Browsing by Author "Karikari, Prempeh"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Effect of Sawdust and Grass Clipping as Bulking Materials on Composting of Organic Waste from KNUST Campus
    (2011) Karikari, Prempeh
    The increase in student population has led to a corresponding increase in the generation of waste on the KNUST or university campus. Composting of the biodegradable portion of waste is seen as a better option to reducing the volume of waste and managing it at the same time. This study hence aimed to investigate the effect of some bulking materials on composting of the biodegradable portion of the waste generated. Bin composting was employed for this analysis. Composting was conducted over a 60 days period at the sewage treatment plant on the KNUST campus. Wastes were mixed in ratios of 1:1, 1:2, and 2:1 (v/v) ratio for sawdust/food waste (SSD 1:1, SSD 1:2, SSD 2:1) and grass clipping/food waste (SGC 1:1, SGC 1:2, SGC 2:1). Turning of compost was done manually at three days interval during which the volume was also recorded. Temperatures were taken on daily basis, three times within a day. Total coliform and faecal coliform decreased to levels even below the standard of less than 3.00log10 MPN/g (< 1000 MPN/g) set by the USEPA for sanitary composting. There was a steady decrease in carbon content, nitrogen content and C/N ratio for all the ratios. Percentage content of potassium, phosphorus and pH all decreased gradually to appreciable levels which was adequate for compost manure. Volume of all bins reduced as percentage organic matter decreased leading to an increase in percentage ash to between 39.1 % and 64.5 %. Percentage moisture showed a decreasing trend as percentage total solids increased. By the end of eight weeks of analysis, the grass clipping/food (SGC 1:1, SGC 1:2, and SGC 2:1) waste ratios were seen to decompose faster than the sawdust/food (SSD 1:1, SSD 1:2, and SSD 2:1) waste ratios. Again, the grass clipping/food waste ratios had C/N ratio levels below 20 which are deemed matured for land or soil application as compared to the sawdust/food waste ratios which had C/N ratio levels above 20. The grass clipping/food waste ratios (especially the SGC 2:1) therefore gave better compost compared to the sawdust/food waste.