【摘要】：近幾十年來,隨著工業(yè)的迅速發(fā)展使得用水需求量不斷增長。環(huán)境污染問題也致使我國淡水資源日益短缺,而同時大量含有氮磷元素的生活污水和工業(yè)廢水進入了水體,出水中氨氮濃度達不到排放標準,嚴重影響了人們的健康水平和制約了經(jīng)濟的發(fā)展。沸石作為一種廉價的吸附劑,對氨氮具有較高的選擇吸附性,天然斜發(fā)沸石的吸附能力有限,但通過改性處理能大大提高其對氨氮的去除能力。針對二級出水中氨氮濃度達不到一級B標排放標準(限值15mg/L)的廢水中氨氮的去除,本文以天然沸石為原材料,篩分后得到粒徑為60～80目,預處理后通過酸、堿、鹽、高溫煅燒及其兩種聯(lián)合處理等多種改性方法,選出了最佳改性沸石來進行去除模擬二級出水中氨氮的實驗研究。本課題的主要研究內(nèi)容包括改性實驗、靜態(tài)實驗、動態(tài)實驗和再生實驗。得出以下結(jié)論：改性實驗對斜發(fā)沸石進行了多種方式處理,包括：高溫處理、氫氧化鈉溶液處理、鹽酸處理、氯化鈉溶液處理、高溫+氯化鈉溶液處理、氯化鈉溶液+高溫處理,得到斜發(fā)沸石經(jīng)60g/L NaCl溶液+400℃高溫處理后去除模擬氨氮廢水效果最佳。靜態(tài)實驗探討了模擬氨氮廢水濃度為15mg/L,60g/LNaCl鹽溶液+400℃高溫處理得到的最佳改性沸石條件下,沸石投加量、反應時間、溫度、pH和起始氨氮濃度對氨氮去除效果的影響。在投加量為1.5g,反應時間為40min,溫度為30℃,pH=8條件下,氨氮去除率達91.4%以上。吸附等溫式模型既符合Langmuir方程式也符合Freundlich方程式,且對Freundlich方程擬合效果更好,相關(guān)系數(shù)R2大于0.98,且吸附反應為自發(fā)吸熱的。吸附動力學模型對Langmuir一級動力學擬合方程擬合效果最好,其相關(guān)系數(shù)R2大于0.99。動態(tài)實驗探討了濾料層厚度、濾速對氨氮飽和穿透曲線的影響,結(jié)果表明濾料層厚度越高對應穿透時間越長,過濾速度越大對應的穿透時間越短。實驗條件下,當濾料層厚度為80cm時,達到吸附穿透點時間為570min；當濾速為5mL/min時,達到吸附穿透點時間為690min。當濾柱內(nèi)徑為4cm時,改性沸石濾料層厚度為80cm,吸附柱濾速控制為5mL/min時,改性沸石濾柱去除模擬氨氮廢水中氨氮的效果更好。說明用改性沸石濾柱處理氨氮廢水是可行的、有效的。再生實驗內(nèi)容探究了NaCl再生液濃度、再生時間和再生次數(shù)對飽和改性沸石再生率的影響,結(jié)果表明NaCl再生溶液濃度為0.6mol/L,再生時間為2.5h時,飽和改性沸石的再生率達到84.5%以上。且在相同條件下,前八次再生處理均可使飽和改性沸石的吸附能力基本恢復在78%～85%,出水氨氮濃度均小于5mg/L,達到實驗要求氨氮出水濃度,說明該種實驗沸石再生能力較強,可以重復利用。
[Abstract]:In recent decades, with the rapid development of industry, the demand for water has been increasing. The problem of environmental pollution also causes the shortage of fresh water resources in our country. At the same time, a large number of domestic sewage and industrial wastewater containing nitrogen and phosphorus elements have entered into the water body, and the concentration of ammonia nitrogen in the effluent water is not up to the discharge standard. Has seriously affected the people's health level and restricted the economic development. As a cheap adsorbent, zeolite has high selective adsorption for ammonia nitrogen, and natural clinoptilolite has limited adsorption ability, but the removal capacity of ammonia nitrogen can be greatly improved by modification. Aimed at the removal of ammonia nitrogen in wastewater with ammonia nitrogen concentration below the first B standard (15mg/L), the natural zeolite was used as raw material and the particle size was 6080 mesh after sieving. After pretreatment, acid, alkali and salt were used. The optimum modified zeolite was selected to remove ammonia nitrogen from simulated secondary effluent by high temperature calcination and two kinds of combined treatment. The main research contents include modification experiment, static experiment, dynamic experiment and regeneration experiment. The conclusions are as follows: the modification experiment has carried on many ways to treat clinoptilolite, including: high temperature treatment, sodium hydroxide solution treatment, hydrochloric acid treatment, sodium chloride solution treatment, high temperature sodium chloride solution treatment, After high temperature treatment with sodium chloride solution, clinoptilolite was treated with 60g/L NaCl solution at 400 鈩，

本文編號：2265147