Effects of Biologically Treated Bleached Kraft Mill Effluent on Cold Water Stream Productivity in Experimental Stream Channels

Abstract

Large-scale outdoor experimental streams were used in a series of effluent addition studies to determine the compatibility of biologically treated bleached kraft mill effluent with satisfactory production of salmonid fishes. Results are reported for 9-to 10-month studies at effluent concentrations representing from 0.5 to 2.0 mg/L of effluent 5 d biochemical oxygen demand (BODS) addition (1.3-5.1% v/v), as well as for an extended 3.5-year study at 0.5 BOD, addition (1.5% v/v). The series of studies indicated a pattern of greater rainbow trout (Oncorhynchus mykiss) cumulative production and average weight in streams receiving effluent and better survival in the control streams. The final long-term study also indicated that successful maturation, spawning, hatching, larval development, and juvenile growth could take place during conditions of continuous effluent exposure. Measurements of the supporting food web suggest that effluent can increase periphyton production at low concentrations through nutrient additions but that higher effluent concentrations may reduce periphyton production due to the effect of color on underwater light transmittance. Macroinvertebrate populations increased in the streams receiving effluent.

Comparison of a test battery for assessing the toxicity of a bleached-kraft pulp mill effluent before and after secondary treatment implementation

“…The present result is consistent with results of other studies observing that secondary treatment considerably reduced the toxicity of pulp mill effluents toward phytoplankton (Kovacs et al 1994;Tarkpea et al 1999). Also, Hall et al (1991) have found that a secondary-treated elemental chlorine-bleached effluent affected periphyton growth, causing stimulation at low and inhibition at high concentrations. Yet, they concluded that stimulation was due to nutrient addition from the effluent, and inhibition was due to the color effect reducing light availability.…”

“…Reductions in the toxicity of pulp and paper mill effluents through the introduction of secondary treatment have been observed in previous studies (Tarkpea et al 1999;Environment Canada 2003;Hewitt et al 2006;Parrott et al 2006). Such toxicity reductions are mainly due to decreases in the levels of critical chemical sum parameters, as was observed in the present study with regard to the TSS, COD, BOD, and AOX values, as well as to declines in the concentrations of chemical constituents (e.g., fatty and resin acids; Hall et al 1991;Kovacs et al 1994). After the implementation of secondary treatment, the levels of these parameters were within ranges observed in other secondary treated effluents, for which no toxic effects were observed toward microalgae, cladocerans, and fish (Kovacs et al 1994;O'Connor et al 2003).…”

“…Also, in the present study, no effects on growth were detected in the 28-day test with D. rerio for both effluent samples. Regarding effects of secondary-treated bleached-kraft pulp mill effluents on fish growth, stimulatory (Hall et al 1991;Soimasuo et al 1995), inhibitory (Kovacs et al 2007), and no effects have been reported (Robinson et al 1994). Although no effects were here observed on D. rerio growth, it should be stated that most of the detrimental effects of pulp mill effluents on fish have been found at the level of reproductive indicators, namely increased age to maturation, reduced fecundity, and reduced gonadal development or levels of active reproductive steroid hormones (Environment Canada 2003;Kovacs et al 2006;McMaster et al 2003).…”

“…Efforts have focused on the replacement of elemental chlorine by chlorine dioxide (elemental chlorine-free bleaching; ECF) or by oxygen-containing compounds, such as ozone and hydrogen peroxide (totally chlorinefree bleaching; TCF; Tarkpea et al 1999;Latorre et al 2005). Also, the installation or the improvement of secondary effluent treatment plants aims at reducing AOX values, together with the levels of other parameters like BOD, COD, and TSS (Hall et al 1991;Kovacs et al 1994;Kostamo et al 2004).…”

Exposure of Reproductively Maturing Rainbow Trout to a New Zealand Pulp and Paper Mill Effluent

“…Our experimental system, as well as those developed by others (Hall et al, 1991(Hall et al, , 1992Haley et al, 1995;DubeH and Culp, 1996;Lehtinen et al, 1999), has been designed to reduce confounding "eld variables while maintaining a level of environmental relevance. Whether used for individual species studies, or community level impacts assessment, this mesocosm approach provides a useful tool, particularly where "eld level risk assessment is di$cult.…”