[Study on preparation of composite nano-scale Fe3O4 for phosphorus control].
Composite nano-scale Fe3O4 particles were prepared in sodium carboxymethyl cellulose (CMC) solution by the oxidation deposition method. The adsorptions of phosphorus by micro-scale Fe3O4 and composite nano-scale Fe3O4 were investigated in water and soil, and the role of cellulase in the adsorption of composite nano-scale Fe3O4 was studied. Kinetic tests indicated that the equilibrium adsorption capacity of phosphorous on the composite nano-scale Fe3O4 (2.1 mg/g) was less than that of micro-scale Fe3O4 (3.2 mg/g). When cellulase was added to the solution of composite nano-scale Fe3O4 to degrade CMC, the removal rate of P by the nanoparticles (86%) was enhanced to the same level as the microparticles (90%). In the column tests, when the composite nano-scale Fe3O4 suspension was introduced in the downflow mode through the soil column, 72% of Fe3O4 penetrated through the soil bed under gravity. In contrast, the micro-scale Fe3O4 failed to pass through the soil column. The retention rate of P was 45% in the soil column when treated by the CMC-stabilized nanoparticles, in comparison with only 30% for the untreated soil column, however it could be improved to 74% in the soil column when treated by both the CMC-stabilized nanoparticles and cellulase, which degraded CMC after the nanoparticles were delivered into the soil.
Li
Lei
L
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085. lilei_0626@sohu.com
Pan
Gang
G
Chen
Hao
H
D000327:Adsorption; D004787:Environmental Pollution / Q000517:prevention & control; D052203:Ferrosoferric Oxide / Q000138:chemical synthesis / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry / Q000302:isolation & purification*; D012989:Soil Pollutants / Q000737:chemistry / Q000302:isolation & purification*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*
D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D052203:Ferrosoferric Oxide