研究聚乙烯醇-海藻酸钠(PVA-SA)固定将金针菇(Flammulina velutipes)、毛木耳(Auricularia polytricha)、杏鲍菇(Pleurotus eryngii)和平菇(Pleurotus ostreatus)加工废弃物小球对Zn^2+的吸附效果、影响因素及吸附机理。结果显示,120 min后Zn^2+的吸附过程基本完成,吸附最适pH值为6.0,固定金针菇、毛木耳、杏鲍菇、平菇加工废弃物吸附小球的最大吸附率分别为金针菇72.34%、毛木耳69.22%、杏鲍菇39.70%和平菇55.25%;采用伪一级动力学模型、伪二级动力学模型、Elovich和颗粒内扩散模型拟合4种吸附剂对Zn2+的吸附过程,伪二级动力学模型更适合用于描述整个吸附过程,化学吸附为限速步骤;固定金针菇、毛木耳、杏鲍菇和平菇加工废弃物吸附小球的等温吸附过程与Langmuir等温模型拟合度高,相关系数R-2分别为0.988 2、0.988 9、0.962 4和0.991 3,单层吸附占主要地位;扫描电镜(SEM)分析显示,固定金针菇加工废弃物吸附小球吸附Zn^2+后,由物理吸附和离子交换吸附形成的沉淀和结晶体使小球细胞壁增厚并有颗粒物出现;SEM显示细胞破损,吸附作用致细胞壁结构中大分子重排和细胞表面电荷变化导致细胞膨胀破坏。固定金针菇加工废弃物对青衣江流域水样低浓度Zn^2+的去除率为66.67%,食用菌加工废弃物对低浓度重金属的生物去除有一定的实际应用价值。
To develop biosorption function of edible mushroom residue for Zn^2+ 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 Zn^2+ was tested by using such instrument as inductively coupled plasma optical emission spectrometry(ICP-OES).The effects of initial pH value and contact time on the Zn^2+ removing behavior were investigated.The results showed that the process for adsorption of Zn^2+ 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 Zn^2+ by four adsorbents,it was proved that the pseudo-second-order kinetics is the best suitable model for characterizing the biosorption process of Zn^2+,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 R-2 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 Zn^2+ biosroption process.Zn^2+ 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 Zn^2+.