本文選題：檸檬酸　切入點：微波　出處：《西華大學》2015年碩士論文

【摘要】：工業(yè)生產中會排出大量的含鉻廢水,鉻作為重金屬類的無機有毒物質對人體的危害極大。吸附法由于其良好的處理效果而被廣泛應用于處理含鉻廢水,隨著人們對于水質的要求越來越高,廢水處理領域出現(xiàn)了大量改性吸附材料的方法來提高吸附效率以達到更好地效果。檸檬酸改性活性炭的研究較為少見,與微波結合改性成為了含鉻廢水處理的新方法。本論文采用檸檬酸-微波對活性炭改性來提高其去除率,制備吸附量更大的改性活性炭,研究其制備工藝和對含鉻廢水的處理效果,具有重要的現(xiàn)實意義。本文以六價鉻溶液為研究對象,采用孔隙結構發(fā)達、比表面積大、化學穩(wěn)定性和熱穩(wěn)定性好的活性炭作為吸附材料,通過檸檬酸、微波、檸檬酸微波組合改性活性炭,分別研究了最佳的改性條件、吸附組合對吸附的影響。運用BET和SEM等研究了活性炭的微觀特性。實驗結果表明:(1)天然活性炭吸附六價鉻最佳條件:六價鉻溶液起始濃度為/20Lmg,投加量為/0.3lg,反應溫度為25℃,反應pH為4,吸附時間為12h。(2)檸檬酸改性活性炭的最佳條件為檸檬酸質量濃度為50%,改性時間為4h,改性溫度為30℃。改性活性炭的最佳吸附條件為室溫下六價鉻離子起始濃度為20mg/L,投加量為/30Lg,反應pH值為0.3,吸附時間為5h。(3)微波改性活性炭的最佳條件為C-1組合,改性時間為2min,裝填量為5g。改性活性炭的最佳吸附條件是室溫下六價鉻離子起始濃度為/20Lmg,投加量為/10Lg,反應pH值為0.3,吸附時間為2h。(4)微波-檸檬酸改性活性炭的最佳條件為微波組合C-1,輻照1min,檸檬酸濃度50%。改性活性炭的最佳吸附條件:室溫下六價鉻離子溶液初始濃度為/20Lmg,吸附時間為0.1h,投加量為/10Lg。(5)四種活性炭的吸附行為過程均符合Langmuir吸附等溫線模型,可用二級吸附動力學模型描述各種影響因素條件下的吸附過程。(6)GAC-N,GAC-W,GAC-NW對Cr(VI)的去除率分別為98.52%,86.25%,93.70%,較GAC-0原炭分別提高了11.86%,1.94%,6.72%。檸檬酸改性的活性炭表面的酸性官能團增加,比表面積下降。微波改性的活性炭比表面有所增大,但是表面酸性官能團大大下降,相反的堿性官能團有所提升。檸檬酸-微波改性活性炭的孔隙結構并沒有破壞很大,但是其比表面積卻增大很多。
[Abstract]:A large amount of chromium-containing wastewater will be discharged from industrial production, and chromium, as an inorganic toxic substance of heavy metals, will do great harm to human body. Adsorption method has been widely used in the treatment of chromium-containing wastewater because of its good treatment effect. With the increasing demand for water quality, a large number of modified adsorption materials have appeared in wastewater treatment field to improve the adsorption efficiency to achieve better results. The study of citric acid modified activated carbon is rare. In this paper, citric acid-microwave modification was used to improve the removal rate of activated carbon, and the modified activated carbon with higher adsorption capacity was prepared. It is of great practical significance to study the preparation process and the treatment effect of chromium-containing wastewater. In this paper, hexavalent chromium solution is used as the research object, the pore structure is developed, and the specific surface area is large. Activated carbon with good chemical stability and thermal stability was used as adsorption material. The optimum modification conditions were studied by combining citric acid, microwave and citric acid microwave to modify activated carbon. The effect of adsorption combination on adsorption. The microcosmic properties of activated carbon were studied by BET and SEM. The experimental results show that the optimum conditions for adsorption of hexavalent chromium from natural activated carbon are as follows: the initial concentration of hexavalent chromium solution is / / 20Lmg, the dosage is / / 0.3lg, and the reaction temperature is 25 鈩，

本文編號：1696871