The characteristic analysis and adsorbing efficiency of formaldehyde by self-made zeolite glass filter

• Main Authors: Li-ying Shu, 徐麗瀅
• Other Authors: Chu-chin Hsieh
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/97910358308993788953

碩士 === 國立雲林科技大學 === 環境與安全工程系碩士班 === 95 === Most people spend as much as 90 % of their time indoors and the studies of human exposure to air pollutants indicate that indoor air levels of many pollutants may be 2-5 times higher than outdoor levels. So indoor air quality （IAQ）has a significant influence on human health. Most of people use method of adsorption to remove volatile organic compounds（VOCs）in indoor. The common absorbent such as activated carbon can adsorb stink and VOCS but it can be adsorbed is limited and easy to influence by aqueous vapor to cause it’s adsorption capacity is bad. Therefore the study self-made zeolite glass filter to remove formaldehyde in indoor and hope promote IAQ. Before self-made zeolite glass filter, the study will produce four kinds of mix proportion zeolites and conduct adsorption and desorption experiments for formaldehyde. And result compare with commercial zeolites. First adsorption capacity of commercial zeolites is 54 mg/g and second adsorption capacity is 5 mg/g. The regenerate capacity of commercial zeolites is bad. First adsorption capacity of self-made zeolite （35 % Y zeolite＋65 % SiO2）is 84 mg/g and second adsorption capacity is 78 mg/g. Self-made zeolite characteristic were analyzes by EDS, BET, XRD analysis. As a result is silicon - aluminum ratio（SAR）of self-made zeolite is 6. Langmuir isotherm is the best description to self-made zeolite adsorb formaldehyde. To find the best operating conditions for zeolite adsorb formaldehyde, the adsorption processes need to be modeled. The accuracies of the predictions were assessed by comparing them with experimental breakthrough curves. Result is that the difference between the two is very little so the formula accuracies is better. The main research is developing the zeolite into the zeolite glass filter and discussing with making conditions and factor for zeolite glass filter. The research use hydrothermal synthesis for 30, 50 and 90 min to produce zeolite glass filters. Self-made zeolite glass filters are characterized by XRD and SEM. Result of XRD is different hydrothermal synthesis conditions cause zeolite crystallization difference. Self-made zeolite glass filter which is hydrothermal synthesis for 50 min produce zeolite crystallization is the best. Result of SEM can confirm this research is to succeed in developing the zeolite into the zeolite glass filter. And then take zeolite glass filters of three hydrothermal synthesis conditions conduct batch adsorption experiments for 250 ppm formaldehyde. Result of remove efficiency for formaldehyde is hydrothermal synthesis for 50 min＞90 min＞30 min. So different hydrothermal synthesis conditions influence intensity of zeolite crystallization and adsorption capacity. The research use adsorption kinetic model to describe self-made zeolite glass adsorption behavior for formaldehyde. Result is that pseudo-secondorder model is better than pseudo-first-order model. In addition, it can also be by pseudo-secondorder model to estimate remove efficiency and adsorption capacity of self-made zeolite glass filter. Hope it can offer basis to make adsorption materials apply indoor environment in the future.