Assessment of Molybdenum and Antimony speciation in excavated rocks and soils from the Parisian basin using mineralogical and chemical analyses coupled to geochemical modelling

AbstractMany safety functions required of the compacted bentonite buffer in the KBS-3 concept rely on processes influenced by the composition of the pore water. Important safety-relevant processes are related to the bentonite buffer,e.g.swelling, precipitation and dissolution reactions, and transport of water, colloids and ions. One of the methods used in analysing pore water in compacted bentonite is the ‘squeezing technique’. Various possible artefacts which can occur during squeezing, such as mixing of different pore-water types, dissolution of accessory minerals and cation exchange, need special attention.The present work describes the methodology for studying the composition of the non-interlamellar pore water by combining squeezing methods, chemical analyses, microstructure measurements and geochemical modelling. Four different maximum pressures were used to squeeze the compacted bentonite pore water. The origin of the pore water was studied by analysing the bentonite microstructure both before and after squeezing using SAXS and NMR, the cation exchange and dissolution reactions were studied by chemical analyses and geochemical modelling.The pore-water yield increased from 32 to 48 wt.% from the initial amount of porewater in the samples when the maximum squeezing pressure was increased from 60 MPa to 120 MPa. About 35 wt.% of the water collected originated from the interlamellar (IL) pores. The ratio between IL and non-IL pore waters as well as the composition of the squeezed porewater was constant in the squeezing-pressure range used. The results of microstructural measurements by SAXS were in perfect agreement with previous studies (e.g.Muurinen & Carlsson, 2013). The dissolving accessory minerals have an effect on the ratio of the cations in the squeezed solution while the migration of anions in bentonite seems to be diffusion limited. According to geochemical modelling the chloride concentration of the non-IL pore water in compacted bentonite before squeezing was 0.34 Mgreater than in the squeezed pore water due to the mixing of two main water types.

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MÖSSBAUER AND CHEMICAL ANALYSES OF SOME SEDIMENTS FROM THE ROMANIAN SHORE OF THE BLACK SEA

Le Journal de Physique Colloques ◽

10.1051/jphyscol:19792155 ◽

1979 ◽

Vol 40 (C2) ◽

pp. C2-445-C2-448

Author(s):

D. Barb ◽

L. Diamandescu ◽

M. Morariu ◽

I. I. Georgescu

Keyword(s):

Black Sea ◽

The Black Sea ◽

Chemical Analyses

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Hydrogeological processes in clay-rich slopes: further insights from geochemical modelling

Rendiconti online della Società Geologica Italiana ◽

10.3301/rol.2015.63 ◽

2015 ◽

Vol 35 ◽

pp. 58-61 ◽

Cited By ~ 2

Author(s):

Federico Cervi

Keyword(s):

Geochemical Modelling

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Analisis Nutrisi Umbi Ubi Jalar (Ipomoea batatas (L.) Lam.) untuk Konsumsi Bayo dan Anak-anak Suku Dani di Distrik Kurulu Kabupaten Jayawijaya

Agrotek ◽

10.30862/agt.v3i2.563 ◽

2018 ◽

Vol 3 (2) ◽

Author(s):

Andrew B. Pattikawa ◽

Antonius Suparno ◽

Saraswati Prabawardani

Keyword(s):

Sweet Potato ◽

Ipomoea Batatas ◽

Nutritional Value ◽

Animal Feed ◽

Ash Content ◽

Infants And Children ◽

Chemical Analyses ◽

Food Crop ◽

Sweet Potatoes ◽

Development Center

<em>Sweet potato is an important staple food crop especially for the local people of Central Highlands Jayawijaya. There are many accessions that have always been maintained its existence to enrich their various uses. Traditionally, sweet potato accessions were grouped based on the utilization, such as for animal feed, cultural ceremonies, consumption for adults, as well as for infants and children. This study was aimed to analyze the nutritional value of sweet potatoes consumed by infants and children of the Dani tribe. Chemical analyses were conducted at the Laboratory of Post-Harvest Research and Development Center, Cimanggu, Bogor. The results showed that each of 4 (four) sweet potato accessions which were consumed by infants and children had good nutrient levels. Accession Sabe showed the highest water content (72.56%), vitamin C (72.71 mg/100 g), Fe (11.85 mg/100 g), and K levels (130.41 mg / 100 grams). The highest levels of protein (1.44%), fat (1.00%), energy (154.43 kkal/100 gram), carbohydrate (35.47%), starch (30.26%), reducing sugar (3.44%), riboflavin (0.18 mg/100 g), and vitamin A (574.40 grams IU/100 were produced by accession Manis. On the other hand, accession Saborok produced the highest value for ash content (1.32%), vitamin E (28.30 mg/100 g), and ?-carotene (64.69 ppm). The highest level of crude fiber (1.81 %) and thiamin (0.36 mg/100 g) was produced by accession Yuaiken.</em>

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