Evaluation of the effect of sulfate, alkalinity and disinfector on iron release of iron pipe and iron corrosion scale characteristics under water quality changing condition using response surface methodology

3rd International Conference on Advances in Energy Resources and Environment Engineering

能源学;生态环境科学

Yang, Fan^1 ; Shi, Baoyou^2 ; Zhang, Weiyu^1 ; Guo, Jianbo^3 ; Wu, Nana^4 ; Liu, Xinyuan^1

College of Engineering and Technology, Tianjin Agricultural University, Jinjing Road, 22, Tianjin

300384, China^1

Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road, 18, Beijing

100085, China^2

Tianjin Key Laboratory of Water Quality Science and Technology, Tianjin Chengjian University, Tianjin

300384, China^3

Jiangsu Prov. Transp. Planning and Design Institute Stock Limited Liability Company-Zhengzhou Branch, Zhengzhou

450046, China^4

关键词: Amorphous iron oxides;    Box-Behnken design;    Corrosion scale;    Groundwater supply;    Pipe section reactors;    Response surface;    Response surface methodology;    Water purification;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/113/1/012008/pdf
DOI  :  10.1088/1755-1315/113/1/012008

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

The response surface methodology (RSM), particularly Box-Behnken design model, was used in this study to evaluate the sulfate, alkalinity and free chlorine on iron release of pipe with groundwater supply history and its iron corrosion scale characteristics under water quality changing experiment. The RSM results together with response surface contour plots indicated that the iron release of pipe section reactors was positively related with Larson Ratio and free chlorine. The thin Corrosion scales with groundwater supply history upon collection site contained Fe3O4(18%), α-FeOOH (64%), FeCO3(9%), β-FeOOH (8%) and γ-FeOOH (5%), besides their averaged amorphous iron oxide content was 13.6%. After the RSM water quality changing experiment, Fe3O4, amorphous iron oxide and intermediate iron products (FeCO3, Green Rust (GR)) content on scale of Cl2Rs increased, while their α-FeOOH contents decreased and β-FeOOH disappeared. The high iron released Cl2Rs receiving higher LR water (1.40-2.04) contained highest FeCO3(20%) and amorphous iron oxide (42%), while the low iron release Cl2Rs receiving lower LR water (0.52-0.73) had higher GR(6.5%) and the amorphous iron oxide (23.7%). In high LR water (>0.73), the thin and non-protective corrosion scale containing higher amorphous iron oxide, Fe(II) derived from new produced Fe3O4or FeCO3or GR was easy for oxidants and sulfate ions penetration, and had higher iron release. However the same unstable corrosion scale didn't have much iron release in low LR water (≤0.73). RSM experiment indicated that iron release of these unstable corrosion scales had close relationship with water quality (Larson Ratio and disinfectant). Optimizing the water quality of new source water and using reasonable water purification measures can help to eliminate the red water case.