- 學位論文
輕骨材應用於平板固定化生物程序去除碳氮
Use of Lightweight Aggregate in Plate Immobilized Biological Process for Removing Carbon and Nitrogen from Wastewater
摘要
固定化生物技術發展單槽式處理程序整合硝化與脫硝於單一槽體進行反應，具有高碳、氮去除效率、佔地面積小及污泥產量少等優勢，可提升或改善傳統生物脫氮程序之處理效率。目前使用的載體中主要分為天然載體及合成載體兩類，天然載體容易為生物所分解之缺點，而合成載體於製備時須使用大量化學溶劑，一來具有毒性，二來對於環境造成不良影響。 為符合永續發展之理念，本研究採用環境友善之固化材料及經高溫燒結之輕質性骨材進行固定生物包埋，其中添加輕質性骨材為提升載體透水率。載體型式以平板固定生物污泥板進行兩階段實驗，分別為載體材料基本特性及操作參數試驗，於基本特性又細分為平板製作條件試驗及溶出試驗，目的為建立初步製作方法及載體於水中之穩定性；操作參數試驗目的為以不同操作條件(水力停留時間及碳氮比)對於COD、硝化及總氮去除率之影響，討論改變固定化生物外型下是否影響其去除效率。 載體基本特性分析結果顯示其固定化平板污泥受外型影響，於壓力3000 kg/cm2與持壓30秒為較佳的製作條件。溶出試驗中，載體在第一天及浸泡24小時之後，其COD、導電度與pH皆呈現最高，其COD為250 mg/L；導電度為8.5 mS/cm；pH則為12.61，隨著浸泡天數增加COD、導電度及pH皆有逐漸減少溶出之效果。 操作參數顯示，碳氮比對於硝化及總氮去除率影響較大，碳氮比由C/N=4調整至C/N=12時，硝化效率由58%提升至63%，總氮去除率由41%提升至53%。而水力停留時間從HRT=6 hr提升至HRT=12 hr，COD去除率、硝化效率及總氮去除效率在三種水力停留時間差異不大。整體而言，若HRT=12、C/N=12，於連續曝氣模式下可獲得較佳的去除效率。
並列摘要
Immobilization of microbial cells technology combined traditional nitrification and denitrification in one single cell process which had many advantages are high organic carbon and nitrogen removal efficiency, small space occupation and less sludge produced. It also can be improved organic and nitrogen removal efficiency simultaneously from an aerobic activated sludge process. Nowadays, the matrix of immobilized microbial cell can be categorized into two groups: natural and synthetic. The most material for immobilized microbial cell are divides into two categories: Natural and Synthetic. The defect of natural material is easily decomposed by microorganism. Synthetic materials in the process of production applied complex chemicals are adverse impact on the environment. For environment sustainable development, in this study used environmental friendly and lightweight aggregates for the production of microbial cell, and the lightweight aggregates are added to hydraulic conductivity. This research is consisted of two parts: analysis of the material characteristics and operation parameters test with a microbial cell plate. Production conditions test of prepared into flat sheet of plates and dissolution test for the purpose to realize the stability of the material. The operational aspect will focus on investigating nitrification, denitrification and total nitrogen removal efficiency under different operating conditions such as carbon vs nitrogen ratio (SCOD/N) and hydraulic retention time (HRT). The microbial cell plate is formed in pressure 3000 kg/cm² and holding over 30 seconds. The dissolution test shown that the microbial cell plate elute COD over 250 mg/L, conductivity over 8.5 mS/cm and pH over 12.61 after the first day. However, the elute concentration of COD, conductivity and turbidity are found to be stable after five days of test, pH remained over 12 after 20 days of elution. The SCOD/N mode shown that is an impact of the total nitrogen removal efficiency. Nitrification removal efficiency was increased from 58% to 63% and TN removal efficiency increased from 41% to 53% when SCOD/N was adjusted from 4 to 12. In conclusion, the optimum operating conditions is SCOD/N of 12, HRT of 12 hr., which resulted in 94% SCOD removal efficiency, 65% nitrification, and 60% TN removal efficiency.