PAPERmaking! g FROM THE PUBLISHERS OF PAPER TECHNOLOGY Volume 1, Number 1, 2015
sample injection. PAHs analyses were performed using an Agilent Technologies 5973A quadrupole mass spectrometer integrated with an Agilent 6890 gas chromatograph (Agilent Technologies, Santa Clara, CA, USA). A 30 m fused silica capillary column of 0.25mm i.d. and 0.25 μm film th ickness using helium as carrier gas was carried in the analysis. GC-MS operating conditions were set at 70eV ionization potential with the source at 200°C and electron multiplier voltage at ~2000eV. The injection port was maintained at 310 °C and the sample was injected with splitless mode followed by purging for 1min after the injection. Column temperature was held at 70°C for 2min, then programmed at 30°C/min to 150°C, and then 4°C/min to 310°C and held for 10min. A selected ion monitoring method was employed after a delay of 4min. PAHs were monitored at: m/z = 178 (phenanthrene anthracene), m/z = 192 (3-methylphenanthrene, 2-methylphenanthrene, 2-methyl-anthracene, 9- methylphenanthrene, 1-methylphenanthrene), m/z = 202 (fluoranthene, pyrene), m/z = 216 (1-methylpyrene), m/z = 228 (chrysene, benzo[a]anthracene), m/z = 252 (benzo[k]fluoranthene, benzo[e]acephenanthrylene, benzo[e]pyrene, benzo[a]pyrene), m/z = 278 (dibenzo[a,h]anthracene). 2.5. Analytical Procedure for Dioxin/Furan Determination of Dioxin/Furan was carried out by the Doping Control Centre (DCC), Universiti Sains Malaysia (USM), Pulau Pinang, Malaysia. MA modified method was developed according to USEPA 8290 and 1613. The dioxin/furan analyses were carried out using gas chromatography-high resolution mass spectrometry (GC-HRMS). Only one paper mill sample was used to determine the dioxin/furan levels, which was then used to represent the dioxin/furan content for sludge produced in Malaysia. Paper Mill 2 (PM2) was selected because this sludge was also used for further studies (laboratory, glasshouse and field conditions). The paper mill sludges produced by the paper industries in Malaysia were wet, sticky and had a strong odour (Figure 2). Almost all mill sludges which were collected from the various mills has similar characteristics, except for the contents of nutrients and heavy metals which varied from each other. The moisture content in the sludge ranged from 45.78% – 78.32% with an average of 65.08%. Pulp and paper mill sludges were generally dewatered mechanically to increase the solids content, reduce the volume and weight and improve their handling properties (Table 1). The composting of paper mill is recognised as the most adequate pre-treatment in order to obtain a material which may respond more efficiently with reduced odour and can help sanitise the material [14]. 3. Results and Discussion 3.1. Physico-Chemical Characteristics of Paper Mill Sludges The mean pH value of the paper mill sludges was 7.09 (Table 1). The alkalinity of paper mill sludges typically arises from causticising materials used in the pulping process and/or
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Article 2 – Environment (sludge)
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