Papers by Keyword: Demineralization

Abstract: This study aims to overcome decreasing cooling tower efficiency at Geothermal Power Plant Kamojang Unit 1. Based on visual observations, there has been a tendency to blockage in the cooling tower's film fill and nozzle areas by mud, sulphate, scale, biofouling, moss, and other impurities. As a coolant, the water quality from the cold basin cooling tower has an essential role in determining the cooling tower performance. Preliminary test results show that cold water from the basin cooling tower contains high sulfate ions and bacteria than typical values. For this purpose, laboratory-scale demineralization with ion exchange is designed for sulfate ion treatment and sodium hypochlorite injection to reduce the bacterial height and validate the treatment, heat transfer, and cooling tower efficiency calculations before and after treatment. The results showed that with demineralization, sulfate levels from 224 ppm to < 5 ppm, and sodium hypochlorite injection, the optimum injection concentration was 2 ppm, from 19000 CFU/ml, it could reduce bacteria to 100CFU/ml. Finally, the improvement in cooling tower efficiency before and after treatment was 17.36%.

Abstract: In the paper we determined the dependence of the parameters of purified on anionite water on its salt composition, hardness and shape of the anion exchanger used. It is shown that the capacity of the ion exchanger in the CO₃^2- form is higher in chlorides and sulfates than in the OH^- -form. It has been established that during the sorption of chlorides and sulfates on the anionite AB-17-8 in the base form, an increase in the alkalinity of water occurs, which in the presence of hardness ions ensures its effective softening.

Abstract: The pyrolysis kinetics of the Jordanian Lajjun oil shale kerogen was investigated inside a TGA reactor. Kerogen samples (extracted by mineral digestion) were non-isothermally heated at rates varying from 1 to 50^°C/min under 350-550C in N₂ atmosphere. Friedman, Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) models were employed to estimate the kinetic parameters at isoconversional points ranging from 0.1 to 0.9. The value of the calculated apparent activation energy (E) was found to vary with both the employed model and the conversion (x). Using the three models, the calculated increased with from 10 to 30% (low level), and then decreased with from 30 to 60% (medium level). At high level (60 to 90%), however, increased with increase using both KAS and FWO models, while it continuously dropped with increase using Friedman model. The frequency factor (k₀) calculated form each model was found to linearly correlate with E. Compared to KAS and FWO models, Friedman' provided a more accurate fit to the experimental data.

Abstract: Disposal of petroleum-based plastics has become a major concern due to its resistance to chemical, physical and biological degradation. As such, the production of an alternative biodegradable material from renewable sources is beneficial. This study aims to produce a polymer blend film, of enhanced formability and durability, from cellulose and chitin, the two most abundant naturally-occurring biodegradable polymers in the environment. Chitin was initially extracted from Portunus pelagicus shells through demineralization and deproteinization. The crude chitin is of comparable crystallinity with the commercially-available. However, other proteins were speculated to be present as indicated by the extra peaks in the XRD profile. This was then followed by the dissolution of the polymer powders in LiCl/DMAc, blending, casting, forming, cold-pressing and drying. The independent variables considered were cellulose-chitin ratio and the forming time. From the results, samples formed after 24 hours are relatively thinner, softer and more flexible. In addition, the best sample with UTS at 27.36 MPa was that of 80:20 cellulose-chitin, while the worst at 14.79 MPa was that of 20:80 cellulose-chitin both formed after 24 hours. ANOVA revealed that neither the main factors nor the interaction significantly affected the measured values. Lastly, thermal and biological degradation tests showed that the film started to degrade at 308°C and supported 4.9 x 10³ and 3.8 x 10⁴ CFU of mold and bacteria, respectively.

Abstract: Collagen for biomedical applications is mainly isolated from animal tissues (bovine or porcine skin and bovine or equine Achilles tendons). Type I collagen has been also extracted from skin, bone, fins and scales of fresh water and marine fishes. Fish scales are composed of collagen covered with calcium salts. In the present study we report the preparation of collagen from fish scales for potential cosmetic, pharmaceutical and implant applications. In our laboratory collagen was isolated from scales of Esox lucius. It was the first time that this species were used as sources of collagen. Extraction of collagen from fish scales was done in two steps. In the first step, fish scales were demineralized using EDTA. Energy dispersive X-ray analysis of demineralized scale was carried out for quantitative estimation of inorganic content. Then, demineralized fish scales were dissolved in acetic acid. Collagen isolated from Esox Lucius may serve as an attractive and safe source of collagen for biomedical and pharmaceutical applications. Fish collagen can be processed in sheet, sponges foams, injectable viscous solution, and dispersions.

Abstract: In this study, the effect of the mineral matter of Huadian (China) Oil Shale on the conversion of organic carbon of oil shale to shale oil. The bioleaching process is taken in a mixed culture of the lithotrophic bacteria Thiobacillus ferrooxidans(Tf). The aim of bioleaching process was to dissolve the inorganic matters and improve the shale oil yield. A series of temperature-programmed pyrolysis operation was performed with raw and bioleached oil shale to find the best retorting temperature, 500oC is the best temperature to retort the oil shale. The oil shale samples were detected by SEM, DG, Fischer assay test, the results show that the surface structure was significantly different from the raw sample, and the shale oil yield improved from 8.9% to 11.7%.

Abstract: Thermogravimetric analysis (TGA) was employed to study the pyrolysis characteristics of two biomass materials (poplar and pine wood) and their demineralized samples under nitrogen atmosphere. Based on the experimental results, the pyrolysis kinetics were calculated. The results indicated that the starting and ending time of devolatilization were delayed after the demineralization of the biomass. For all the materials, the temperature of the maximum weight loss rate occurred at around 390°C, while the maximum values increased a little after demineralization. The pine wood was more difficult to decompose than the poplar wood, due to its high activation energy values. In addition, after demineralization, the activation energy values of the pine wood decreased, while the values of the poplar wood were not significantly changed.

Abstract: This paper considers the demineralization of mine water using a lab-scale electrodialysis unit EDR-Z/10-1.0. Experiment were carried out on real mine water from Jeremenko water pit complex (DIAMO s.p., ODRA Ostrava branch, Czech Republic). These mine water greatly affect surface water quality, especially high concentration of dissolved solids, sulfates and chlorides. Aim of research was to treatment of mine water to quality corresponding with legislative limits for surface water. Electrodialysis tests were conducted in the batch and feed-and-bleed modes. It was demonstrated that electordialysis is good way for mine water treatment.

Abstract: This study aimed to evaluate the anticariogenic and remineralization effects of the glass ionomer dental luting cement containing nano-β-TCP in vitro. The β-Tricalcium Phosphate (β-TCP) are the components of dental enamel and bone mineral as biological apatites. In addition, β-TCP contains a significant amount of calcium and phosphate, which can promote remineralization of enamel subsurface lesions in animal and human. RelyXTM glass ionomer cement(3M/ESPE, USA) was used as dental luting cement. Film thickness, setting time, and compressive strength was measured for each group of pure glass GIC, 15% nano-β-TCP GIC. Human molars were prepared in box-shaped cavities that were filled with the GIC with and without the 15% nano-β-TCP were placed in 25ml of pH 5.0 acid buffer for 4 days at 37°C. After 4 days, longitudinal sections (1007m) were obtained through the center of each restoration. The sections were analyzed using a scanning electronic microscope (SEM) and confocal laser scanning microscopy (CLSM) to identify the change in the enamel surface. A significant difference in the CLSM images between pure GIC and nano-β-TCP-GIC. CLSM allows the demineralized surface layers of sound enamel to be visualized down to approximately 100 μm. The pure GIC specimens had a relatively thick fluorescent layer. On the other hand, the fluorescent layer of the nano-β-TCP-GIC specimens were thinner. The SEM images of micro surfaces demonstrate that nano-β-TCP-GIC is less rough than pure GIC. Therefore, the addition of nano-β-TCP enhanced protection against acid demineralization and promoted remineralization of enamel surface.

Abstract: To improve ostegenic healing efficiency by demineralized bone matrix, we evaluated the ectopic bone formation induced by variously demineralized allogenic cortical bone matrices at subcutaneous and muscular sites in rats. The rat tubular cortical bone matrices were demineralized in heated 0.6N HCl at 60 °C for 5 and 20 mins, respectively, using a controlledheat ultrasonic cleaner and implanted in rat dorsal subcutaneous pouches and thigh muscles for 1-3 weeks. The influence of the demineralized condition of bone matrix on cellular proliferation and osteogenic differentiation was also evaluated in vitro by MTT assay and ALP staining. The cortical matrices were completely demineralized within 20 mins by sonication and heating of diluted 0.6 N HCl. The sonicated bone matrices in heated acidic solution at 60 °C revealed no adverse immunogenic and inflammatory response in vivo regardless of demineralized condition. Cellular proliferation and osteoblastic differentiation was facilitated by more fully demineralized. Ectopic bone formation was induced only by demineralized bone matrices and were more favorable in fully demineralized matrices. The ectopic bone induction was more favorably in subcutaneous pouches than in muscular tissue. These findings suggest that a fully demineralized cortical bone matrix maximizes osteogenic repair by exposing more bioactive molecules which in turn induce chondro- and osteognic differentiation of mesenchymal cells around the implanted matrices, and that the sonication of diluted 0.6 N HCl heated at 60 ° C is a rapid and effective method for sterile demineralized graft preparation.