Odor Control without Chemicals MWEA/AWWA Joint Conference August 11, 2010 Mark Prein, P.E.

Odor Control without Chemicals

MWEA/AWWA Joint Conference

August 11, 2010

Mark Prein, P.E.

Why Odor Control?

Be a Good Neighbor – Public Image Issue Health and Safety Asset Management

Treat the Symptom or the Disease

Big choice Do you / can you prevent it from ever happening? Potential huge cost ramifications

Where is it coming from?

Different processes have different smells Once ID, how do you collect odor laden air? If contain, then corrosion?

Not All Odors Are the Same

Sulfur Compounds Ammonia

VOCs Other

Treatment Options

Chemicals Caustic, Hydrogen Peroxide, Bioxide or equivalent

Scrubbers Masking Agents Salts Enzymes Carbon Ozone Seal it and forget it.

The Solution

to Odor is

Dilution

Case #1 – Feasibility Study

What about using the odor laden air? Collect and use as feed air for treatment process Caution needed

Quantity of air constant vs. end use

Quality of air Depends on source

Potentially cost effective Understand risks

Case #2 – NKSA Collection EPA recommends laminar flow of wastewater Significant Odor Issue System Sealed to prevent odor complaints Collection System failure(s) from H2S Corrosion

Case #2 – NKSA Collection

Case #2 – NKSA Collection Proposed Alternate

System Reconstruction Required

Add carbon filters and open the system up

Add re-aeration to system (turbulence)

Use available grade Prevent from becoming

anaerobic

Case #2 – NKSA Collection

Results Eliminated odor

complaints No active odor

treatment in reconstructed lines

Eliminated H2S generation

Reduced overall construction cost

Case #3 – NKSA Four Mile LS

Original Built in 1968 Significant Odor and

Corrosion Problem Located in Residential

Neighborhood Previously Tried

Chlorine Scrubber Station Sealed

Case #3 – NKSA Four Mile LS

Biofilter Treatment for wet well 150 ppm ave. Hydrogen

Sulfide, Mercaptans Air Volume = 2,000 scfm Two Modules (package) 36 second bed time Negative pressure Redundant blowers Roof Discharge

Case #3 – NKSA Four Mile LS

The Plan

Case #3 – NKSA Four Mile LS

Constructed

The Look and What Smell

Case #3 – NKSA Four Mile LS

Case #4 - MCWMS

Rehab of Existing Odor Stripper and Treatment Rehab odor reduction building Replace control gates and mixers Update electrical Address issues with significant chamber corrosion Still issue with channels – long term proposed to cover Estimated cost ~$750,000

Proposed alternate – eliminate both!

Case #4 - MCWMS

Alternate - Plant Feed Rerouting Prevent the odor from ever getting to the air Simple No active treatment system, eliminate existing system Complete as part of overall system improvement Eliminate O&M costs Capital cost ~$600,000

Case #4 - MCWMS

Case #4 - MCWMS

And No More Channel

Case #5 – NKSA CWP

Process Control NKSA Biosolids Holding Tanks Avoid odor issues Minimize Energy Accomplish with Process Control

SCADA with DO and ORP probes Cost – Minimal cost for probe and

programming Saving – Significant reduction in

operating costs

Case #5 – NKSA CWP

West Tank

Case #5 – NKSA CWP

SCADA Control

Case #5 – NKSA CWP Tracking -Trend Screen

Case #6 – NKSA CWP

Case #6 – NKSA CWP

Biofilter Treatment for Headworks and Solids Handling Rooms Air Volume = 15,000 scfm Hydrogen Sulfide, VOCs, Mercaptans, Ammonia 30 second bed time Built in Place – equipment cost 310K Positive Pressure Redundant blowers w/VFDs

Cost of Biofilter Equipment = $310,000*

Case #6 – NKSA CWP

Case #6 – NKSA CWP

The Plan

Case #6 – NKSA CWP

Support Grading Collect all Headworks and Solids Handling Room air

Case #6 – NKSA CWP

Lower Irrigation Maintain negative pressure in rooms

Upper IrrigationLower Irrigation

Case #6 – NKSA CWP

Upper Media No hazardous chemical usage

Case #6 – NKSA CWP

Polishing Media Treat to none detectable levels – Nose test

Case #6 – NKSA CWP

Covers and Pipe Consider freezing issues

Case #6 – NKSA CWP

Most Frequent Comment?

Thank you.