| 载镁天然沸石复合材料对污水中氮磷的同步回收 |
| 摘要点击 2208 全文点击 857 投稿时间：2017-04-10 修订日期：2017-06-22 |
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| 中文关键词 天然沸石 氧化镁 鸟粪石 氮磷回收 钙离子 |
| 英文关键词 natural zeolite magnesium oxide struvite nutrient recovery calcium ion |
| 作者 | 单位 | E-mail | | 成雪君 | 同济大学环境科学与工程学院, 污染控制与资源化研究国家重点实验室, 上海 200092 | 1945612857@qq.com | | 王学江 | 同济大学环境科学与工程学院, 污染控制与资源化研究国家重点实验室, 上海 200092 | wangxj@tongji.edu.cn | | 王浩 | 同济大学环境科学与工程学院, 污染控制与资源化研究国家重点实验室, 上海 200092 | | | 张志昊 | 同济大学环境科学与工程学院, 污染控制与资源化研究国家重点实验室, 上海 200092 | | | 赵建夫 | 同济大学环境科学与工程学院, 污染控制与资源化研究国家重点实验室, 上海 200092 | |
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| 中文摘要 |
| 采用载镁天然沸石为沉淀剂，以鸟粪石的形式回收模拟污水中的营养物质，考察了投加量、溶液pH、反应时间和共存Ca2+对回收过程的影响，并利用FTIR、XRD、BET和SEM等手段对回收沉淀产物进行了化学组分和表面形貌分析，以揭示其回收机制.结果表明当材料投加量为0.4 g·L-1，溶液初始pH为7，反应时间为2 h时，载镁天然沸石对溶液中磷酸盐和氨氮的回收性能最佳，最大吸附量分别高达119.2 mg·g-1和48.5 mg·g-1.载镁天然沸石对溶液中磷酸盐和氨氮的回收过程均符合拟二级动力学模型（R2>0.99）.载镁天然沸石对污水中营养物质的回收机制有鸟粪石化学沉淀、物理吸附、离子交换和静电吸附等，其中以鸟粪石沉淀法为主.共存Ca2+会干扰载镁沸石对溶液中氮磷的同步回收，导致回收的沉淀组分除鸟粪石晶体外，还会存在部分磷酸钙等副产物. |
| 英文摘要 |
| Using MgO modified natural zeolite (NZ-MgO) as a settling agent, nutrients from synthetic contaminated waters were recovered as a struvite precipitate. Different reaction conditions, including reagent dosage, solution pH, contact time, and coexisting calcium ions, were investigated. In order to understand the recovery mechanism, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were utilized to analyze the chemical composition of recovered precipitates, and Brunauer-Emmett-Teller (BET) and field-emission scanning electron microscopy(SEM) were used to detect the surface area and morphology. The results showed that NZ-MgO exhibited a strong removal capacity, with a maximum removal capacity of 119.2 mg·g-1 for phosphate and 48.5 mg·g-1 for ammonium nitrogen at a dosage of 0.4 g·L-1, initial pH of 7, and contact time of 2 h. The kinetics of both phosphate and ammonia nitrogen followed the pseudo-second-order kinetic model (R2>0.99), which revealed that the chemical process occurred at the solid-liquid interface. The mechanisms for nutrient recovery by NZ-MgO were struvite crystallization, physical adsorption, ion exchange, and electrostatic attraction, with struvite crystallization being the main mechanism. Existing calcium ions would hinder the simultaneous recovery of nutrients from wastewater, resulting in a struvite decline and calcium phosphate increase. |
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