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

作　　者：Nipon Tanpaiboonkul Suwimol Asavapisit Wichai Sungwornpatansakul 

机构地区：[1]Division of Environmental Technology,School of Energy Environment and Materials,King Mongkut's University of Technology Thonburi [2]National Center of Excellence for Environmental and Hazardous Waste Management,Department of Environmental Engineering,King Mongkut's University of Technology Thonburi [3]Department of Civil Engineering,Faculty of Engineering,King Mongkut's University of Technology Thonburi

出　　处：《Journal of Environmental Sciences》2010年第12期1993-1998,共6页环境科学学报（英文版）

基　　金：funded by TRF Research Scholar(No. RMU5080007);the Royal Golden Jubilee Ph.D. Program under the Thailand Research Fund

摘　　要：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 = 1.0） 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/cme compared to 0.9 kg/cm^2 for the control sample. XRD patterns 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.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 = 1.0） 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/cme compared to 0.9 kg/cm^2 for the control sample. XRD patterns 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.

关 键 词：rice husk ash heavy metals sodium silicate STRENGTH LEACHING microstructure 

分 类 号：X712[环境科学与工程—环境工程]