巯基改性粘土矿物制备及固汞性能研究

发布时间：2018-01-16 03:15

  本文关键词：巯基改性粘土矿物制备及固汞性能研究　出处：《北京化工大学》2016年硕士论文　论文类型：学位论文

  更多相关文章： 土壤 粘土矿物 固化剂 汞 改性 巯基材料

【摘要】：随着经济快速发展,生活和工业中越来越多的重金属释放到环境中,造成严重的环境污染。汞是一种液态的重金属,因其具有较强的毒性、挥发性及生物富集性,受到国内外很多研究人员的关注。现阶段,污水重金属汞处理技术已很成熟,但土壤中汞污染问题的解决还面临很大挑战。固化剂的固化作用能将重金属汞的活动态转化为稳定态,降低汞的迁移性,固能降低对环境和人类的危害。因此研究一种高效、稳定的固化剂尤为重要。本实验以四种天然粘土矿物为基材：海泡石、硅藻土、膨润土和膨胀蛭石,先对其进行高温焙烧,再用一定浓度硫酸酸化,最后负载3-巯丙基三甲氧基硅烷,即得到改性复合材料。通过红外表征及实际固化性能测试结果表明,膨润土、海泡石的固化效果最好。对两基材进行单因素变量条件改性,实际固化性能结果显示,膨润土的固化效果较为明显,最优的单因素改性条件：改性温度225-330℃；改性硫酸用量：10g粘土矿物需200 mL浓度1.5-2.4 mol·L-1,改性巯基材料用量：10g粘土矿物需12-18 mL 3-巯丙基三甲氧基硅烷。本研究在单因素改性实验基础上通过设计正交实验得出改性的最优条件组合：温度260℃,硫酸浓度1.8 mol·L-1；硅烷偶联剂16 mL和粘土10g,三因素中巯基材料浓度对固汞效果影响水平最大,该条件下固化率达67.7%。探究固化率环境的耐受程度：汞污染土壤固化率受有机质含量影响不大,有机质含量增加在一定程度上促进了活动态汞的固化；在一定温度和pH值范围内有较好的稳定效果,且固化时间越长,稳定性越好。
[Abstract]:With the rapid development of economy, more and more heavy metals are released into the environment in life and industry, causing serious environmental pollution. Mercury is a liquid heavy metal, because of its strong toxicity. Volatility and bioconcentration are concerned by many researchers at home and abroad. At present, the treatment technology of heavy metal mercury in sewage is very mature. However, the problem of mercury pollution in soil is still facing a great challenge. The solidification of curing agent can transform the active state of heavy metal mercury into a stable state and reduce the migration of mercury. It is very important to study a kind of high efficient and stable curing agent. In this experiment, four kinds of natural clay minerals were used as substrates: sepiolite, diatomite, bentonite and expanded vermiculite. It was calcined at high temperature, then acidified with a certain concentration of sulfuric acid, and finally loaded with 3-mercapto trimethoxysilane, the modified composite was obtained. The curing effect of bentonite and sepiolite is the best. The optimum conditions of single factor modification were as follows: modification temperature 225-330 鈩，

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