Albert Robbat, Jr.Tufts University, Chemistry Departmentalbert.robbat@tufts.edu, 617-627-3474

Anthony SillariCity of Somerville, Chief Plumbing & Gas Inspectorasillari@somervillema.gov, 617-625-6600 ext 5633

A Collaboration BetweenTufts University and the City of Somerville

AimElimination of Fat, Oil, and Grease (FOG) Buildup

Using a Protein-based Degreaser

FOG is a Problem Everywhere

• Creates problems for homeowners, commercial restaurants, schools, universities, and hospitals

• Creates blockages in sink traps, interceptor wells, and underground pipes

• Results in inefficient operations and increasing maintenance costs

• Results in fines when FOG concentrations exceed regulatory limits

How do we deal with it?

constrained space access, time-

consuming and costly cleanouts

dangerous sodium

hydroxide

ineffective bacteria and

enzymes

The Solution

• Protein Matrix is a patent-pending technology that converts FOG into salts of fatty acids. The degreaser is– A mixture of proteins and polypeptides extracted from plants– Water-based– Non-toxic, non-volatile, non-flammable– Biodegradable– Environmentally safe – Contains NO bacteria or enzymes

Mechanism of Action

• The degreaser converts− FOG to a liquid byproduct that remains in solution by disrupting the

intermolecular forces that form FOG− FOG into much smaller compounds that are soluble in water

• Protein Matrix prevents FOG buildup in pipes, interceptors, and lift stations and reduces maintenance and cleaning costs

Protein Matrix Makes Liquid Soap

Fat Conversion

TrioleinPre-treatment

Oleic AcidTriolein treated with

=

=

Triolein has been converted to oleic acid!

• Pre-pilot: – Facilities contracted Wind River to pump traps quarterly– Some traps backed before scheduled pumping, increasing maintenance

costs

• Pilot: – Designed and built an automated spray application system– Each night 15 to 20 oz of Protein Matrix was sprayed into the trap

• Questions:– Did PM convert the mat of FOG into a flowable liquid without cleaning the

trap prior to application

– Once cleaned, did PM keep the trap clean and flowing

Grease Trap Study

Dining Hall Results

Tufts ResultsAfter 1-Month After 2-months

Kitchen

Bakery

Concentration Overtime

Tufts Pipes Cleaner

Before After

• Despite installing two 1500 gal gravity interceptor wells, which are pumped every other month, the restaurant continued to exceed FOG compliance levels

• Aqua America (PA), a $4 billion wastewater treatment plant owner and operator, suggested McDonald’s test the degreaser under normal operating conditions

• Unlike the tufts pilot, Protein Matrix was dosed continually into the floor drain

• Water quality parameters were measured for both interceptor influent and effluent streams

McDonald’s, Jennersville (PA)

GGI 1 (inlet) GGI 1 (outlet) GGI 2 (inlet)

Prior to treatment and after

1-month of buildup

After 3-months of treatment

McDonald’s Results

Video VideoVideo 14

McDonald’s FOG Levels Decreased

0

20

40

60

80

100

120

140

160

Fat,

iOil,

&G

reas

e (F

OG

) mg/

L

McDonald's Jennersville Pilot StudyInfluent Breakdown Maintenance

breakdown of preexisting Fat

maintenance periodFree of FOG mats

Dramatic Improvement in Effluent Qualitysample dateHJV cBOD (mg/L) FOG (mg/L) TSS (mg/L) N AMMONIA (mg/L) P (mg/L)

10-Feb-13 513 85 266 17.8 31.6724-Feb-13 370 69 302 80.2 23.839-Mar-13 297 49 274 41.6 32.67

23-Mar-13 750 14 216 52.8 21.56-Apr-13 467 36 260 18.1 31.525-Apr-13 1470 106 672 24.7 30.58-May-13 600 10.1 292 40.6 10.328-May-13 600 32 722 15.7 3110-Jun-13 450 103 426 15.6 10.523-Jun-13 605 134 108 43.2 27.513-Jul-13 371 62 168 31.4 20.527-Jul-13 508 6.3 362 23.1 2.615-Sep-13 900 141 1310 124 35.528-Sep-13 1065 54 340 47.7 28.57-Oct-13 303 8.1 288 16.4 7.628-Oct-13 198 6 188 27.3 14.311-Nov-13 535 42.6 612 37.9 3123-Nov-13 360 25.4 174 29.4 13.57-Dec-13 162 31.2 382 21.3 21.523-Dec-13 600 52.3 380 21.1 3211-Jan-14 413 26.4 204 41.6 3127-Jan-14 515 19.4 502 39.6 14.38-Feb-14 990 33.6 378 5.4 17.323-Feb-14 439 46 556 36 7.6

2-Dec-14 608 24 120 46.8 9

16-Dec-14 750 87 98 48.8 8

30-Dec-14 765 56 114 28.6 7.2

13-Jan-15 422 21 130 66 7.75

29-Jan-15 585 35 220 24.9 27.9

10-Feb-15 2130 62 290 5.7 15

24-Feb-15 1740 89 308 12.9 10.3

11-Mar-15 1335 5 170 9.5 5.25

24-Mar-15 1245 13 134 19.7 2.1

7-Apr-15 388 12 15 12.4 4.7

5-May-15 2940 57 565 12 2.4

19-May-15 12 9 6.6 0.26 0.12

2-Jun-15 840 39 60.5 21.7 0.31

McDonald’s PipesBefore After

Vent Degreaser

BakeryRackVideo

Pilot Study

• These studies demonstrate Protein Matrix– Prevents FOG accumulation grease traps and interceptor wells– Reduces risk of FOG buildup in pipes– Reduces risk of exceeding regulatory limits and, in turn, fines – Decrease long-term maintenance and operations costs

Summary

Acknowledgements

• Post-doctoral fellows, PhD, Patrick Antle and Christian Zeigler

• Thomas Atmer, undergraduate, BS• Tufts University facilities and plumbers