Project Number: 8042-21660-004-09
Start Date: Sep 01, 2010
End Date: Dec 01, 2013
ARS will conduct side-by-side comparison tests of composting using four distinct technologies described to handle highly unstable organic residuals such as crab chum: 1) Aerated Static Pile with compost blanket covers, 2) Ag-Bag (containerized) composting, 3) RCM containerized composting, and 4) Wright Environmental In-vessel composting. Input feedstock material will be the same mixture for all four systems, approximately two parts woodchips to three parts crab chum. Systems 1, 2, and 3 will use 40 cu yds. of the residuals mixture and each will be mechanically exhausted independently to biofilter piles composed of mature compost and wood chips (6 cu yd each) and operated according to the manufacturer's recommended best practice. Biofilter piles will be containerized so that all exit air can be analyzed real-time by infrared sensor technology. Residence time in the primary phase thermophilic composting is expected to range from 20-30 days and curing period is expected to range from 30-45 additional days. System 4 is smaller (600 lbs per day (1.5 cu yd)) and will be operated as the manufacturer suggests for 14 days with its own containerized biofilter. Wright compost will then subsequently be cured in an open-air non-mechanically aerated compost pile. This Wright Environmental unit accommodates for 14 days and is also biofiltered. Temperature profiles from exterior most positions to the core will be continuously measured and referenced to ambient temperatures. Exhaust gases, before and after the biofiltration units, will be collected and measured with a Jerome meter (for reduced-S compounds), GasTec for amines and ammonia, Innova (for CO2, CH4, N2O), PPBRae (for total VOCs). Field-based olfactometry tests (Scentometer) also will be conducted on biofilter exhaust. Solids and leachate samples initially and at periodic intervals will be characterized according to U.S. Composting Council, USDA, and USEPA compost quality standards. Information will be used by both ARS and the Cooperator to jointly determine which methods will provide the best option for an economically and environmentally sustainable practice for transforming currently landfilled crab waste to a beneficial horticultural planting medium.