Biosorption Function of Zinc(Zn2+) in Water by Four Kinds of Immobilized Edible Mushroom Residues

LI Xia; ZHANG Dan; SHEN Fei; QING Hui; YANG Yang

doi:10.3969/j.issn.1003-6504.2017.02.020

Abstract：To develop biosorption function of edible mushroom residue for Zn2+ removal from water,polyvinyl alcohol-Naalginate (PVA-SA) was used to immobilise Flammulina velutipes,Auricularia polytricha,Pleurotus eryngii and Pleurotus ostreatus residues for making adsorbents respectively.The concentration of Zn2+ was tested by using such insmument as inductively coupled plasma optical emission spectrometry (ICP-OES).The effects of initial pH value and contact time on the Zn2+ removing behavior were investigated.The results showed that the process for adsorption of Zn2+ can be basically finished in 120 min with suitable pH value 6.0.The maximum biosorption ratio of immobilized F.velutipes,A.polytricha,P.eryngii and P.ostreatus residue were 72.34％,69.22％,39.70％ and 55.25％,respectively.We compared the pseudo-first-order kinetics,the pseudo-second-order kinetics,Elovich and intraparticle diffusion kinetics model to present the biosorption of Zn2+ by four adsorbents,it was proved that the pseudo-second-order kinetics is the best suitable model for characterizing the biosorption process of Zn2+,chemisorption were the rate-limiting step of adsorption process.Langmuir isotherm model fitted well with the adsorption process of F.velutipes,A.polytricha,P.eryngii and P.ostreatus residues with the correlation value R2 of 0.988 2,0.988 9,0..962 4 and 0.991 3,respectively,indicating the monolayer adsorption was dominate.Scanning electron microscopy (SEM) of F.velutipes exhibited broken cell and thickened cell wall,indicating that the molecular rearrangement and cells swell play an important role in Zn2+ biosroption process.Zn2+ in the water could be efficiently removed by F.velutipes residue with removal ratio of 66.67％,which was efficient in the adsorption of low concentration Zn2+.