Effect of Influent Strength on Granulation of Sludge in UASB Reactor
进水浓度对UASB颗粒污泥形成的影响研究

Using synthetic glucose wastewater, the effect of influent strength on granulation of sludge in UASB reactor was investigated. Results show that granulation could be well achieved in an operatinal period of 2 months or more, when UASB reactor was directly fed with high strength influent of 9000 mg/L COD. The granular sludge were 1.0-2.5mm (mostly 2.0mm) in diameter, SVI 16.03ml/g. The organic loadings of UASB reactor reached 30.8kg COD/m3. d and COD removal efficiency over 85%. The granular sludge could also be cultivated but the granulation of sludge was found to be comparatively slow and incomplete, when the low strength influent of 1000mg/L COD was fed to the reactor. The size of sludge granule was smaller, in the range of 0.5-1.5mm, and the maximum organic loadings was 10.2 kg COD/m3. d, COD removal efficiency approximately 75%. The relationship be-tween influent strength and granulation of sludge and the practical operation technology forthe tre atment of industrial wastewater with UASB reactor were discussed.