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The aim of this work is to study the IR spectra of the different lignins precipitated from the produced liquor of different pulping conditions of bagasse and cotton stalks, also to study their antimicrobial activities towards some bacteria and fungi. ,Materials and Nethods Organisms and iMediaBacillus subtilis NRRL 543, Bacillus mywids NRRL 614: Escherichia mli NRRL 210 and Aspergillus niger NRRL 599 were obtained from Northern Regional Research Lab. Peoria, IU 61604 USA. These strains were used as test organisms for the study of antimicrobial activity of the isolated lignins using cup plate method technique [l]. These organisms were maintained on media containing [g/l]: Dextrose, 1.0; Peptone 6.0; yeast extract, 3.0; meat extract, 1.5 and agar agar, 20.0. Lignin PrecipitationBlack liquor was produced after cooking bagasse with 12% and 15% sodium hydroxide at 130°C and 160°C for one hour in presence and absence of 0.1% (based on bagasse) anthraquinone (A&). Another cooking process of bagasse was carried out by 15% NaOH in presence of 25% Na2S for one hour at 130°C. Cotton stalks was carried out with 18% NaOH a t 160°C for 2 hours in absence and presence of 0.1% anthraquinone. Lignins were separated from black liquors by acidifying with E2S0,. Infrared SpectrumIR spectra of lignin samples were carried out using BECEMAN 4250 spectrophotorneter.IR spectra of the samples were obtained as a solid usinn Kbr disc technique.

Bagasse fibers were chemically modified with the aim to prepare lignocellulosic materials that have the ability to remove heavy metal ions from waste water. Three different reactions were used for the modification: etherification using monochloroacetic acid, esterification using succinic anhydride, and oxidation using sodium periodate and sodium chlorite. Bagasse was crosslinked using epichlorohydrin before chemical modification to avoid loss of its constituents during the chemical modification or application. The structure of the prepared derivatives was proofed using Fourier transform infrared and chemical methods. The ability of the prepared bagasse cation exchangers to adsorb heavy metal ions (Cu 2ϩ , Ni 2ϩ , Cr 3ϩ , Fe 3ϩ ), on a separate basis or in a mixture of them, at different metal ion concentration was tested. Thermal stability of the different bagasse derivatives was studied using thermogravimetric analysis.

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