Research
| Title： | Mechanisms of enhanced inorganic phosphorus accumulation by periphyton in paddy fields as affected by calcium and ferrous ions |
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| First author： | Li, Jiu-yu; Deng, Kai-ying; Hesterberg, Dean; Xia, Yong-qiu; Wu, Chen-xi; Xu, Ren-kou |
| Journal： | SCIENCE OF THE TOTAL ENVIRONMENT |
| Years： | 2017 |
| DOI： | 10.1016/j.scitotenv.2017.07.117 |
| Abstract： | The effect of periphyton propagation in paddy fields on phosphorus biogeochemical cycling has received little attention. In this phytotron study, inorganic phosphorus (P-i) accumulation by periphyton was investigated for varying inputs of calcium[Ca(II)] or ferrous iron [Fe(II)], and lighting conditions. Results indicated that additions of Ca(II) or Fe(II) enhanced abiotic accumulation of P-i by up to 16 times, and decreased solution P-i concentration by up to 50%, especially under light condition. The enhanced P-i accumulation into periphyton intensified with increasing P-i concentration, and P-i accumulation showed a positive linear relationship with Ca or Fe accumulation. Abiotic accumulation of P-i induced by Ca(II) was mainly through Ca-phosphate precipitation, and co-precipitation of P with carbonates at pH > 8. Accumulation with added Fe(II) was mainly considered to be through Fe(III) phosphate precipitation coupled with adsorption of P-i by ferric hydroxides. Moreover, Fe(II) was more effective than Ca(II) in promoting abiotic accumulation of P-i by periphyton. Our results indicate the potential for controlling environmental factors to enhance the role of periphyton in biogeochemical cycling and P-use efficiency in paddy rice fields and to reduce P discharged to neighboring water bodies. (C) 2017 Elsevier B.V. All rights reserved. |
