03390cas|a2200241 i 450000500170000000800410001703500150005810000180007324501040009126000520019530000100024749000270025750001550028450200580043952023240049765000210282170000380284270000560288070000410293671000470297781000590302485600650308320260818214633.0160399s1990    th  uzm rtt  00|  a1eng d  a.b106179171 aYoun, Jong-ho10aSolidification of laboratory wastes by using ordinary portland cement and lime-rice husk ash cement  aBangkok :bAsian Institute of Technology,c1990  a81 p.1 aThesis ;vno. EV-90-27  aA thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development  aThesis (M.Eng.) - Asian Institute of Technology, 1990  aA 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 . 0aHazardous wastes0 aChongrak Polprasert,eChairperson1 aVigneswaran, Saravanamuthu, eExamination Committee1 aKim, Sun Il, eExamination Committee2 aRoyal Thai Government, eScholarship Donor2 aAsian Institute of Technology.tThesis ;vno. EV-90-27  3Full-Textuhttp://203.159.5.9/ait-thesis/detail.php?q=B18380