Summary: | Commercial extraction of rare earth elements (REE) from ion adsorption clay (IAC) may release toxic elements and radionuclides and pollute the environment. Dicranopteris linearis is a fern species available in Malaysia and can accumulate REE and uranium (U) with greater efficiency, especially when IAC is treated with a leaching agent such as hydrolyzed humic acid (FA). This study aims to investigate the growth of D. linearis and its uptake for REE and U in an IAC treated with FA produced at pH 1 (1 % w/w FA pH 1) and pH 6 (1 % w/w FA pH 6). The results were compared with those of commercial ammonium sulfate (0.45 M (NH4)(2)SO4), and artificial rain (10 mM CaCl2). The REE and U content were analyzed using inductively coupled plasma-optical emission spectrometry (ICP-OES). The t-test showed a significance value (p<0.05), indicating that the difference between the REE and U uptake of D. linearis with different treatments are significant. The highest Bioconcentration Factor (BCF) and Translocation Factor (TF) values for scandium (Sc) (5.29 +/- 0) were recorded when IAC was treated with FA pH 1. Treatment of IAC with FA pH 6 also allows translocation of cerium (Ce) to the shoot of D. linearis (TF= 1.96 +/- 0). A significantly higher uptake for praseodymium (Pr) and U was observed when IAC was treated with (NH4)(2)SO4, possibly due to a greater mobilization that allows more uptake at the shoot of D. linearis. Using FA pH 6 may offer a safer alternative to (NH4)(2)SO4 for selectively extracting Ce and lanthanum (La).
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