Papers by Keyword: Peat

Abstract: High content of organic matter and fibre within peat results in a high degree of porosity; causing peat to have low bearing capacity. This study focuses on the application of nylon fibre as reinforcing material with fly ash as the chemical stabilizer to enhance the strength of the peat. The standard proctor tests were conducted to obtain the optimum moisture content (OMC) for all samples in which these OMC is then used for sample preparation of both the Unconfined Compressive Strength (UCS) tests and the California Bearing Ratio (CBR) tests. Samples for this study were categorized into control samples and modified samples for comparison purposes. Additives that were being used in this study are 5% cement, 5% nylon fibre and 10%, 15%, and 20% fly ash. For UCS test, the samples were cured for 7, 14, 28 and 56 days, whereas only 7 days of curing for CBR test. Throughout the study, improvements of strength were observed where sample added with 5% cement, 5% nylon fibre and 10% fly ash recorded the highest compressive strength value, of 123.71 kN/m2. As for CBR test, all samples exceeded the minimum requirement of 12% CBR value for subgrade design recommended by JKR Malaysia with the highest CBR value obtained from samples added with 5% cement and 10% fly ash. The CBR values were 43.85% and 43.70% for unsoaked and soaked condition, respectively.

Abstract: This paper presents the peat ground improvement techniques using waste-tire as a fibre reinforced material. In this study, two sizes of the waste-tire are chosen, which are 0.05 mm and 1-3 mm, respectively. The collected peat is classified as Sapric peat with the degree of decomposition of H7 based on von Post classification with high moisture content of 400% was recorded. The Sapric peat is treated with the waste-tire at designated percentages of 5%, 10% and 15% with the addition of 5% of cement acting as a binder. The untreated and treated peat without and with cement content are compacted at the optimum moisture content for both the Unconfined Compressive Strength (UCS) test and Direct Shear Box Test. The specimens were air-cured for 7, 28, 56, and 90 days. Hypothetically, higher percentages of rubber improve the shear stress value of the treated peat. According to the results the finer size (0.05mm) of the tire produces a higher shear stress, which may due the finer sizes of the waste-tire filled the void between the soil particles. Further, from the 90 days of curing UCS results, there is a significant increase in compressive strength with the increase percentage of the waste-tire peat mixed samples. In summary, soil stabilized by the scrap-tire is believed to decrease the optimum moisture content and the maximum dry densities, but it helps in increasing the unconfined compressive strength value. Stabilizing by using the tire wastes not only increasing the strength of the soil, but it also helps in reducing the disposal problems.

Abstract: The scientific article "Application of Modified Peat Aggregate for Lightweight Concrete" presents the results of studies of the properties of a new composite material for use in enclosing structures of residential and public buildings. Physical and mechanical characteristics of possible aggregates of local production for this type of concrete affecting its operational properties are considered. The prospects of using fly ash as an additive improving the characteristics of polystyrene concrete with the addition of modified peat have been established. The analysis was made and the optimal compositions for obtaining lightweight concrete based on peat and polystyrene foam were selected. The desorption properties of lightweight concrete important for its effective operation as a wall material were tested. It was found that the use of new types of surfactants can improve the water wettability of peat particles and polystyrene granules, thereby reducing the water-cement ratio and improving the compressive strength of the material. Possible efficiency of application of this type of concrete for use in enclosing structures of buildings and constructions under construction in seismic regions of Russia is considered. The presence of damping effect manifested in the material due to the presence of polystyrene granules in the perception of a certain level of load, which is important for the work of concrete under seismic influences, was experimentally established.

Abstract: Conversion of organic-containing sludges to a high value fertilizer is considered to be a rational solution from a recycling point of view. Aerobic respiration could serve as an indicator of stability and maturity of the treated sewage sludge (SS). The aim of this study was to characterize two SS samples, obtained from different wastewater treatment plants („D” and „J”), i.e, at the initial stage of treatment, alone and with amendments. Two methods for estimation of microbial respiration, as well as dehydrogenase activity were used. The SS-J demonstrated the higher microbial biodegradation activity, as compared to SS-D. In experiments with OxiTop® device, statistically significant (p<0.05) differences of the pressure drop between SS-J and SS-D have been revealed. Addition of peat to SS resulted in a more intensive pressure drop, compared to non-amended SS, i.e., -145 hPa vs. -76 hPa for SS-D and-199 hPa vs. -180 hPa for SS-J, respectively. The obtained results represent a methodical approach for characterization of raw SS in order to evaluate the amount of aerobically degradable organic substances and intensity of their oxidation. Further research is needed for highlighting the mechanisms responsible for interrelation of respiration intensity, bacterial community activity and other metabolic changes towards SS stabilization.

Abstract: Peat can be used as a natural adsorbent due to its humic acid content having various active functional groups such as carboxylates and hydroxyl groups. Peat soil samples obtained from Pelalawan district, Riau province of Indonesia were selected and their adsorption capacities were investigated using Mn(II) solution as a model solution. The raw peat samples were first prepared by drying at 110°C for 12 h. The adsorption experiment was conducted in batch test using Mn(II) solutions for 360 mins at pH of 5.2 as optimum conditions. The peat samples were analyzed using the Fourier Transform Infrared Spectroscopy, Surface Area Analysis and Scanning Electron Microscopy- Energy Dispersive Spectroscopy. The obtained adsorption data were fitted using Langmuir, Freundlich and BET isotherm models. It was found that the adsorption data followed the Langmuir isotherm model with correlation coefficients (R²) ranging between 0.9866-0.9997 and the adsorption capacities were between 11.99-22.94 mg/g.

Abstract: The article presents the fractal approach to the study of the five peat structure samples. Digital images from natural porous raw peat, intended for fractal studies of the porosity, are proposed. Peat active porosity is used in this study. In this study, the peat active porosity, fractal dimension (D), and their relationship with different peat samples were investigated in an experiment. The results of this study demonstrate that a fractal dimension analysis of peat compositions texture is a useful method for the quantitative description of the active porosity. The received results should be considered in the theoretical and pilot studies connected with physicomechanical processes occurring on the porous surfaces of peat raw materials during its mechanical processing.

Abstract: The article contains the results of research on the development of optimal in terms of time and complexity of work, energy intensity, consumption of materials and cost, the design of the roadbed for use in the construction of oilfield roads in wetlands. Trunk oil and gas pipelines in Western Siberia and north of the European part of Russia began to be built approximately from the mid-1960s. From the very beginning, designers faced serious problems: complex natural and heavy ground and hydro geological conditions, namely, permafrost soils and swamps. The length of the swamp sections is tens and hundreds of meters, and in some cases – tens of kilometers. Road construction in wetlands is a very difficult engineering task. Conditions of excessive moisture, extremely low load-carrying capacity of marsh soils, a characteristic deficiency of quality mineral materials - all this creates obstacles, the overcoming of which is associated with significant material costs. The average cost of road construction through the swamp is 3-5 times higher than in normal conditions. A constructive solution for the roadbed using a layer of non-woven synthetic material in the cage to ensure year-round and uninterrupted movement of technological transport for maintenance of oil facilities was chosen.

Abstract: Statistical techniques are particularly useful in the engineering, objecting the optimization of fabrication processes. This paper had the purpose of evaluating if the variables such as mechanical resistance, linear shrinkage, apparent porosity, density and water absorption are influenced by the amount of peat added to refractory clay, to ensure the porosity on the production of porous ceramics used as ceramic filters. In order to treat the data it was used the technique of variance analysis, with the regression analysis and the Scott-Knott test. According to the variance analysis, there were some differences between the treatments for all properties analyzed and, by the regression analysis, optimum peat levels were found for all properties analyzed, for some properties these levels were considered inadequate for being superior to the limit stablished.

Abstract: Significant attention is paid to the production of peat-based materials in modern days. The study explores the influence of natural peat thermal modification on its properties by applying class-modeling techniques. Modification of different types of peat is achieved by heating at 250 °C. The set of peat properties such as component composition, g-factor and IR-spectra is used to obtain data matrix. It is shown that class-modeling techniques, such as partial least-squares discriminant analysis (PLS-DA) and simple independent modeling of class analogy (SIMCA), allow estimating peat class (natural or modified) by a set of properties without prediction errors by using three latent variables. According to the results of classification, it is established that thermal modification can be considered as a means of regulating the composition and physico-chemical properties of natural peats as a raw material

Abstract: The paper presents the study of the absorption mechanism of organic pollutants such as formaldehyde and oxalic acid by natural zeolite and peat materials modified by iron (III) ions using the limited volume method.The relevance of this paper is a search for the use of inexpensive and available natural sorbents for waste water purification from ecologically hazardous water-soluble organic pollutants. The impact produced by the solution concentration and temperature and the size of natural composite particles on the sorption rate of organic substances is described in this paper. The effective factors for diffusion and energy of the process activation are calculated. It is found that the mixed-diffusion kinetics is the determinant stage of the process. In case of peat and zeolite composites, the internal diffusion prevails in the mixed-diffusion kinetics.