By a membrane bioreactor with a settle tank in long-term operation and batch experiments, the effects of floes, soluble microorganism products (SMPs) and metal ions in activated sludge liquor on membrane fouling wer...By a membrane bioreactor with a settle tank in long-term operation and batch experiments, the effects of floes, soluble microorganism products (SMPs) and metal ions in activated sludge liquor on membrane fouling were investigated. The results showed that foulants absorbed each other and formed a fouling layer as a "second membrane" influencing the permeability of the membrane. The "gel layer" caused by SMPs and "cake layer" by floes showed great differences in morphology by analysis of scanning electron microscope and atomic force microscope. The "gel layer" was more compact and of poor permeability. When the membrane flux was 40 L/(m^2·h), the rate of membrane fouling caused by supernatant (0.011 MPa/h) was greater than that by sludgc liquor (0.0063 MPa/h). SMPs played very important roles on membrane fouling. In the bulking sludge, with SMPs increasing, the rate of membrane fouling (0.0132 MPa/h) was faster. While after flocculation of the SMPs, the rate of fouling decreased to 0.0034 M Pa/h. Floes could keep holes in their overlaps. They could alleviate membrane fouling by preventing the SMPs directly attaching on membrane surface.展开更多
Three sequencing batch reactors supplied with different carbon sources were investigated. The system supplied with glucose gained the best enhanced biological phosphorus removal although all of the three reactors were...Three sequencing batch reactors supplied with different carbon sources were investigated. The system supplied with glucose gained the best enhanced biological phosphorus removal although all of the three reactors were seeded from the same sludge. With the measurement of poly-β-hydroxyalkanoate (PHA) concentration, phosphorus content in sludge and extracellular exopolymers (EPS) with scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS), it was found that the biosorption effect of EPS played an important role in phosphorus removal and that the amount of PHA at the end of anaerobic phase was not the only key factor to determine the following phosphorus removal efficiency.展开更多
基金The National Basic Research Program (973) of China (No. 2004CB418505) and the Teaching and Research Award Program forOutstanding Young Teachers in Higher Education Institutions of MOE, China
文摘By a membrane bioreactor with a settle tank in long-term operation and batch experiments, the effects of floes, soluble microorganism products (SMPs) and metal ions in activated sludge liquor on membrane fouling were investigated. The results showed that foulants absorbed each other and formed a fouling layer as a "second membrane" influencing the permeability of the membrane. The "gel layer" caused by SMPs and "cake layer" by floes showed great differences in morphology by analysis of scanning electron microscope and atomic force microscope. The "gel layer" was more compact and of poor permeability. When the membrane flux was 40 L/(m^2·h), the rate of membrane fouling caused by supernatant (0.011 MPa/h) was greater than that by sludgc liquor (0.0063 MPa/h). SMPs played very important roles on membrane fouling. In the bulking sludge, with SMPs increasing, the rate of membrane fouling (0.0132 MPa/h) was faster. While after flocculation of the SMPs, the rate of fouling decreased to 0.0034 M Pa/h. Floes could keep holes in their overlaps. They could alleviate membrane fouling by preventing the SMPs directly attaching on membrane surface.
文摘Three sequencing batch reactors supplied with different carbon sources were investigated. The system supplied with glucose gained the best enhanced biological phosphorus removal although all of the three reactors were seeded from the same sludge. With the measurement of poly-β-hydroxyalkanoate (PHA) concentration, phosphorus content in sludge and extracellular exopolymers (EPS) with scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS), it was found that the biosorption effect of EPS played an important role in phosphorus removal and that the amount of PHA at the end of anaerobic phase was not the only key factor to determine the following phosphorus removal efficiency.