- 學位論文
以固定化細胞程序進行TFT-LCD有機廢水處理
Entrapped Mixed Microbial Cell (EMMC) Process for Treatment of TFT-LCD Wastewater
摘要
本研究是利用固定化細胞(Entrapped mixed microbial cell, EMMC)技術進行薄膜電晶體液晶顯示器 (Thin film transistor-liquid crystal display, TFT-LCD)有機廢水的處理。取三醋酸纖維作為擔體，利用包埋的方法固定活性污泥中的微生物，並將包埋微生物的EMMC顆粒以填充的方式置入反應器中，使生物反應器內達到每單位公升173.5g的生物質量，以增加廢水處理之效率。 在程序的操作上我們使用填充床(Packed bed)式的生物反應器(Bio-reactor)，探討EMMC顆粒於TFT-LCD廢水處理時進料廢水的化學需氧量(Chemical oxygen demand, COD)濃度、反應物的水力滯留時間和間歇通氣時間此三項實驗變因對放流水品質之影響。一般而言微生物的活性會依外在的環境之因素而有不同的表現，如水力滯留時間越久廢水處理的程度越好。當進料之COD越高時微生物的負荷越重。另外通氣時間越長越有利於好氧微生物的活動，反之則有利於厭氧微生物對於氨氮轉換。因此本研究將三項實驗變因範圍分別設定於6~12hr的水力滯留時間，500~1000 mg/L 的COD濃度和0~4小時的間歇通氣時間。藉由均勻設計（Uniform Design）的實驗方式安排9組實驗點，依據所得到之設計條件作為實驗的操作條件進行廢水處理，來探討這3項變因對TFT-LCD廢水處理的效果。結果顯示以進料的COD值為635 mg/L ，12小時的水力滯留時間和間歇供氣為2.5小時通氣與1.5小時不通氣為操作條件時，可以得到最佳之結果：COD的去除率為94%，放流水可降至36 mg/L ；總氮的去除率為83%，放流水可降至15 mg/L ； 的放流水可降至9.6 mg/L 。上述條件下TFT-LCD廢水處理之結果已達到國家放流水之標準。
並列摘要
Entrapped mixed microbial cell (EMMC) technique was used to remove organic matter from the wastewater from Thin Film Transistor-Liquid Crystal Display (TFT-LCD) plant. Cellulose triacetate was selected as the material for the matrix entrapment of microbial cell from the activated sludge from the treatment of TFT-LCD waste water. The bioreactor was filled with EMMC pellets. By this way, a 173.5 g /L biomass based on bulk volume was loaded in the reactor. In the built packed-bed bioreactor, we evaluated the effects of the operating variables on the performance of the TFT-LCD waste water: COD concentration of the inlet wastewater, hydraulic retention time of the feed, and the aeration and non-aeration time ratio in a four-hour operating time interval. In general, the activities of the entrapped mix microbial cells will be affected by the environmental conditions. A longer hydraulic retention time usually results in a better extent of treatment of the waste water. A feed with higher COD concentration usually increases the load of the entrapped mix microbial cells in transforming the organic components into the resulting species. In the mean time, increasing the aeration time will be beneficial for the activity of aerobic cells, while reducing the aeration time will be beneficial for the activity of anaerobic cells. Therefore, in this experimental work we examined the effects of these three operating variables. The operating region for hydraulic retention time was ranged from 6 to 12 hr; the adjusted COD concentration of the feed was ranged from 500 to1000 mg/L ; the aeration and non-aeration time ratio was varied in a four-hour operating time interval. A night-level of these three operating variables was chosen based on the uniform design method to locate the 9 experiments to evaluate the outputs of the built EMMC bioreactor. We found the optimized operating condition was located at the feed COD concentration 635 mg/L , HRT 12h and the aeration time 2.5 h and non-aeration time1.5 h over very a four-hour time interval. At this optimized condition, COD removal efficiency was 94% and the COD was reduced to 36 mg/L . Total nitrogen removal efficiency was 83% and the outlet concentration of total nitrogen was reduced to 15 mg/L . In the mean time, ammonia nitrogen was reduced to 9.6 mg/L in the treated water. The qualities of the treated TFT-LCD wastewater at this operating condition achieved the national standard of the treated waste water.