Abstract:
The purpose of this study was to investigate appropriate composting conditions in order to construct a suitable Garbage Automatic Decomposer Extinguisher for compost making in Thailand.To produce the compost, researcher focused on the effect of the moisture content, the particle size of sawdust, and the composting method. In constructing the Garbage Automatic Decomposer Extinguisher,the Japanese Garbage Automatic Decomposer Extinguisher (model AI) was used as a prototype in this research and development. The decomposed materials were consisted of food waste and bulking agents such as mixed sawdust from various kinds of hardwood.The result from the study showed that the appropriate conditions for making the fedbatch compost were the ratio between food waste and mixed sawdust (60 mesh) which started from 1: 5 (kg.: kg.) and the food waste feed rate that was 1.0 kg,/day. The controlled moisturecontent through out the whole process was at 40 - 60 % level. Twenty-eight kilograms of garbage could be digested in this machine within 28 days. The reduction rate of the organic carbon was 0.10 %/day. An approximate curing was 28 days. Thus the compost was produced at the end of this process.Another method in making the compost was the multistage fed-batch using the same starting condition as in the single-stage. The result of the first stage using this method showed that the reduction rate of the organic carbon was down to 0.05 %/day. Nine kilograms maximum capacity of food waste could be added into the machine.within no morethan 9 day and undergoing 60 days of the curing time. In the second stage, the decomposed remain from the first stage (1 kilogram) was used as a seed to be mixed with sawdust and food waste at the ratio of 4: 1 (kg.:kg.) The reduction rate of organic carbon increased to 0.1 1 %/day. Within this stage, the 12 kg, food waste could be added into the machine within maximum 12 days with 25 days approximate curing time. Then, the compost was produced within more than 69 days in total. Twenty-six kilograms of fresh garbage could be discarded into the machine using this method.Although the multistage fed-batch composting has a lower food waste loading capacity than the single stage fed-batch method, the advantageof the former one was that it could produce the compost daily without unpleasant smell through this process. Besides, the result showed that the efficiency of our own developed Garbage Automatic DecomposerExtinguisher Machine for fed-batch composting was comparable to that of the prototype one. The compost processing period using the two GADE machines was similar, both of which lasted about the month before the system started to fail.