發(fā)布時(shí)間：2018-06-01 12:35

  本文選題：還原氧化石墨烯 + 天然有機(jī)物��； 參考：《哈爾濱工業(yè)大學(xué)》2016年碩士論文

【摘要】：隨著石墨烯系納米材料(graphene family nanomaterials,簡稱GFNs)的發(fā)現(xiàn)、生產(chǎn)及廣泛應(yīng)用,其進(jìn)入水環(huán)境系統(tǒng)的幾率大大增加,可能會對水環(huán)境系統(tǒng)造成不利影響。但目前關(guān)于GFNs在水環(huán)境中的遷移轉(zhuǎn)化行為及其對水環(huán)境系統(tǒng)的潛在污染的了解較少。為了進(jìn)一步明確GFNs在水環(huán)境中的遷移轉(zhuǎn)化行為及其對水生態(tài)系統(tǒng)的影響,研究以GFNs中的還原氧化石墨烯(reduced graphene oxide,簡稱r GO)為對象,首先主要利用耗散型石英晶體微天平(quartz crystal microbalance with dissipation,簡稱QCM-D)技術(shù)分析手段,分別考察了不同離子強(qiáng)度下r GO在天然有機(jī)物腐殖酸(HA)和富里酸(FA)表面的沉積特性并分析了其作用機(jī)理,并與其在有利條件PLL表面的沉積特性進(jìn)行了對比。其次以銅綠微囊藻作為受試對象,首次探究了r GO進(jìn)入水環(huán)境后對水生生物的影響;并在調(diào)查研究的基礎(chǔ)上,以聚合氯化鋁(PAC)作為混凝劑對r GO水處理過程中的混凝去除進(jìn)行了初步探索。利用QCM-D手段考察了p H為7.4、不同濃度的Na Cl和Ca Cl2電解質(zhì)溶液下r GO在HA和FA表面的沉積。表面總沉積量、初始沉積率和沉積效率的研究結(jié)果一致表明:隨著Na Cl離子強(qiáng)度的增大,r GO的沉積作用呈現(xiàn)先增加后降低,低離子強(qiáng)度下(25m M)Na+的電荷屏蔽作用導(dǎo)致沉積作用的增加,符合經(jīng)典的DLVO理論;高離子強(qiáng)度下(25m M)r GO的脫穩(wěn)聚集導(dǎo)致其沉積作用的降低。二價(jià)陽離子Ca2+對r GO沉積的影響比一價(jià)陽離子Na+大。與HA相比,r GO在FA表面的沉積作用更強(qiáng),但均比在PLL表面弱。這是由于FA表面具有相對較高含量的羧基官能團(tuán),能夠與r GO表面少量的含氧基團(tuán)發(fā)生作用。另外,HA對應(yīng)較高的|ΔD/Δf|值表明,與FA相比,r GO在HA表面形成的沉積層更松散。另外,以銅綠微囊藻作為受試對象,首次探究了r GO對水生生物的影響。研究從銅綠微囊藻密度、表面形態(tài)、及葉綠素a含量變化進(jìn)行了分析,結(jié)果表明r GO能夠通過遮光效應(yīng)和物理接觸損傷效應(yīng)抑制銅綠微囊藻的生長,對水生生態(tài)系統(tǒng)構(gòu)成潛在污染。在分析了r GO對水環(huán)境系統(tǒng)潛在污染的基礎(chǔ)上,進(jìn)一步對r GO納米顆粒從水系統(tǒng)中的去除做了初步的研究,并考察了HA對r GO顆粒混凝去除的影響,確定了兩種條件下混凝劑的最佳投加量。初步研究結(jié)果表明,沒有HA存在的條件下,聚合氯化鋁的最佳投加量僅為3 mg/L,混凝作用機(jī)制主要為吸附架橋作用;HA存在情況下,聚合氯化鋁的最佳投加量達(dá)40 mg/L,其主要混凝作用機(jī)制為電荷中和。
[Abstract]:With the discovery, production and wide application of graphene family nanomaterials (GFNs), the probability of its entry into water environment system has increased greatly, which may have a negative impact on water environment system. However, little is known about the transport and transformation behavior of GFNs in water environment and its potential pollution to water environment system. In order to further clarify the migration and transformation behavior of GFNs in water environment and its effect on water ecosystem, the reductive graphene reduced-graphene oxide (rgox) in GFNs was studied. Firstly, the deposition characteristics of r go on the surfaces of natural organic matter humic acid (HA) and fulvic acid (FA) under different ionic intensities were investigated by means of dissipative quartz crystal microbalance with dissipation, (QCM-D-) technique, and its mechanism of action was analyzed. The results are compared with the deposition characteristics on the favorable PLL surface. Secondly, using microcystis aeruginosa as the subject, the effects of r go on aquatic organisms after entering water environment were studied for the first time, and on the basis of investigation, The coagulation removal of r go water was studied with polyaluminum chloride (PAC) as coagulant. The deposition of r go on HA and FA surfaces with pH 7.4 and different concentrations of NaCl and Ca Cl2 electrolyte solutions was investigated by QCM-D. The results of total surface deposition, initial deposition rate and deposition efficiency show that with the increase of NaCl ion intensity, the deposition of rgo increases first and then decreases. The charge shielding effect of 25m M)Na at low ion intensity leads to the increase of deposition, which is in line with the classical DLVO theory, and the destability and aggregation of 25m MGo at high ionic strength results in the decrease of deposition. The effect of divalent cation Ca2 on r go deposition is greater than that of monovalent cation Na. Compared with HA, the deposition of PLL on FA surface is stronger than that on HA, but is weaker than that on PLL surface. This is due to the relatively high content of carboxyl functional groups on the surface of FA, which can interact with a small amount of oxygen-containing groups on the surface of r go. In addition, the higher value of 螖 D / 螖 F shows that the depositional layer formed on HA surface is looser than that of FA. In addition, microcystis aeruginosa was used to study the effect of RGO on aquatic organisms for the first time. The changes of density, surface morphology and chlorophyll a content of Microcystis aeruginosa were studied. The results showed that RGO could inhibit the growth of Microcystis aeruginosa by shading effect and physical contact damage effect. Potential pollution to aquatic ecosystems. Based on the analysis of the potential pollution of RGO to the water environment system, the removal of rgo nanoparticles from the water system was studied, and the effect of HA on the removal of rgo particles from the water system was investigated. The optimum dosage of coagulant was determined under two conditions. The preliminary results showed that the optimum dosage of polyaluminium chloride was only 3 mg / L without HA, and the coagulation mechanism was mainly under the condition of adsorption bridging action and the presence of HA. The optimum dosage of polyaluminium chloride is 40 mg / L, and the main coagulation mechanism is charge neutralization.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：O613.71;X52
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本文編號：1964201