高含固餐厨垃圾有机组成对其流变特征的影响

Effect of organic composition of high solid food waste on its rheological behaviors

餐厨垃圾在厌氧消化过程中的流变特征直接关系到搅拌传质和产甲烷效率,而餐厨垃圾的有机物组成差异可能导致其表现出不同的流变特征.本研究以碳水化合物、蛋白质、脂肪和纤维素等不同有机组成比例的餐厨垃圾为对象,通过单因素实验,研究单一组分对餐厨垃圾流变特征的影响.结果表明,在TS 15%的条件下,淀粉类碳水化合物比例的增加将增大餐厨垃圾的粘度,使屈服应力和宾汉粘度分别呈指数(τ_(B)=6.098x0.14)和线性关系(μ_(B)=0.795x+0.0971)增长;热加工后的豆制品蛋白质比例增加反而降低餐厨垃圾粘度,使屈服应力和宾汉粘度分别呈线性(τ_(B)=6.976x+12.043)降低和指数(μ_(B)=0.668e^(-1.584x))降低的变化趋势;粮油类脂肪因其为牛顿流体特征,其比例的增加不仅降低了餐厨垃圾粘度,屈服应力和宾汉粘度均呈对数降低(τ_(B)=8.459lnx+37.184和μ_(B)=0.373lnx+1.676)的变化趋势;而蔬菜类纤维素比例的增加将增大餐厨垃圾粘度,屈服应力和宾汉粘度均呈指数关系(τ_(B)=4.938e^(14.138x)和μ_(B)=0.263e^(11.76x))增加.因此,未来需依据不同有机组分组成差异下餐厨垃圾的不同流变特征变化规律,合理考虑不同组成餐厨垃圾搅拌控制策略和物料含固率.

The rheological behaviors of food waste in anaerobic digestion are related to efficiencies of the stirring,mass transfer and methane production,and the difference of organic composition of food waste may lead to different rheological behaviors.In this study,the food waste with different organic components of carbohydrate,protein,lipid and cellulose was selected in order to investigate effects of each organic component on the rheological behaviors of food waste by single factor experiment.The results showed that under the condition of total solids(TS)at 15%,the viscosity of food waste increased with the increase of starch carbohydrate percentage,and the yield stress and Bingham viscosity increased exponentially(τ_(B)=6.098x0.145)and linearly(μ_(B)=0.795x+0.0971),respectively.With the increase of protein proportion with hot-processed bean products,the viscosity of food waste decreased,and the yield stress and Bingham viscosity decreased linearly(τ_(B)=6.976x+12.043)and exponentially(μ_(B)=0.668 e^(-1.584x)),respectively.As grain and oil fats is characterized as Newtonian fluid,the viscosity of food waste decreased with the increase of its proportion,and both yield stress and Bingham viscosity decreased logarithmically(τ_(B)=8.459 lnx+37.184 and μ_(B)=0.373 lnx+1.676).The viscosity of food waste increased with the increase of the proportion of vegetable cellulose,and both the yield stress and Bingham viscosity increased exponentially(τ_(B)=4.938 e^(14.138x) and μ_(B)=0.263 e^(11.76x)).Therefore,considering the rheological behaviors of food waste vary with different organic components,it is necessary to optimize the mixing control strategies and solid content of food waste with different components during the AD treating the food waste in the future.