Activated Sludge Workshop Techniques and Tools that Improve Clarifier Performance Mike Beattie Operations and Reliability

Troubleshooting: Provide some simple things to assist Can you run your plant using only a settleometer? Diagnostics Fundamental biology vs. Operating adjustments Topics Today Develop a Robust Operational Scheme Limit Standard Deviation Limit changes on other areas Avoid CTRL-ALT-DEL Brown and Caldwell 2

Reduce overflows No more convenience pressure relief Treat more/bypass less Would a clarifier that could only treat 3 MGD be of any use? My History 1992 Administrative Order Brown and Caldwell 3

Foaming, Scum Bulking Solids Washout Rising Sludge Ashing Straggler Floc Plant could only handle 3 MGD Anything > = MASSIVE WASHOUT Seen it All Brown and Caldwell 4 16 X 120 Clarifiers

What causes all of these things to happen? What where the commonalities? The end result had to be a simple decision making tool Operators had to Understand Original Design Intent (train, train, train, 21 conversations) SOR, Weir Overflow Rate, Solids Loading Rate, Solids Under-loading Rate Nuances of settled sludge Too much or too little food results in poor sludge quality Questions and Quest for Knowledge (The Grail) Brown and Caldwell 5

Drawings Influent Distribution Baffles Pump Capacities Flow Meters Calibration Needed to Understand Original Design Intent and Changes Brown and Caldwell 6

Found that the tanks were built in 1956 Original Primary Clarifiers Original operating depth was 7 feet Institutional knowledge was “ever since (1972) we got that aeration basin and those new primary clarifiers these final clarifiers have been nothing but a problem” Drawing Review Brown and Caldwell Grit Removal Primary Clarifiers Aeration Basin series/and parallel Gas Storage Digester Retrofit old primary clarifiers to finals Disinfection

Added Three Ponds (did I mention our collection system 240 MGD) 1978 Upgrade Brown and Caldwell 8

Drawings Said Yes Tank Inspection=NO! Most taken out during collector upgrade but not replaced $3,000 fix Final Clarifiers-I (used to) Have Baffles Brown and Caldwell 9

Inspecting for debris is very helpful Sampling the entire water column? Could a sludge judge, some buckets and a little laboratory work tell you anything? Proper Sludge Judge Use (ITA Study) Dye testing can be helpful CFD modeling can be helpful Influent Distribution Brown and Caldwell 10

Quieted the entry of the aeration basin effluent (no waterfalls into clarifier) mid-depth entry is was best Adjusted influent gates to even flow Leveled and set effluent the weirs Bucket tests of the RAS pumps Additional Efforts Brown and Caldwell 11

Identify all parameters where someone could make a decision, adjustment, equipment on and off Calculate standard deviation for the parameters Found out RAS Flow standard deviation was 200% MLSS standard deviation was 1500 mg/L WAS Concentration similar Design Issues Vetted-Next Step-Operate Brown and Caldwell 12

Can the operator directly influence RAS TSS? Can the operator directly influence MLSS TSS? Can the operator directly influence WAS parameters? How does the tail wag the dog here? How ?? Brown and Caldwell 13

What is Quality Sludge? Activated sludge that: Flocculates Settles and filters Compacts The influences did not matter unless I understood the goal: Quality sludge to get the most out of our clarifiers! Brown and Caldwell 14

Recommends Using the Settleometer Recommends that RAS Flow Control is Very Important Discusses the concept of different settling sludges exist that can do the same thing Learn the Blues Before You Learn How to Rock and Roll Brown and Caldwell 15

Flocculation? Settling? Compaction? What does Sludge Volume Index have to do with any of these? When is it done flocculating, settling, compacting? What is SVI Really? Does SVI allow you to measure- Brown and Caldwell 16

Sludge can settle at a rapid rate Sludge can settle at a normal rate Sludge can settle at a slow rate Rate of Settling All three types of sludge can flocculate, settle and compact All three can remove enough BOD to meet permit All three can perform well in a clarifier Brown and Caldwell 17

How Does RAS Concentration respond to Changes in RAS Flow? Brown and Caldwell 18

How does MLSS respond to changes in RAS Flow? Brown and Caldwell 19

How Do Solids Filter and Compact in the Settleometer? Brown and Caldwell 20

Collect more data during settle test 5, 10, 15, 20, 25, 30, 60, 120, 180, 240 minutes 5 minute-measures settling 15 minute-filters 30 minute-compaction Recommendations from Al’s Work Brown and Caldwell 21

Less than 500   900 or higher  Use 5 minute reading on MLSS to Type I have a Rapid Settling Sludge I have a Normal Settling Sludge I have a Slow Settling Sludge Brown and Caldwell 22

The goal is to determine when is the RAS sludge done settling, filtering and compacting in the final clarifier Spending the correct amount of time in the final clarifier allows much better process control Al Says - How do I know when its time to send the bugs back to the aeration tank? RAS Settleometer Test Collect Data at: 30 Minute 60 Minute 120 Minute Brown and Caldwell 23

<500  Rapid  RAS at 30 Min  Normal  RAS at 60 Min 900 or higher  Slow  RAS at 60 Min Use 5 minute reading on MLSS to Decide RAS Test Brown and Caldwell 24

What kind of sludge Use appropriate RAS Reading (30, 60 or 120 min) When RAS is at 900 its done What Now? Is reading above or below 900? If above 900 RAS turn RAS rate up 5-10% If below 900 turn RAS rate down 5-10% Brown and Caldwell 25

Before No more than 3 MGD Massive solids loss during storm events Permit Anxiety Flow diverted to other facilities Extreme STD DEV Remember My Plant? After 13 MGD Highest effluents out of plant were 50 ppm Reduced flow diversion by 85% MLSS STD DEV 300 mg/L RAS STD DEV 25% Brown and Caldwell 26

Unlock hidden capacity without adding any concrete Reduce energy usage Nutrient removal UV disinfection Your ready to rock and roll! If you can master this simple settleometer technique Brown and Caldwell 27

Questions?? Mike Beattie Brown & Caldwell Operations/Reliability Brown and Caldwell 28