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Improving the technology to restore well tightness in underground rock salt reservoirs
Published in Vladimir Litvinenko, Topical Issues of Rational Use of Natural Resources 2019, 2019
R.А. Gasumov & Yu.S. Minchenko
The plugging solution for bridge installation should meet the following requirements: increased compressive strength of the cement stone to hold the column of plugging solution while isolating the annular space of the main casing and cementing the additional casing;good adhesion to rock salt well walls and casing;low gas permeability of cement stone;increased crack resistance of cement stone under the action of shock loads;adaptability in preparation and use.
Supai salt karst features: Holbrook Basin, Arizona
Published in Barry F. Beck, Felicity M. Pearson, Karst Geohazards, 2018
The Meade Salt Well is a natural sinkhole in Meade County, Kansas, that formed suddenly in 1879 in an area that contains numerous hollows and sinks, some of which can be attributed to solution collapse into cavities in the underlying Permian salt beds. Some evaporites younger than the Permian salt may be involved here. Geological study some 60 years after the collapse showed that faults updip from the sinkhole transmit fresh groundwater under hydrostatic pressure and dissolve openings in the underlying salt beds [Frye and Schoff, 1942]. Evidence for the dissolution is seen at lower altitudes to the east where salt springs emerge.
Interpreting improved geotechnical properties from RCPTUs in KCl-treated quick clays
Published in Michael A. Hicks, Federico Pisanò, Joek Peuchen, Cone Penetration Testing 2018, 2018
T.E. Helle, M. Long, S. Nordal
Unfortunately, the measured pore pressures (u2) in the RCPTUs conducted around salt-well no. 7 were affected by the close proximity to the open sampling boreholes. The measured u2 was in the order 50–100 kPa lower than in the original quick clay Therefore one of the RCPTU soundings nearby salt-well no. 3 is used for interpretation of the geotechnical properties in the salt-treated clay. The clay around salt-well no. 3 (Fig. 3) has about the same salt content, fall-cone undrained and remolded shear strength as found in the clay around salt-well no. 7.
Application of solid-phase extraction based on magnetic nanoparticle adsorbents for the analysis of selected persistent organic pollutants in environmental water: A review of recent advances
Published in Critical Reviews in Environmental Science and Technology, 2021
Aiming Wu, Xiaoli Zhao, Junyu Wang, Zhi Tang, Tianhui Zhao, Lin Niu, Wenqiang Yu, Chunyan Yang, Mengyuan Fang, Hongzhou Lv, Shasha Liu, Fengchang Wu
As a new type of crystalline porous carbonaceous material, covalent organic frameworks (COFs) are promising MSPE adsorbent materials because of their unique properties, such as low density, homogeneous and rigid pore structure, high thermal/chemical stability, and large specific surface area (Chen et al., 2019; Ma et al., 2018; Qian, Yang, Wang, Yang, & Yan, 2018; Ren et al., 2018). CTF/Fe2O3 microspheres were synthesized by the ionothermal polymerization of 1,4-dicyanobenzene catalyzed by ZnCl2 in the presence of FeCl3·6H2O under microwave irradiation (Ma et al., 2018; Ren et al., 2018). The MSPE method based on the microspheres was more appropriate for analysis of PFCs than chlorophenols in environment water because lower LODs (0.62–1.39 ng/L) and good recoveries (81.8–114.0%) were obtained by this method when used for the analysis of PFCs. Moreover, the CTFs/Fe2O3 composites could be reused more than 50 times without evident loss in the extraction efficiency. Polyethyleneimine (PEI) was self-assembled on the Fe3O4 nanoparticle surface (PEI@Fe3O4) via electrostatic interactions. Covalent organic framework-Lan Zhou University-1 (COF-LZU1), which was prepared from 1,3,5-triformylbenzene and 1,4-diaminobenzene through a Schiff base reaction, could be covalently bonded to the amino groups on the surface of PEI@Fe3O4 to form COF-LZU1@PEI@Fe3O4 nanoparticles (Wang & Chen, 2017). Magnetic bouquet-shaped COFs (TpPa-1) were synthesized by a hydrothermal method in the presence of 1,3,5-triformylphloroglucinol (Tp) and p-phenylenediamine (Pa-1)) (He, Zeng, Wang, Niu, & Cai, 2017). Finally, low LODs of 0.24–1.01 and 0.2–20 ng/L and good recoveries of 73–110 and 90.9–107.8% (with great accuracy) were achieved by using highly porous and stable TpPa-1 and COF-LZU1@PEI@Fe3O4 nanoparticles, respectively, for the MSPE and analysis of PAHs in environmental water samples. More importantly, the ratio of the extraction solution volume (200 mL) to the amount of TpPa-1 sorbent (5 mg) was significantly higher than those of most reported MSPE sorbents because of its large specific surface area and high porosity, as well as low mass density. In addition, the magnetic TpPa-1 nanoporous material was pH-independent (3–11) and tolerated salt well (0–0.1 mol/L), thus revealing the promise of magnetic COF materials for the MSPE of POPs in complex environmental water samples.