| Abstract: | 本研究從大量的廢棄物中，選擇常見的海綿廢棄物，作為生物碳及活性碳的原物料，希望可以藉由碳化或碳化加活化的過程使廢棄物得以成為一可再利用物質，可應用於廢水處理進行吸附作用之多孔結構材料。由於生物碳或活性碳之吸附效果主要取決於選擇之原物料本身的元素組成，因此本研究選擇三種不同組成成分的海綿，一為木漿纖維海綿(CS)，二為美耐皿海綿(MR)，最後為生物海綿(Bio)。
本研究主要分為兩個方向進行，第一部分以三種等溫吸附模式Langmuir、Freundlich、BET及三種吸附動力Pseudo-first-order kinetic、Pseudo-second-order kinetic、Intraparticle diffusion來評估吸附模式，並通過FESEM、TEM、BET、FTIR及EA進行生物碳及活性碳的物化分析。第二部分則是選擇最佳材料CS-TS作為殼聚醣和TiO2複合光觸媒的載體此外選擇二氧化矽(SBA-15)及奈米碳管(CNT)做為比較的支持物，以微波輔助多元醇法進行製備。為了研究光催化因子在實驗中的效果，選擇田口法直交表有效設計光催化製備的參數，選擇四個因子三個Level分別為Support (SBA-15、CNT、CS)、Ti Loading (10、30、50wt.%)、Chitason Loading (10、20、30wt.%)、Power (600、800、1000W)。最後使用田口法通過ANOVA分析和S/N比來評估光催化因子影響結果。實驗結果顯示，三種不同海綿的活性碳具有比生物碳更高的比表面積，三種活性碳比表面積大小依序為CS-TS(415.6 m2/g) > Bio-TS(87.7 m2/g) > MR-TS(0.59 m2/g)，並且電子顯微鏡TEM也證實了三個樣品的多孔性結構，測試結果也顯示CS-TS具有最大吸附量，吸附量大小依序為CS-TS（733 mg / g）> MR-TS（242 mg / g）> Bio-TS（134 mg / g）。等溫吸附分析結果表示，三種活性碳CS-TS、MR-TS、Bio-TS皆符合BET多層吸附。由動力模式探討則可以發現三種活性碳CS-TS、MR-TS、Bio-TS皆符合Pseudo-second-order kinetic，該結果表示化學吸附為反應的限速步驟。
複合光觸媒的研究結果顯示，CS-TS + 30% Ti + 10%chi、1000W製備條件下的光觸媒有最好的降解效果，在紫外光的照射下對於亞甲基藍溶液的去除率達98.34%。通過SAS統計軟體進行ANOVA分析三種載體九種不同光觸媒的測試結果，結果表示只有Support具有顯著差異(p<0.05)，但是其他因子也會影響光催化活性，透過S/N ratio結果表明，四種因子對降解污染物的影響程度依序 Support (43.11) > Chitosan Loading (wt.%) (13.88) > Ti Loading (wt.%) (13.55) > Power (W) (11.59)。本研究中最佳製備參數為Support (CS-TS) + Ti Loading (50wt.%) + Chitason Loading (20wt.%) + Power (800W)。
In the study, a sponge waste was chosen as precursor for reuse energy production by the carbonation or carbonation with activation from a large amount of various wastes. A biochar or activated carbon was produced with the characteristics of good adsorption capacity and the porous structure for wastewater treatment. There are different compositions of various sponges, and the pollutant adsorption capacity of reuse samples would be affected. Therefore, three kinds of sponge, cellulose sponge (CS), melamine sponge (MR), and biological sponge (Bio), were chosen and studied in this experiment.
Firstly, three sponges were reproduced by carbonation and carbonation with activation, respectively. Methylene Blue was used as a pollutant to study the adsorption capacity over the samples, and three models (Langmuir, Freundlich, and BET) were studied for isothermal adsorption according to the MB adsorption tests. Adsorption Kinetic was evaluated by the Pseudo-first order kinetic, Pseudo-second order kinetic, and Intraparticle diffusion, respectively. The biochar and activated carbon were characterized by FESEM, TEM, BET surface area analyzer, FTIR, and EA. Then, the optimal adsorption material-CS activated carbon (CS-AC) was chosen as a support for the composite photocatalyst preparation with the chitosan and TiO2. Moreover, SBA-15 and carbon nanotube (CNT) were chosen as supports for the comparison. The microwave assistant polyol process was employed for the photocatalyst preparation. In order to study the effect of photocatalytic factors in this experiment, the Taguchi method-L9 OA table was chosen to efficiently design the parameters in the photocatalyst preparation. Four factors with three levels were chosen as preparation parameters: Support (SBA-15, CNT, CS-AC), Ti loading (10, 30, 50 wt.%), Chitosan loading (10, 20, 30 wt.%), and Power (600, 800, 1000 W). Final, the Taguchi method was employed to evaluate the photocatalytic factors by analysis of variance (ANOVA) and S/N ratio.
The experiment results show that the activated carbons derived from the three sponges owned the higher specific surface area (SBET) than that of prepared biochar, and the SBET of three activated carbon is in the order CS-AC (415.6 m2/g) > Bio-AC (87.7 m2/g) > MR-AC (0.59 m2/g). TEM images also confirm the porous structures of three samples. The test results presence that CS-AC owned the optimal adsorption capacity, and the capacity is in the order CS-AC (733 mg/g) > MR-AC (242 mg/g) > Bio-AC (134 mg/g). The isothermal adsorption analysis show that the BET model fitted the MB adsorption results over CS-AC, Bio-AC, and MR-AC. Pseudo-second order kinetic was fitted the results of three kinds of AC, and this result suggests that the chemical adsorption was the rate-determining step on MB removal.
For the composited photocatalyst study, CS-AC+30%Ti+10% Chitosan +1000W was the optimal parameters for the high activity photocatalyst preparation on the MB adsorption, and the removal efficiency arrived at 98.34% under UV light irradiation. Nine test results of three supports supported photocatalysts were analyzed by the ANOVA method via the soft SAS. Among the four factors, the study of P value shows that there was only one factor-Support affected the removal efficiency obviously while its P value was below 0.05. However, MB removal efficiency might be affected by other factors. S/N ratio results suggest that the level effects of the four factors were in the order Support (43.11) > Chitosan loading (13.88) >Ti loading (13.55) > Power (11.59). In this study, the optimum preparation parameter for the support was CS-AC; that for the Ti loading was 50 wt.%; that for the chitosan loading was 20 wt.% ;and that for the power of microwave was 800 W. |
