ammonia removal and main operating parameters were also discussed. Additionally, the mechanisms and economic evaluation of ammonia oxidation were conducted. All these results clearly proved that this electro-oxidation process could efficiently remove ammonia and achieve high N2 selectivity.

show abstract

Section: Resultsmentioning

confidence: 99%

Process Optimization of Electrochemical Oxidation of Ammonia to Nitrogen for Actual Dyeing Wastewater Treatment

Yao

Xia

et al. 2019

IJERPH

Self Cite

View full text Add to dashboard Cite

show abstract

“…Current studies for wastewater treatment by electrochemical method mainly concentrate on the removal of a single pollutant or two mixed pollutants, and there are few investigations on the electrochemical treatment of wastewater containing COD, NH 4 + , NO 3 − , and NO 2 − . In our previous work [ 23 ], the feasibly of simultaneous removal of COD and TN was proven; however, it should be noticed that one of the issues for COD and TN removal is to restrain the problems of side reactions of NH 4 + over-oxidation on anode and NO 3 − /NO 2 − over-reduction on cathode. Actually, many literatures indicate that the over-oxidation or over-reduction is a common phenomenon in the process of nitrogen-containing wastewater treatment by electrochemical method [ 24 , 25 , 26 ], which means that the TN removal is limited.…”

Section: Introductionmentioning

confidence: 99%

Process Optimization of Electrochemical Treatment of COD and Total Nitrogen Containing Wastewater

Yao

Jiang²,

Xia

2022

IJERPH

Self Cite

View full text Add to dashboard Cite

In this work, an electrochemical method for chemical oxygen demand (COD) and total nitrogen (TN, including ammonia, nitrate, and nitrite) removal from wastewater using a divided electrolysis cell was developed, and its process optimization was investigated. This process could effectively relieve the common issue of NO3−/NO2− over-reduction or NH4+ over-oxidation by combining cathodic NO3−/NO2− reduction with anodic COD/NH4+ oxidation. The activity and selectivity performances toward pollutant removal of the electrode materials were investigated by electrochemical measurements and constant potential electrolysis, suggesting that Ti electrode exhibited the best NO3−/NO2− reduction and N2 production efficiencies. In-situ Fourier transform infrared spectroscopy was used to study the in-situ electrochemical information of pollutants conversion on electrode surfaces and propose their reaction pathways. The effects of main operating parameters (i.e., initial pH value, Cl− concentration, and current density) on the removal efficiencies of COD and TN were studied. Under optimal conditions, COD and TN removal efficiencies from simulated wastewater reached 92.7% and 82.0%, respectively. Additionally, reaction kinetics were investigated to describe the COD and TN removal. Results indicated that COD removal followed pseudo-first-order model; meanwhile, TN removal followed zero-order kinetics with a presence of NH4+ and then followed pseudo-first-order kinetics when NH4+ was completely removed. For actual pharmaceutical wastewater treatment, 79.1% COD and 87.0% TN were removed after 120 min electrolysis; and no NH4+ or NO2− was detected.

show abstract

“…During this process, there is simultaneous oxidation and reduction, i.e., gain and loss of electrons in the cathode and anode chambers, which can act as induction electrodes. In this method, the contaminant is degraded and valuable byproducts are obtained. , …”

Section: Chemical Methodsmentioning

confidence: 99%

A Critical Review on the Sustainable Approaches for the Removal of Toxic Heavy Metals from Water Systems

Carolin

Kamalesh

Kumar³

et al. 2023

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Heavy metal pollution results in enormous environmental impacts and significant human health problems. Because of their extreme toxicity and lack of biodegradability, heavy metal ions in water are considered problematic. Although the removal of various heavy metal ions from wastewater has been widely investigated, heavy metal contamination still requires effective and suitable remediation. With special attention on heavy metal removal, this study reviews recent advances, breakthroughs, and potential applications of various physical, chemical, and biological methods. Each treatment method has specific mechanisms of interaction with metal ions, which are described in this review. The discussion in this review leads to the conclusion that adsorption has the best potential which leads to the sustainable remediation of heavy metals. In summary, the review provides a new perspective on heavy metal reduction and encourages the development of innovative strategies for heavy metal removal. The main current problems and prospects in this field are highlighted in this review.

show abstract

Differential control of anode/cathode potentials of paired electrolysis for simultaneous removal of chemical oxygen demand and total nitrogen

Cited by 36 publications

References 52 publications

Process Optimization of Electrochemical Oxidation of Ammonia to Nitrogen for Actual Dyeing Wastewater Treatment

Process Optimization of Electrochemical Oxidation of Ammonia to Nitrogen for Actual Dyeing Wastewater Treatment

Process Optimization of Electrochemical Treatment of COD and Total Nitrogen Containing Wastewater

A Critical Review on the Sustainable Approaches for the Removal of Toxic Heavy Metals from Water Systems

Contact Info

Product

Resources

About