Kraft mills wastewater

Hall, E.R. Randle, W.G. AOX removal from bleached Kraft mill wastewater. A comparison of three biological treatment processes. Water Set Technol. 1992, 26 (1-2), 387-396. 

Livemoche, D. Jurasek L. Desrochers, M. Dorica J. Veliky, LA. Removal of color from Kraft mill wastewaters with the cultures of white-rot fungi and with immobilized mycelium of Coriolus versicolor. Biotechnol. Bioengg. 1983, 25, 2055-2065. 

Saski EK, A Vahatalo, K Salonen, MS Salkinoja-Salonen (1996b) Mesocosm simulation on sediment formation indnced by biologically treated bleached kraft pulp mill wastewater in freshwater recipients. In Environmental Fate and Effects of Pulp and Paper Mill Effluents (Eds MR Servos, KR Munlittrick, JH Carey, and GJ van der Kraak), pp. 261-270. St Lucie Press, Delray Beach, FL. 

Kraft pulp mills treat wastewater using primary (physical) and secondary (biological) treatment to reduce pollutant discharges to receiving waters. Kraft mills typically collect and treat the following wastewaters36 ... 

Figure 21.8 shows a typical sequence of the major equipment systems in a wastewater treatment plant.36 The function of primary treatment is to remove suspended solids from the wastewater, and then to remove organic materials by biological secondary treatment. Primary treatment processes used by kraft mills typically involve screening followed by either sedimentation or flotation.40... 

About 75% of U.S. kraft mills use aerated stabilization basins.36 These basins are equipped with continuous mechanical aerators or diffusers to introduce air into the wastewater. By aerating the... 

Some kraft mills use basins without mechanical aerators. Known as stabilization basins, this is the simplest form of aerobic treatment. This process uses shallow basins that cover very large areas and relies on natural diffusion of air into the wastewater and algae to create aerobic conditions. At depths greater than 1.2 m (4 ft), anaerobic microorganisms will become active in lower depths thus, stabilization basins are shallow. Typically, the basin is earthen although some are lined with compacted clay. Wastewater retention time may last up to 30 d to achieve up to 90% BOD5 removal. 

Keith LH. 1976. Identification of organic compounds in unbleached treated kraft paper mill wastewaters. Environ Sci Technol 10 555-564. 

A number of studies have evaluated the toxicity of pulping hquors, in particular the black liquors generated from Kraft mills. Table 8 shows a partial representation of toxicity data compiled by the NCASI (National Council of the Paper Industry for Air and Stream Improvement) and McKee and Wolf for Kraft mill pulping wastewaters [15,16]. The table indicates that hydrogen sulfide, methyl mercaptan, crude sulfate soap, and salts of fatty and resin acids are particularly... 

H202 oxidizes S02 to sulfate, H2S to sulfate and sulfur, RSH and RSSR to sulfonic acid and sulfate and RSR to sulfoxides and sulfones. The products of oxidation are all odorless. Hence, H202 may provide an economic effective means for odor and wastewater quality control in kraft mills. For the case of RSSR which are resistant to complete oxidation, catalytic oxidation by a peroxide in acidic medium can be employed. The fact that H202 is a liquid completely miscible with water and does not give solubility (or mass transfer) problems under any conditions, makes it an attractive choice for pollution control. 

R.R. Fulthorpe, S.N. Liss, andD.G. Allen, Characterization of Bacteria Isolated from a Bleached Kraft Pulp-mill Wastewater Treatment System. Can. J. Microbiol. 39(1), 13—24 (1993). 

Aerobic biological treatment systems such as aerated stabilisation basins and activated sludge are most commonly used to treat pulp mill wastewaters. A considerable reduction in BOD and TSS occurs in these systems, but color remains relatively unaltered. For example, the secondary treatment system of an integrated bleached kraft mill showed a 92 % reduction in BOD, a 60 % reduction in TSS but only a 1 % reduction in color (16),... 

Fig. 17. Pretreatment of organic wastewater on trickling filters. Industry types for which coordinates have been plotted are 1, kraft pulp and paper 2, mixed iadustry 3, wet com milling 4, dairy 5, tannery 6, meat packiag 7, food 8, pharmaceutical 9, refinery and 10, textile.

FIGURE 21.8 Typical wastewater treatment plant. (Taken from U.S. EPA, Kraft Pulp Mill Compliance Assessment Guide (CAA, CWA, RCRA and EPCRA), U.S. EPA, EPA/310-B-99-001, Washington, May 1999.)... 

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