Estimations of the Heating Value and Composition of Infectious Waste Discharged from Medical Institutions

Abstract

Information about waste properties (heating value, water content, etc.) is important in waste incinerating operations. However, investigating the properties of infectious waste discharged from medical institutions is difficult to due to its infectiousness. In this study, the properties of infectious waste were investigated by considering the heat balance and material balance in a waste incineration plant that co-burns infectious waste and industrial waste. The total amount of heat generated in the incinerator was estimated by considering the amount of heat in the combustion gas. Then, the lower heating value of the infectious waste (28.3 MJ kg −1 -wet) was estimated by subtracting the amount of heat derived from the industrial waste from the total amount of heat. The proportions of chlorine (3.23 wt%-wet) and ash (4.93 wt%-wet) in the infectious waste were estimated by the same method. The chlorine and ash derived from the industrial waste were subtracted from the total amounts output from the incinerator. To obtain the properties of the infectious waste itself (not including containers), the contribution of sealed containers (plastic containers and cardboard boxes, total 14.7 wt%-wet) were estimated. The biobased content of the infectious waste itself (14.2%C) was estimated by analyzing 14 C content in a sterilized sample.