| Human and animal feces as pollutants have the characteristics of high content of germs and microorganisms,high infectivity,and irritating odor.If the harmless and effective treatment cannot be carried out in time but directly discharged into the environment,the organic matter,nitrogen,phosphorus and other substances rich in feces will cause great harm to the environment.Therefore,how to efficiently and quickly treat feces has become a current research hotspot.The heat treatment technology of manure includes dry pretreatment technology of manure,pyrolysis technology of manure,technology of incineration and ashing of manure,etc.This technology has the advantages of short treatment cycle,high degree of harmlessness,high energy utilization rate,high bacteria removal rate,and maximum volume reduction.Among them,the pyrolysis technology of manure is able to produce various products with added value.However,this type of technology usually uses electric heating,which consumes high energy and has a slow temperature rise.Therefore,on the basis of fecal heat treatment technology,the use of microwave heat treatment of feces can further shorten the fecal treatment cycle and achieve real-time treatment of feces,and the energy consumption is much lower than the use of electric heating fecal treatment technology.This article uses fresh cow dung as a treatment object,and explores the effect of microwave radiation technology on manure treatment.The effects of microwave power,radiation time,atmospheric conditions,and temperature on the results of manure treatment were studied.Based on the research results of microwave direct radiation treatment of feces,it is found that microwave drying technology and microwave pyrolysis technology are far superior to the use of electric heating fecal drying technology and fecal pyrolysis technology.The results show that it takes 180S to dry 5g of feces by microwave drying,and 40 minutes by electric drying,which is 13 times that of microwave drying.However,due to the poor wave absorption ability of the feces,microwave ashing of feces cannot be achieved.On this basis,a combustion synthesis method is used,using silicon powder and carbon black as raw materials,aluminum powder as a solid solution doping raw material,and polytetrafluoroethylene(PTFE)as a combustion aid,to synthesize Al-SiC materials under a nitrogen atmosphere at 1350?.This is used as a microwave sensitizer to achieve the effect of assisting the heating and ashing of human and animal feces in the microwave field.In addition,the optimal synthesis conditions of Al-SiC were explored.The results showed that when the molar ratio of C:Si:Al material was 10:9:0.5 and PTFE was 15w%,the synthesized Al-SiC material had the best performance.Under the microwave field of 1400W,it can be heated to above 1000? within 7-8 minutes,and the temperature rise rate is above 125?/min.In addition,the highest withstand temperature of Al-SiC has been tested to 800?.Adding Al-SiC as an additive to the feces can raise the feces to 1000? in a microwave field of 1400w,which takes less than 10 minutes.The treatment results show that the fecal quality can be reduced by about 83%.Finally,XRD,infrared chromatography,thermogravimetric analyzer(TG),SEM,EDS,microwave tube furnace thermometer and element analyzer were used to analyze and characterize Al-SiC materials and feces.The superiority of microwave treatment technology for feces is discussed. |
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