green clay
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2021 ◽  
Vol 15 (1) ◽  
pp. 360-369
Author(s):  
Monther Abdel Hadi ◽  
Ibrahim Khliefat ◽  
Nafeth Abdelhadi ◽  
Nidhal Saada

Introduction: Jordan is awarded huge areas in the north and western part of the country in which brown and green clay is dominant. This research focuses on the problems and behaviour of the green clay only. The main problem of the green clay is its high swelling pressure which is the main cause of excessive settlement and wall cracks in buildings, especially during the wet season. Methods: This study aims to investigate the engineering properties and behaviour of the green clay deposits in the Amman area, which will serve as a guide for both geotechnical and structural engineers when preparing the foundation design. Results: Based on the consolidation test, the investigated green clay showed high swelling pressure of 3.11 kg/cm2, liquid limit (LL) of 73%, plasticity index (PI) of 40%, the shrinkage limit (SL) of 12%, and liquidity index (LI) of 0.125. The moisture content at saturation is 35.14%, while the natural moisture content is 28%, dry density is 1407 kg/m3, cohesion (C) is 0.20 kg/cm2 and unconfined compressive strength is 1.05 kg/cm2. The XRD results of the clay size fraction have confirmed the presence of the expansive clay mineral smectite as the essential clay mineral together with kaolinite. Results provide a general understanding of the behaviour and properties of the green clay, and the regression analysis showed good correlations between the liquid limit and initial moisture content with the compression index and also between the initial void ratios with the swelling index. Conclusion: Changes in the volume are due to the unsaturation level of clay when provided with initial water content.


2021 ◽  
Vol 40 (4) ◽  
pp. 379-383
Author(s):  
Kateryna Kolesnykova ◽  
Galina Zadorozhna

Abstract Density variability of a population of the mollusk Brephulopsis cylindrica (Menke, 1828) was studied at a reclaimed site in the Nikopol manganese ore basin. This study was conducted on sod-lithogenic soil on grey-green clay. The samples were collected over 3 years, 3 times a year, on a regular grid. Lexis aggregation index (λ) and geostatistical tools were used to characterise spatial distribution of the mollusks. The correlation between the distribution of B. cylindrica and environmental factors was established using correlation analysis. Valid correlations were identified between distribution of the mollusk and variation of the fraction content in composition of structural aggregates of soil. Also, valid correlations were identified with plant species composition at the reclaimed site.


Author(s):  
Mahmoud Mohammed Ahmed ◽  
Emad Alkatory ◽  
Atef Hemdan Ali ◽  
Wafaa Mahmoud Abd-Elhamied

The aim of this paper is to improve the quality of superphosphate fertilizer resulting from the use of low quality phosphate rock by the use of additives as Illite clay, The use of Glauconite rock (green sand) and illite rock (green clay) in the abu tartur phosphate's region – new valley and mixing it with low quality phosphate rock (22%) for the production of fertilizers with higher quality and rich with the essential elements for plants (N, K) which aren't exist in low quality phosphate rock individually, an industrial sample test had been done and a mixed fertilizer had been produced (Elayte rock and low quality phosphate (22% ) as 1:1).


2021 ◽  
Author(s):  
Andre Baldermann ◽  
Santanu Banerjee ◽  
György Czuppon ◽  
Martin Dietzel ◽  
Juraj Farkas ◽  
...  

Abstract Retrograde clay mineral reactions (i.e., reverse weathering), including glauconite formation, are first-order controls on element (re)cycling vs sequestration in modern and ancient marine sediments. Here, we report substantial K–Mg–Fe sequestration by glauconite formation in shallow marine settings from the Triassic to the Holocene, averaging 4 ± 3 mmol K·cm−²·kyr− 1, 4 ± 2 mmol Mg·cm−²·kyr− 1 and 10 ± 6 mmol Fe·cm−²·kyr− 1, which is ~ 2 orders of magnitude higher compared to deep-sea settings. Upscaling of glauconite abundances in shallow-water (< 200 m) environments predicts a global K–Mg–Fe uptake of ~ 0.05–0.06 Tmol K·yr− 1, ~ 0.04–0.06 Tmol Mg·yr− 1 and ~ 0.11–0.14 Tmol Fe·yr− 1. We conclude that authigenic clay elemental uptake had a large impact on the global marine K, Mg and Fe cycles throughout Earth`s history, in particular during ‘greenhouse’ periods with sea level highstand. Quantifying authigenic clay formation is key for better understanding past and present geochemical cycling in marine sediments.


2021 ◽  
Vol 11 (6) ◽  
Author(s):  
Nouria Nabbou ◽  
Elhassan Benyagoub ◽  
Meriem Belhachemi ◽  
Mustapha Boumelik ◽  
Moncef Benyahia

AbstractThis present work is a part of the liquid discharges treatment topic by studying the removal performance for thermotolerant coliforms (FC) and fecal streptococci (F.Strep) by a local natural light green clay from Kenadsa (Bechar-Algeria) under continuous adsorption processes in a fixed-bed column. The study estimated the clay adsorbing efficiency by the adsorption technique for bacteria contaminating the dairy effluent by determining the bacterial load before and after treatment. The mean log counts per 100 ml for FC and F.Strep were assessed by MPN method on liquid medium. The clay material characterizations were made through X-ray diffraction, X fluorescence spectrometry and Fourier transform infrared spectroscopy analysis. Besides, some parameters were estimated such as the breakthrough time tb (clay filter breakdown); the amount of the contaminating bacteria that was removed at the breakthrough time Xb and the exhaustion of disinfection capacity Xe; the total amount of contaminating bacteria flowing through the column Xtotal; and the total removal efficiency (Y). According to the XRD, XRF and FTIR results, the predominant mineral constituents were silicon dioxide, aluminum oxide, ferric oxide and magnesium oxide with rates of 59,44; 18,09; 7,79; and 3,87%, respectively, and hence, their classification among non-swelling clay minerals, illite is the major mineral group of this material. The results of the bacteriological analysis of raw dairy effluents showed an average bacterial load of 3,88 Log10 and 4,1 Log10 CFU/100 mL for FC and F.Strep, respectively, exceeding the thresholds set by the national and the international regulations. The results of the dairy effluents treated by the tested material have shown that the used clay has a relatively high adsorption property for the clay fixed-bed system (3 cm of bed height), expressed by a total removed efficiency Y (%) of FC and F.Strep used to evaluate the column performance ranging from 55 to 84%. It gives a higher log removal for FC and F.Strep (0.98–1.65 Log10) reported from the first adsorption process, and a breakthrough time ranged from 100 to 250 min, which was inversely proportional to the initial bacterial load of discharges and also linked to the nature of the bacterial contaminants. When the breakthrough occurs earlier, the column service life will be shortened. For the studied parameters, the results of treated effluent complied with national and WHO regulations for unrestricted agricultural irrigation, otherwise, as authorized effluents to be discharged into nature without risks. These preliminary results are very promising at laboratory scale as an innovative green technology, treatment method respecting the environment and opens up prospects for the future, where the modification or the optimization of operating conditions such as the bed height of the fixed bed for adsorption, the volumetric flow rate or the clay structure like the particle size distribution of the adsorbents, known as one of the adsorbent classes endowed with an antimicrobial property, can improve the column performance, and further, the removal or even more the disinfection process by adsorption method.


Author(s):  
Luana Araújo de Oliveira ◽  
Meiry Gláucia Freire Rodrigues ◽  
Antonielly dos Santos Barbosa ◽  
Rochélia Silva Souza Cunha ◽  
Joseane Damasceno Mota

Background: The generation of wastewater contaminated with organic compounds, release or spill into these water bodies can lead to serious environmental problems. The removal of chemical pollutants in water presents itself as one of the central issues regarding the issue of environmental remediation. In this sense, membranes, haves gained increasing importance in the environmental area. Objective: This present study aims to develop a composite membrane using UHMWPE/LDPE/CTAC-HGC to be used for oil/water separation of wastewater effluents. Methods: The polymeric membrane and composite membrane were prepared by uniaxial dry compaction and sintering. Both hard green clay (HGC) and hard green clay organophilized with cetyl trimethyl ammonium chloride (CTAC-HGC) were characterized by X-ray Diffraction (XRD), infrared spectroscopy (IR) and scanning electron microscopy (SEM). UHMWPE, polymeric membrane and composite membrane were characterized by XRD and SEM. Result: The water flux through the composite membrane was evaluated using pure water as a permeate. The potential of the composite membrane to separate oil-water emulsions was tested. Conclusions: The composite membrane showed excellent removal of the oil, exhibiting removal of more than 99.60 %, evidencing the process of composite membrane separation as an alternative technology for the treatment of oil.


2020 ◽  
Vol 259 ◽  
pp. 119659 ◽  
Author(s):  
Sahar Iftikhar ◽  
Khuram Rashid ◽  
Ehsan Ul Haq ◽  
Idrees Zafar ◽  
Fahad K. Alqahtani ◽  
...  

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