Abstract
Immobilization of phosphorus (P) in sediments is essential for controlling eutrophication in natural waters. As sediment is a complex assemblages of minerals, it is necessary to explore the intrinsic mechanisms of immobilization from the view of mineral composition. In this study, nano zero-valent iron (nZVI) is used as an example to immobilize P in sediment from Tai Lake and minerals of quartz, hematite, potassium feldspar, illite, montmorillonite, calcite, and kaolin (i.e. the main components of natural sediment), to consider the role of mineral composition on P immobilization). Results show that the immobilization efficiency increases gradually with the increasing amount of adopted nZVI, until a maximum value of about 60% - 80% when 0.03–0.05 g/g of nZVI is added. Particularly, the maximum P immobilization efficiency is the highest for hematite (about 86%) due to the chemical reaction between hematite and P that inhibiting P release, followed by quartz, illite, montmorillonite, and kaolin (about 64% - 72%) which only physically adsorb P. However, the maximum P immobilization efficiency of nZVI is only 31% and 17% for potassium feldspar and calcite, respectively, due to their relatively high pH values that reducing the formation of iron (Fe)-P precipitation and inhibiting P immobilization. Thus, the P immobilization is mainly due to the reaction between nZVI/mineral and P to form FeP precipitates, followed by physical adsorption; and the particle size, elemental composition (e.g. the calcium (Ca) in calcite and Fe in hematite) and pH value also affect the P immobilization efficiency. Moreover, based on the P immobilization efficiencies for various minerals, P immobilization in sediments can be reasonably predicted from the mineral composition through methods such as component additivity.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.