Biomaterial Database

Kinetic parameters and mechanisms of the batch biosorption of Cr(VI) and Cr(III) onto Leersia hexandra Swartz biomass. 2009

Jianping Li, and Qingyu Lin, and Xuehong Zhang, and Yan Yan

Department of Material and Chemical Engineering, Guilin University of Technology, Guilin 541004, China. likianping@263.net

The hyperaccumulative plant species Leersia hexandra Swartz, particularly, has been considered for its detoxification mechanism for phytoremediation of chromium-contaminated water environments. This study investigates the role of the adsorption mechanism of the L. hexandra Sw. biomass on the removal of chromium ions Cr(VI) and Cr(III) from an aqueous solution. The interaction between chromium ions and the L. hexandra Sw. biomass was characterized by using infrared spectroscopy. The results indicate that the binding process of the chromium ions involves the active participation of ligands present in the biomass, such as acylamide, carbonyl, amino, carboxyl, and hydroxyl groups, to immobilize the chromium ions. Equilibrium biosorption experiments were carried out to investigate the effects of pH values and contact time. Adsorption isotherms were modeled with the Langmuir and Freundlich equations and isotherm constants were calculated. Kinetic experiments showed the rapid process of biosorption and the pseudo-second-order model was successfully applied to predict the rate constant of biosorption. This study firstly discovered the kinetics equilibrium modelling of L. hexandra Sw. biomass on biosorption Cr(VI) and Cr(III).

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D002857	Chromium	A trace element that plays a role in glucose metabolism. It has the atomic symbol Cr, atomic number 24, and atomic weight 52. According to the Fourth Annual Report on Carcinogens (NTP85-002,1985), chromium and some of its compounds have been listed as known carcinogens.
D006109	Poaceae	A large family of narrow-leaved herbaceous grasses of the order Cyperales, subclass Commelinidae, class Liliopsida (monocotyledons). Food grains (EDIBLE GRAIN) come from members of this family. RHINITIS, ALLERGIC, SEASONAL can be induced by POLLEN of many of the grasses.	Alopecurus,Arundo,Gramineae,Grasses,Imperata,Grass,Imperata cylindrica
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000327	Adsorption	The adhesion of gases, liquids, or dissolved solids onto a surface. It includes adsorptive phenomena of bacteria and viruses onto surfaces as well. ABSORPTION into the substance may follow but not necessarily.	Adsorptions
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
D013055	Spectrophotometry, Infrared	Spectrophotometry in the infrared region, usually for the purpose of chemical analysis through measurement of absorption spectra associated with rotational and vibrational energy levels of molecules. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	IR Spectra,Infrared Spectrophotometry,IR Spectras,Spectra, IR
D013499	Surface Properties	Characteristics or attributes of the outer boundaries of objects, including molecules.	Properties, Surface,Property, Surface,Surface Property
D018533	Biomass	Total mass of all the organisms of a given type and/or in a given area. (From Concise Dictionary of Biology, 1990) It includes the yield of vegetative mass produced from any given crop.	Biomasses