加热方式对固体废物水分含量测定的影响研究

Research on the Influence of Heating Methods on the Determination of Moisture Content of Solid Waste

通过条件实验确定烘箱加热法的恒重条件,确定微波加热法、红外加热法和烘箱加热法测定固体废物水分含量的最佳样品称取量。采用3种方法的最佳条件分别测定了10余种不同类型的固体废物的水分含量,比较了3种方法的测定时间、精密度和测定值的差异性。结果表明:烘箱加热法的最佳恒重条件为前后2次测定差值不超过最终测定质量的±0.1%。烘箱加热法最优称样量范围为25~45 g,红外加热法和微波加热法的最优称样量分别为3.0 g和2.5 g。烘箱加热法所需测定时间最长,约8~28 h,红外加热法和微波加热法所需测定时间分别为4~65 min和1~2 min。3种方法中烘箱加热法精密度最好,且样品水分含量越高精密度越好,烘箱加热法、红外加热法和微波加热法的相对标准偏差范围分别为0.31%~12%、4.6%~18%和1.1%~22%。在0.05的显著性水平上,3种方法测定值不存在显著性差异。

The constant weight condition of the oven heating method was determined by the condition experiment The optimum sample weight for the microwave heating method,the infrared heating method and the oven heating method to determine the moisture content of solid waste was determined,too.The moisture content of more than ten different types of solid wastes was determined by using the optimum conditions of three methods,and the differences of determination duration,precision and datas of the three methods were compared.The experimental results showed that the optimum constant weight condition of the oven heating method was that the difference between the two measurements did not exceed±0.1%of the final mass.The range of the optimum sample weight for oven heating method was 25-45 g,while the optimum sample weight for infrared heating method and microwave heating method was 3.0 g and 2.5 g,respectively.The determination duration required by oven heating method was the longest,about 8-28 h,and the determination duration required by infrared heating method and microwave heating method was 4-65 min and 1-2 min,respectively.Among the three methods,the oven heating method had the best precision,and the higher the moisture content of the sample,the better the precision.The relative standard deviations ranges of oven heating method,infrared heating method and microwave heating method were 0.31%-12%,4.6%-18%and 1.1%-22%,respectively.At the significance level of 0.05,there was no significant difference among the three methods.