Fractionation Analysis of Iron in Coastal Rivers to Yantai Sishili Bay with a Bismuth Microrods-Based Electrochemical Sensor

Xueping Hu,Chenchen Wang,Haitao Han,Xingliang Song

doi:10.3390/jmse9101063

Abstract

As an essential metal micronutrient, Fe plays an important role in the marine biogeochemical cycling process, and the bioavailability of Fe has a direct relationship with its fractions in water. The fractionation analysis of iron in main coastal rivers to Yantai Sishili Bay was achieved with an electrochemical sensor based on bismuth microrods (BiMRs). The sensor was characterized by scanning electron microscope and electrochemical methods, and the reliability of the sensor was verified by the determination of the standard samples. Different fractions of iron in coastal river waters, including total iron (TFe), total dissolved iron (TDFe) and particulate iron (PFe), have been determined by combining simple sample pretreatments and cathodic stripping voltammetry with the BiMRs-based sensor. The average concentrations of TFe in Guangdang River, Xin’an River and Yuniao River were 4.02, 3.66 and 4.42 μmol L−1, respectively. The main fractionation of iron in three rivers was PFe, which accounts for 84.46%, 87.56% and 92.34%, respectively. Furthermore, the relationships between iron concentration and tidal action, salinity, dissolved oxygen and other factors were also investigated.

Highlights

Iron (Fe) is a relatively abundant metal element in the earth’s crust, with an abundance of about 5–6% [1,2,3], its content in water environments is relatively low
The concentration of Fe in river water is about 10−6 mol L−1, and the concentration range of
Surface morphology of the bismuth microrods (BiMRs) was characterized by SEM

Summary

Introduction

Iron (Fe) is a relatively abundant metal element in the earth’s crust, with an abundance of about 5–6% [1,2,3], its content in water environments is relatively low. The concentration of Fe in river water is about 10−6 mol L−1 , and the concentration range of. Fe in coastal waters is 10−9 to 10−6 mol L−1 [4,5]. It was found that Fe, like other macronutrients, is an important factor limiting marine primary productivity [7,8]. In addition to the rich nitrogen and phosphorus nutrients, Fe may be the key factor in the formation of red tide [9]. The fractionation analysis of iron is a priority to understand coastal water dynamics

Methods

Discussion

Conclusion