Effect of chemical and thermal activations on the properties of rice husk ash-based solidified waste

• 作 者: Nipon Tanpaiboonkul Suwimol Asavapisit Wichai Sungwornpatansakul
• 机 构: Division of Environmental Technology,School of Energy Environment and Materials,King Mongkut’s Unive
• 出 处: 环境科学学报（英文版）
• 发表日期: 2010年12期
• 关键词: rice husk ash heavy metals sodium silicate strength leaching microstructure

Strength development,leachability and microstructure of heavy metals from the solidified waste using synthesis rice husk ash(Srha)and lime blended at the weight ratio of 1:1 were used as binders.The heavy metal-containing sludge was used at the level of 0 wt.%,30 wt.%,and 50 wt.% dry weight,respectively.The sample specimens with and without 1.5 wt.% of sodium silicate(SiO2/Na2O＝1.O) were cured under the ambient condition and elevated temperature curing at 50℃ for 24 hr.Experimental results showed that the introduction of sodium silicate solution and elevated temperature curing to Srha-based solidified waste containing 30 wt.% of heavy metal sludge gave one day strength of 20 kg/cm2 compared to 0.9kg/cm2 for the control sample.XRD patts indicated that most metal-sulfides present in the sludge were appeared in the solidified waste and SEM coupled with EDX techniques reveal these metal-sulfide particles were trapped within the lime-Srha matrices.In addition,cumulative leaching behavior by tank test(EA NEN 7375:2004)showed that solidified waste containing up to 30 wt.% of heavy metal sludge was suitable to dispose in a secured landfill.