65    STATIC PILE COMPOSTING OF CRANBERRY RECEIVING
WASTES AND PROCESSING RESIDUES
Frederic C. Blanc, Professor
Department of Civil Engineering
Northeastern University
Boston, Massachusetts 02115
James C. O'Shaughnessy, Professor and Head
Department of Civil Engineering
Worcester Polytechnic Institute
Worcester, Massachusetts 01609
INTRODUCTION
Cranberry fruit receiving and cranberry processing operations produce a large amount of solid
waste which is presently being disposed of by landfilling in some locations. Because of the agricultural
nature of the waste products, the opportunity of composting to produce a soil conditioner is attractive. This chapter presents results from a large static pile pilot composting study conducted on such
residues in the winter and spring of 1985. The wastes in this study may be characterized as vines, pulp,
screenings, leaves, rice hulls and berries. These materials are organic in nature, low in available
nutrients, and low in pH [in the 2.5 to 4.5 range]. The wet putrescible solids from the processing and
receiving operations are not appropriate for incineration and must be disposed of by landfilling, land
application or composting. Composting will stabilize the materials, reduce the volume and produce a
finish product which is marketable.
BACKGROUND
Composting can be accomplished by a variety of different methods. Categorically, the static pile
process, in-vessel process, and windrow composting are the methods normally used. The static pile
process is one in which solids to be composted are placed on piles constructed with an internal
aeration pipe system. Figure 1 depicts a series of aerated static compost piles. Such piles are constructed by placing a perforated aeration pipe on the ground and covering it with a thin layer of wood
chips, other bulking agents or unscreened finished compost. This porous layer allows rapid distribution of the air which is either forced or drawn through the pile of solid waste created on top of the
layer. The trapezoidal static pile created in this fashion is generally 8 to 10 feet in height. This height is
limited by the equipment used in the pile construction. The base width and length of such piles can
vary considerably.
Aerobic decomposition of the volatile organic solids in the waste occurs as the pile is aerated over a
period of time. Without aeration, anaerobic decomposition would occur in the pile creating malodorous intermediate substances. Aeration is also useful in lowering the moisture content of the composting material in the pile.
Biological activity is a function of temperature up to a maximum allowable temperature. The static
pile becomes very warm due to aerobic decomposition. Thermophilic bacteria begin to dominate the
process at high temperatures. In the case of sewage sludge composting, the high temperatures which
might be developed can destroy pathogenic organisms originally present in the sludge.
PILOT STUDY OBJECTIVES
The objectives of the pilot study were:
• Analysis of the cranberry receiving trash and other residues.
• Determination of reasonable requirements for supplemental nutrients, buffering agents,
and bulking agent needed for mix design.
43rd Purdue Industrial Waste Conference Proceedings, © 1989 Lewis Publishers, Inc., Chelsea, Michigan 48118.
Printed in U.S.A.
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