《微生物学 Microbiology》课程PPT教学课件（英文版）environmental microbiology 3/3

Chapter 27,part C Environmental Microbiology

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings B.E Pruitt & Jane J. Stein Chapter 27, part C Environmental Microbiology

Algal Blooms ● Pollutants (nutrients)may cause algal blooms. 。Algal blooms lead to eutrophication. Figure 27.15

• Pollutants (nutrients) may cause algal blooms. • Algal blooms lead to eutrophication. Algal Blooms Figure 27.15

Coliforms Aerobic or facultatively anaerobic,gram-negative, non-endospore forming rods that ferment lactose to acid gas within 48 hr,at 35 C 。Indicator organisms Used to detect fecal contamination 。MPN Most probable number/100 ml of water

• Aerobic or facultatively anaerobic, gram-negative, non–endospore forming rods that ferment lactose to acid + gas within 48 hr, at 35°C • Indicator organisms • Used to detect fecal contamination • MPN • Most probable number/100 ml of water Coliforms

Multiple-Tube Method Volume of Inoculum for Tubes of Nutrient Medium Number of Positive Each Set of (Sets of Five Tubes) Tubes in Set Five Tubes 10ml 1ml 目日日0目 3 0.1ml 6日i0司 (a)Most probable number(MPN)dilution series Figure 6.18a

Multiple-Tube Method Figure 6.18a

Multiple-Tube Method 95%Confidence Limits Combination MPN Index/ of Positives 100 ml Lower Upper 42-0 22 9 56 4-2-1 262 12 65 43-0 12 6 4-3-1 33 1 1 4-4-0 34 16 80 5-0-0 23 9 86 5-0-1 10 110 5-0-2 40 20 140 5-1-0 10 120 5-1-1 50 20 150 5-1-2 30 180 5-2-0 50 20 170 5-2-1 30 210 5-2-2 9 40 250 5-3-0 80 30 250 5-3-1 110 40 300 5-3-2 140 60 360 (b)MPN table Figure 6.18b

Multiple-Tube Method Figure 6.18b

MUG Test ONPG causes E.coli to make B-galactosidase B-galactosidase 。MUG fluorescent compound Fecal coliforms Figure 27.16

• ONPG causes E. coli to make -galactosidase • MUG Test Figure 27.16 MUG fluorescent compound - galactosidase

Municipal Water Treatment Pumping Storage tanks station Flocculant Raw water reservoir Mixing tank Flocculation tank Particulate filter Consumer ①Raw water held 2④Water is mixed As aggregates ③Water ⑤Water is stored in reservoir to with flocculant of floc settle out, undergoes可 before use by allow particulates they carry colloidal filtration consumers to settle particles out of suspension Water is disinfected by chlorination, ozone treatment, or exposure to UV light Figure 27.17

Municipal Water Treatment Figure 27.17

Municipal Sewage Treatment (a)PRIMARY TREATMENT (b)SECONDARY TREATMENT (c)DISINFECTION AND RELEASE (Biological oxidation) Screening,skimming, ③Primary effluent Effluent is disinfected grinding of sewage. undergoes aeration: by chlorination and microorganisms released. 2 Solid matter oxidize organic Trickling filter settles out. matter. (see Figure 27.22) Primary Chlorinator Sewage Effluent Primary sedimentation tank Settling tank Activated Secondary sludge system effluent (see Figure 27.20) Primary sludge Secondary sludge from settling tank Sludge effluent Sludge is is dried. removed and disposed of Key Sludge in landfill or Physical ⑤Remaining sludge effluent agricultural processes is digested anaerobically. land. Microbial producing methane. processes Anaerobic sludge digester Chemical (d)SLUDGE DIGESTION (see Figure 27.23) Drying bed processes Figure 27.19

Municipal Sewage Treatment Figure 27.19

Activated Sludge Primary sewage effluent Aeration Settling tank tank Clear effluent Air To Activated sludge sludge digestion return Excess secondary sludge (a)Diagram of an activated sludge system (b)An aeration tank.Note surface is frothing from aeration. Figure 27.20a,b

Activated Sludge Figure 27.20a,b

Anaerobic Sludge Digester C02+4H2→CH4+2H2O 。 CH3COOH→>CH4+CO2 Gas outlet Methane gas Flame Sludge inlet Scum layer Scum removal Supernatant Supernatant removal Actively digesting sludge Stabilized sludge Sludge outlet Figure 27.23

• CO2 + 4 H2 → CH4 + 2 H2O • CH3COOH → CH4 + CO2 Anaerobic Sludge Digester Figure 27.23