02604nam a2200241   450000500170000000800410001703500150005810000190007324500740009226000520016630000110021849000270022950001560025650200580041252015050047065000510197570000320202670000460205870000560210471000780216081000590223885600650229720260817162850.0120399s1988    th      r    0000|00eng d  a.b100876671 aMahmood, Talat10aApplication of direct membrane separation to activated sludge process  aBangkok :bAsian Institute of Technology,c1988  a111 p.1 aThesis ;vno. EV-88-25  aA Thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development  aThesis (M.Eng.) - Asian Institute of Technology, 1988  aFeasibility of . hollow fiber microfiltration for solid  liquid separation from the aeration tank of an activated  sludge process was investigated. The study was divided into  short term experiments and a long term experiment. From the  short term experiments results. cyclic operation was found  effective against inter' module clogginq and hence resulting  in stable membrane flux.  Out of three different organic loadings given in the  long term experiment. 3 kg/Cm3. d) was found to be the  critical one. concerning solid liquid separation. 2  kg/( m3. d) was the most suitable loading. Membrane permeate  was free of turbidity, free of bacteria, completely  nitrified, partially denitrified and very low in effluent  COD concentration. The process operated at very high MLSS  concentration without sludge wastage. Low values of kinetic  coefficients (kd and Y) and F/M ratio were obtained showing  little sludge production at steady state.  0. 45 æm membranes operated at '1ower suction pressures  than 0.1 æm membranes. The · highest pressure requirement  during, around 4 months of operational period was within 0. 5  m head of water employing O'. 45 æm membranes. This idea  motivated the use of elevation difference as a · driving force  for membrane separation, precluding the pump suction.  The proposed system showed better quality of effluent  with much lower HRT. and high enough organic 1oading, when  compared with the extended aeration process, in context of  sludge production. 0aSewagexPurificationxActivated sludge process1 aYamamoto, K., eChairperson1 aOrth, Hermann M., eExamination Committee1 aVigneswaran, Saravanamuthu, eExamination Committee2 aThe Royal Norwegian Government  (Norade Scholarship), eScholarship Donor2 aAsian Institute of Technology.tThesis ;vno. EV-88-25  3Full-Textuhttp://203.159.5.9/ait-thesis/detail.php?q=B18895