Treatment of Saline Wastewater by Usingthe Anaerobic Sludge of Seawater Aqualture Pond

• Main Authors: Kuan-Hung Lin, 林冠宏
• Other Authors: Chu-Yang Chou
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/40648142607480044323

碩士 === 國立臺灣大學 === 生物產業機電工程學研究所 === 96 === Thermal treatment was usually adopted in dealing with the hypersaline wastewater in the past. However, treatment cost was unable to reduce due to the huge amounts of energy consumption. Therefore, to produce the methane gas from the wastewater organics through the anaerobic fermentation is a possible measure to supply the fuel source of the thermal treatment, as well as to effectively reduce the treatment cost. In this study, the anaerobic filter has been used to treat the artificial saline wastewater. The seed was obtained from the sludge of a private seawater shrimp pond located in Jiaosi Twonship, Yilan County, Taiwan. Salt content was slowly increased in the wastewater during different fed-batch tests to allow the anaerobic bacteria were able to adapt the saline environment, and to enhance their capability to degrade the organics and to produce the methane gas. The experimental results showed that, when salt content increased, the pH was affected firstly, and accumulation of the COD was observed when salt content kept on increasing, and then the decline of the methane production. When operated at 12.5 d of hydraulic retention time (HRT), 3.2 g COD/L/d of organic loading rate (OLR) and 9% of salt content, the performance of pH 6.77, 85% of COD removal efficiency, 67.47 g/L of TS, 3.59 g/L of SS, 1.11 L/L/d of gas production rate (GPR), 47.12% of methane component and 0.58 L CH4/L/d of methane production rate was obtained. For the other comparison experiment, which was operated at 25 d of HRT, 1.6 g COD/L/d of OLR and 11% of salt content, the performance of pH 6.84, 89.89% of COD removal efficiency, 83.70 g/L of TS, 3.84 g/L of SS, 0.73 L/L/d of gas production rate (GPR), 53.52% of methane component and 0.46 L CH4/L/d of methane production rate was obtained. In summary, the endurability of the bacteria of the salt content will improve when increasing HRT and decreasing OLR, the performance of 85% of COD removal efficiency and 40% or higher of methane component could be achieved.