以酵母為生物模板製備二氧化鋯空心微球觸媒降解多氯聯苯之研究

Study of PCB photocatalytic degradation using yeast bio-template to prepare the microspheres of zirconia

張凱翔(Jhang-Kai Siang)

指導教授 ： 林耀堅

國立屏東科技大學/工學院/環境工程與科學系所/碩士(2014年)

https://doi.org/10.6346/NPUST.2014.00131

摘要

亞甲基藍(Methylene Blue)為一種普遍的染料，能在很多物質表面產生吸附作用，常被用於光觸媒分解實驗中。多氯聯苯(PCBs)具高度穩定性、不易被生物分解且易累積於脂肪中之特性，排放至環境後將危害生物體及人體的健康。本研究以水熱法製備ZrO2並添加酵母於系統中，以不同條件製備ZrO2空心微球，並使用不同的實驗因子如光照時間、光源、批次或循環系統等來評估此光觸媒對亞甲基藍光解效率之差異，並找出最佳條件對PCBs進行降解測試。
研究結果顯示在X射線繞射分析儀(XRD)分析方面，本實驗所使用之觸媒為四方晶相(Tetragonal)。經由掃瞄式電子顯微鏡(SEM)之結果顯示酵母能增加ZrO2顆粒之比表面積及孔隙，使受光照射之面積增加，而提高光催化效果；光降解試驗中得知，以酵母/ ZrO2質量比為0.35，調節pH 5經鍛燒溫度700℃下，在自然日光照射下對亞甲基藍有最佳降解效果，經光照8小時後降解率為87%；最後以上述最佳操作條件針對絕緣油中之多氯聯苯進行降解，其去除率為43%，礦化率18%；於持久性試驗結果發現，本研究自行製備之觸媒隨使用次數增加，而降低降解率。

關鍵字

生物模板、亞甲基藍、多氯聯苯、ZrO2、 ； 降解率、光觸媒

並列摘要

Methylene blue is a common dye, and its high adsorption ability capability took place with the surface of various materials. The MB was used for photocatalytic decomposition experiments due to decolorization. Polychlorinated biphenyls (PCBs) that are highly stable man-made organic matters have been widely used in industries. However, PCBs are not easily biodegradable, which are a group of persistent organic pollutants. When PCBs released to the environment through the transportation of atmosphere, water, and soil in the various environmental media, they can be accumulated in organisms because of the contamination in the nature. In this study, ZrO2 was prepared using hydrothermal method, and the yeast was added in the system under different conditions for the preparation of ZrO2 hollow microspheres. Different experimental factors such as exposure time and light sources were conducted to evaluate this photocatalytic system. The best experimental conditions were used for the study of PCBs degradation tests.
The results of X-ray diffraction analyzer (XRD) analysis, showed that the catalyst used in this experiment was tetragonal phase (Tetragonal). Results of scanning electron microscopy (SEM) with yeast can increase the display surface area and pore side of ZrO2 particles. Therefore, the light irradiation of the area was increased, to improve the photocatalytic effect. Photodegradation experiments with yeast/ZrO2 mass ratio of 0.35 ( pH 5) (700 ℃) under natural sunlight for degradation of methylene blue has the best results. After 8 hours of light exposure, the degradation percentage was 87%. Using the same experimental factor to degrade the PCBs, the degradation percentage and mineralization were 43% and 18%, respectively. Durability experiment confirmed that self-prepared catalysts in this study may be inhibited with the increase of frequent use.

並列關鍵字

bio-template , methylene blue, zirconia, ； polychlorinated biphenyls, degradation percentage, ； photocatalysts

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