The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform

Zheng Zheng - One of the best experts on this subject based on the ideXlab platform.

  • a preliminary study of simultaneous Lime Treatment and dry digestion of smooth cordgrass for biogas production
    Chemical Engineering Journal, 2011
    Co-Authors: Yue-gan Liang, Zheng Zheng
    Abstract:

    Abstract The technical feasibility of simultaneous Lime Treatment and dry digestion (SLTD) of smooth cordgrass in a leaching bed reactor at 55 ± 1 °C is discussed. SLTD was carried out in a single reactor with a high initial biogas production rate and volatile solids (VS) removal rate. Biogas yields reached 283.9 and 192.7 mL/g VS, with 10.0 and 9.5 L/d maximum biogas production rates for asynchronous Lime Treatment and dry digestion (ALTD), and SLTD, respectively. VS removal efficiency reached 69.0% and 71.9% for ALTD and SLTD, respectively. 83.7% and 99% total biogas yields were obtained at the beginning of 30 days digestion for ALTD and SLTD, respectively. The biogas production rate constant gradually reduced with the reduction of easily biodegradable material. Inhibition of anaerobic bacteria occurred at the SLTD experiment during dry digestion, as shown by very little total volatile fatty acid and biogas production after day 20. Sodium, potassium and calcium ions were not responsible for SLTD inhibition.

Farimah Masrouri - One of the best experts on this subject based on the ideXlab platform.

  • Long-Term Behavior of Lime-Treated Clayey Soil Exposed to Successive Drying and Wetting
    Geo-Congress 2014 Technical Papers, 2014
    Co-Authors: Olivier Cuisinier, Guillaume Stoltz, Farimah Masrouri
    Abstract:

    The positive effects of Lime Treatment are likely to be altered by weathering, and the sustainability of Lime-Treatment positive effects is in question. In this study, the effects of successive drying/wetting cycles on the hydromechanical properties of a Lime-treated clayey soil are assessed. Osmotic suction-controlled oedometers were used to determine the swelling/shrinkage behavior of soils subjected to successive drying/wetting cycles of small amplitude. Significant degradation of the yield stress was observed while the efficiency of the Treatment on volumetric behavior remained unchanged, this being related to the stabilization process. This study showed that the evaluation of the mechanical sustainability of a Lime-treated material subjected to wetting and drying cycles requires tests in realistic conditions.

  • Multi-scale analysis of the swelling and shrinkage of a Lime-treated expansive clayey soil
    Applied Clay Science, 2012
    Co-Authors: Guillaume Stoltz, Olivier Cuisiner, Farimah Masrouri
    Abstract:

    The main purpose of this paper is to examine the impact of a wetting and drying path on the swelling/shrinkage of a compacted Lime-treated expansive clayey soil both at the macro- and micro-scales. At the macro-scale, the soil water characteristic curves (SWRCs) of the compacted Lime-treated materials (0%, 2% and 5% of Lime content) were determined for three curing times (0, 28 and 180 days). The modifications at the micro-scale were assessed with mercury intrusion porosimetry (MIP) tests. The results showed that Lime Treatment was efficient to prevent the volumetric swelling from the initial state upon wetting. Even if no significant macroscopic volumetric variation was observed, a reorganisation of the microstructure was evidenced. Upon drying, the Lime addition led to an alteration of the hydro-mechanical soil behaviour from the initial state by increasing the compacted shrinkage limit suction. However, the volumetric shrinkage of the compacted Lime-treated samples remained on the same order of magnitude of the untreated compacted soil, regardless of Lime content and curing time. At the micro-scale, the \MIP\ tests showed that drying altered both the macro- and micro-porosity fabric of the Lime-treated soils. This study showed that Lime Treatment had a limited effect on Lime-treated compacted soil shrinkage whilst preventing swelling.

Yue-gan Liang - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Lime loading on the performance of simultaneous Lime Treatment and dry anaerobic digestion of smooth cordgrass
    Energy Sources Part A-recovery Utilization and Environmental Effects, 2016
    Co-Authors: Yunhua Zhang, Yue-gan Liang, Jian-feng Chen, Hua Chen
    Abstract:

    ABSTRACTThe effects of Lime loading on simultaneous Lime Treatment and dry digestion (SLTDD) of smooth cordgrass (SC) were evaluated at 35°C by batch reactors and leaching bed reactors (LBRs). Biogas yields of 1.5%, 3%, and 5% (w/w) Lime loadings decreased by 7.1%, 20%, and 75.7%, respectively, compared with no-Lime Treatment with 198.0 mL/g total solids (TS) by batch reactors. The LBRs with liquid recycling and pH adjustment enhanced biogas production with 148.1–236.1 mL/g TS. The inhibition occurred SLTDD may be ascribed to be high pH and temperature from Lime hydration at the initial stage. The activity for methanogenic bacteria was more inhibited than other anaerobic bacteria.

  • a preliminary study of simultaneous Lime Treatment and dry digestion of smooth cordgrass for biogas production
    Chemical Engineering Journal, 2011
    Co-Authors: Yue-gan Liang, Zheng Zheng
    Abstract:

    Abstract The technical feasibility of simultaneous Lime Treatment and dry digestion (SLTD) of smooth cordgrass in a leaching bed reactor at 55 ± 1 °C is discussed. SLTD was carried out in a single reactor with a high initial biogas production rate and volatile solids (VS) removal rate. Biogas yields reached 283.9 and 192.7 mL/g VS, with 10.0 and 9.5 L/d maximum biogas production rates for asynchronous Lime Treatment and dry digestion (ALTD), and SLTD, respectively. VS removal efficiency reached 69.0% and 71.9% for ALTD and SLTD, respectively. 83.7% and 99% total biogas yields were obtained at the beginning of 30 days digestion for ALTD and SLTD, respectively. The biogas production rate constant gradually reduced with the reduction of easily biodegradable material. Inhibition of anaerobic bacteria occurred at the SLTD experiment during dry digestion, as shown by very little total volatile fatty acid and biogas production after day 20. Sodium, potassium and calcium ions were not responsible for SLTD inhibition.

Anh Minh Tang - One of the best experts on this subject based on the ideXlab platform.

  • effects of Lime Treatment on the microstructure and hydraulic conductivity of hericourt clay
    Journal of rock mechanics and geotechnical engineering, 2014
    Co-Authors: Thanh Danh Tran, Anh Minh Tang, Martine Audiguier, Roger Cojean
    Abstract:

    This study aims at evidencing the effects of Lime Treatment on the microstructure and hydraulic conductivity of a compacted expansive clay, with emphasis put on the effect of Lime hydration and modification. For this purpose, evolutions of hydraulic conductivity were investigated for both Lime-treated and untreated soil specimens over 7 d after full saturation of the specimens and their microstructures were observed at the end. Note that for the treated specimen, dry clay powder was mixed with quickLime prior to compaction in order to study the effect of Lime hydration. It is observed that Lime hydration and modification did not affect the intra-aggregate pores but increased the inter-aggregates pores size. This increase gave rise to an increase of hydraulic conductivity. More precisely, the hydraulic conductivity of Lime-treated specimen increased progressively during the first 3 d of modification phase and stabilised during the next 4 d which correspond to a short period prior to the stabilisation phase. The microstructure observation showed that stabilisation reactions took place after 7 d. Under the effect of stabilisation, a decreasing hydraulic conductivity can be expected in longer time due to the formation of cementitious compounds.

  • effects of the maximum soil aggregates size and cyclic wetting drying on the stiffness of a Lime treated clayey soil
    Geotechnique, 2011
    Co-Authors: Anh Minh Tang, Minhngoc Vu
    Abstract:

    Lime Treatment is a well-known technique to improve the mechanical response of clayey subgrades of road pavements or clayey soils used for embankment. Several studies show that Lime Treatment significantly modifies the physical and hydromechanical properties of compacted soils. Nevertheless, studies on the scale effect under climatic changes are scarce. Actually, wetting–drying cycles might significantly modify the microstructure of treated soils, giving rise to changes in hydromechanical properties. This modification could be dependent on the size of soil aggregates before Lime Treatment. In the present work, this scale effect was studied by investigating the stiffness of a compacted Lime-treated clayey soil using bender elements. The studied soil was first air-dried and ground into a target maximum soil aggregates size (Dmax). For each aggregate size, the soil was humidified to reach the target water contents wi, then mixed with 3% of Lime powder (mass of Lime divided by mass of dried soil) prior to the...

  • Effects of the maximum soil aggregates size and cyclic wetting–drying on the stiffness of a Lime-treated clayey soil
    Geotechnique, 2011
    Co-Authors: Anh Minh Tang, Minhngoc Vu
    Abstract:

    Lime Treatment is a well-known technique to improve the mechanical response of clayey subgrades of road pavements or clayey soils used for embankment. Several studies show that Lime Treatment significantly modifies the physical and hydromechanical properties of compacted soils. Nevertheless, studies on the scale effect under climatic changes are scarce. Actually, wetting–drying cycles might significantly modify the microstructure of treated soils, giving rise to changes in hydromechanical properties. This modification could be dependent on the size of soil aggregates before Lime Treatment. In the present work, this scale effect was studied by investigating the stiffness of a compacted Lime-treated clayey soil using bender elements. The studied soil was first air-dried and ground into a target maximum soil aggregates size (Dmax). For each aggregate size, the soil was humidified to reach the target water contents wi, then mixed with 3% of Lime powder (mass of Lime divided by mass of dried soil) prior to the...

Guillaume Stoltz - One of the best experts on this subject based on the ideXlab platform.

  • Long-Term Behavior of Lime-Treated Clayey Soil Exposed to Successive Drying and Wetting
    Geo-Congress 2014 Technical Papers, 2014
    Co-Authors: Olivier Cuisinier, Guillaume Stoltz, Farimah Masrouri
    Abstract:

    The positive effects of Lime Treatment are likely to be altered by weathering, and the sustainability of Lime-Treatment positive effects is in question. In this study, the effects of successive drying/wetting cycles on the hydromechanical properties of a Lime-treated clayey soil are assessed. Osmotic suction-controlled oedometers were used to determine the swelling/shrinkage behavior of soils subjected to successive drying/wetting cycles of small amplitude. Significant degradation of the yield stress was observed while the efficiency of the Treatment on volumetric behavior remained unchanged, this being related to the stabilization process. This study showed that the evaluation of the mechanical sustainability of a Lime-treated material subjected to wetting and drying cycles requires tests in realistic conditions.

  • Multi-scale analysis of the swelling and shrinkage of a Lime-treated expansive clayey soil
    Applied Clay Science, 2012
    Co-Authors: Guillaume Stoltz, Olivier Cuisiner, Farimah Masrouri
    Abstract:

    The main purpose of this paper is to examine the impact of a wetting and drying path on the swelling/shrinkage of a compacted Lime-treated expansive clayey soil both at the macro- and micro-scales. At the macro-scale, the soil water characteristic curves (SWRCs) of the compacted Lime-treated materials (0%, 2% and 5% of Lime content) were determined for three curing times (0, 28 and 180 days). The modifications at the micro-scale were assessed with mercury intrusion porosimetry (MIP) tests. The results showed that Lime Treatment was efficient to prevent the volumetric swelling from the initial state upon wetting. Even if no significant macroscopic volumetric variation was observed, a reorganisation of the microstructure was evidenced. Upon drying, the Lime addition led to an alteration of the hydro-mechanical soil behaviour from the initial state by increasing the compacted shrinkage limit suction. However, the volumetric shrinkage of the compacted Lime-treated samples remained on the same order of magnitude of the untreated compacted soil, regardless of Lime content and curing time. At the micro-scale, the \MIP\ tests showed that drying altered both the macro- and micro-porosity fabric of the Lime-treated soils. This study showed that Lime Treatment had a limited effect on Lime-treated compacted soil shrinkage whilst preventing swelling.