Validation of MIL SPEC Tests for Evaluating Biodegradable Degreasing Agents for Shipboard Applications
Client: U.S. Navy
Project Size: $43,000
Duration: 6 months
In an attempt to reduce the environmental burden caused by the operation
of military ships, U.S. Navy operational regulations call for the use of
environmentally benign technologies where possible. The objective of the
work performed in this project was to evaluate, assess and make recommendations
on a set of three draft protocols intended to determine the efficacy of
bioaugmented cleaning products likely to be used in Navy shipboard operations.
The three protocols involved waste from galley discharge, oil water separators
and the bilge. Each of the three draft protocols was performed as described in
the Draft Protocol document (prepared by NSWC, Carderock Division, Code 632),
with appropriate modifications as noted. The results were evaluated to determine
whether the protocols address the question of product efficacy. Specific
recommendations were presented to improve the performance of the test protocols.
Protocol #1 is for testing the efficacy of cleaning agents used
in Galley Areas as well as Containment, Holding and Transfer (CHT) tanks.
The intent of this protocol is to demonstrate the ability of enzymatic and
bacterial-based cleaners to remove grease build-up from the wastewater in
galleys, food preparation areas, heads and laundries that empty through the
piping into the CHT tanks. These systems contain animal and vegetable wastes
and present a challenge in dealing with residual congealed oils, fats and greases.
The test protocol was designed to simulate shipboard environmental conditions.
Protocol #2 is for testing products used in the cleaning of Oil-Water
Separators. The objective of this protocol is to demonstrate the ability of
enzymatic and bacterial-based cleaners to remove oily waste deposits from
polypropylene plates used in oil-water separators. The method involves a
two-tier procedure aimed at monitoring the cleaning of the plates through
visual inspection (Tier 1) and quantitative measurement of the released waste
(TPH assay). Design of the protocol simulates oil-water separator operations.
Protocol #3 is for testing cleaning agents used in Bilge
Water/Ballastable Fuel Tanks. The intent of this protocol is to demonstrate
the ability of enzymatic and microbial-based cleaners to remove petroleum product
found on the surfaces of oil/water separators. Protocol #3 was designed to mimic
the challenges of handling emulsified oil and discharges from machinery and bilge
areas of the ship. A single tier method is employed. Product efficacy is assessed
by the ability to form an emulsion of an oil substrate in water. Visual and
analytical methods are used to assess efficacy.
From our analysis, protocols #2 and #3 provide the information needed
for effectively assessing the utility and efficacy of bioaugmented cleaning
products intended for handling oily wastes. Several modifications to each protocol
were suggested and adopted in order to simplify and reduce the cost of performing
the procedures. These two protocols were recommended for reduction to standard
operating procedures with specified criteria (MIL SPECs) for product performance
in the tests. It was further recommended that the performance criteria be related
to actual shipboard cleaning tests using the products tested in the study. In this
way, the efficacy of each product in a real-world setting could be correlated to
its performance in the evaluation protocols. Protocol #1 did not work as designed
and several recommendations for protocol changes were made to improve the utility
of the test procedure.