碩士 / 國立雲林科技大學 / 環境與安全衛生工程系 / 105 / Arsenic is a highly toxic metalloid. Arsenic water pollution mainly from industrial pollution, such as arsenic ore mining, smelting and arsenic compounds as raw materials for glass, pigments, semiconductors and other industries, arsenic wastewater treatment will cause a huge threat to the environment, the scope of impact can be expanded to groundwater, fresh water, sea water and soil, inadvertent intake will cause bioaccumulation, causing skin, cardiovascular, respiratory and nervous system lesions, great harm to human health.
Many water treatment technologies can effectively treat arsenic-containing wastewater, including chemical coagulation, membrane filtration and adsorption technology. However, the chemical coagulation method will produce a large number of harmful waste sludge, increase the processing cost; membrane filtration technology operation and maintenance costs are high, difficult to accept. At present, the adsorption technology is simple and low operating cost of water treatment technology, and the process of sludge-free output, the adsorbent can be recycled and other characteristics of the adsorption technology should be in the water treatment with economic feasibility.
Magnetic nanoparticles (MNPs), with nano-size, high surface area and volume ratio, excellent magnetic properties, can effectively adsorb the target pollutants in water, in recent years used in water treatment of emerging adsorbent materials. However, MNPs also exist on the use of restrictions, such as acid and alkali buffer capacity is low, exposure to water oxidation and other shortcomings. In this study, polyvinyl alcohol (PVA) and sodium alginate (SA) were added to immobilize MNPs, reduce the potential risk of MNPs, increase the applicability of magnetic materials in water treatment technology, and use PVA / SA-MNPs treat arsenic-containing wastewater.
The results show that PVA/SA-MNPs are acid-resistant magnetic materials, 100 g/L PVA/SA-MNPs, placed in pH 1-6 solution, stirring at 120 rpm for 30 min, the measured iron concentration in water are controlled at 16 mg/L, much lower than that released from MNPs (18-4045 mg / L). In the adsorption experiment, PVA/SA-MNPs in the acidic case, by the MNPs surface electrical properties, in the pH 3-6, the arsenic has a high removal rate of 76% -82%. The average unit adsorption of PVA/SA-MNPs was about 382 ± 27 μg / g at pH 5. Regeneration method is washed with DI water and then soaked in acid, can be recycled 3 times, PVA / SA-MNPs on the arsenic adsorption capacity can be maintained at 300 μg / g or more.
The advantage of adding PVA / SA and immobilized MNP is that PVA / SA-MNPs can naturally settle without the use of an external magnetic field for collection and simple operation. In an acidic solution, only a small amount of iron is dissolved, friendly to the environment, Removal of arsenic has a certain effect.
| Identifer | oai:union.ndltd.org:TW/105YUNT0633030 |
| Date | January 2017 |
| Creators | WU, CHENG-YONG, 吳丞墉 |
| Contributors | WAN, TERNG-JOU, 萬騰州 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 76 |
Page generated in 0.0105 seconds