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農作物秸稈熱解制備高效吸附材料及其對含氮廢水的處理

時間:2019-06-22 21:57來源:畢業論文
生物質炭對銨的吸附等溫線更符合Freundlich 模型,說明生物質炭對NH+ 4的吸附以不均一的多分子層吸附為主。[結論]:農作物秸稈熱解制備的生物炭可作為高效吸附劑處理含氮廢水

摘要:[目的]:用農作物秸稈制備生物質炭吸附劑,為含氮廢水處理提供新方法。[方法]:選擇稻草秸稈、玉米秸稈和花生秸稈,分別在300℃、400℃和500℃下經馬弗爐厭氧熱解制備生物質炭;以活性炭和沸石為對照材料,用一次平衡法研究銨的吸附等溫線,采用改進的醋酸銨取代法測定吸附材料的CEC;從氮肥廠獲取含銨態氮的廢水,用生物質炭進行凈化處理,驗證生物質炭對銨態氮的去除效果。[結果]:生物質炭具有較大的CEC,且隨著炭化溫度的升高,生物質炭的CEC均有所降低。此外,生物質炭對銨的吸附等溫線更符合Freundlich 模型,說明生物質炭對NH+ 4的吸附以不均一的多分子層吸附為主。[結論]:農作物秸稈熱解制備的生物炭可作為高效吸附劑處理含氮廢水。36572
畢業論文關鍵詞:生物質炭;銨態氮;吸附;CEC
Efficient adsorption materials prepared by pyrolysis of crop straw and their use in treatment of wastewater containing nitrogen
Abstract: [Objectives]: The biochar adsorbents were prepared from crop straws, which provided a new method for treatment of swastewater containing nitrogen. [Methods]: Rice straw, maize straw and peanut straw were pyrolyzed under oxygen-limited conditions by muffle furnace at 300℃,400℃ and 500 ℃. An activated carbon and a zeolite were also used for comparison. The adsorption isotherms for NH+ 4 were investigated with a batch method, and the CECs of these adsorption materials were measured by a modified ammonium acetate compulsory displacement method. The wastewater containing ammonium nitrogen was obtained from nitrogen fertilizer plant, and biochars were used for purification treatment of the wastewater in order to verify the removal efficiency of ammonium nitrogen by the biochars. [Results]: Biochars had considerable CECs, and their CECs decreased with the increase of pyrolysis temperature, the CEC of the biochars decreased. In addition, the adsorption isotherms of ammonium on these biochars were fitted the Freundlich model well, which showed that the adsorption of NH+ 4 by the biochars from aqueous solution was dominated by heterogeneous multi-molecular layer adsorption. [Conclusions]: The biochars prepared by pyrolysis of crop straws can be used as an efficient adsorbents for ammonium in wastewater containing nitrogen. 源¥自%六^^維*論-文+網=www.aftnzs.live
Key Words:biochar;ammonium nitrogen;adsorption;CEC
目  錄

摘要1
關鍵詞1
Abstract1
Key words1
引言1
1材料與方法2
1.1 生物質炭的制備2
1.2 溶液的配制2
1.3 吸附實驗2
1.4 生物質炭CEC的測定2
1.5 生物質炭改性處理2
1.6 實際含氮廢水的處理3
2 結果與討論3
2.1 不同熱解溫度下農作物秸稈生物質炭的產率3
2.2 生物質炭、活性炭及沸石的CEC3
2.3 沸石、活性炭及生物質炭對銨的吸附量4
2.4 吸附等溫線擬合9
2.5 不同地區稻草秸稈生物質炭對銨的吸附量 10
2.6 改性前后生物質炭的Zeta電位 11
2.7生物質炭對實際含氮廢水的處理 12
3 討論13
3.1 結論 13
3.2 問題與展望 13
致謝13
參考文獻14
農作物秸稈熱解制備高效吸附材料及其對含氮廢水的處理
引言:污水中氮的形態有四種,即有機氮、氨氮、亞硝酸鹽氮和硝酸鹽氮。其中,氨氮主要以游離氨態氮(NH3-N)和銨鹽態氮(NH+ 4-N)的形式存在。水體中氨氮的來源有兩個方面,一個是有機氮化合物的分解,另一個是工業含氮廢水的排放。當氨氮大量進入水環境后,會消耗水體中的溶解氧,引起部分水生動物的死亡,導致水質迅速惡化;另外,它還會引起水體富營養化,促進藻類等浮游生物的繁殖,產生水華、赤潮等現象[1, 2]。因此,去除含氮廢水中的氨氮是水環境治理過程中亟待解決的問題。目前,廢水中氨氮常用的去除方法有化學沉淀法[3, 4]、離子交換法[4]、生物法[5]和吸附法[6]等。其中,吸附法的工藝較為簡單,且具有高效、吸附劑可再生等優點,因而被廣泛關注,而決定污水中氨氮去除效果的關鍵在于吸附劑的選擇。 農作物秸稈熱解制備高效吸附材料及其對含氮廢水的處理:http://www.aftnzs.live/shengwu/20190622/35074.html
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