| Summary: | 碩士 === 逢甲大學 === 環境工程與科學學系 === 103 === The study explores the feasibility of utilizing bio-film treatment system to manage wastewater from science-based industrial park. During the study period, administration bureau included ammonia into its regulation. As a result, the discussion will be separated into two periods: before and after the regulation of ammonia(Stage1and Stage2). At the beginning of the study, using wastewater of stage 1 to domesticate bio-film until COD concentration stabilized. When COD concentration stabilized, beginning our study by periodic and sampling analysis.
In Stage1, pH dropped and consequently, inhibited the formation of biofilm. In Stage2, the pH of the wastewater increased and benefited the growth of the biofilm. The wastewater maintained dissolved oxygen at 7mg/L and affected the overall elimination rate of nitrogen. Rate of elimination of organic substances found lower of biological and chemical oxygen demand ratio. It’s mean wastewater belong recalcitrant organics. Both of this reason is that TMAH or DMSO lead to underestimate of COD in wastewater, so join total organic carbon(TOC) and dissolved organic carbon(DOC) evaluation together. Both of TOC and DOC effect of treatment are 75%, so bio-film treatment system has a good effect of treatment at organic. The main nitrogen source in the wastewater remains to be ammonia and nitrate regardless of stage1 or stage2. Ammonia removal efficiency of 14% and 69% in Stage1 and Stage2, respectively. Differences of ammonia removal related to the influence of ammonia concentration. The rate of nitrate elimination is not significant. It is hypothesized that SND can not formed at high dissolved oxygen.
In terms of phosphorus, the main source remains to be phosphate regardless of stage1 or stage2. The reason for the rate of total phosphorus elimination being 12% and 6% in Stage1 and Stage2, respectively, is possibly due to no growing of phosphorus accumulating organisms(PAOs) and high level of dissolved oxygen.
Additionally, carbon: nitrogen: phosphorus ratio is close to 100：5：1 in stage2. If use carbon: nitrogen ratio can find higher C/N ratio beneficial to treat total nitrogen. If use compose of organism ratio find nutrient of stage1 become organism, in stage2, most of nutrient become secondary product.
The result of the possibility to recycle effluent indicates that the temperature is under the cooling water standard. However, pH value of the effluent only meets the minimum requirement for water of lavatory, boiler, and manufacturing process in stage2. Conductivity only meets boiler water standard. TOC, ammonia, and nitrate all fail to meet the manufacturing process water standard. However, the ammonia concentration in effluent is low enough to be used as cooling water standard. SDI assessment turns out to be 14.7 and 13.1, which are both much higher than reference value of 5 and is considered serious scaling. As a result, it revealed that solid and colloid concentration are high in the wastewater.
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