Feasibility of using reject fly ash in cement-based stabilization/solidification processes

被引:7
作者
Poon, CS [1 ]
Qiao, XC
Cheeseman, CR
Lin, ZS
机构
[1] Hong Kong Polytech Univ, Dept Civil & Struct Engn, Kowloon, Hong Kong, Peoples R China
[2] Wuhan Univ Technol, Inst Mat, Hubei 430070, Peoples R China
[3] Univ London Imperial Coll Sci Technol & Med, Dept Civil & Environm Engn, London SW7 2AZ, England
关键词
reject fly ash; chemical stabilization and solidification; leaching; TCLP; progressive TCLP; DLT;
D O I
10.1089/ees.2006.23.14
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Stabilization/solidification (s/s) has been routinely used for the final treatment of hazardous wastes prior to land disposal. These processes involve adding one or more solidifying reagents into the waste to transform it into a monolithic solid with improved structural integrity. Cement-based systems with partial replacement by pulverized fuel ash (PFA) have been widely used to minimize leaching of contaminants from hazardous wastes. The finer fraction of PFA (<45 mu m, fine fly ash, MA), produced by passing the raw ash through a classifying process is commonly used in s/s processes. Low-grade fly ash is rejected (rFA) from the ash classifying process, and is largely unused due to high carbon content and large particle size but represents a significant proportion of PFA. This paper presents experimental results of a study that has assessed the feasibility of using rFA in the cement-based s/s of a synthetic heavy metal waste. Results were compared to mixes containing fFA. The strength results show that cement-based waste forms with rFA replacement are suitable for disposal at landfill and that the addition of heavy metal sludge can increase the degree of hydration of fly ash and decrease the porosity of samples. Adding Ca(OH)(2) and flue gas desulphurization sludge reduces the retarding effect of heavy metals on strength development. The results of the Toxicity Characteristic Leaching Procedure and Dynamic Leach Test show that rFA can be used in cement-based s/s wastes without compromising performance of the product.
引用
收藏
页码:14 / 23
页数:10
相关论文
共 16 条
[1]  
*AM NUCL SOC, 1986, MEAS LEACH SOL LOW L
[2]   Permeability of lime-activated pulverised fuel ash to metal-containing permeants [J].
Awe, Y ;
Cheeseman, C ;
Sollars, C .
WASTE MANAGEMENT & RESEARCH, 2001, 19 (01) :35-44
[3]  
CHENG KY, 1996, ASTM STP, V1240
[4]  
Conner JR., 1990, CHEM FIXATION SOLIDI
[5]  
Cote P. L., 1987, Nuclear and Chemical Waste Management, V7, P129, DOI 10.1016/0191-815X(87)90007-6
[6]   Evaluation of leaching tests for cement based immobilization of hazardous compounds [J].
Leist, M ;
Casey, RJ ;
Caridi, D .
JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE, 2003, 129 (07) :637-641
[7]  
Means J. L., 1995, APPL SOLIDIFICATION
[8]   Potential use of fly ash and bentonite mixture as liner or cover at waste disposal areas [J].
Mollamahmutoglu, M ;
Yilmaz, Y .
ENVIRONMENTAL GEOLOGY, 2001, 40 (11-12) :1316-1324
[9]   Pozzolanic properties of reject fly ash in blended cement pastes [J].
Poon, CS ;
Qiao, XC ;
Lin, ZS .
CEMENT AND CONCRETE RESEARCH, 2003, 33 (11) :1857-1865
[10]   The limitation of the toxicity characteristic leaching procedure for evaluating cement-based stabilised/solidified waste forms [J].
Poon, CS ;
Lio, KW .
WASTE MANAGEMENT, 1997, 17 (01) :15-23