title: Performance of a laboratory-scale membrane bioreactor consisting mixed liquor with aquatic worms under toxic conditions.
abstract: A laboratory scale membrane bioreactor (MBR) consisting of worms was operated for 214days. The objective was to evaluate the treatment and operating performance of the MBR with and without the addition of Ametryn which is a toxic and persistent herbicide. Removal of Ametryn was doubled (up to 80%) in the MBR when the worms were present. Increased rate (2.5kPa/day) of trans-membrane pressure (TMP) and low concentration of MLSS (5.5g/L) were recorded when the worm population was high (80-100 worms per 70μL). Short-term critical flux values were increased from 7.5 to 15 and then to 30L/m(2)/h when the worm numbers decreased from 90 to 35 and then to 18 per 70μL of mixed liquor respectively. Further, high levels of carbohydrate concentration of soluble microbial products (SMP) and smaller sludge floc-sizes were found when the worm numbers were high.
authors.affiliation: College of Engineering and Science, Victoria University, Footscray Park Campus, Ballarat Road, Footscray, Melbourne, VIC 8001, Australia. Electronic address: dimuth.navaratna@vu.edu.au.
authors.forename: Dimuth
authors.initials: D
authors.lastname: Navaratna
authors.affiliation: School of Engineering, Deakin University, Waurn Ponds Campus, Geelong, VIC 3216, Australia.
authors.forename: Li
authors.initials: L
authors.lastname: Shu
authors.affiliation: School of Engineering, Deakin University, Waurn Ponds Campus, Geelong, VIC 3216, Australia. Electronic address: jega.j@deakin.edu.au.
authors.forename: Veeriah
authors.initials: V
authors.lastname: Jegatheesan
mesh_terms: D000818:Animals; D019149:Bioreactors; D006540:Herbicides / Q000378:metabolism* / Q000633:toxicity; D008567:Membranes, Artificial; D008856:Microscopy, Fluorescence; D009835:Oligochaeta / Q000378:metabolism*; D010316:Particle Size; D012722:Sewage / Q000382:microbiology / Q000469:parasitology*; D017550:Spectroscopy, Fourier Transform Infrared; D014227:Triazines / Q000378:metabolism* / Q000633:toxicity; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D006540:Herbicides; D008567:Membranes, Artificial; D012722:Sewage; D014227:Triazines; C100057:ametryne
keywords: Ametryn; Extra-cellular polymeric substances (EPS); Membrane bioreactor (MBR); Soluble microbial products (SMP); Worms