Membrane Bioreactor For Treating Sewage Test - Film Materials And Their Selection

In this paper, membrane bioreactor process for sewage treatment was researched, the main contents and conclusions are as follows:1. In order to resolve the problem of membrane fouling and high cross velocity when hollow fiber ultrafiltration membrane was used in membrane bioreactor, six types of membrane modules with different inner diameter and material were used in membrane bioreactor to investigate membrane performance, treatment effect and operational parameters respectively.2. The result shows that the six types of membrane bioreactors have little difference in treatment effect for COD_Cr, BOD₅, NH₃—N, SS and so on. The treatment effect is satisfactory. The removal rate of COD_cr, BOD₅, NH₃—N, SS can get to 83.0-98.0%, 95.8-98.0%, 96.7-99.4%, >99% respectively and quality of the effluent could meet the Standard for miscellaneous water issued by the Ministry of Construction of China.3. The result shows that relative big inner diameter is the premise for MBR to run stably. Canada composite membrane and PAN 25 membrane with inner diameter of 1.16 mm and 1.1 mm respectively could not control the clogging of activated sludge at the initial velocity of 3.0m/s and 2.6m/s respectively, which resulted that MBR could not run stably. On the contrary, the other four membrane modules with inner diameter between 1.5mm and 1.6mm could maintain the stability of cross velocity.4. The anti-clogging character of a membrane material is the crucial factor in flux. PS 9 and PAN 24 membrane have good anti-clogging character, which result in relative high flux. PS 10 and PS 13 membrane do not have good anti-clogging character, which results in relative low flux.5. PS 9 and PAN 24 membranes run stably and have relatively high flux. PS 9 membrane module runs for 42 days with stable flux about 57.0 L/m²Â·h and PAN 24 membrane module runned for 22 days with stable flux more than 70.0 L/m²Â·h. PS 9 and PAN 24 membranes share some common characteristic: relatively big inner diameter and good anti-clogging character.