Effect of adsorptive fouling on membrane performance: Case study with a pulp mill effluent

The evaluation and process risk assessment of (a) lignin precipitation from black liquor, and (b) the near-neutral hemicellulose pre-extraction for recovery boiler debottlenecking in an existing pulp mill is presented in Part I of this paper, which was published in the July 2012 issue of TAPPI Journal. In Part II, the economic assessment of the two biorefinery process options is presented and interpreted. A mill process model was developed using WinGEMS software and used for calculating the mass and energy balances. Investment costs, operating costs, and profitability of the two biorefinery options have been calculated using standard cost estimation methods. The results show that the two biorefinery options are profitable for the case study mill and effective at process debottlenecking. The after-tax internal rate of return (IRR) of the lignin precipitation process option was estimated to be 95%, while that of the hemicellulose pre-extraction process option was 28%. Sensitivity analysis showed that the after tax-IRR of the lignin precipitation process remains higher than that of the hemicellulose pre-extraction process option, for all changes in the selected sensitivity parameters. If we consider the after-tax IRR, as well as capital cost, as selection criteria, the results show that for the case study mill, the lignin precipitation process is more promising than the near-neutral hemicellulose pre-extraction process. However, the comparison between the two biorefinery options should include long-term evaluation criteria. The potential of high value-added products that could be produced from lignin in the case of the lignin precipitation process, or from ethanol and acetic acid in the case of the hemicellulose pre-extraction process, should also be considered in the selection of the most promising process option.

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Occurrence of Various Off-Flavours in Fish in Finland from 1969 to 1981

Water Science & Technology ◽

10.2166/wst.1983.0129 ◽

1983 ◽

Vol 15 (6-7) ◽

pp. 47-58 ◽

Cited By ~ 3

Author(s):

T Kuusi ◽

M Suihko

Keyword(s):

Research Laboratory ◽

Kraft Pulp ◽

Pulp Mill ◽

Northern Pike ◽

Research Centre ◽

Pulp Mill Effluent ◽

Technical Research ◽

Kraft Pulp Mill ◽

Food Research ◽

Numerical Scale

Off-flavours in fish were studied from 1969 to 1981 at the Food Research Laboratory of the Technical Research Centre of Finland using sensory methods. In all, 1982 samples of 18 species of Finnish fish, most of them suspected of being tainted, were studied. A trained taste panel scoring on a numerical scale of 0-10, where a score of 5 or less was unacceptable, was used. The off-flavours described were oil, kraft pulp mill effluent, sewage (musty), muddy, rancid, and others. Of all these samples, 34.9% were unacceptable. The most common off-flavour was kraft pulp mill effluent, present in 41.2 % of the unacceptable samples. In acceptable fish slight off-flavours were somet imes found. Of the muddy fish, only 35.2 % of the bream and 28.8 % of the northern pike were unacceptable. The panel was able to discriminate between the different off-flavours, but, in some cases, the boundaries were vague.

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Characterization of odorous compounds from bleached kraft pulp mill effluent

Water Science & Technology ◽

10.2166/wst.1995.0396 ◽

1995 ◽

Vol 31 (11) ◽

pp. 35-40 ◽

Cited By ~ 6

Author(s):

B. G. Brownlee ◽

S. L. Kenefick ◽

G. A. MacInnis ◽

S. E. Hrudey

Keyword(s):

Gas Chromatography ◽

Kraft Pulp ◽

Pulp Mill ◽

Dimethyl Disulfide ◽

Gas Chromatography Mass Spectrometry ◽

Pulp Mill Effluent ◽

Kraft Pulp Mill ◽

Bleached Kraft Pulp ◽

Methyl Phenyl Sulfide ◽

Library Spectrum

Odour compounds in extracts of bleached kraft pulp mill effluent (BKME) have been characterized by olfactory gas chromatography (OGC) and gas chromatography-mass spectrometry. A variety of sulfury odours was detected by OGC in addition to woody and pulp mill-like odours. Three sulfur compounds were identified by comparison of retention times and partial mass spectra with authentic standards: dimethyl disulfide, 3-methylthiophene and thioanisole (methyl phenyl sulfide). Typical concentrations in BKME were 1, 0.05, and 0.5 μg/l, respectively. Their odour intensity is relatively low and they were not detected by OGC. Dimethyl trisulfide was tentatively identified by comparison of its partial mass spectrum with a literature (library) spectrum. Its concentration in BKME was estimated at 0.5-2 μg/l. It corresponded to a skunky odour in the OGC profiles. Efforts to identify another odour peak, eluting just after 3-methylthiophene, with a pronounced alkyl sulfide odour were unsuccessful.

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Growth responses of periphyton and chironomids exposed to biologically treated bleached kraft pulp mill effluent

Water Science & Technology ◽

10.2166/wst.1997.0553 ◽

1997 ◽

Vol 35 (2-3) ◽

pp. 339-345 ◽

Cited By ~ 1

Author(s):

M. G. Dubé ◽

J. M. Culp

Keyword(s):

Kraft Pulp ◽

Pulp Mill ◽

Pulp Mill Effluent ◽

Growth Responses ◽

High Concentration ◽

Wood Extractives ◽

Kraft Pulp Mill ◽

Bleached Kraft Pulp ◽

Low Levels ◽

High Concentrations

Experiments were conducted in artificial streams to determine the effects of increasing concentrations of biologically treated bleached kraft pulp mill effluent (BKPME) on periphyton and chironomid growth in the Thompson River, British Columbia. Periphyton growth, as determined by increases in chlorophyll a, was significantly stimulated at all effluent concentrations tested (0.25%, 0.5%, 1.0%, 5.0% and, 10.0%). Chironomid growth (individual weight) was also significantly stimulated at low effluent concentrations (≤1.0%). At higher concentrations (5.0% and 10.0%), chironomid growth was inhibited relative to the 1.0% treatment streams. Increases in growth were attributed to the effects of nutrient and organic enrichment from BKPME. The effluent contained high concentrations of phosphorus and appears to be an important source of carbon for benthic insects grazing on the biofilm. In high concentration effluent streams, chironomid growth decreased despite low levels of typical pulp mill contaminants. This suggests that other compounds in the effluent, such as wood extractives, may be inhibiting chironomid growth. These results support findings of field monitoring studies conducted in the Thompson River where changes in periphyton and chironomid abundance occurred downstream of the bleached kraft pulp mill.

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