CHARACTERIZATION OF COMPOST FROM A PILOT PLANT-SCALE COMPOSTER UTILIZING SIMULATED SOLID-WASTE

A pilot plant-scale composter using simulated solid waste was develope d to test the fate of consumer products such as disposable diapers. Th e simulated waste consisted of a mixture of rabbit chow (which include d alfalfa), shredded newspaper, sand, and composted cow manure. The co mpost mass self-heated from an ambient temperature of 27-degrees-C to about 55-degrees-C in the first 24 h. Dissolved ammonia levels, high i n the early stages of the process, began to decrease after about 4 wee ks as nitrate concentration began to increase. Both volatile solids an d carbon:nitrogen ratios exhibited gradual decreases with time. Microb ial biomass, esterase activity, cellulose mineralization, direct micro scopic counts (AODC), and relative APIZYM enzyme activity increased si gnificantly in the first several days, and maintained higher levels th an initial measurements throughout the 22-week testing period. We conc luded that the simulated solid waste underwent physical, chemical, and microbiological changes that would be expected to occur in municipal solid waste in a full-scale composting system. The pilot plant-scale c omposter should prove to be a valuable tool in assessing the fate of p roducts and materials under simulated compost conditions.