Papers by Keyword: Polyacrylamide

Abstract: The article considers a method of recycling citrogypsum – the сіtric acid production waste. A modified gypsum binder was obtained by means of dehydration of citrogypsum suspension and adding a modifier - polyacrylamide (PAA) - to it in conditions of autoclave treatment. The application of PAA as a modifying admixture causes the necessity to reduce the water-gypsum ratio (W/G) of the mix in order to prevent lamination at the molding product forming; at the same time, to provide the necessary flowability of the mix the introduction of plasticizing admixtures is needed, or the application of the harsher moulding mixtures or pressing technologies. For cylindrical samples, obtained by the compaction method at W/G=0.25 and the specific compacting pressure 20МPа, the optimal content of polyacrylamide as a modifying admixture amounts to 2% of the initial citrogypsum weight. This allows increasing the compression strength of the ready samples by more than 5 times. The samples, produced on the basis of modified gypsum binders, are characterized with high water resistance – the softening coefficient amounted to over 0.8.

Abstract: By means of solution polymerization, a series of cross-linked starch-g-polyacrylamide/ montmorillonite (St-g-PAM/MMT) nanocomposites were prepared and used to adsorb methylene blue (MB). The effects of different preparation conditions on the adsorption capacity of the nanocomposites were investigated. The experimental results demonstrated that the prepared St-g-PAM/MMT nanocomposites were effective adsorbents for removal of MB from aqueous solution. Furthermore, adsorption capacity increased with the MMT contents up to 14% and decreased as the MMT contents further increased. Adsorption capacity increased with the increasing of the ratio of starch to acrylamide, whereas adsorption capacity decreased with the increasing of crosslinking agent contents.

Abstract: The theoretical method of molecular dynamics was applied to study H₂O molecular diffusion behavior in PAM/PVA Polymer blends, investigated the effects of component ratios, temperatures and water contents on diffusion coefficient. Results show that with the increase of PVA content in blend systems, the H₂O molecule diffusion coefficient first increased and then decreased. This indicates there is an optimum component ratio to make the H₂O molecule diffusion coefficient maximum. There is a certain influence of temperature on H₂O molecular diffusion in PAM/PVA blend system, the higher the temperature, the bigger the H₂O molecular diffusion coefficient. When the less H₂O molecules contained in system, there is a less impact on the diffusion coefficient. As the number of H₂O molecules reaches a certain amount, the effect on the diffusion coefficient is more obvious.

Abstract: Palygorskite/polyacrylamide (PAM) composited thickeners were prepared via in-situ polymerization. To optimize the preparation, the dependence of the viscosity, rheological properties and electrolyte resistance of the composited thickeners on the initiator concentrations, sodium hydroxide concentrations and palygorskite contents was investigated. By measuring their dynamic rheological properties, thickening mechanism of composited thickeners was explored. The composited thickeners showed excellent electrolyte resistance which represented good synergistic effect of inorganic/organic composited thickener.

Abstract: In this paper,the different form of polyacrylamide and the production of polyacrylamide at home and abroad are summarized.The history, development and the tendency of polyacrylamide around the world are presented.

Abstract: The Polyacrylamide (PAM) is a frequently used flocculant for high concentration suspensions removal in water treatment characterized by the generation of large and dense flocs. In this paper, by using the anionic PAM as flocculant, a full-scale experimental study was carried out on flocculating ferric flocs sludge with pelleting flocculation blanket process under scale of 19~38 m³/h. The investigation aimed to optimum the dosage of the PAM and evaluate the application of the PAM in ferric flocs sludge treatment. The experimental results indicated that the increasing of PAM dosage could improve both outlet turbidity and thicken sludge concentration obviously, under the raw wastes concentration of 285~1022 mg/L, the system could achieve ideal operation effect with PAM dosage of 0.3~2.7 mg/L and treatment unit surface loading of 19~38 m³/m²·H. The investigation results also proved that there exists an approximately linear relationship between optimal PAM dosage and raw sludge concentration, that is, the increasing of raw sludge concentration would require synchronously rising of the optimal dosage. While the relationship between maximum surface loading and raw sludge concentration appeared negatively linear dependence, the maximum surface loading would decreased linearly with the increasing of inlet sludge concentration.

Abstract: Wastewater containing oil and polyacylamide is a kind of organic wastewater, which is hard to treat. The combined process of moving-bed biofilm reactor and sulphate-reducing bacteria was used to treat the wastewater. Operating conditions of moving-bed biofilm reactor and sulphate-reducing bacteria were studied. Results indicate that the oil removal efficiency by moving-bed biofilm reactor can reach above 90% with 9 hours hydraulic retention time at 25°C, but it has no effect on polyacylamide. Sulphate-reducing bacteria can degrade polyacylamide, and polyacylamide conversion is about 50% at 37°C with 4 days culture time and 9ml inoculation size. The effluent quality of wastewater containing oil and polyacylamide can meet requirements of the first level in integrated wastewater discharge standard.

Abstract: The scaling is the primary bottleneck problem which blocks the industrialization of ASP technology. Exploitation mining into the late period of the scaling, particulate scaling is appeared in the environment condition of ASP flooding produced liquid. In this paper, the research on validation and evaluation for the particulate scaling was done inside. Using the treatment of hydrochloric acid and burning for the produced liquid of the Fourth Plant of Daqing Oilfield, it can confirm that the particulate scaling is in ASP produced liquid. Then, the method which is the exploitation of the particulate scaling is established. The data analysis by IR confirm that the particulate scaling is calcium carbonate which is micron or smaller.

Abstract: This paper is closely related to chemical degradation of PAM. The degradation refers to any process that breaks down the molecular structure of macromolecules. The most important degradation pathways in oil recovery applications are oxidation reduction, ironic ions and divalents. The influences of each factor is discussed, and preventive measures are also put forward. It is beneficial to provide the degradation of the polymer, and it can largely improve the utilization rate of PAM.

Abstract: In order to study the mechanism of salt-bearing polymer flooding, using micro-flow technology, experimental study of salt-bearing polymer flooding residual oil process was carried outin two microscopic models of hydrophilic and lipophilic formation.Its microscopic percolation mechanism wasinspected. In hydrophilic model, after injecting salt-bearing polymer residual oil is capturedand migrated, and there is residual oil drawinganddeformation phenomena which is consistent with common polymer; while flooding process due to larger viscoelasticity of salt-bearing polymer, normal stress is generated in the flow, so the cutting action of the residual oil is obvious. In lipophilic model, after injecting salt-bearing polymer, residual oil migration, the film gathering,interface transport, a bridge and drawing phenomenon happened which is consistent with common polymer; polymer difference between salt-bearing polymer andcommon polymeris that from the ordinary and the residual oil film formed by common polymer is flexible and easier to form "emulsion.