Application of biological attached-growth technique with grave-based medium to the treatment of domestic sewage

• Main Authors: Chang, Huang-Yu, 張皇煜
• Other Authors: Fan, Chih-Hao
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/51402872554784844799

碩士 === 明志科技大學 === 生化工程研究所 === 98 === The purpose of this study is to investigate the removal efficiency of a biofilm system treating artificial domestic wastewater under aerobic condition. The reactor used is an acrylic rectangular reacting tank with length in 216 cm, width in 14 cm and height in 21.5 cm. Using golf balls as the contact media, the biofilm system was acclimated with artificial wastewater containing biological oxygen demands, ammonia, phosphorus and other trace elements prior to the treatment experiments at the influent chemical oxygen concentrations of 50, 100 and 150 mg/L. The results showed that the artificial wastewater was treated with the biofilm system with excellent contaminant removing efficiency. The analytical and statistical (two-way ANOVA) results indicated the BOD, TOC and PO4¯ have the best removal rates within 2 hours of detention time. The average removal rates for BOD, TOC and PO4¯ were 95.71%, 96.2% and 100% respectively. The removal rates did not have any noticeable increase with an increase in detention time to 3 hours. The chemical oxygen demand (COD) removal rate increased as the detention time increased, and the average removal rate ranged from 55.59% to 96.71%. For NH3-N, the best removal rate was 98.93% when detention time was 1 hours. The removal rate increased almost to 100% as the detention time increased to 2 hours. However, the production of NO2¯-N and NO3¯-N was not observed during the aerobic treatment process. The phenomenon shows NH3-N was removed by microorganism assimilation. The nitrification may possibly be inhibited due to the significant decrease in pH by the generation of small molecule acids. The analytical result by SEM revealed that the bacteria in the biofilm system were bacillus at the front and middle sections of the reacting channel. The secondary predominant might be the fungi and cocci, and they are mostly observed toward the end of the reacting channel. Through the phylogenetic analysis, the biomass in the system was identified as Enterobacter sp. FC1, Enterobacter sp. FC2, Enterobacter sp. FC3, Enterobacter sp. FC4, Enterobacter sp. FC5 and Enterobacter sp. FC6 with most likelihool, whch belonged to the intestinal bacteria.