DOI: 10.1016/j.watres.2018.01.055
Scopus记录号: 2-s2.0-85041660970
论文题名: Synergistic adsorption of phosphorus by iron in lanthanum modified bentonite (Phoslock®): New insight into sediment phosphorus immobilization
作者: Ding S. ; Sun Q. ; Chen X. ; Liu Q. ; Wang D. ; Lin J. ; Zhang C. ; Tsang D.C.W.
刊名: Water Research
ISSN: 431354
出版年: 2018
卷: 134 起始页码: 32
结束页码: 43
语种: 英语
英文关键词: Capping
; Diffusive gradients in thin films
; Iron redox
; Lanthanum modified bentonite (Phoslock®)
; Phosphorous
; Sediment
Scopus关键词: Adsorption
; Bentonite
; Lanthanum
; Phosphorus
; Redox reactions
; Sediments
; Thin films
; Water
; Batch adsorption experiments
; Capping
; Diffusive gradients
; Diffusive gradients in thin films
; Immobilization mechanisms
; Modified bentonites
; Phosphorous
; Synergistic adsorptions
; Iron compounds
; bentonite
; iron
; lanthanum
; phosphorus
; bentonite
; iron
; lanthanum
; phosphorus
; active layer
; adsorption
; bentonite
; concentration (composition)
; experiment
; film
; immobilization
; iron
; mobility
; phosphorus
; porewater
; rare earth element
; redox potential
; sediment capping
; sediment core
; stabilization
; synergism
; adsorption
; Article
; comparative study
; immobilization
; microcosm
; oxidation reduction potential
; oxidation reduction reaction
; oxidation reduction state
; priority journal
; sediment
; species differentiation
; supernatant
; surface property
; adsorption
; chemistry
; sediment
; water pollutant
; Adsorption
; Bentonite
; Geologic Sediments
; Iron
; Lanthanum
; Oxidation-Reduction
; Phosphorus
; Water Pollutants, Chemical
英文摘要: Iron redox cycle plays a primary role in controlling the mobility of P in sediments. It is crucial to better understand how lanthanum (La) modified bentonite (LMB, Phoslock®), an increasingly employed capping agent, immobilizes P from sediments by altering Fe redox-coupled P cycling. Batch adsorption experiments found that LMB effectively adsorbed Fe(II) with a capacity of 8.51 mg g−1. Fe(II)-preloaded LMB effectively retained P during a 518-hour equilibration, while up to 16.7% of adsorbed P was release-sensitive in LMB without Fe(II) preloading. A 60-day incubation experiment was performed using sediment cores, with an LMB amendment dosage of up to 200 LMB/Pmob (w/w, Pmob denotes the amount of mobile P in the surface 40 mm sediment layer). The concentrations of pore water soluble reactive P (SRP) and labile P were measured by high resolution dialysis (HR-Peeper) and by diffusive gradient in thin films (DGT), respectively, at a vertical millimeter scale. They stratified into static layers with extremely low concentration distribution in the top 16–22 mm sediments (mean SRP ≤ 0.28 mg L−1 and mean DGT-labile P ≤ 0.051 mg L−1) and active layers with decreased upward diffusion potential (≤5.85 for SRP and ≤12.7 for DGT-labile P) below the static layer, when the applied dosage reached 60 LMB/Pmob. The LMB amendment reduced the pore water Fe and DGT-labile Fe in sediments, while considerable amounts of Fe and Fe-bound P existed in the LMB binding layer (25% of the total P in 200 LMB/Pmob treatment). These findings show that the adsorption of Fe by LMB plays a significant role in the stabilization of LMB-bound P, possibly by adsorbing release-sensitive P initially bound to the rhabdophane surface. LMB adsorbed Fe and P were not released until the redox potential decreased to extremely reductive conditions (−150 mV to −300 mV), possibly due to the re-adsorption of Fe and P by LMB. This study reveals synergistic effects of Fe adsorption and provides new insight into the immobilization mechanisms of P by LMB application. © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112897
Appears in Collections: 气候减缓与适应
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作者单位: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China; Shanghai Waterway Engineering Design and Consulting Co., Ltd., Shanghai, 200120, China; University of Chinese Academy of Sciences, Beijing, 100049, China; International Network for Environment and Health, School of Geography and Archaeology, National University of Ireland, Galway, Ireland; Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
Recommended Citation:
Ding S.,Sun Q.,Chen X.,et al. Synergistic adsorption of phosphorus by iron in lanthanum modified bentonite (Phoslock®): New insight into sediment phosphorus immobilization[J]. Water Research,2018-01-01,134