Advanced Wastewater Treatment and Disposal Systems. Wastewater Utility Operation and Management for Small Communities

Transcription

1 Advanced Wastewater Treatment and Disposal Systems Wastewater Utility Operation and Management for Small Communities

2 Preliminary Treatment Primary Treatment Secondary Treatment Tertiary Treatment Disinfection Sludge Removal Treatment System

3 Preliminary Treatment Screening Remove Large Solids Parallel Bars Placed in Channel Course Screen (2-4 Inch Range) Fine Screen ( Inch Range) Manual or Mechanical copyright

4 Gravity/Velocity Removal Cyclone Degritter Preliminary Treatment

5 Preliminary Treatment Inspect Periodically to Ensure Screen is Free of Obstructions Replace Hydraulic Fluid if Necessary Oil Change/Checks Should Be Done on an Annual Basis Dispose of Screenings at an Approved Location

6 Primary Treatment s City of Hagerstown, Utilities Department

7 Manage Fats, Oils, and Grease at the Source FOG Management Source: Grease Interceptors: Commercial and industrial facilities Management plan in place for frequent pumping based on loading Tank pumping by grease hauler or septic tank pumper Recordkeeping

8 Rotating Biological Contactor

9 Name two recommended maintenance procedures that should be performed after 3 months of startup of an RBC system.

10 Sequence Batch Reactor

11 Sequence Batch Reactor

12 Sequence Batch Reactor Basic Maintenance Needs Check air distribution Adjust cycle times to meet treatment goals Follow manufacturer s recommendations

13 Activated Sludge

14 Activated Sludge Blower with Air Piping

15 Activated Sludge Daily Operation Checks: Tank Appearance Equipment Operation and Lubrication Return Sludge Line Hose Down Accumulated Sludge From Hoppers and Clarifier Tanks Brush Weirs to Remove Algae and Captured Materials Skim Off Grease and Other Floating Material

16 Wasting Sludge: Activated Sludge Required to Maintain a High Degree of Effluent Quality Rule of Thumb - Waste 5% of Solids Each Week During Summer To Prevent Excessive Solids Burping Measuring MLSS in Aeration Tank >Laboratory Equipment >Jar Test

17 What is white fluffy foam in the aeration chamber a sign of? Copyright Environmental Leverage Inc.

18 What is brown leathery foam in the aeration chamber a sign of? Copyright Environmental Leverage Inc.

19 Oxidation Ditch

20 Oxidation Ditches Control Methods Similar to Activated Sludge Process: Food Supply Dissolved Oxygen Levels (DO) Ditch Environment Ditch Detention Time Proper Water/Solids Separation Copyright Jewett City WWTP, CT Copyright Williams Industrial Services Ltd

21 Oxidation Ditches Food Supply for Microorganisms: Measured as Biological Oxygen Demand (BOD) No Toxicants Proper Pretreatment Facility Inspection

22 DO Levels: Oxidation Ditches Rotors Supply Oxygen to Waste Flow Maintain DO Concentration of 0.5 To 2.0 Mg/L Upstream of Rotors Over Oxygenation can Cause Floc to Form Control of Rotor Oxygenation by Adjusting Outlet Control Weir Copyright 2010 Spaans Babcock Copyright 2004 by City of Princeton

23 Membrane Bioreactors Reactor Basin Permeate Pumps Reactor Basin Permeate Pumps Infrastructure Alternatives Inc.2007 Infrastructure Alternatives Inc.2007

24 Membrane Bioreactors Monitor Trans Membrane Pressure (TMP) Clean Membranes with Sodium Hypochlorite Solution (0.5%) Cleaning Typically 2-4 Hours Once Every 6 Months

25 To Anerobic Tank Train 1 Train 2 Influent To Anerobic Tank Anoxic Tank, Mixing & Carbon Addition Kaiser Blowers Aeration Membrane RAS Permeate Pumps (Under Vacuum) RAS Effluent to UV Sludge Wasting

26 Chlorine Disinfection All Rights Reserved by Conrad Strehlau

27 UV Disinfection 2011 Copyright Calgon Carbon Corporation

28 UV Disinfection 2011 Copyright Calgon Carbon Corporation

29 Treated Effluent Disposal Return Treated Effluent to Environment Receiving Waters Reclaimed Water Use Land Disposal

30 Treated Effluent Disposal

31 Treated Effluent Disposal Caution needed to prevent heavy equipment above facilities not designed to take the weight

32 Treated Effluent Disposal Regular removal of vegetation in open soil beds required Be careful not to compact soils

33 Treated Effluent Disposal

34 Sludge Disposal Major Problem facing Operators Solids Removal Originates from: Bar Racks Screens Grit Removal Aerobic Processes Anaerobic Processes

35 Disposal Options: Dewatering Direct Burial Incineration Composting Land Application Sludge Disposal

36 Removing Wasted Sludge: Pumper Truck Removal Aerobic Digester Portable Pumping Unit Sludge Disposal Drying Beds Copyright 2010 ITT Water & Wastewater Copyright 2009 Color Bold Copyright ECO Friendly Shelters

37 Sampling and Analysis Sample per facility discharge permit requirements Samples must be representative of the water/effluent being tested Two sample types - Grab - Composite

38 Sampling Considerations Frequency varies based on the facility Always collected from the same location Proper Sample Handling Chain of Custody

39 Sampling Summary Test Location Common Range ph Effluent Dissolved Oxygen (DO) Effluent 4-12 mg/l Temperature Effluent Varies BOD Suspended Solids Influent Effluent Influent Effluent mg/l mg/l mg/l 30 mg/l Total Nitrogen Influent? Phosphorus Influent?

40 Safety An operator should always be accompanied by a helper when performing any task that is dangerous. Immediate aid might be needed to prevent serious injury of loss of life.

41 Catwalks and Headworks Catwalks should have guardrails and non skid surfaces Headworks and enclosed equipment should be well ventilated

42 Debris Removal Be careful when removing debris from channels Do not lift too much Make sure of secure footing Never stand in a boat or lean over too far to one side Always wear a life jacket when in a boat

43 Electrical Exercise caution when cutting weeds or removing vegetation near electrical wires Always turn off, tag and lock out electric current when repairing equipment Beware of electrical wires in damp areas

44 Infections and Disease Two bacteria - Clostridia tetani - Clostridia gangrene Apply first aid to all cuts and scrapes Injuries involving punctures or severe tissue damage immediate medical attention must be given Always wash after maintenance practices

45 What Have We Learned? Components of Wastewater Treatment Facilities Typical Treatment Systems Used in Larger Facilities Common O&M Issues, Including Sampling and Analysis Safety