Agropolymer containing a carbohydrate and silica matrix from plants

#The present invention generally relates to the field of agricultural biotechnology. In particular, this invention pertains to a novel agropolymer and a method of manufacturing the agropolymer from plant parts such as seed coats, hulls, husks or seed covers of plants including agricultural crops. The agropolymers disclosed herein have extensive industrial application and may be useful in purifying water of aqueous solutions polluted or contaminated by metal or ions.

#Several biologically originating metal sequestration agents are known in the art. Examples of such agents include tannins, humic acid, whole cell biomass, chitin and chitin derivatives, metallothioneins, microbial polysaccharides, melannins, polyphenolic biopigments, bacterial cell wall polymers, microbially produced chelating agents (siderophores), and the like. However, the above materials may be costly and often are not available in sufficient quantities. Specifically, the substances known in the art have not been successfully produced on large scale for industrial use because of the low availability of raw materials and the high production costs.

#Furthermore, the substances known in the art may be less effective than the agropolymer disclosed herein. Thus, the present invention is aimed at producing agropolymers, which are effective in sequestering metals and ions from polluted or contaminated aqueous solutions and which derive from inexpensive, widely available plant materials, preferably raw agricultural materials, such as seed coats, hulls, husks, or seed covers of agricultural crops.

#The present invention may be better understood with reference to the attached drawings described below:

#FIGS. 1(A), (B), and (C): IR spectra of a raw rice husk sample.

#FIGS. 2(A), (B), and (C): IR spectra of a rice husk sample treated with alkaline hydrogen peroxide.

#The present invention is directed to providing a novel agropolymer having metal binding sites, which are incorporated into a matrix of the agropolymer either by alkali treatment, hydrogen peroxide treatment, or a combination alkaline hydrogen peroxide treatment. More particularly, this invention relates to the use of the agropolymer disclosed herein in the purification of water or aqueous solutions polluted by metals or ions, including the purification of industrial ground water and drinking water. Such a purification method is possible because of the capability of the agropolymer to sequester metals and/or ions found in polluted or contaminated water or aqueous solutions.

#The matrix of the agropolymer is obtained from any plant parts such as seed coats, seed covers, hulls and husks. The metal binding reactive sites (which facilitate organometallic bonds) are created by reacting the agropolymers with metals as observed under infrared (IR) spectroscopy.

#The agropolymers of the present invention may be produced from plant materials (such as seed coats, seed covers, hulls, or husks) of agricultural crops, and the crops appropriate for use herein may include Oryza sativa, Panicum miliaceum, Setaria italica, Cajanus cajan, Vigna mungo, Vigna radiata, Triticum sp., Ricinus communis, Helianthus annus, Gossypium sp. Arachis sp. These crops are used in certain preferred embodiments because they better facilitate the sequestration of metals and ions.