Magnetic resonance analysis of carbon content in paper mill sludge–soil mixtures used in remediation practices

Abstract

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Evaluation of effect of soil organic matter on pores by 1H time‐domain magnetic resonance relaxometry and adsorption–desorption of N2

“…The dashed line in Figure is the distribution of relaxation times of sample SP1 after centrifugations; the distribution is bimodal. This is probably in part because of a partial gravimetric grain size redistribution (see international standards, ASTM D422), which leads to two distinct spin populations with no exchange between each other; the one at short times corresponds to the BWP observed previously by Bonoli et al (). A T 1 cut‐off value that varies roughly within the range of 10 to 20 ms, which is the maximum relaxation time achievable by the water inside BWP, was detected in all samples.…”

“…The magnetic resonance relaxometry in the time domain ( TD‐MRR ) pore‐size distribution ( PSD ) of samples with (b) small total organic carbon ( TOC ) content and (c) large TOC content. The dark part of the graph corresponds to the bound‐water pores ( BWP ) domain obtained with a ρ 1 of about ≈ 180 µm s −1 (Bonoli et al , ).…”

“…Pore type Dimensions IUPAC Micropore < 2 nm Mesopore 2-50 nm Macropore > 50 nm Petrophysical cut-off BWP (bound-water pores) ≤ 2 μm FWP (free-water pores) > 2 μm shown in Bonoli et al (2015). The TD-MRR is used in many fields because it is a non-destructive non-invasive technique, which can provide, among other things, information on porous media PSD, water content, water uptake and redistribution (Bayer et al, 2010).…”

“…The pore-size distribution (PSD) in its differential form (dV/dD, where V is the pore volume and D the pore diameter) for the amended soil obtained by the Barrett-Joyner-Halenda (BJH) method with the isotherm adsorption branch; (a) small total organic carbon (TOC) content group and (b) large TOC content group. (Bonoli et al, 2015).…”

“…We applied TD‐MRR to characterize the PSD and the irreducible water content (Dunn et al , ), also known as bound water (i.e. water with low mobility generally confined in small pores), which can be associated with porosity of a few micrometres, as shown in Bonoli et al (). The TD‐MRR is used in many fields because it is a non‐destructive non‐invasive technique, which can provide, among other things, information on porous media PSD, water content, water uptake and redistribution (Bayer et al , ).…”