Removal of metal ions with rice husk-based sorbents

Regularities of the effects of the nature of polysaccharide materials on distribution of heavy metal ions in a heterophase biosorbent–water solution system

“…The selectivity of sorption in relation to ions of different metals is caused, first, by the properties of sorbents, which depend not only on their composition, but also on pore sizes, and, second, the capability of ions to be sorbed, which depends on their radius and the charge density, as well as the state of metals in solution, which is determined by the pH level [44]. Lead ions have the largest radius; therefore, the sorption capacity in relation to Pb(II) ions must be the highest, which was confirmed experimentally: the maximum sorption capacity determined from the Langmuir equation amounted to 4.66 mg/g for Fe(III), 6.76 mg/g for Cu(II), 7.09 mg/g for Cd(II), and 20.14 mg/g for Pb(II) [42]. However, in the majority of investigations, this rule breaks down, indicating the existence of a more complicated interrelation of sorption capacity of the sorbent in relation to the recovered ion with properties of both the sorbent and metal ion.…”

“…3 2016 NIKIFOROVA, KOZLOV removal of Fe(III), Cu(II), Cd(II), and Pb(II) ions [42], sorption isotherms related to the L-type according to the Giles system of classification [43] were obtained for the original sorbent, which was evidence of predominant interactions between sorbate and solvent, as was the isotherm for modified samples related to the H-type indicating stronger interactions between the recovered component and sorbent. The authors explained the difference in behaviors of the sorbents as being due to the increase of the specific surface and the formation of activated carbon in the composition of the sample resulting from the heat treatment.…”

Dependence of Porosity of Amorphous Silicon Dioxide Prepared from Rice Straw on Plant Variety

“…Varying extraction conditions (low ratio solid:liquid, high acidity of medium, or repeated acid treatment) can be achieved at 99.84% purity of SiO2 prepared from RS. Moreover, high purity of the product is not always important, and the presence of carbon as an impurity in silica may have a positive influence on the sorption properties of the material (Sheveleva et al 2009). It is known from literature (Abou-El- Enin et al 1999;Zemnukhova et al 2005;Wang et al 2006;Ghasemi et al 2013) that various varieties of rice differ considerably by the straw composition, which includes 40 to 69% of cellulose, 34 to 43% of hemicelluloses, and about 4 to 14% of lignin.…”

“…equilibrum (Sheveleva et al 2009). The Mn 2+ concentration in solution was estimated by the atomic absorption method, with a AA-770 spectrophotometer (Nippon, Jarrell Ash, Japan) in the acetylene-air flame.…”

Antioxidant, Antimicrobial, Cytotoxicity and HPLC Studies of Sophora mollis

“…The aqueous fractions of stem of plant showed less haemolytic effect (1.40 %). The seeds of S. mollis contain an alkaloid cytosine which resembles to nicotine and similarly toxic 43 . HPLC analysis of S. mollis: Different phenolic acids were identified from different fractions (n-butanol, ethyl acetate and chloroform) of S. mollis stem and leaves (Table-7).…”