巰基改性粘土礦物制備及固汞性能研究
發(fā)布時間:2018-01-16 03:15
本文關鍵詞:巰基改性粘土礦物制備及固汞性能研究 出處:《北京化工大學》2016年碩士論文 論文類型:學位論文
【摘要】:隨著經(jīng)濟快速發(fā)展,生活和工業(yè)中越來越多的重金屬釋放到環(huán)境中,造成嚴重的環(huán)境污染。汞是一種液態(tài)的重金屬,因其具有較強的毒性、揮發(fā)性及生物富集性,受到國內(nèi)外很多研究人員的關注,F(xiàn)階段,污水重金屬汞處理技術已很成熟,但土壤中汞污染問題的解決還面臨很大挑戰(zhàn)。固化劑的固化作用能將重金屬汞的活動態(tài)轉化為穩(wěn)定態(tài),降低汞的遷移性,固能降低對環(huán)境和人類的危害。因此研究一種高效、穩(wěn)定的固化劑尤為重要。本實驗以四種天然粘土礦物為基材:海泡石、硅藻土、膨潤土和膨脹蛭石,先對其進行高溫焙燒,再用一定濃度硫酸酸化,最后負載3-巰丙基三甲氧基硅烷,即得到改性復合材料。通過紅外表征及實際固化性能測試結果表明,膨潤土、海泡石的固化效果最好。對兩基材進行單因素變量條件改性,實際固化性能結果顯示,膨潤土的固化效果較為明顯,最優(yōu)的單因素改性條件:改性溫度225-330℃;改性硫酸用量:10g粘土礦物需200 mL濃度1.5-2.4 mol·L-1,改性巰基材料用量:10g粘土礦物需12-18 mL 3-巰丙基三甲氧基硅烷。本研究在單因素改性實驗基礎上通過設計正交實驗得出改性的最優(yōu)條件組合:溫度260℃,硫酸濃度1.8 mol·L-1;硅烷偶聯(lián)劑16 mL和粘土10g,三因素中巰基材料濃度對固汞效果影響水平最大,該條件下固化率達67.7%。探究固化率環(huán)境的耐受程度:汞污染土壤固化率受有機質含量影響不大,有機質含量增加在一定程度上促進了活動態(tài)汞的固化;在一定溫度和pH值范圍內(nèi)有較好的穩(wěn)定效果,且固化時間越長,穩(wěn)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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