Wet, Anaerobic, Composting of Dissolbing Kraft Primary Treatment Sludge and Brown Stock Knotter Rejects, 1996 Environmental Conference Proceedings

Rayonier operates a 1700 ton per day dissolving Kraft mill at Jesup, Georgia. The operation generates on average 175 tons per day of primary treatment sludge and 35 tons per day of brown stock knotter rejects. Prior to 1995, the majority of these wastes were disposed through landfilling, with a smaller amount going to dredge spoils basins. Inspection of existing landfills revealed little decomposition of deposited material over periods up to twenty five years. Experience with the dredge spoils basins indicated that wet, anaerobic composting could reduce the sludge and knotter rejects to a stable beneficial soil amendment. An enhanced system for seeding, blending, and holding the materials was developed. Following a successful trial period, the wet composting process has been employed to manage all primary sludges and knotter rejects as they arc generated. The composting system has been included within the facility NPDES permit and the compost product has been approved by the Georgia Department of Agriculture as a soil amendment. The existing landfills for sludge and knotter rejects arc being reclaimed through the compost system with an overall objective of fully recovering the landtills over a ten to fifteen year period.