本文關(guān)鍵詞： 乳狀液膜 含鉈廢水 穩(wěn)定性 去除率 破乳　出處：《湘潭大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著工業(yè)化進(jìn)程加快,礦產(chǎn)資源不斷開(kāi)發(fā)利用,鉈污染造成的環(huán)境危害嚴(yán)重威脅到人類的健康,引起了社會(huì)廣泛關(guān)注。目前,湖南省環(huán)境保護(hù)廳頒布了《工業(yè)廢水鉈污染物排放標(biāo)準(zhǔn)》,其排放限值為5μg/L。最近在湖南湘江流域中卻發(fā)現(xiàn)鉈含量超標(biāo),經(jīng)調(diào)查后發(fā)現(xiàn)部分鉈污染物來(lái)源于湖南某鋼鐵公司的燒結(jié)煙氣脫硫廢水。傳統(tǒng)方法一般難以對(duì)較低濃度含鉈廢水進(jìn)行深度處理,而乳狀液膜法處理較低濃度的含鉈廢水具有較好的效果。本文中乳狀液膜以航空煤油作為有機(jī)溶劑,2-乙基己基膦酸2-乙基己基酯(P507)作為載體,聚異丁烯丁二酰亞胺(T154)作為表面活性劑,聚異丁烯(PIB)作為添加劑,硫酸作為內(nèi)相溶液制成。由于乳狀液膜的穩(wěn)定性會(huì)直接影響到金屬離子分離效果,所以首先對(duì)乳狀液膜的穩(wěn)定性進(jìn)行了研究,分別考察了表面活性劑種類與濃度、載體濃度和內(nèi)相濃度等因素對(duì)其穩(wěn)定性的影響。研究表明,T154較于Span 80能更好的維持體系的穩(wěn)定;在各影響因素中表面活性劑濃度和水乳比對(duì)乳狀液膜的穩(wěn)定性影響較大,破裂率在6%以上,因此要適當(dāng)增大表面活性劑濃度并減小水乳比使體系達(dá)到穩(wěn)定狀態(tài)。在乳狀液膜穩(wěn)定性實(shí)驗(yàn)的基礎(chǔ)之上,進(jìn)一步研究了該乳狀液膜體系對(duì)含鉈廢液的處理效果。在最優(yōu)條件下,即載體濃度為2%、表面活性劑濃度為5%、內(nèi)相硫酸濃度為0.5 mol/L、攪拌速度為350 rpm、水乳比為500:40、油內(nèi)比為3:1,反應(yīng)15分鐘后,經(jīng)電感耦合等離子體質(zhì)譜儀檢測(cè),處理后廢水中的鉈濃度低于5μg/L,鉈離子的去除率為99.76%,達(dá)到了湖南省鉈污染物排放的地方標(biāo)準(zhǔn)。隨后考察了廢水中主要的鈣、鎂共存離子對(duì)乳狀液膜體系提取鉈離子的影響。結(jié)果表明,當(dāng)外水相由于體系內(nèi)的離子交換快速轉(zhuǎn)變?yōu)樗嵝原h(huán)境時(shí),有利于該乳狀液膜體系從含有較多鈣、鎂共存離子的廢水中提取鉈。反應(yīng)后的乳液需要破乳進(jìn)行回收復(fù)用,故本文對(duì)破乳條件也進(jìn)行了研究。分別采用超聲、離心、加熱和破乳劑等方法進(jìn)行破乳。研究表明單一方法并不能使體系有效破乳,而在加熱-破乳劑聯(lián)合破乳法中:溫度為70℃、氧氧化鈉作為破乳劑基本可以使體系完全破乳,破乳后的油相經(jīng)重復(fù)利用對(duì)鉈離子的去除率依然能夠達(dá)到90%以上。最后本文進(jìn)行了乳狀液膜的膜內(nèi)研究,解釋了鉈離子發(fā)生遷移的途徑。綜上所訴,乳狀液膜作為一種高效分離的液膜技術(shù),較于傳統(tǒng)方法具有傳質(zhì)速率快、傳質(zhì)面積大和選擇性好等優(yōu)點(diǎn),且乳液破乳后油相能夠回收復(fù)用,在處理鋼鐵冶金燒結(jié)煙氣脫硫含鉈廢液上有著良好的應(yīng)用前景。
[Abstract]:With the acceleration of industrialization and the continuous exploitation and utilization of mineral resources, the environmental hazards caused by thallium pollution have seriously threatened the health of human beings and caused widespread social concern. The Environmental Protection Department of Hunan Province promulgated the "Standard for the discharge of Thallium pollutants from Industrial Wastewater", the emission limit of which is 5 渭 g / L. Recently, it was found that the content of thallium exceeded the standard in the Xiangjiang River Basin in Hunan Province. After investigation, it was found that some of the thallium pollutants originated from the flue gas desulphurization wastewater from a certain iron and steel company in Hunan Province, and it was generally difficult to treat the wastewater with lower concentration of thallium by the traditional methods. In this paper, aviation kerosene was used as the organic solvent, 2-ethylhexyl phosphonate 2-ethylhexyl phosphonate (P507) was used as the carrier. Polyisobutene succinimide (T154) as surfactant, polyisobutene (PIBB) as additive and sulfuric acid as internal phase solution. The stability of emulsion liquid membrane will directly affect the separation effect of metal ions. Therefore, the stability of emulsion liquid membrane was studied, and the effects of surfactant type and concentration, carrier concentration and inner phase concentration on the stability of emulsion liquid membrane were investigated. The results showed that T154 could maintain the stability of the system better than Span 80. Among the influencing factors, the concentration of surfactant and the ratio of water to milk have great influence on the stability of emulsion liquid membrane, and the rupture rate is more than 6%. Therefore, it is necessary to increase the concentration of surfactant properly and reduce the water / milk ratio to make the system stable. On the basis of the stability experiment of emulsion liquid membrane, the treatment effect of the emulsion liquid membrane system on thallium waste liquid is further studied. That is, the carrier concentration is 2: 5, the surfactant concentration is 5, the internal phase sulfuric acid concentration is 0.5 mol / L, the stirring speed is 350 rpm, the water / milk ratio is 500: 40, and the oil / oil ratio is 3: 1. After 15 minutes of reaction, the reaction is detected by inductively coupled plasma mass spectrometer. The concentration of thallium in the treated wastewater is less than 5 渭 g / L, and the removal rate of thallium ion is 99.76, which is up to the local standard of thallium pollutant discharge in Hunan Province. The effect of mg coexisting ions on the extraction of thallium ion from emulsion liquid membrane system was studied. The results showed that the external water phase changed rapidly to acidic environment due to ion exchange in the emulsion liquid membrane system, which was favorable for the emulsion liquid membrane system to contain more calcium. Thallium is extracted from waste water containing magnesium ions. The emulsion after reaction needs to be reclaimed and reused by demulsification, so the conditions of demulsification are also studied in this paper. The results of demulsification by heating and demulsifying agent show that the single method can not effectively demulsify the system, but in the combined demulsifying method of heating and demulsifying agent: the temperature is 70 鈩，

本文編號(hào)：1520859