OWEA 2013 Technical Conference and Exposition June 18 21, 2013

Transcription

1 1 OWEA 2013 Technical Conference and Exposition June 18 21, 2013 Michael H. Gerardi ArchaeaSolutions, Inc.

2 2 Nitrogenous Wastes in Domestic Wastewater Urine Urea as major component of urine Chemical formula: NH 2 COH 2 N Urea contains two (2) amine groups (-NH 2 ) Urea is hydrolyzed in the sewer system Hydrolysis results in the release of reduced nitrogen (NH 4+ /NH 3 )

3 3 Dominant Form of Reduced Nitrogen 100 as Determined by ph 0 % % NH 3 NH ph 7 ph 9 ph 11

4 4 Nitrogenous Wastes in Domestic Wastewater Feces Proteins (organic-nitrogen) as a major component Proteins made of amino acids Amino acids contain amine groups (-NH 2 ) Deamination of proteins and degradation of amino acids in sewer system and aeration tank results in the release of amine groups and the release of reduced nitrogen (NH 4+ /NH 3 ) Therefore, organic-nitrogen represents bonded nitrogen (amine groups) that may/must be released in aeration tank

5 5 Amino acid, cysteine HSCH 2 CHNH 2 COOH Thiol group H 2 S/H 2 S /HS - /SO 4 2- H 2 S (1 to 3 mg/l) toxic to nitrifying microbes Amine group NH 3 /NH 4+ /NO 2- /NO 3 -

6 6 Free and Organic-Nitrogen Free reduced nitrogen NH 4+ /NH 3 in solution Determined by ammonia testing Organic-nitrogen Bonded nitrogen that may/must be released Determined by total Kjeldahl nitrogen (TKN) and ammonia testing: TKN NH 3

7 7 Archaeal and Bacterial Roles in Nitrification and Denitrification Remove soluble cbod Provide maximum time for nitrification Provide acceptable nitrification and denitrification Perform cold weather nitrification

8 8 Archaea What are Archaea?

9 9 What are Archaea? Separate domain of life Formerly known as ancient bacteria Significant differences Some Archaea degrade wastes that bacteria cannot Some Archaea out-compete bacteria for substrate and nutrients Some have a higher metabolic rate than bacteria Provides for more rapid degradation of cbod Provide for more HRT for nitrification Removes soluble, short chain, inhibitory cbod Some have a syntrophic relationship with bacteria

10 10 Inhibitory Soluble cbod Methanol CH 3 OH 1 Methylamine CH 3 NH 2 1 Ethanol CH 3 CH 2 OH 2 n-propanol CH 3 CH 2 CH 2 OH 3 Ethyl acetate CH 3 CO 2 C 2 H 5 4

11 What is Arkea? 11

12 12 What is Arkea? ArchaeaSolutions, Inc. produces Arkea, a proprietary blend of Archaea organisms and other microbes. Several species of Archaeal methanogens have been identified in Arkea through gene sequencing analysis.

13 Nitrogen Removal 13

14 14 Nitrogen Removal from Wastewater Air stripping of ammonia (NH 3 ) Assimilation of ammonium (NH 4+ ) Nitrification/denitrification Nitrification: NH > NO 3 - Denitrification NO > Insoluble molecular nitrogen (N 2 ) Insoluble nitrous oxide (N 2 O ) Simultaneous nitrification/denitrification (SND) Anammox

15 15 Conversion of NH 4 + to NH 3 with increasing ph; Air stripping of NH 3 to atmosphere NH 3 Influent NH 4 + Effluent

16 16 Assimilation of NH 4 + as nitrogen nutrient for microbial growth (MLVSS production) Influent NH 4 + MLVSS Effluent Approximately 12 15% of microbial dry weight is nitrogen. NH 4 + is the preferred nitrogen nutrient. NH 3 is toxic!

17 17 Nitrification*/Denitrification *Nitrification does not remove nitrogen from the wastewater!

18 18 What is Nitrification? Biological oxidation of ammonium (NH 4+ ) to nitrite (NO 2- ) and/or the biological oxidation of nitrite to nitrate (NO 3- ) NH O > 2 H + + NO H 2 O NO O > NO 3 -

19 19 Nitrification Influent NH 4 + NO 2 - NO 3 - Effluent

20 20 Nitrifying Systems One-stage system Two-stage system

21 21 One-stage Nitrification System Aeration Tank Removes cbod and Nitrifies Clarifier

22 22 Two-stage Nitrification System Aeration Tank Removes cbod Aeration Tank Nitrifies Clarifier

23 23 Microbes That Perform Nitrification? Ammonium-oxidizing bacteria NH > NO 2 - Nitrosomonas and Nitrosospira Nitrite-oxidizing bacteria NO > NO 3 - Nitrobacter and Nitrospira Ammonium-oxidizing Archaea (Crenarachaeota) AOA more competitive than AOB AOA more competitive than NOB Some protozoa Epistylis Vorticella

24 Stalk ciliates, Epistylis 24

25 Stalk ciliate, Vorticella 25

26 26 Monitoring Nitrification Alkalinity/pH Temperature cbod including slug discharges Inhibitory/toxic wastes NH 3 /NH 4 + concentration in aeration tank Dissolved oxygen Phosphorus Form of nitrification (complete, incomplete #1, 2, 3, 4)

27 27 Forms of Nitrification* Complete Incomplete 1 Incomplete 2 Incomplete 3 Incomplete 4 < 1 mg/l < 1 mg/l > 1 mg/l < 1 mg/l > 1 mg/l < 1 mg/l > 1 mg/l < 1 mg/l > 1 mg/l < 1 mg/l > 1 mg/l > 1 mg/l > 1 mg/l > 1 mg/l > 1 mg/l *Based upon mixed liquor effluent filtrate from an on-line aeration tank.

28 28 What is Denitrification? The biological use of typically nitrate (NO 3- ), atypically nitrite (NO 2- ) by denitrifying microbes to degrade soluble cbod. Denitrification occurs in the absence of free molecular oxygen (O 2 ).

29 29 Denitrification Tank 1-stage or 2-stage nitrification system Carbon Source Denitrification Tank Clarifier Denitrification tank: Slow, surface mixing

30 30 Denitrification Soluble cbod (methanol) + NO > cells (sludge) + H 2 O + CO 2 + N 2 + N 2 O + OH - 3 gases produced return of alkalinity

31 31 Monitoring Denitrification Soluble cbod or carbon source Residual dissolved oxygen

32 32 Simultaneous Nitrification/Denitrifica tion (SND)

33 33 Oxygen Gradient X-sectional view of floc particle with oxic (O 2 use) and anoxic (NO 3 - use) zones Soluble cbod > 100 μm OXIC ZONE Dissolved oxygen Nitrate ANOXIC ZONE Perimeter: DO < 1.0 mg/l; cbod removal via O 2 ; nitrification occurs; destroy alkalinity; grow low dissolved oxygen filamentous organisms. Core; DO is 0; cbod removal via NO 3- ; denitrification occurs; return alkalinity; destroy low dissolved oxygen filamentous organisms.

34 34 Anaerobic Ammonia Oxidation (Anammox)

35 35 Organic-nitrogen ammonification NH 4 + AOB + O 2 N 2 NO 2 - Denitrifying bacteria + carbon source NO 3 - NOB + O 2 Nitrification/Denitrification

36 36 Organic-nitrogen ammonification NH 4 + Anammox Archaea Anammox bacteria + O 2 N 2 Anammox Archaea Anammox bacteria NO 2 - Denitrifying bacteria + carbon source NO 3 - NOB + O 2 Anammox Reduced dissolved oxygen requirement; carbon addition not required.

37 37 Benefits of Anammox Use represents 10% of current cost for nitrification and denitrification Reduces greenhouse gas carbon dioxide (CO 2 ) addition

38 38 ArchaeaSolutions, Inc. Consulting.Bioaugmentation.Results. Scientists, Engineers, and Wastewater Professionals Specializing in Process Consulting, Bioaugmentation Strategies, Plant Optimization, and Troubleshooting Support 100 Lloyd Ave., Suite D, Tyrone, GA Low Cost Performance-Based Arkea Trials Available Call us today to schedule a consultation and site visit!