Analysis of Cellulose Pulp Characteristics and Processing Parameters for Efficient Paper Production

For economic reasons, increasing the use of various fibrous pulps with high lignin contents—i.e., chemothermomechanical pulp (BCTMP and CTMP), thermomechanical pulp (TMP), and semichemical pulp—is desirable. The relatively good quality and increased efficiency of these pulps make them attractive paper semi-products. In particular, they could alleviate the severe shortage of paper semi-products. Although mechanical pulp and semichemical pulp are achieving increasing quality with substantially increased wood efficiency, their production is often characterised by high consumption of electricity to defibre chips or refine high-lignin-content fibrous pulps. Technological, environmental, and economic evaluations of the manufacture and application of increased efficiency cellulose pulps that take into account potential profits from increased cellulose pulp efficiency and losses due to energy costs and degradation in the properties of the resulting paper are relevant and essential to paper mills. This article reports such an analysis. The authors have analysed the usable properties of ten cellulose pulps with various degrees of digestion and identified the optimum pulp that yields the optimum product properties, considering the yield; pulp refining time, which determines the cost of paper manufacture; and strength properties of the obtained paper.

Effects of Neutral Sulfite Semichemical Pulp Mill Effluent in the Mummichog (Fundulus heteroclitus.) Adult Fish Reproductive Test

Short-term adult fish reproductive tests using freshwater species have demonstrated negative impacts on egg production in fish exposed to complex pulp and paper mill effluents. In an effort to address the ability of laboratory tests to predict effects on wild fish, mummichog (Fundulus heteroclitus) were exposed in saltwater conditions for 21 days to 3 and 30% final effluent of a neutral sulfite semichemical pulp mill that discharges into an estuarine environment in eastern Canada. Although no effects on gonad size, liver size, or condition factor were found, egg production was significantly increased by 31% and decreased by 30% when fish were exposed to 3 and 30% final effluent, respectively. This study i) is the first to demonstrate a decrease in egg production when fish are exposed to complex effluents under estuarine conditions and ii) provides the first linkage of effects on gonad size in wild fish to egg production from laboratory testing in the same species. In so doing, this study also demonstrates the utility of egg production measurements to further investigate the causes and solutions to the effects of mill effluents in both freshwater and marine wild fish.