Research On The Treatment Of Heavy Metals Acidic Wastewater By Chitoson-loaded On Zeolite Resins

Chitin and chitosan are renewable and abundant natural macromoleculecompounds, which are nontoxic, biocompatible and biodegradarable, and haveantiseptic, bactericidal functions. These biopolymer are easily modified and canbeused as macromolecular sorbent. Chitosan is a liner polyamine whose aminogroups are readily available for chemical reaction and salt formation with acids and issignificant for the research of wastewater sorbent based on chitosan its derivatives.T'his work is studied the preparation of chitosan-loaded on zeolite resins and theiradsorption properties.It is unreported that the sorbent of chitosan bade on zeolite can be used onCu²⁺,Fe²⁺, so that it is necessary to have exploring research in this field.In this paper, three parts of work were included:1. A novel sorbent material based on chitosan loaded on zeolite (shortening:ZEO-CTS) was synthesized. The appearance and structure of ZEO-CTS werecharacterized by SEM andXRD. XRD spectra show that the adsorption of zeolite forchitosan attributes to obvious chemical process. SEM indicates chitosan is loaded onzeolite equably. The special surface area of ZEO-CTS is6.57m²/g.The experimental data for adsorption reveal ZEO-CTS has the best adsorptioncapacity for Cu²⁺, Fe²⁺ at pH4, 3—5, and the saturation capacities are0.3249mmol/g, 0.7213mmol/g respectively. At the same time, the equilibriumisotherms for adsorption are well correlated to the Langrnuir equation and theFreundlich equation; the saturation capacity of ZEO-CTS has a little decrease afterregeneration times, so that ZEO-CTS is hopeful in waste water treatment.2. The adsorption of sorbrnt adding porogenic agents in the course of sythesisand the effect of the adsorption on zeta potential have been studied. The results ofexperiments showed that the optimun conditions of adsorption by sorbent were:ethanol in sorbent was 10% and has good sorption properties to Cu²⁺, the saturationcapacity for Cu²⁺ of sorbent has also greater than that of ZEO-CTS and uptakesreached 0.3940mmol/g, and the adsorption capacities is greatest on pH=2. 3. Chitosan reacts with vanillin aldehyde by Schiffs base reaction in water, apolymer product Z-CTS can be prepared. The molecular structure is as deemed baseon the analysis result by infrared spectrum. The results of experiments showed thatthe modified sorbent has higher adsorption capacities and enhancing the resistance ofsorbent against acid than unmodified one and has good kineticproperties -uneasilyrunning off and being regenerated easily.