Phosphorus immobilization by the surface sediments under the capping with new calcium peroxide material

JOURNAL OF CLEANER PRODUCTION

卷:247

Article

Zhou, Jing¹  Li, Dapeng¹  Zhao, Zhehao¹  Song, Xiaojun¹  Huang, Yong¹  Yang, JingJing¹ 

[1] Suzhou Univ Sci & Technol, Sch Environm Sci & Engn, 1 Kerui Rd, Suzhou 215009, Peoples R China

关键词: Calcium peroxide;    Remediation;    Adsorption;    Phosphorus fractions;    Surface sediment;   

DOI  :  10.1016/j.jclepro.2019.119135

来源: Elsevier

【 摘 要 】

Capping material plays an important role in P (phosphorus) control. However, P immobilization on surface sediments due to the remediation by the capping materials has been neglected. Herein, we conducted an experiment to research the mechanism of surface sediment on P immobilization under new calcium peroxide material (NCPM) capping at different ratios of the sedimentary mobile phosphorus (P-mobile, the sum of NH4Cl-P, BD-P and NaOH-nrP) to NCPM (1:1-1:4). The concentrations of soluble reactive P (SRP), ammonium (NH4+) and ferrous (Fe(II)) in water and sedimentary P fractions were analyzed. The study also presents the results of Langmuir isotherm model for surface sediments and sedimentary P release under anaerobic conditions. The results show that the surface sediments under NCPM capping improved the SRP reduction both from overlying and pore water. This was attributed to Ca2+ precipitation and sedimentary micro-environment change from anaerobic conditions to aerobic conditions which resulted from the NH4+ and Fe(II) concentration reductions. This remediation increased maximum adsorption capacity (S-max) and decreased equilibrium concentration of P adsorption and desorption (EPC0) in those surface sediments under NCPM capping, which was favourable for P adsorption and immobilization. The X-ray diffraction and energy-dispersive X-ray spectroscopy analyses results confirmed aforementioned results. The conversion of P fractions from P-mobile to inert P in the surface sediments was more obvious than control. The inert P increased from 50.15% (1:1) to 69.88% (1:4), resulting in lower P release from the surface sediments under NCPM capping, compared with the control. The results show that NCPM capping improved P removal and immobilization of the surface sediments, beneficial for controlling sedimentary P release. (C) 2019 Elsevier Ltd. All rights reserved.

【 授权许可】

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