PAPERmaking! g FROM THE PUBLISHERS OF PAPER TECHNOLOGY Volume 1, Number 1, 2015
Table 3. Concentrations (ng·g − 1 , dry weight) of individual polycyclic aromatic hydrocarbons compounds in recycled paper mill sludges of different Malaysian paper mills.
* PAHs = polycyclic aromatic hydrocarbons (PAHs), # PM = paper mill, n.d. the value of the PAHs were not detected in the analysis. Classifications were followed for land spreading of pulp and paper mill sludge by the British Columbia Pulp and paper Association [25]. 3.5. 13C-NMR Spectra of Paper Mill Sludge Among the various paper mills it was found that PM2 was the better sludge compared to the other as it has high in moisture content, pH, EC, C, OM, CEC, lower in heavy metals, PAHs, and dioxins and furans. With these all properties it can be utilised for the improvement of acidic soils (most of the agricultural soils in Malaysia) and can be selected for further use in laboratory, glasshouse and field studies. Hence, only PM2 was chosen to record the 13C-NMR spectra due to its better suitability for land application (Figure 3). The spectrum of raw RPMS showed the presence of peaks at 20, 23, 31, 56, 63, 65, 72, 75, 83, 89, 102, 106 and 174ppm. Jackson and Line [41] reported a similar 13C-NMR spectrum for paper mill sludge in their study. The peaks at 20, 23 and 31ppm are attributable to non-substituted alkyl carbons. The most prominent peak was centred at 31ppm, which suggests the presence of methylene (-CH2) groups in long aliphatic chains, with a possible contribution from lipids and proteins too. Since no phenolic signals were present in the spectrum (145 – 160), the RPMS could be assumed to contain little or no lignin. The only signal that may indicate the presence of lignin was at 56ppm which is usually assigned to methoxyl groups (OCH3) associated to lignin and lignin-like products [41].
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Article 2 – Environment (sludge)
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