Biofilm thickness/biomass control in anaerobic filter via hydrodynamic detachment and cell lysis of biofilms

• Main Authors: Pei-Syun Du, 杜沛勳
• Other Authors: Chun-Sheng Wu
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/72513683424817299139

碩士 === 立德大學 === 休閒資源暨綠色產業研究所 === 98 === An advantage of using upflow anaerobic filter (UAF) systems is that it is easy to operate, but internal biofilms build up in the filters. Excessive biofilm thickness leads to UAFs becoming dead zones, which decreases the efficiency in the treatment of waste water. The purposes of this research are to solve the problem of excessive biofilm thickness by building a UAF system with a hydrodynamic detachment at different recycle-flows (200, 500, 1000,and 1500 ml/min). Then in different hydrodynamic conditions, we added NaCl to perform cell lysis and with two different methods to decrease the thickness of biofilms. The study reveals that as the recycle-flow increases from 200 to 1500 ml/min, the internal pressure drop of the UAF system goes up from 250 mb to 588.6 mb, the specific energy dissipation rate (ωt) from 0.11 to 0.43 erg/cm2-s, the biofilm detachment rate (Rdt) from 25.7 to 283.3 μg/s, and the VSSe concentration of the effluent from 154 to 1700 mg/L. This shows that the excessive biofilm thickness can be detached by hydrodynamic force. In another experiment, we futher added NaCl in different recirculation flow rates (200, 500, and 1000 ml/min) to perform cell lysis. The results show that the biofilm detachment rate (Rdt), specific biofilm detachment rate (rdt) and VSSe increased 20~48%. Thus, adding NaCl to perform cell lysis with hydrodynamic defachment is more effective in sloughing off the thickness of biofilms than applying hydrodynamic detachment alone.