• Title/Summary/Keyword: biopolymer injection

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Pore network approach to evaluate the injection characteristics of biopolymer solution into soil

  • Jae-Eun Ryou;Beomjoo Yang;Won-Taek Hong;Jongwon Jung
    • Smart Structures and Systems
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    • v.34 no.1
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    • pp.51-62
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    • 2024
  • Application of biopolymers to improve the mechanical properties of soils has been extensively reported. However, a comprehensive understanding of various engineering applications is necessary to enhance their effectiveness. While numerous experimental studies have investigated the use of biopolymers as injection materials, a detailed understanding of their injection behavior in soil through numerical analyses is lacking. This study aimed to address this gap by employing pore network modeling techniques to analyze the injection characteristics of biopolymer solutions in soil. A pore network was constructed from computed tomography images of Ottawa 20-30 sand. Fluid flow simulations incorporated power-law parameters and governing equations to account for the viscosity characteristics of biopolymers. Agar gum was selected as the biopolymer for analysis, and its injection characteristics were evaluated in terms of concentration and pore-size distribution. Results indicate that the viscosity properties of biopolymer solutions significantly influence the injection characteristics, particularly concerning concentration and injection pressure. Furthermore, notable trends in injection characteristics were observed based on pore size and distribution. Importantly, in contrast to previous studies, meaningful correlations were established between the viscosity of the injected fluid, injection pressure, and injection distance. Thus, this study introduces a novel methodology for integrating pore network construction and fluid flow characteristics into biopolymer injections, with potential applications in optimizing field injections such as permeation grouting.

Evaluation of Injection capabilities of a biopolymer-based grout material

  • Lee, Minhyeong;Im, Jooyoung;Chang, Ilhan;Cho, Gye-Chun
    • Geomechanics and Engineering
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    • v.25 no.1
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    • pp.31-40
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    • 2021
  • Injection grouting is one of the most common ground improvement practice to increase the strength and reduce the hydraulic conductivity of soils. Owing to the environmental concerns of conventional grout materials, such as cement-based or silicate-based materials, bio-inspired biogeotechnical approaches are considered to be new sustainable and environmentally friendly ground improvement methods. Biopolymers, which are excretory products from living organisms, have been shown to significantly reduce the hydraulic conductivity via pore-clogging and increase the strength of soils. To study the practical application of biopolymers for seepage and ground water control, in this study, we explored the injection capabilities of biopolymer-based grout materials in both linear aperture and particulate media (i.e., sand and glassbeads) considering different injection pressures, biopolymer concentrations, and flow channel geometries. The hydraulic conductivity control of a biopolymer-based grout material was evaluated after injection into sandy soil under confined boundary conditions. The results showed that the performance of xanthan gum injection was mainly affected by the injection pressure and pore geometry (e.g., porosity) inside the soil. Additionally, with an increase in the xanthan gum concentration, the injection efficiency diminished while the hydraulic conductivity reduction efficiency enhanced significantly. The results of this study provide the potential capabilities of injection grouting to be performed with biopolymer-based materials for field application.

Evaluation of Injection Degree of Biopolymer Grouting Using Electrical Resistivity (전기비저항을 이용한 바이오폴리머 그라우팅 주입도 평가)

  • Jun, Minu;Cho, Hyunmuk;Ryou, Jae-Eun;Hong, Won-Taek
    • Journal of the Korean Geotechnical Society
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    • v.40 no.4
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    • pp.61-68
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    • 2024
  • Monitoring the injection degree of biopolymers in soils is required in estimating the performance of biopolymer-treated grounds. In this study, the degree of saturation and injection process of biopolymer solutions in sandy soils were evaluated using electrical resistivity. To assess the changes in electrical resistivity according to the contents of the biopolymer solutions, electrical resistivities were measured for Jumunjin sand-xanthan gum biopolymer solution (weight concentration of 0.5%) mixtures with different degrees of saturation of 20%, 40%, 60%, 80%, and 100%. In addition, electrical resistivities were measured at eight layers in oven-dried Jumunjin sand during the upward injection of the xanthan gum biopolymer solution to monitor the injection process. Experimental results showed that the electrical resistivity decreased as the degree of saturation of the mixture increased, and their relationship was constructed. During the injection of the xanthan gum biopolymer solution into the sandy soils, the electrical resistivity decreased and converged and the degree of saturation at each layer could be estimated on the basis of the above-constructed relationship. This study demonstrated that electrical resistivity may be an effective physical property for monitoring the injection degree of biopolymer solutions in the ground.

Penetration behavior of biopolymer aqueous solutions considering rheological properties

  • Ryou, Jae-Eun;Jung, Jongwon
    • Geomechanics and Engineering
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    • v.29 no.3
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    • pp.259-267
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    • 2022
  • The rheological and penetration characteristics of sodium alginate and xanthan gum aqueous solutions were analyzed for the development of biopolymer-based injection materials. The results of viscosity measurements for the rheological characteristics analysis show that all aqueous biopolymer solutions exhibit a tendency for shear-thinning, i.e., the apparent viscosity decreases as the shear rate increases. In addition, a regression analysis using several models (Power-law, Casson, Sisko, and Cross) was applied to the shear-thinning fluid analysis results, the highest accuracy was determined by applying the power-law model. The micromodel experiment for the penetration characteristics analysis determined that all biopolymer aqueous solutions show higher pore saturation than water, and that pore saturation tends to increase as the flow rate and concentration increases. When comparing the rheological and penetration characteristics of the biopolymer aqueous solution used in this study, the xanthan gum aqueous solution showed a fully developed shear-thinning tendency, unlike the sodium alginate aqueous solution. This tendency is considered to have the advantage of enhancement injectability and pore saturation.

Effect of Chitosan on the Elimination of Intraperitoneally Administered Radiostrontium (Sr-85) (마우스복강내 투여한 방사성스토론튬의 체외배설 촉진제로서 카이토산의 효과에 관한 연구)

  • Kim, Ji-Yeul;Kim, Kwang-Yoon;Bom, Hee-Seung;Kim, Hee-Kyung
    • The Korean Journal of Nuclear Medicine
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    • v.27 no.2
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    • pp.293-297
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    • 1993
  • Chitosan is a natural chelating agent. It is derived from chitin which is a cellulose-like biopolymer distributed widely in nature, expecially in shellfish, insects, fungi, and yeast. The purpose of the present study is to investigate whether orally given water soluble chitosan can eliminate intraperitoneally injected radiostrontium (Sr-85) in mice. Water soluble chitosan and usual food was mixed as 10:90 by weight. The mixed food were fed for 60 (group 1) or 90 days (group 2). No chitosan was given to the control group. Each group consists of 5 mice. Sr-85 ($0.2{\mu}Ci$) was intraperitoneally injected after completion of prefeeding of usual or mixed food. The same food was given for more 5 days. The animals were sacrificed at the 6th day. Isolated spines, skulls, femurs, tibias, teeth, and tails were counted by a gamma counter. The retention of Sr-85 in bones was significantly lowere in the prefeeding groups (p<0.01). It was lowest in the 90 day prefeeding group. Therefore, prefeeding of water-soluble chitosan was effective on the removal of intraperitoneally injected radiostrontium.

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Erosion Characteristics of TGase-added Biopolymers (TGase 첨가 바이오폴리머의 침식특성 연구)

  • Kanghyun Kim;Seunghyun Kim;Dohee Kim;Jongho Shin
    • Journal of the Korean GEO-environmental Society
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    • v.24 no.9
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    • pp.5-13
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    • 2023
  • Cement-based reinforcement materials, which are representative slope reinforcement materials, can cause contamination of ground and groundwater when ground injection or surface application is applied. Accordingly, slope reinforcement materials using eco-friendly biopolymers are attracting attention as a means of replacing existing materials, but the biopolymers currently used are easily dissolved when exposed to groundwater or rainfall environments, reducing strength. In order to solve this problem, the cross-linking of protein between sodium casein and Transglutaminase (TGase, C20H16N4O2S2) was used to increase the water resistance of biopolymers, and a rainfall slope test was conducted to evaluate their usability and applicability as a slope reinforcing material. In the case of reinforcement with only sodium casein, the precipitation dissolved sodium casein, and the slope was completely destroyed in 1 hour. On the other hand, it was observed that the slope reinforced by adding a small amount of TGase (0.5%) do not collapse even after 80 hours of rainfall duration due to increased water resistance. Strength and water resistance increases due to the addition of a small amount of TGase, and its applicability as an eco-friendly reinforcement is confirmed.

Effects of Dietary Chitosan on Blood and Tissue Levels of Lead, Iron, Zinc, and Calcium in Lead Administered Rats (납 투여 흰쥐에서 혈액과 조직의 무기질 함량에 미치는 키토산의 섭취효과)

  • Park, Joo-Ran;Lee, Yeon-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.3
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    • pp.336-341
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    • 2005
  • Chitosan, which is a biopolymer, composed of glucosamine units linked by β-l, 4 glycoside bonds, is rich in shells of crustacean such as crabs and shrimps. We examined effects of dietary chitosan on blood and tissue levels of lead, iron, zinc and calcium in lead administered rats. Male Sprague-Dawley rats were divided into 4 groups (n=32). Basal diet group was fed 3% cellulose diet and lead administered groups were fed 0%, 3% and 5% chitosan diets, respectively for 8 wks. To lead administered groups, lead (20㎎/day) was given three times per week by oral injection. Blood, liver, kidney and femur were collected for lead, iron, zinc, and calcium analyses. There was no significant difference in weight gain and food intake among groups. Blood and femur lead levels were lower in lead administered groups fed 3% and 5% chitosan diets than in lead administered control (0% chitosan diet) group (p&lt;0.05). Blood and liver levels of iron and zinc in lead administered group fed 5% chitosan diet were significantly lower than those in basal diet group (p&lt;0.05), but those in lead administered group fed 3% chitosan diet were not significantly different with those in basal diet group. These results show that chitosan diets have beneficial effects on lowering the accumulation of lead, but high chitosan diet may have negative effects on mineral levels.