Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China; Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing 100084, China.
School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Brackenhurst Campus, Nottinghamshire NG25 0QF, United Kingdom; Centre of Integrated Water-Energy-Food studies (iWEF), Nottingham Trent University, Nottinghamshire NG25 0QF, United Kingdom; Cranfield Water Science Institute, Cranfield University, College Road, Cranfield, Bedfordshire MK43 0AL, United Kingdom.
Sci Total Environ. 2020 Jul 10;725:138424. doi: 10.1016/j.scitotenv.2020.138424. Epub 2020 Apr 4.
Biogenic phosphorus (P), such as organic P and inorganic pyrophosphates, could substantially contribute towards eutrophication in aquatic systems by internal loading of P from sediment through P species transformation. Previous eutrophication management studies mainly focus on the removal of orthophosphate (Ortho-P), however, an effective approach for biogenic P control from water sources, prior to incorporation in sediment, is still lacking. In this study, a lanthanum/aluminum-hydroxide (LAH) composite was demonstrated to provide both superior removal of Ortho-P and biogenic P, employing myo-inositol hexakisphosphate (IHP) and pyrophosphate (Pyro-P) as model compounds. The maximum IHP and Pyro-P adsorption capacities by LAH attained 36.4 and 21.8 mg P g, respectively. In order to understand the mechanisms of adsorption, zeta potential, P solid-state nuclear magnetic resonance (NMR) spectroscopy and P K-edge X-ray absorption near edge structure (XANES) techniques were used to characterize the LAH after adsorption. The results supported the hypothesis that the interaction between LAH and P species was through surface adsorption, by the formation of inner-sphere complexes. Linear combination fitting results of XANES data indicated that IHP and Pyro-P preferentially bonded with La-hydroxide in LAH. This study elucidates the adsorption properties and binding mechanisms of IHP and Pyro-P on lanthanum-bearing compounds at the molecular level, indicating that LAH is a promising material for the control of eutrophication.
生物磷（P），如有机磷和无机焦磷酸，通过磷物种转化从沉积物中内部加载 P，可大量促成水体富营养化。先前的富营养化管理研究主要集中在去除正磷酸盐（Ortho-P）上，然而，在磷被纳入沉积物之前，从水源中控制生物磷的有效方法仍然缺乏。在这项研究中，证明了镧/氢氧化铝（LAH）复合材料具有优越的去除正磷酸盐和生物磷的能力，采用肌醇六磷酸（IHP）和焦磷酸（Pyro-P）作为模型化合物。LAH 的最大 IHP 和 Pyro-P 吸附容量分别达到 36.4 和 21.8 mg P g。为了理解吸附机制，使用zeta 电位、P 固态核磁共振（NMR）光谱和 P K 边 X 射线吸收近边结构（XANES）技术对吸附后的 LAH 进行了表征。结果支持了这样的假设，即 LAH 与磷物种之间的相互作用是通过表面吸附，形成内球络合物。XANES 数据的线性组合拟合结果表明，IHP 和 Pyro-P 优先与 LAH 中的 La-氢氧化物键合。这项研究阐明了 IHP 和 Pyro-P 在含镧化合物上的吸附特性和结合机制，表明 LAH 是控制富营养化的一种有前途的材料。
