MICROBIAL ACTIVITIES DURING COMPOSTING OF PULP AND PAPER-MILL PRIMARYSOLIDS

In this study, bench-scale aerobic reactors were used to monitor micro bial activities and determine the degradability of pulp and paper-mill primary solids. Over the 43-day composting period, the level of micro organisms detected increased four-fold. However, based on amounts of C O2 produced, the increase expected was 19-fold, suggesting lysis of so me cells in the population. The composition of the microbial populatio n, determined through species identification by the BIOLOG(R) method, and by spot plating, changed throughout the composting process with Ce llulomonas spp. not appearing until day 22. Chemical analyses suggeste d a fall of 33% in the cellulose content, but no other statistically s ignificant chemical changes were observed.