ABSTRACT
Municipal solid waste (MSW) is being generated every day, and its safe disposal is one of the major environmental challenges nowadays. The main focus of this research is to examine the usability of the soil-like inorganic component of MSW, named MSW rejected waste, as a geopolymer binder. In this study, the effect of mutual replacement of MSW rejected waste with ground granulated blast furnace slag (GGBFS) at 10% interval on the synthesis of geopolymer binder with reference to density, alkali concentration, and curing period is studied by conducting compressive strength, permeability, and durability tests. The design of mixes follows, according to their pre-determined compaction parameters, optimum moisture content, and maximum dry density. The curing conditions were found to be significant in affecting the properties of the geopolymer. The effect of acid environment on strength properties of geopolymer mixes has also been studied. The unconfined compressive strength, pulse wave velocity, water absorption, and microstructural analysis have been performed on designed mixes to identify the optimized design of the mixtures. Results showed that the strength increased with the increment of GGBFS percentage and increment of concentration of sodium hydroxide (NaOH) up to 8 M.
Subject(s)
Alkalies , Solid Waste , Compressive Strength , Dust , Pulse Wave AnalysisABSTRACT
The study aims to enhance the efficacy of surfactants using salt and multi-walled carbon nanotubes (MWCNT) for washing used engine oil (UEO) contaminated soil and compare the geotechnical properties of contaminated soil before and after washing (batch washing and soil washing). From batch washing of the contaminated soil the efficacy of the cleaning process is established. Contamination of soil with hydrocarbons present in UEO significantly affects its' engineering properties manifesting in no plasticity and low specific gravity; the corresponding optimum moisture content value is 6.42% while maximum dry density is 1.770â¯g/cc, which are considerably lower than those of the uncontaminated soil. The result also showed decrease in the values of cohesion intercept and increase in the friction angle values. The adopted soil washing technique resulted increase in specific gravity from 1.85 to 2.13 and cohesion from 0.443 to 1.04â¯kg/cm2 and substantial decrease in the friction angle from 31.16° to 17.14° when washed with most efficient combination of SDS surfactant along with sodium meta-silicate (salt) and MWCNT. Effectiveness of the washing of contaminated soil by batch processing and soil washing techniques has been established qualitatively. The efficiency of surfactant treatment has been observed to be increased significantly by the addition of salt and MWCNT.
ABSTRACT
Though the majority of research on fly ash has proved its worth as a construction material, the utility of bottom ash is yet questionable due to its generation during the pulverized combustion process. The bottom ash produced during the fluidized bed combustion (FBC) process is attracting more attention due to the novelty of coal combustion technology. But, to establish its suitability as construction material, it is necessary to characterize it thoroughly with respect to the geotechnical as well as mineralogical points of view. For fulfilling these objectives, the present study mainly aims at characterizing the FBC bottom ash and its comparison with pulverized coal combustion (PCC) bottom ash, collected from the same origin of coal. Suitability of FBC bottom ash as a dike filter material in contrast to PCC bottom ash in replacing traditional filter material such as sand was also studied. The suitability criteria for utilization of both bottom ash and river sand as filter material on pond ash as a base material were evaluated, and both river sand and FBC bottom ash were found to be satisfactory. The study shows that FBC bottom ash is a better geo-material than PCC bottom ash, and it could be highly recommended as an alternative suitable filter material for constructing ash dikes in place of conventional sand.
