Effect of Dissolved Silica on Immobilization of Boron by Magnesium Oxide

Abstract

Abstract:The effect of silica on the immobilization reaction of boron by magnesium oxide was investigated by laboratory experiments. In the absence of silica, due to dissolution of the magnesium oxide, boron was removed from solutions by the precipitation of multiple magnesium borates. In the presence of silica, magnesium silica hydrate (M-S-H) was formed as a secondary mineral, which takes up boron. Here 11 B magic-angle spinning nuclear magnetic resonance (MAS-NMR) and Fourier transform infrared spectrometer (FT-IR) data show that a part of the boron would be incorporated into M-S-H structures by isomorphic substitution of silicon. Another experiment where magnesium oxide and amorphous silica were reacted beforehand and boron was added later showed that the shorter the reaction time of the preceding reaction, the higher the sorption ratio of boron. That is, boron was incorporated into the M-S-H mainly by coprecipitation. The experiments in the study here show that the sorption of boron in the presence of silica is mainly due to the incorporation of boron during the formation of the M-S-H structure, which suggests that boron would not readily leach out, and that stable immobilization of boron can be expected.

Interactions of Silicon With Essential and Beneficial Elements in Plants

“…Moreover, both elements are taken up as uncharged acids (H 4 SiO 4 0 , pKa of 9.8; H 3 BO 3 0 , pKa of 9.2) either actively or passively depending on their external concentrations. Under certain environmental conditions it is therefore possible that Si complexes with B in soil solution thus reducing availability of B and its potential phytotoxic effect ( Nozawa et al, 2018 ). Although ameliorative effect of Si via decreased B accumulation has been reported in numerous species, i.e., tomato ( Kaya et al, 2011 ), grapevine rootstocks ( Vitis sp.)…”

Relationships Among Arsenic-Related Traits, Including Rice Grain Arsenic Concentration and Straighthead Resistance, as Revealed by Genome-Wide Association

“…In shoots, Si interacts with phytohormones and amino acids, and metabolites lower oxidative stress by further modulating the antioxidant enzymes (Liang et al, 2003;Li et al, 2012;Chalmardi et al, 2014) and simultaneously maintaining or even inducing higher photosynthetic efficiency resulting in plant growth and development (Detmann et al, 2012). On the other hand, for mineral or heavy metal toxicity, Si forms a complex with some heavy metals (Cd) or minerals (Zn, Fe, Cu) in the root cell wall, therefore reducing uptake and translocation to the shoots (Liu et al, 2013;Kopittke et al, 2017;Nozawa et al, 2018;Bosnic et al, 2019). In shoots, Si accumulation further mitigates metal toxicity by sequestration of minerals (Cu, Zn) and heavy metals (As, Cd) into the vacuoles of leaf cells (Keller et al, 2015;Kopittke et al, 2017;Nozawa et al, 2018).…”

“…On the other hand, for mineral or heavy metal toxicity, Si forms a complex with some heavy metals (Cd) or minerals (Zn, Fe, Cu) in the root cell wall, therefore reducing uptake and translocation to the shoots (Liu et al, 2013;Kopittke et al, 2017;Nozawa et al, 2018;Bosnic et al, 2019). In shoots, Si accumulation further mitigates metal toxicity by sequestration of minerals (Cu, Zn) and heavy metals (As, Cd) into the vacuoles of leaf cells (Keller et al, 2015;Kopittke et al, 2017;Nozawa et al, 2018). Overall, Si has the potential of enabling the plant to react adaptively against nutritional stress and promotes tolerance.…”

Unraveling the Mechanisms of Zn Efficiency in Crop Plants: From Lab to Field Applications

“…Similarly, ferredoxins involved in electron transport from the photo-reduced photosystem-I to NADP + reductases. The chlorophyll a-b binding protein 6A (ZmAffx.1219.1.S1_s_at) acts as a component of the light-harvesting complex (LHC) which is involved in the formation of a full-size NAD(P)H dehydrogenase-PSI super complex (NDH-PSI) that triggers cyclic and chlororespiratory electron transport in chloroplast thylakoids, especially under stress conditions [70]. Therefore, the Fe and Zn deficiency-induced overexpression of APOCYTOCHROME F, CHLOROPHYLL A-B BINDING PROTEIN 6A and FERREDOXIN 3 affects photosynthesis by disrupting the cellular redox poise and electron transfer mechanisms [69,71].…”