03655nas a2200433 4500 20260818095008.0 011298s1986 th r 000| 0eng d .b10690505 AIT Thesis no.EV-86-19 Waraporn Hirunwatsiri The effect of linear alkylbenzene sulfonate (LAS) in activated sludge system Bangkok : Asian Institute of Technology, 1986 57 p. Thesis ; no. EV-86-19 A research study submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development Thesis (M.Sc.) - Asian Institute of Technology, 1986 The effect of linear alkylbenzene sulfonate (LAS) in activated sludge system, focusing on its influence in COD removal efficiency was studies. Experiments have been done at different LAS concentrations, varying from 20 to 120 mg/L in continuous activated sludge process and at 20 and 40 mg/L of MBAS (Methylene blue active substance) in batch-fed activated sludge process. OECD (organization for Economic Co-operation and Development) synthetic sewage with 230-300 mg/L of COD was used throughout this experiment. In the batch activated sludge process, at 1500 mg/L of MLSS the synthetic sewage was biologically degraded mainly within the first 2 h. ninety three (93), 88 and 80% COD removal efficiencies were achieved within 3 h. corresponding to 0, 20, 40 mg/L of MBAS. In the continuous activated sludge process with 2 h. detention and 2500 mg/L of MLSS, the COD removal efficiency were 84.68, 81.33, 74.25% which corresponded to 30, 70, 120 mg/L of MBAS and 1.81, 2.25, 2.73 kg COD/ kg MLSS-d of organic loadings. The COD removal was not a result of adsorption onto the sludge since less MBAS concentration was detectable upon extraction of the sludge. The results showed that increasing LAS concentrations at the same time as increasing organic loading affected COD removal efficiency. LAS as high as 120 mg/L showed no inhibitory effect on the growth late of microorganisms in the continuous activated sludge system. It can degrade very fast and achieve 98% of MBAS removal at this concentration. In the batch-fed activated sludge system, no inhibitory effect on the growth rate of microorganism was observed at LAS concentrations as high as 40 mg/L. Sewage Purification Activated sludge process Samorn Muttamara, Chairperson Hanaki, K., Examination Committee Shin, Hang Sik, Examination Committee Swiss Government, Scholarship Donor Asian Institute of Technology. Thesis ; no. EV-86-19 Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B19647 .b10690505 mnait x 240402 2 951012 m a x 4 000:001:PDF:b1069050:004660:0:0:0:0:0:0 Abstract n mnait mnait mnarc 22 40 20 Barcode : 30050120749923 CREATED : 2014-03-28 RECORD # : i12782075 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 Barcode : 30050120223994 CREATED : 2016-09-05 RECORD # : i12973002 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 Barcode : 30050121073752 CREATED : 2023-10-04 RECORD # : i13442661 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 34466 34466 0 0 0 0 MAIN MAIN mnait 2026-08-18 50.00 0 AIT Thesis no.EV-86-19 30050120749923 2026-08-18 09:50:08 3 2026-08-18 22 0 0 0 0 MAIN MAIN mnarc 2026-08-18 0 AIT Thesis no.EV-86-19 30050120223994 2026-08-18 09:50:08 2026-08-18 40 0 0 0 0 MAIN MAIN mnait 2026-08-18 50.00 0 AIT Thesis no.EV-86-19 30050121073752 2026-08-18 09:50:08 1 2026-08-18 20