UMass Amherst CE-ENGIN 697W - Accepted Manuscript (37 pages)

Previewing pages 1, 2, 17, 18, 19, 36, 37 of 37 page document View the full content.
View Full Document

Accepted Manuscript



Previewing pages 1, 2, 17, 18, 19, 36, 37 of actual document.

View the full content.
View Full Document
View Full Document

Accepted Manuscript

37 views


Pages:
37
School:
University of Massachusetts Amherst
Course:
Ce-Engin 697w - ST-Advanced Topics in Water Chemistry and Process Engineering
ST-Advanced Topics in Water Chemistry and Process Engineering Documents
Unformatted text preview:

Accepted Manuscript Title Biodegradation of the Endogenous Residue of Activated Sludge Authors Abdellah Ramdani Peter Dold St phane D l ris Daniel Lamarre Alain Gadbois Yves Comeau PII S0043 1354 09 00849 5 DOI 10 1016 j watres 2009 12 037 Reference WR 7819 To appear in Water Research Received Date 29 July 2009 Revised Date 23 November 2009 Accepted Date 22 December 2009 Please cite this article as Ramdani A Dold P D l ris S Lamarre D Gadbois A Comeau Y Biodegradation of the Endogenous Residue of Activated Sludge Water Research 2009 doi 10 1016 j watres 2009 12 037 This is a PDF file of an unedited manuscript that has been accepted for publication As a service to our customers we are providing this early version of the manuscript The manuscript will undergo copyediting typesetting and review of the resulting proof before it is published in its final form Please note that during the production process errors may be discovered which could affect the content and all legal disclaimers that apply to the journal pertain ACCEPTED MANUSCRIPT 1 Biodegradation of the Endogenous Residue of Activated Sludge a b c d d 2 Abdellah Ramdani Peter Dold St phane D l ris Daniel Lamarre Alain Gadbois Yves 3 Comeau RI PT a 4 5 a 6 P O Box 6079 Station centre ville Montreal Quebec H3C 3A7 Canada 7 b 8 Canada 9 c SC Department of Civil Geological and Mining Engineering Ecole Polytechnique of Montreal M AN U EnviroSim Associates Ltd 7 Innovation Drive Suite 205 Flamborough Ontario L9H 7H9 Anjou Recherche Veolia Environment BP79 Chemin de la Digue 76 400 Maisons Laffitte 10 France 11 d 12 Corresponding author Tel 1 514 340 4711 ext 3966 Fax 1 514 340 5918 13 E mail address abdellah ramdani polymtl ca 14 15 Abstract EP TE D John Meunier Inc 4105 Sartelon Street Saint Laurent Quebec H4S 2B3 Canada This study evaluated the potential biodegradability of the endogenous residue in activated sludge 17 subjected to batch digestion under either non aerated or alternating aerated and non aerated 18 conditions Mixed liquor for the tests was generated in a 200 L pilot scale aerobic membrane 19 bioreactor MBR operated at a 5 2 days SRT The MBR system was fed a soluble and 20 completely biodegradable synthetic influent composed of sodium acetate as the sole carbon 21 source This influent which contained no influent unbiodegradable organic or inorganic AC C 16 ACCEPTED MANUSCRIPT materials allowed to generate sludge composed of essentially two fractions a heterotrophic 23 biomass XH and an endogenous residue XE the nitrifying biomass being negligible less than 24 2 The endogenous decay rate and the active biomass fraction of the MBR sludge were 25 determined in 21 day aerobic digestion batch tests by monitoring the VSS and OUR responses 26 Fractions of XH and XE 68 and 32 were obtained respectively at a 5 2 days SRT To assess 27 the biodegradability of XE two batch digestion units operated at 35 C were run for 90 days using 28 thickened sludge from the MBR system In the first unit anaerobic conditions were maintained 29 while in the second unit alternating aerated and non aerated conditions were applied Data for 30 both units showed apparent partial biodegradation of the endogenous residue Modeling the 31 batch tests indicated endogenous residue decay rates of 0 005 d 1 and 0 012 d 1 for the anaerobic 32 unit and the alternating aerated and non aerated conditions respectively 33 Keywords Activated sludge endogenous residue aerobic digestion anaerobic digestion 34 biodegradation modeling 35 1 36 The activated sludge process is the most commonly used method for biological wastewater 37 treatment of both municipal and industrial effluents In this process organic and inorganic 38 pollutants are transformed into acceptable end products and treated water can be discharged to 39 the receiving environment A significant amount of excess activated sludge containing more 40 than 99 water is generated in this process however The treatment and disposal of this sludge 41 is expensive and accounts for up to 60 of the total operating costs of wastewater treatment 42 plants Canales et al 1994 Low and Chase 1999 Wei et al 2003 Reducing sludge 43 production in wastewater treatment plants thus presents an obvious economic interest TE D AC C EP Introduction M AN U SC RI PT 22 ACCEPTED MANUSCRIPT Earlier studies dealing with aerobic and anaerobic digestion of activated sludge studied ways to 45 design and optimize processes aimed at stabilizing the active heterotrophic biomass XH fraction 46 of the activated sludge Solids degradation usually was the most important parameter used to 47 evaluate the efficiency of aerobic and anaerobic digestion processes The effect of these 48 processes on the degradation of each organic fraction of the activated sludge however was 49 rarely investigated Furthermore it is generally considered that the inactive organic fractions of 50 sludge unbiodegradable influent organic matter XU Inf and endogenous residue XE do not 51 undergo transformation in such digestion processes 52 The objective of this work was to study the potential biodegradation of endogenous residue XE 53 under either anaerobic conditions or under alternating aerated and non aerated conditions To 54 target XE in this investigation a biological sludge was developed in an activated sludge system 55 fed with synthetic and completely soluble and biodegradable influent 56 A concise review is first presented about the endogenous residue in activated sludge systems the 57 mathematical models describing its generation the composition of the mixed liquor in activated 58 sludge systems fed with municipal influent and with soluble and completely biodegradable 59 synthetic influent the theoretical considerations for the active fraction determination in activated 60 sludge systems and a summary of earlier studies dealing with the biodegradation of XE 61 1 1 Endogenous residue in activated sludge systems 62 Ordinary heterotrophic biomass XH utilizes readily biodegradable substrate SS for growth 63 according to Monod kinetics in an activated sludge system not limiting in oxygen Grady et al 64 1999 Metcalf Eddy et al 2003 More complex substrates e g particulate organics first 65 must be hydrolyzed into this SS substrate prior to being metabolized Endogenous respiration 66 including decay lysis maintenance and predation of the heterotrophic biomass results in the AC C EP TE D M AN U SC RI PT 44 ACCEPTED MANUSCRIPT generation of an endogenous residue XE Two


View Full Document

Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...
Login

Join to view Accepted Manuscript and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Accepted Manuscript and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?