【摘要】：廢水中的鈾離子具有放射性,若進(jìn)入人體會(huì)造成內(nèi)輻射,嚴(yán)重危害人體健康。尤其是兒童飲用含鉛超標(biāo)的飲用水雖然沒(méi)有放射性,但會(huì)對(duì)兒童的健康和智力發(fā)育產(chǎn)生嚴(yán)重影響,因此,尋找一種處理含鈾、鉛廢水的高效方法迫在眉睫。而目前研究最多的含鈾、鉛等重金屬的處理方法是吸附法。本研究以二氧化硅材料為載體對(duì)其進(jìn)行有機(jī)改性,進(jìn)而探討其對(duì)鈾、鉛離子的吸附性能及機(jī)理。通過(guò)功能化修飾將對(duì)鈾具有優(yōu)異選擇性的偕胺肟基和剛性有機(jī)基團(tuán)乙烷基接入二氧化硅材料,合成偕胺肟基乙烷橋鍵介孔二氧化硅材料(AO-PMOs)。通過(guò)靜態(tài)吸附實(shí)驗(yàn),研究了p H值、初始溶液濃度、吸附劑投加量等因素對(duì)AO-PMOs吸附鈾、鉛的影響,并對(duì)吸附過(guò)程進(jìn)行了吸附等溫線模型、吸附動(dòng)力學(xué)模型擬合分析,采用紅外光譜、掃描電鏡對(duì)材料吸附前后的基團(tuán)、形貌進(jìn)行表征,分析探討其吸附機(jī)理。實(shí)驗(yàn)結(jié)果表明:(1)AO-PMOs對(duì)水溶液中鈾的吸附適宜p H值為5-7,其中以p H=5為最佳。吸附過(guò)程的前10min能夠迅速吸附,30min之后吸附速率逐漸減慢即達(dá)到吸附平衡。吸附平衡時(shí)能使99%以上的鈾離子被吸附去除。對(duì)鈾離子的吸附量受其初始溶液的影響比較小,不同濃度的含鈾溶液基本都可以用其進(jìn)行吸附。(2)利用等溫吸附模型對(duì)實(shí)驗(yàn)數(shù)據(jù)進(jìn)行擬合分析,結(jié)果表明Langmuir模型可以用于描述AO-PMOs對(duì)鈾的吸附過(guò)程,用Langmuir模型擬合30℃、40℃下的實(shí)驗(yàn)數(shù)據(jù),經(jīng)過(guò)分析計(jì)算可得到這兩種溫度下的吸附容量分別可以達(dá)到151.98mg/g和153.84mg/g,此結(jié)果表明隨著溫度的升高其吸附量也在增加,即其對(duì)鈾的吸附過(guò)程為吸熱反應(yīng),且以單層吸附為主。而動(dòng)力學(xué)擬合結(jié)果顯示AOPMOs吸附鈾過(guò)程遵循準(zhǔn)二級(jí)動(dòng)力學(xué)模型,其對(duì)鈾離子的吸附主要是胺肟基團(tuán)與鈾的配位作用。(3)AO-PMOs吸附鉛在p H值為6.0時(shí)的效果最好,在60min后吸附基本處于平穩(wěn)狀態(tài),平衡時(shí)對(duì)鉛的去除率最高到80%以上。材料對(duì)鉛的吸附遵循Freundlich等溫線模型,說(shuō)明以多層吸附為主。可以用準(zhǔn)二級(jí)動(dòng)力學(xué)模型描述材料吸附鉛的過(guò)程。通過(guò)材料吸附鉛前后紅外光譜圖分析可知吸附鉛起主要作用的是胺肟基團(tuán),主要以化學(xué)吸附為主。
[Abstract]:The uranium ion in the wastewater is radioactive, and it will cause internal radiation if it enters the human body, which seriously endangers human health. Especially, children drinking water containing lead has no radioactivity, but it will have serious influence on children's health and intellectual development. Therefore, it is urgent to find an efficient way to treat waste water containing uranium and lead. At present, adsorption is the most widely studied method for treating heavy metals such as uranium and lead. In this study, silicon dioxide was used as the carrier to study the adsorption properties and mechanism of uranium and lead ions. The amidoxime group and rigid organic group ethyl group with excellent selectivity for uranium were added to the silica material by functionalization to synthesize the amidoxime ethane bridged mesoporous silica material (AO-PMOs). Through static adsorption experiments, the effects of pH value, initial solution concentration and adsorbent dosage on the adsorption of uranium and lead by AO-PMOs were studied. The adsorption isotherm model and the adsorption kinetics model were used to fit the adsorption process. The group and morphology before and after adsorption were characterized by IR and SEM, and the adsorption mechanism was analyzed. The experimental results show that: (1) the suitable pH value of AO-PMOs for the adsorption of uranium in aqueous solution is 5-7, among which pH 5 is the best. The adsorption rate of pre- 10min could decrease gradually after 30 minutes of rapid adsorption, and the adsorption equilibrium could be reached. More than 99% of uranium ions can be removed by adsorption equilibrium. The adsorption amount of uranium ion is less affected by its initial solution, and it can be used to adsorb uranium ions in different concentrations. (2) the experimental data are fitted and analyzed by isothermal adsorption model. The results show that the Langmuir model can be used to describe the adsorption process of uranium by AO-PMOs, and the experimental data at 30 鈩，

本文編號(hào)：2218881