【作者】 郭军；

【导师】 代群威； 张自全；

【作者基本信息】 西南科技大学 ， 环境工程（专业学位）， 2022， 硕士

【摘要】 铜冶炼烟尘含有大量的重金属元素,既是潜在资源又有着巨大的环境风险。本文在铜冶炼烟尘基本理化性质基础上,分别研究了氧化亚铁硫杆菌和硫酸盐还原菌对铜冶炼烟尘中重金属的作用特性,同时也初步探究了在助剂协同下微生物对冶炼烟尘中重金属迁移转化行为的影响。探究铜冶炼烟尘的矿物相及元素组成、重金属含量、赋存状态、生物有效性和化学浸出行为,确定其中的典型重金属。结果表明,铜冶炼烟尘主要为小球颗粒状粉尘,含有的主要金属元素为Pb、Bi、Zn、As、Cd、Sn、Cu和Fe,质量比依次降低;其矿物相主要为Pb SO₄,Pb S,Cd S,Zn O。其中Cd、Cu、Zn主要赋存形态为可交换态,属于迁移性和生物可利用度较大的金属;As、Bi、Sn、Fe主要赋存形态为残余态,Pb主要赋存形态为硫化物结合态和残余态,属于迁移性和生物可利用度较小的金属。铜冶炼烟尘在酸性环境下各金属元素的浸出率明显大于中性和碱性环境,其中在p H=2.0条件下重金属元素Cd、Cu、Zn属于易浸出重金属,其他金属元素属于较难浸出重金属。通过氧化亚铁硫杆菌对冶炼烟尘中重金属作用特性分析发现,在1%铜冶炼烟尘矿浆浓度下,氧化亚铁硫杆菌能够稳定生长,液相p H由1.8上升到了2.1后又下降到1.7;Eh由320m V上升到630m V。氧化亚铁硫杆菌对As的溶出有较大贡献,对Pb和Bi的溶出具有抑制作用,对其他的金属元素溶出影响较小,作用后冶炼烟尘主要为硫酸铅和黄钾铁矾。在3种助剂协同下,对较易浸出金属Cd和Zn的液相浓度无较大影响;钙华协同氧化亚铁硫杆菌对As、Cu、Pb和Bi倾向于吸附作用;膨润土协同氧化亚铁硫杆菌对As、Cu、Pb、Bi表现为吸附作用,Cu的液相浓度变化幅度较小;沸石协同氧化亚铁硫杆菌能够促进As释放,对Pb、Cu和Bi的影响较小,对其他金属的溶出有一定抑制作用。通过对硫酸盐还原菌作用冶炼烟尘中重金属特性分析,在0.1%的矿浆浓度中硫酸盐还原菌能够生存良好,液相p H由6.6上升到7.5,Eh先下降到-210m V后上升到50m V。硫酸盐还原菌能够使各重金属液相浓度在前5d维持在较低水平,6～7d则出现了液相浓度升高,对Zn、Cd、Pb和Cu的吸附矿化尤其明显,作用后冶炼烟尘主要为硫酸铅、硫化锌、硫化铅、硫化镉。3种助剂能够一定程度上可以减轻硫酸盐还原菌的生存压力,致使Cu、Bi、Cd、Zn浓度最终维持在低水平,钙华、膨润土、沸石协同硫酸盐还原菌可以强化SRB对As和Pb的作用效果。更多还原

【Abstract】 Copper smelting fume contains a large amount of heavy metal elements,which is both a potential resource and a huge environmental risk.Based on the basic physical and chemical properties of copper smelting fume,this paper studies the effect of acidihiobacillus ferrooxidans and sulfate-reducing bacteria on heavy metals in copper smelting fume.At the same time,the effect of microorganisms on the migration and transformation behavior of heavy metals in smelting fume was also preliminarily explored under the synergy of additives.Taking copper smelting fume as the research object,the heavy metals in smelting fume were extracted by means of digestion and Tessier five-step extraction method,what’s more,the mineral phase,element composition,heavy metal content,occurrence state,bioavailability and chemical leaching of copper smelting fume were explored.So it can identify typical heavy metals in them.The results show that the copper smelting fume is mainly spherical granular dust.The main metal elements are Pb,Bi,Zn,As,Cd,Sn,Cu and Fe,which mass ratio decreases in turn.It’s mineral phases are mainly Pb SO₄,Pb S,Cd S,Zn O.Among them,Cd,Cu,and Zn are mainly in the exchangeable state,which are metals with high mobility and bioavailability.As,Bi,Sn,Fe are mainly in the residual state and Pb is mainly in the sulfide state along with the bound state,which belong to the metal with less mobility and bioavailability.The leaching rate of each metal element in acid environment is significantly higher than that in the neutral or alkaline environment.The Cd,Cu and Zn are easily leached under the condition of p H=2.0,on the contrary,other metal elements are relatively leaching difficultly.Through the analysis of the action characteristics of acidihiobacillus ferrooxidans on heavy metals in smelting fume,it was found that At.f could grow stably at the 1%copper smelting fume.In the liquid phase,the p H increased from 1.8 to 2.1 and then decreased to 1.7.The Eh rise from 320m V to 630m V.The At.f has a great contribution to the dissolution of As,an inhibitory effect for Pb and Bi and little effect for other heavy metal elements.For the phases,it concentrates in lead sulfate and jarosite.Under the synergy of the three additives,the liquid concentration of Cd and Zn,which are more easily leached out,has no great effect;travertine cooperates with At.f to adsorb As,Cu,Pb and Bi;bentonite cooperates with At.f showed adsorption of As,Cu,Pb and Bi,and the liquid concentration of Cu changed little;zeolite cooperates with At.f to promote the release of As,which has little effect on Pb,Cu and Bi.The dissolution of other metals has a certain inhibitory effect.Through the analysis of the action characteristics caused by sulfate reducing bacteria for heavy metals in the smelting fume.The SRB can resist less than 0.1%copper smelting fume.The p H increases from 6.6 to 7.5.Moreover,the Eh first drops to-210 m V and then increased to 50 m V.The concentration of each heavy metals is at a low level in the first 5 days and increases slightly in 6～7 days with the action of SRB.There is the adsorption and mineralization of Zn,Cd,Pb and Cu in particular.For the phases,it mainly includes lead sulfate,zinc sulfide,lead sulfide and cadmium sulfide.The three additives can reduce the survival pressure of SRB to a certain extent,which leads concentrations of Cu,Bi,Cd,and Zn are finally maintained at a low level.The effect on As and Pb could be enhanced by the synergistic action of travertine,bentonite and zeolite with SRB,respectively.更多还原