Composting toilet is accepted for environmentally sound and cost effective alternative of flushing toilet. In this paper, advantages of using composting toilet compared to flushing or pit toilet in terms of environmental quality were described. And principles of human waste decomposing processes within composting toilet were explained. The potential problems of adopting composting toilet to our rural area were also discussed. Treatment efficiency was tested on-site and results confirmed that the composting toilet could be used as alternative one in rural area.

The sewage sludges and livestock manures, respectively, were composted with sawdust used for control moisture in the static piles system composter. The variations of temperature, pH, moisture, C/N ratio, inorganic content, forms of organic materials and nitrogen, and contents of heavy metals were investigated. The results were summarized as follows ; The temperature for composting the sewage sludges reached the highest temperature of 52℃, after 3 days and lasted for 7 days, and then went down 30℃ after 52 days. In the case of composting livestock manures, the temperature reached to 63℃ after 10 days, that lasted for 10 days, and then went down gradually. After upsetting the sewage sludges and livestock manures, the temperature went up but was little changed after 52 days. Thus we decided that the terminal of composting periods would be 52 days. The moisture contents of the sludges and livestock manures for composting were decreased to 30% and 36%, respectively. The contents of inorganic matters and heavy metals were changed by the characteristics of raw materials but increased gradually during composting process. The total contents of organic materials in the sewage sludges and livestock manures for composting were decreased to 7% and 9%, respectively. The contents of ether extracts, resins, hemicellulose and cellulose were decreased but those of water soluble polysaccharides and lignins were not changed. The total contents of nitrogen in sewage sludges and livestock manures were decreased to 43% and 34%, respectively.

To study the optimum conditions of composting with industrial wastewater sludge, the variations of temperature and CO_2 generation amount during the composting periods were investigated. The conditions were that industrial wastewater added to bulking agents such as sawdust and rice hull was used, and differently treated with microorganism seeding or not, initial C/N ratios, air flow rate and initial moisture contents, respectively. The results were summarized as follows ; Seeding 5% of microorganism was higher the temperature than not seeding. And using sawdust as bulking agents, and adjusting 30∼40 of initial C/N ratio, 200㎎/ℓ·min. of air flow rate and 67∼68% of initial moisture contents were higher the temperature than any other conditions. Seeding 5% of microorganisms was higher CO_2 generation amount than not seeding. And that was much in the order of 7∼40, 30∼34 and 22∼23 of initial C/N ratio. Judging from the results, it should be considered that the optimum conditions in the composting of industrial wastewater sludge were seeding of 5% microorganisms, and adjusting 30∼34 of initial C/N ratio, 200㎎/ℓ·min. of air flow rate and 67∼68% of initial moisture contents. The contents of inorganic matters and C/N ratio during the composting periods at optimum condition were a little increased, and heavy metals contents after composting were lower than standard for fertilizer.