Study of nitrate contaminants removal from groundwater on copper modified BDD electrode

Peijing Kuang,Yasuaki Einaga,Yubo Cui,Chuanping Feng,R Weerasinghe,J Wu,C.-H Weng

doi:10.1051/e3sconf/202019404024

Peijing Kuang, Yasuaki Einaga + Show 5 more

Open Access

https://doi.org/10.1051/e3sconf/202019404024

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Abstract

The electrochemical nitrate reduction by using boron-doped diamond (BDD) and copper modified boron-doped diamond (Cu-BDD) electrodes was investigated at various potentials. Nitrate reduction efficiency and the products distribution was strongly dependent on the applied potential for both electrodes. The highest nitrate reduction efficiency of 77% was obtained at −2.0 V (vs. Ag/AgCl) by using Cu-BDD. Compared with BDD electrode, nitrate reduction on Cu-BDD electrode occurred at more positive potential. Copper oxides formed on BDD surface efficiently promoted enhanced conductivity of electrode to promote electrons transfer during nitrate reduction process. Meanwhile, the catalytic ability of copper was also conductive to the nitrate transformation. Therefore, the developed Cu-BDD would be a promising approach for efficient nitrate removal from groundwater.

Highlights

Nitrate concentration has increased in groundwater and soil because of the heavy use of nitrogen based fertilisers and the discharge of agricultural effluent, causing the serious nitrate pollution [1]
Kuang et al found that Born doped diamond (BDD) electrode had the higher nitrogen gas selectivity of 45.2% than Cu of 8% for nitrate reduction under the same electrolytic conditions, which might result from the inhibition of ammonia generation by the wide potential of BDD [5]
The behavior of electrochemical nitrate reduction at BDD and Cu-BDD electrodes was investigated by applying different potentials, and the results showed that the performance was strongly depended on the applied potential

Summary

Introduction

Nitrate concentration has increased in groundwater and soil because of the heavy use of nitrogen based fertilisers and the discharge of agricultural effluent, causing the serious nitrate pollution [1]. The complex nitrate electroreduction process depends strongly on the experimental parameters such as the pH, electrolyte and the electrode material, which results in a mass of nitrite, ammonia and some other undesirable by-products. In this sense, a mass of materials have been explored to promote nitrate transformation towards nitrogen gas. Kuang et al found that BDD electrode had the higher nitrogen gas selectivity of 45.2% than Cu of 8% for nitrate reduction under the same electrolytic conditions, which might result from the inhibition of ammonia generation by the wide potential of BDD [5]. We examined CuBDD for the electrochemical reduction of nitrate and the selectivity of nitrogen gas under different potentials

Experimental

Characterization

Findings

Conclusion