Wastewater Treatment Options For The Food Processing Industry. William F Ritter Professor Emeritus University of Delware July 27, 2018

Transcription

1 Wastewater Treatment Options For The Food Processing Industry William F Ritter Professor Emeritus University of Delware July 27, 2018

2 Food Processing Categories ufruit and Vegetable Industry udairy Industry umeat Industry uspeciality Foods Industry ubrewery and Wine Industry

3 Chemical And Physical Parameters Of Concern u Organics- Biochemical Oxygen Demand (BOD) u Suspended Solids (SS) u Fat, Oil and Grease (FOG) u ph u Nitrogen u Phosphorus u Temperature

4 Treatment Options udischarge directly to a municipal treatment plant upretreatment and discharge to a municipal treatment plant utreatment plan on site ustream discharge or land application

5 Wastewater Treatment Plant Flow Diagram

6 Picture Of Treatment Plant

7 Preliminary Treatment uflow Measurement -flow rate information needed for efficient operation, chemical addition, etc uflow Equalization to cut down on flow variations for better treatment u Screening remove solids u Dissolved Air Flotation remove FOG

8 1 Dissolved Air Flotation

9 Primary Treatment Primary treatment includes uscreening uprimary Sedimentation - designed to remove settleable solids and reduce the organic load (BOD) on the secondary units.

10 Rectangular Basin

11 Circular Basin

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15 An Empty Primary Clarifier 15

16 Secondary Treatment

17 Activated Sludge

18 Activated Sludge Flow Diagram

19 Some Modifications To The AS System u u u u u u u u Complete mix AS Contact stabilization Extended aeration Tapered aeration Pure oxygen systems Oxidation ditch Membrane bioreactors Sequencing batch reactors (SBRs)

20 Type Of Reactors uplug Flow ucomplete Mix

21 Primary aeration tank

22 Oxidation Ditch

23 Oxidation Ditch

24 Sequencing Batch Reactors

25 Lagoon Systems

26 Types Of Lagoons u u u u u Aerobic lagoons Facultative lagoons Partial-mixed aerated lagoons Tertiary lagoons Anaerobic lagoons

27 Typical Lagoon System #1 Influent #3 Effluent #2

28 Facultative Lagoon

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30 Zonal Relationships in a Lagoon SUN Dike O 2 Aerobic Zone (Dissolved Oxygen Present) Facultative Zone O 2 Anaerobic Zone (No Dissolved Oxygen Present) Sludge Sludge Influent

31 Aerated Lagoon

32 Nitrogen And Phosphorus Removal

33 Nitrogen Removal Systems

34 N WASTEWATER TREATMENT Of Nitrogen Primary Effluent (Secondary Influent) Organic Nitrogen (Less) Ammonia

35 Nitrification Nitrification of Ammonia Occurs in Two Steps NH 3 -N NO 2 -N *Autotrophic Bacteria Utilize Inorganic Compounds Ammonia N (and CO 2 as a Carbon Source) Nitrosomonas Nitrite N NO 2 -N Nitrite N Nitrobacter NO 3 -N Nitrate N

36 Biological Denitrification u Nitrate Reduction: NO 3 NO 2 NO N 2 O N 2 u Wastewater/methanol/acetate reduction of NO 3 u C 10 H 19 O 3 N + 10NO 3 5N 2 +10CO 2 +3H 2 O+NH 3 +10OH u 5CH 3 OH+6NO 3 3N 2 +5CO 2 +7H 2 O+6OH u 5CH 3 COOH+8NO 3 4N 2 +10CO 2 +6H 2 O+8OH

37 N Removal Technologies 1. Single Process for Nitrification-Denitrification 2. Separate Stage Nitrification 3. Separate Stage Denitrification u These systems can be either suspended growth or attached growth systems or hybrid systems

38 Modified Ludzack-Ettinger System

39 Downflow Denitrification Filter

40 Upflow Sand Filter

41 Phosphorus Removal ubiological uchemical Precipitation

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43 EBPR Initial Anaerobic Stage PAOs grab organics / Release cellular PO 4 Aeration Uptake PO 4 for Energy Production & Storage

44 Chemical Phosphorus Removal Total Phosphorus Organic Phosphorus Condensed (Poly) Phosphates Ortho Phosphates Ortho Phosphates Metal Salt Addition

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46 Anaerobic Treatment Systems u u u u u u Anaerobic Lagoon Anaerobic Contact Reactor Anaerobic Filter Upflow Anaerobic Sludge Blanket (UASB) Expanded Granular Sludge Bed Anaerobic Sequencing Batch Reactor

47 Anaerobic Systems urequire less energy then aerobic systems ulow sludge production uproduce biogas that can be used ucannot meet effluent discharge standards

48 Anaerobic Processes

49 Upflow Anaerobic Sludge Blanket

50 Anaerobic Filter

51 Membrane Bioreactors

52 Membrane Classification Processes 1. Microfiltration 2. Ultrafiltration 3. Nanofiltration 4. Reverse Osmosis 5. Dialysis 6. Electrodyialysis

53 Membrane Bioreactors In U.S. 1. Zenon Environmental 2. US Filter 3. Kubota Corporation 4. Mitsubishi Rayon Corporation 5. Huber Technology

54 Huber Bioreactor

55 Kubota Membrane Bioreactor

56 Membrane Tanks

57 Application ureplace activated sludge ureplace sand filtration after conventional activated sludge

58 Effluent Quality u u u u u BOD 5-10 mg/l Total N 3mg/l Phosphorus mg/l Turbidity 0.2 NTU Remove bacteria and viruses

59 Sludge Treatment And Disposal

60 Removal of These Pollutants Produces Residuals Often called Sludge Settleable Suspended Dissolved Wastewater Pre Organic Inorganic Treatment Suspended Dissolved Effluent Rock Grit Plastic Etc. Primary Clarifier Sludge Secondary Sludge Secondary Clarifier Note: These residuals are sometimes called Biosolids, however that term is usually reserved for sludge that has been stabilized and meets specific requirements (pathogen reduction, vector attractions, metals concentration)

61 ANAEROBIC DIGESTION Advantages Low operating costs Proven effectiveness Burnable gas produced Disadvantages Long start-up time Affected by changes in Explosive gas produced loading and conditions

62 ANAEROBIC DIGESTION

63 TYPICAL Two-Stage ANAEROBIC DIGESTER SYSTEM Gas Gas Recirculation Pump Heat Exchanger Hot Water Transfer Pump Note: Two-Stage System here refers to two separate tanks (One for the treatment process and one for water-solids separation)

64 Sludge Dewatering And Disposal u Belt Filter Press u Centrifuge usand Drying Beds udewatered sludge may undergo composing before disposal uland application is the most common method of disposal

65 Centrifuge

66 Belt Filter Press