本文關(guān)鍵詞： 垃圾衍生燃料 飛灰 重金屬 浸出機(jī)制　出處：《西南交通大學(xué)》2017年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：隨著垃圾焚燒技術(shù)在國(guó)內(nèi)的發(fā)展,垃圾衍生燃料(Refuse Derived Fuel,RDF)憑借燃燒充分、熱值高、燃燒產(chǎn)物污染程度低等優(yōu)勢(shì),在國(guó)內(nèi)開(kāi)始被廣泛關(guān)注。RDF燃燒后產(chǎn)生的飛灰具有潛在的資源化利用前景,但是處置不當(dāng)仍對(duì)環(huán)境存在一定的危害。目前,國(guó)內(nèi)外對(duì)RDF飛灰的理化特性做了大量的研究,但對(duì)RDF燃燒飛灰中重金屬的浸出機(jī)制研究甚少。本論文旨在研究填埋場(chǎng)堆積的RDF飛灰中重金屬的浸出機(jī)制,為RDF飛灰的資源化利用提供參考依據(jù)。重點(diǎn)進(jìn)行以下幾方面的工作:(1)本論文以不同地區(qū)填埋場(chǎng)堆積的2種陳化飛灰(堆積時(shí)間半年)及2種新鮮飛灰(堆積時(shí)間一周)為研究對(duì)象,進(jìn)行了不同pH值下的浸出實(shí)驗(yàn),實(shí)驗(yàn)結(jié)果表明,兩種RDF飛灰中,Cu、Zn、Cd、Cr及Pb的浸出行為均為陽(yáng)離子浸出模式,隨著pH值的增加浸出液中元素浸出濃度會(huì)降低;Cr的浸出行為也類(lèi)似于兩性浸出模式,浸出液中的元素浸出濃度在中性pH條件(pH約為7)時(shí)最低,而在酸性和堿性環(huán)境下增大。(2)采用地球化學(xué)模擬軟件Visual MINTEQ模擬室溫下不同pH值下重金屬浸出過(guò)程,從而通過(guò)模擬結(jié)果分析比較重金屬的浸出機(jī)制。結(jié)果表明:Cr及Cu屬于氧化還原反應(yīng)敏感型元素,Cd、Pb及Zn則屬于敏感性較低或無(wú)氧化還原敏感型元素;重金屬元素中 Cr、Cu、Cd、Pb 及 Zn 分別以 Cr(Ⅲ)、Cu(Ⅱ)、Cd(Ⅱ)、Pb(Ⅱ)及 Zn(Ⅱ)形態(tài)存在。(3)采用地球化學(xué)模擬軟件Visual MINTEQ模擬不同溫度下重金屬浸出過(guò)程,從而研究溫度是否對(duì)重金屬的浸出行為存在影響。結(jié)果表明:不同溫度下,同種重金屬在陳化飛灰與新鮮飛灰中的浸出行為表現(xiàn)一致;溫度對(duì)重金屬元素Cd、Pb和Zn的浸出影響很小,而對(duì)Cr及Cu的浸出有一定的影響,在一定pH范圍內(nèi),溫度越高Cr及Cu重金屬元素越易浸出,溫度越低越不利于Cr及Cu重金屬元素的浸出。本論文完成了對(duì)RDF燃燒飛灰中重金屬浸出機(jī)制的研究,模擬分析了不同溫度對(duì)重金屬浸出行為的影響,對(duì)RDF燃燒飛灰的資源化利用具有一定參考價(jià)值。
[Abstract]:With the development of MSW incineration technology in China, the MSW derived fuel Refuse Derived fuel (RDF) has the advantages of sufficient combustion, high calorific value and low pollution degree of combustion products. In China, the fly ash produced by the combustion of .RDF has the potential prospect of resource utilization, but the improper disposal is still harmful to the environment. The physical and chemical properties of RDF fly ash have been studied extensively at home and abroad. However, the leaching mechanism of heavy metals in RDF combustion fly ash is rare. This paper aims to study the leaching mechanism of heavy metals in RDF fly ash accumulated in landfills. To provide a reference for the utilization of RDF fly ash. Focus on the following aspects of work: 1) this paper based on different landfills to accumulate two kinds of fly ash (deposition time half a year). And two kinds of fresh fly ash (the accumulation time is one week) as the research object. Leaching experiments at different pH values have been carried out. The results show that the leaching behavior of the two kinds of RDF fly ash is cationic leaching mode. With the increase of pH value, the leaching concentration of elements will decrease. The leaching behavior of Cr is similar to that of amphoteric leaching. The leaching concentration of elements in leaching solution is the lowest when pH is about 7 under neutral pH. The geochemical simulation software Visual MINTEQ was used to simulate the leaching process of heavy metals at different pH values at room temperature. The leaching mechanism of heavy metals was analyzed and compared by the simulation results. The results showed that: cr and Cu belong to the redox sensitive elements (CD). Pb and Zn belong to less sensitive or non-oxidation-reduction sensitive elements. In the heavy metal elements, Cr (鈪，

本文編號(hào)：1456344