Youn, Jong-ho creator Chongrak Polprasert Chairperson Vigneswaran, Saravanamuthu Examination Committee Kim, Sun Il Examination Committee Royal Thai Government Scholarship Donor text series technical report th Bangkok Asian Institute of Technology 1990 continuing eng 81 p. A laboratory study was conducted to investigate the immobilization of the laboratory waste s ludge, mainly from chemical oxygen demand {COD) waste , using cementitious binders. The binders were Ordinary Portland Cement {OPC), and lime - Rice Husk Ash (RHA) cement. The sludges were mixed with cement - sand mortar having a cement to sand ratio of 0.5, and water to cemen t ratio of 0.5 for OPC mortar and 0.9 for lime - RHA ceme nt mortar, respectively. Physical properties lik e compressive strength and leachability were studied to assess the effectiveness of the binders in containing the waste sl udg es within their matrix . Leachability was determined by the US EPA Extraction Procedure. The leachability was found to be proportional to the sludge/ cement ratios and inversely proportional to the curing time. The compressive strength of OPC mortar was found to be proportional to the curing time and inversely proportional to the sludge/ cement ratios. On the contrary , the compressive strength of lime - RHA cement mortar was found to be proportional to the sludge/ cement ratios and a pyramidal trend was observed to curing time. The compressive strength of OPC mortar was found to be greater than that of lime - RHA cement mortar. On the other hand , leachabili ty of lime - RHA cement mortar was invariably much less than that of OPC mort ar in all the tests. In this way , lime - RHA cement was found to be a better immobilizer than OPC. Economic evaluation was done for three different kinds of cementitious binders, namely, OPC, Portland Rice Husk Ash Cement {PRHAC ) which contain ed rice hu sk ash 50 percent by dry weight, and lime - RHA cement. The result showed that lime - RHA cement was cheapest. The applicability of Freundlich' s desorption isotherm was studi ed to assess the l eachability of sludges. The leachability of both cement mortars were found to follow the desorption isotherms. From this study , it is concluded that lime - RHA cement , which is cheaper than OPC, can be used as a cementitious binder to solidify heavy metal sludge with much less leachability than that of OPC, and its compressive strength s are high enough for landfill disposal. Moreover , it is expected that lime - RHA cement can be a solution to rice husk disposal problem . A thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development Thesis (M.Eng.) - Asian Institute of Technology, 1990 Hazardous wastes Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B18380 http://203.159.5.9/ait-thesis/detail.php?q=B18380 160399 20260818214633.0