Environmental BiotechnologyCE421/521 Tim EllisOctober 25, 2007INDICATOR MICROORGANISMS•Need for indicator organisms•Not possible to test for every pathogen•Use indicator that will be easy to test routinely•Early warning if there is a problem•Used in regulations•Water treatment and distribution•Wastewater treatment discharges (NPDES permit)•When to close beaches and lakes for recreational uses•Beaches closed when FC is over 300 colony forming units per 100 mL or when monthly average is over 140 CFU per 100 mLINDICATOR MICROORGANISMS• Use of indicator organisms dates back to 1914 when U.S. Public Health Service adopted the c______________ test as an indication of fecal contamination• Ideal indicator should have the following characteristics:1. Found in i___________________ of warm blooded animals2. Should be present when p__________________ are present and absent when pathogens are absent3. Present in greater n___________________ than pathogens4. As r____________________ as (or more resistant than) pathogens5. It shouldn’t m__________________ in the environment6. Easily detectable by r___________, inexpensive method7. Non-p_____________________ itselfE.coliE.coliTotal Coliforms•Characteristics:• Aerobic and f___________________ anaerobic organisms• gram n_________________• non s_____________ forming• r_______ shaped• ferment l__________________ within 48 h at 35°C as evidenced by gas production•includes E. coli, Enterobacter, Kleibsiella, and Citrobacter• high levels in human and animal feces ______ per capita per dayFecal Coliforms• all coliforms that can ferment lactose at 44.5°C as evidenced by g________ production• includes groups such as E. coliand Kleibsiella• p________________ is an indication of human and animal contamination• human and animal contamination cannot be d_______________• s___________________ pattern is similar to bacterial pathogens• much l______ resistant to disinfection than protozoan pathogensFecal Streptococci• includes groups such as Streptococcus faecalis, S. bovis, S. equinus,and Kleibsiella• inhabit i______________ of warm blooded animals and humans• Historically fecal coliform/fecal strep r_______ serves as useful indicator of origin of contamination• ratios greater than 4 indicate h____________ origin• ratios less than ________ indicate animal contamination• In-between ratios indicate a m__________________ of human and animal contamination• Currently there are probably better indicators of human contamination (pharmaceuticals and personal care products)Clostridium perfringens•Anaerobe• forms s______________ that are resistant to disinfection and environmental stress• possibly t_____ resistant to be useful as an indicator• good for tracking contamination in m__________ environmentshttp://chem.ch.huji.ac.il/~eugeniik/biofuel/biofuel_cells_bacteria12.jpgBacteriophages• Similar to enteric v___________ and found in higher numbers• Suggested as water quality indicators in e___________________, seawater, recreational waters, and drinking water• C________________ exhibit best correlation to enteric virusesHeterotrophic Plate Count (HPC)• Measure of aerobic and facultative anaerobic bacteria that derive their c______________ and e________________ from organic compounds• No known effects of high HPC on h____________ health• HPC in drinking water ranges from less than _____ CFU/mL to more than ____ CFU/mL• Good indicator of pathogens in r___________________ wastewaterBULKING and FOAMING•Sludge settling can be the most important operational problem in an activated sludge plantCiliatesNematodesRotifersFILAMENTOUS BULKING•Measurement of sludge settleability•Sludge v___________ index•Measure of s_____________ characteristics•Measured in a g_____________ cylinder after 30 min of settling•Units of mL/g•A d_____________ SVI is in the range of 75-150Bulking and FoamingFilamentous Bulking•Kinetic Selection Theory (Chodoba et al.Types of Filaments• filament s_________• size and shape within filament• b___________• motility (e.g. Beggiatoamove by g___________ )• presence of s_____________• presence of epiphytic b_____________ on filament surface• filament size and d__________________• presence of g_____________________Isolation of Filaments• m___________________ analysis•fluorescent-a___________________ techniques• RNA chemotaxonomy (g____________ p____________)Predominant FilamentsCAUSES• Waste composition• high c___________________• v__________ a__________• readily d__________________ substratesCauses• Substrate Concentration• l_____ s__________ concentrations favor filaments due to their low KSvalues• Sludge Loading (Food to Microorganism Ratio)Type 1701Type 021NType 0041NThiothrix spp.Microthrix parvicellaPhotos of bulking organismsCauses•pH• l________ pH tends to favor filaments•Sulfide• sulfide tends to encourage growth of s_______ f_______________ such as •Thiothrix•Beggiatoa•021N•D.O.•Sphaerotilus natansKSfor oxygen is 0.01•KSfor oxygen for floc formers is 0.15BULKING CONTROL • C_________________ or O_____________________ of RAS• Biological Selector• a______________ selector• a______________ selector• a_________________ selectorFOAMING IN ACTIVATED SLUDGE• Types of activated sludge foams:• s______________ a_______________ compounds• d____________________• s___________ (e.g., as a result of denitrification)• actinomycetes f___________Foam Nuisance• a____________________ and safety hazard (e.g., slippery walkways)• increased levels of o_________________ c________________ in effluent• foaming in a____________________ digesters• nuisance o_______________• opportunistic p___________________ (e.g., Nocardia asteroides)Foam Microbiology• A_______________________ is the most predominant foam causing organism• N________________ is a predominant member of this classification (e.g.,Gordona amarae, formerly Nocardia amarae, N. asteroides, N. pinensis, and Rhodococcus).•Gordona amaraeand N. pinensisare usual suspects• foaming is problematic when Nocardiaconcentration exceeds ______ mg Nocardiaper g VSSMechanisms of Foam Production• Gas b__________ from aeration or denitrification assist in flotation• h_____________________ nature of cell wall assist in their transport to air-water interface•