关键词: 医疗垃圾, 飞灰, 活性炭, 水泥, 固化

Abstract: The cement solidification tests of hospital waste incineration fly ash (FA) and of the ignited fly ash (IFA) were respectively carried out to ascertain the effect of activated carbon in FA on the solidification process. The results show that activated carbon in FA results in delay of setting, and decrease of compressive strength and excessive heavy metal leachability. The setting time of the cement mixture with 60% FA is prolonged up to 63 h, exceeding acceptable time of 48 h. The unconfined compressive strengths of the solidified products with 40% FA and 60% FA are respectively 0.187 and 0.16 MPa after 7 d below the minimum limit of 0.2 MPa. Conversely, the solidified products of IFA at the same ration can measure up in setting time and compressive strength. The Pb leaching concentrations of solidified products incorporating 40% FA and 60% FA are respectively 5.634 and 6.032 mg/L, which can not meet the leaching standard (5 mg/L). However, the solidified products incorporating 60% IFA are merely unacceptable.

Key words: hospital waste, fly ash, activated carbon, Portland cement, solidification