本文選題：針鐵礦 + 多聚磷酸鹽��； 參考：《安徽建筑大學(xué)》2016年碩士論文

【摘要】：多聚磷酸鹽是存在于自然環(huán)境中的無機磷形態(tài)的一種,排入到環(huán)境中的多聚磷酸鹽在自然界中遷移轉(zhuǎn)化,對水體富營養(yǎng)化和生物可利用性有一定的影響。針鐵礦廣泛存在于各種沉積物和土壤中,和自然界中污染性元素的遷移轉(zhuǎn)化有著密切的關(guān)系,一直被研究者用來進(jìn)行了多方面的研究。自然環(huán)境是復(fù)雜的,大部分地表環(huán)境中都能追蹤到有機質(zhì)的存在,其作為第三方添加物來研究各種污染物質(zhì)的遷移轉(zhuǎn)化機制已經(jīng)得到越來越多的重視。為深入了解自然水體中多聚磷酸鹽的遷移轉(zhuǎn)化行為,選定焦磷酸鹽和三聚磷酸鹽作為代表性的多聚磷酸鹽,以表生環(huán)境中廣泛存在的穩(wěn)定礦物-針鐵礦為研究對象,系統(tǒng)研究了其對多聚磷酸根的吸附過程,探索了不同實驗條件下(pH、電解質(zhì)、時間、溫度)針鐵礦對多聚磷酸根吸附的影響。并通過不同添加順序的腐殖酸(HA)和富理酸(FA)深入研究有機質(zhì)-針鐵礦-多聚磷酸鹽三元體系的吸附行為:(1)通過研究有機質(zhì)-針鐵礦-焦磷酸根的體系發(fā)現(xiàn),溶液pH值從6.27升至10.99時,總磷吸附量從3.00 mg/g降低至0.75 mg/g;電解質(zhì)濃度越低越有利于針鐵礦對焦磷酸根的吸附;吸附劑對焦磷酸根的吸附量在最初1 h內(nèi)增長較快,隨后漸漸達(dá)到吸附平衡;溶液溫度的升高對吸附量提高具有增強作用。用動力學(xué)和熱力學(xué)模型對吸附過程進(jìn)行擬合,發(fā)現(xiàn)準(zhǔn)二級動力學(xué)和Langmuir模型具有更好的適用性。針鐵礦吸附焦磷酸根受HA影響吸附量大小變化為:Goe+PP,HA≈Goe+PP+HA≈HA+PP,GoeGoe+HA,PP。針鐵礦吸附焦磷酸根受FA影響吸附量整體也呈促進(jìn)趨勢,吸附量大小變化為:Goe+PP,FA≈FA+PP,GoeGoe+PP+FAGoe+FA,PP。結(jié)合材料吸附焦磷酸根前后的表征,推導(dǎo)出針鐵礦對焦磷酸根的吸附機制可能是以表面絡(luò)合和物理吸附為主導(dǎo)。(2)通過研究有機質(zhì)-針鐵礦-三聚磷酸根的體系發(fā)現(xiàn),溶液pH值從8.43升至10.97時,總磷吸附量從1.98 mg/g降低至0.27mg/g;電解質(zhì)濃度越高越有利于針鐵礦對三聚磷酸根的吸附;吸附劑對三聚磷酸根的吸附量在最初1 h內(nèi)增長較快,隨后漸漸達(dá)到吸附平衡;溶液溫度的升高對吸附量提高具有增強作用。用動力學(xué)和熱力學(xué)模型對吸附過程進(jìn)行擬合,發(fā)現(xiàn)準(zhǔn)二級動力學(xué)和Freundilich模型具有更好的適用性。針鐵礦吸附三聚磷酸根受HA影響能抑制吸附量,吸附量大小變化為:Goe+TPP,HAGoe+TPP+HAHA+TPP,GoeGoe+HA,TPP。針鐵礦吸附三聚磷酸根受FA影響吸附量整體也呈促進(jìn)趨勢,可能是因為在針鐵礦表面形成了針鐵礦-FA絡(luò)合物。結(jié)合材料吸附三聚磷酸根前后的表征,推導(dǎo)出針鐵礦對三聚磷酸根的吸附機制。
[Abstract]:Polyphosphate is a kind of inorganic phosphorus that exists in the natural environment. The polyphosphate discharged into the environment has a certain influence on the eutrophication and bioavailability of water body. Goethite exists widely in various sediments and soils and is closely related to the migration and transformation of polluting elements in nature. The natural environment is complex, most of the surface environment can trace the existence of organic matter, as a third party additive to study the mechanism of transport and transformation of various pollutants has been paid more and more attention. In order to understand the migration and transformation behavior of polyphosphate in natural water, pyrophosphate and tripolyphosphate were selected as representative polyphosphate, and goethite, a stable mineral widely existed in supergene environment, was chosen as the object of study. The adsorption process of polyphosphate was systematically studied, and the effects of pH, electrolyte, time and temperature on the adsorption of polyphosphate were investigated under different experimental conditions. The adsorption behavior of organic matter goethite polyphosphate ternary system was studied by means of humic acid (HA) and fulvic acid (FAA) in different order. The results showed that the adsorption behavior of organic matter goethite / polyphosphate ternary system was studied by studying the system of organic matter goethite and pyrophosphate. When pH value increased from 6.27 to 10.99, the total phosphorus adsorption decreased from 3.00 mg/g to 0.75 mg / g. The lower the electrolyte concentration was, the better the adsorption of pyrophosphate on goethite was. Then the adsorption equilibrium was gradually reached, and the increase of solution temperature enhanced the adsorption capacity. The kinetic and thermodynamic models were used to fit the adsorption process, and it was found that the quasi-second-order kinetic model and Langmuir model were more suitable. The adsorption capacity of goethite adsorbed pyrophosphate is changed from 1: Goe PPN HA 鈮，

本文編號：2022549