Research On Resource Utilization And Harmless Treatment Of Food Waste

With the rapid development of my country’s economy and urbanization,food waste pollution has gradually become one of the main environmental factors affecting human health.Food waste has high moisture content,rich organic matter content,and perishable deterioration.If it is not handled properly,it will pollute the environment and threaten the health of people.In addition,the cost of collecting and transporting household kitchen waste is too high.If aerobic composting reduction treatment of kitchen waste can be carried out in the home,it can effectively reduce the cost of treatment and save manpower.The products of kitchen waste composting can still be used for plant cultivation.In this study,the kitchen waste from the canteen of Nanchang University was used as the experimental object.The collected kitchen waste was drained into gravity water,and large pieces of waste were crushed.The paper scraps and bones and other refractory substances were manually removed,and mix evenly with wood chips,the ratio was 1:11.After that,use a simple garbage compost bucket as a container for aerobic composting.At the same time,a four-factor and three-level orthogonal experiment was designed,and the seed germination index（GI）was used as the evaluation index to analyze the influence of compost environment temperature,initial moisture content,EM bacteria dosage,and mixing frequency on waste composting.Finally,in view of the shortcomings of the simple composting bucket,a household kitchen waste composting equipment that can control the ambient temperature,aeration volume,and mixing frequency with uniform aeration is designed.The kitchen waste composting experiment was conducted on the basis of the new equipment,and compared the composting efficiency with simple composting bucket.The IBM SPSS STATISTICS 22 software was used to analyze temperature,moisture content,total carbon,total nitrogen,C/N,p H,conductivity,Correlation between water-soluble total nitrogen,water-soluble ammonia nitrogen,water-soluble total Phos Phorus,water-soluble nitrate nitrogen and other indicators and GI,calculate the range of relevant indicators when the stockpiles reach different states.The conclusions are follows:（1）Through orthogonal experiments,it is concluded that the best reaction conditions when the simple compost bucket is used as the reaction device are the ambient temperature of 45℃,the initial moisture content of 55%,the dosage of EM bacteria is 1.5%of the pile,and the stirring frequency is one day once.The degree of influence of related factors on the GI of the stockpile is from large to small:ambient temperature（8.61）,moisture content（5.67）,EM bacteria dosage（2.96）,stirring frequency（1.92）.In the 20-day composting cycle,the GI of No.4 sample was reaching to 87.89%;the GI of No.2 sample was about 74.51%.（2）Using the new equipment to simulate the composting experiment,the conditions were follows:ambient temperature was 45°C,initial moisture content was55%,stirring frequency was 20r/min,the dosage of EM bacteria was 1.5%of the pile,and the ventilation volume was aboub 0.35L/min.It takes 3～5 days for GI≥50%to reach half maturity;7～9 days for GI≥80%to reach full maturity;and 13～15 days for GI≥100%toxicity to disappear.The time required for composting was about 70～75%of the simple composting bucket.（3）GI is used as the criterion to judge whether the compost product is mature.Through analysis,it is found that the conductivity,water-soluble nitrate nitrogen,C/N and GI have the strongest correlation,and the correlation coefficients are-0.936,0.918,0.910,respectively.Stack temperature,water-soluble total nitrogen,and water-soluble ammonia nitrogen have the weakest correlation with GI,and the correlation coefficients are-0.309,0.109,0.055,respectively.（4）When the GI≥80%,The range of indicators with strong correlation were as follows:C/N drops below 15;water-soluble nitrate nitrogen reaches and stabilizes above 390mg/kg;EC drops and remains at 3750 u Scm^-1or less.When the GI≥100%,C/N drops below 13;water-soluble nitrate nitrogen rises and stabilizes above420mg/kg;EC drops below 3550u Scm^-1.