Optimum Research On The Tower Aerobic Composting Reactor

With the increasing of population and demand of livestock food, waste, such asorganic waste, increases unceasingly, which will be one important pollution sourcewithout properly treated. Aerobic composting is an effective treatment method fororganic waste.At present, the aerobic composting system used by the ventilation mode can bedivided into natural ventilation systems, passive ventilation systems and mechanicalaeration systems. The natural ventilation systems cost less energy, but ventilated effectis poor and vulnerable to climate influence; The passive ventilation systems is easy tooperation and control, but its operation and maintenance cost is higher, the energyconsumption in severe cases. Summing up the above characteristics, and combined withtower biological filter ventilation mode and high-rise building in the chimney effectventilation theory, developed a tower aerobic composting reactor, in natural ventilationas the main way, assisted by forced ventilation. But the reactor natural ventilation effectis poor, the processing efficiency is low, therefore, the performance optimization isparticularly important.Through the theoretical calculation, add ventilation tube with the originalcomposting reactor, and pull test to verify its effectiveness in composting. The mainconclusions are as follows:(1) Without the drawing pipe, composting was carried out on the different materialratio (human feces/sawdust=1/2.5,1/3,1/4) with the tower aerobic composting reactor.The COD degradation effect of1/4is little better than1/2.5and1/3, but the processingcapacity of1/2.5is high, at the same time, can meet the basic conditions of the compost.The material ratio of1/2.5can be set the best material ratio for this reactor. (2) Added different height of vent pipe for the reactor (total height2m,3m,4m),and carried a compost test. When material total weight is5.65kg and reactor totalheight is3m, compared with2m and4m, the composting process had a hightemperature period and the temperature is higher, meet the national waste harmlesshealth standard. The COD removal rate is56.45%, which is higher than that of2m and4m of47.26%and52.82%, and this show this compost effect is better. The resultsproved that the reactor height theoretical calculation is correct.(3) For the common composting problems, such as the heat is difficult toaccumulate in winter, high temperature composting period is shorter, COD removal rateis low, ect, a inoculating composting experiment during the winter (November) wascarried out, compared with the control experiment without inoculating microbes.Results showed that the inoculated material heat up fast, and the high temperatureperiod concentrated, and the highest temperature is higher than the material withoutinoculation, but the COD removal rate are basically same. Vaccination has noteffectively promoted the compost were.In addition, high temperature compost nitrifying bacteria activity test resultsshowed that at45℃, the nitrifying bacteria still has certain activity;50℃, the nitrifyingbacteria inactivation. Heating up the temperature of the metiral to high temperaturestage (above50℃), in order to shorten the composting period and to omit the normaltemperature fermentation stage, is not workable.