Search results for "Elemental chlorine free"
showing 4 items of 4 documents
Vertical distribution of AhR-activating compounds in sediments contaminated by modernized pulp and paper industry
2013
Increased ethoxyresorufin-O-deethylase (EROD) activity is a sensitive biomarker of exposure to the chemicals which activate the aryl hydrocarbon receptor (AhR) and induce the cytochrome P450 system, such as many polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs). Pulp bleaching was one of the main sources of PCDDs and PCDFs until elemental chlorine free (ECF) and total chlorine free bleaching processes since 1990s have remarkably decreased but not completely eliminate discharges of these chemicals. In addition, historically contaminated sediments may act as a source of these persistent contaminants. In this study, the contam…
Confirmation of in situ exposure of fish to secondary treated bleached-kraft mill effluent using a laboratory simulation
1998
To corroborate the responses in whitefish (Coregonus Iavaretus L.) exposed to elemental chlorine free (ECF) bleached-kraft pulp mill effluent (BKME) in situ, a 30-d laboratory exposure was carried out at concentrations simulating the field conditions. The flow-through exposures were conducted at four secondary (activated sludge) treated effluent (STE) concentrations: 1.3, 2.3, 3.5, and 7%. To evaluate the role of the secondary treatment, fish were also exposed to one concentration (3.5%) of pretreated effluent (PTE) from the mill. Compared to the control, whitefish liver 7-ethoxyresorufin-O-deethylase (EROD) activity was twofold in fish exposed to 3.5% STE, which was similar to monooxygenas…
Concentration of retene and resin acids in sedimenting particles collected from a bleached kraft mill effluent receiving lake
2000
Abstract The concentration of retene, a di-alkyl substituted PAH derived microbially and thermally from dehydroabietic acid, eight resin acids and their derivatives were analysed from sedimenting particles collected from five lake sites receiving pulp and paper mill effluents and from two reference sites. At five of the sites, samples were collected prior and after a conventional aerated lagoon wastewater treatment system of the mill was modernized with an activated sludge plant, and elemental chlorine free bleaching (ECF) had replaced chlorine bleaching. The highest level of retene was 30.0–53.8 μ g/g dry weight (d.w.), observed 3 km downstream from the mill. Nine kilometers downstream fr…
Modulation of immune parameters of roach, Rutilus rutilus, exposed to untreated ECF and TCF bleached pulp effluents
2000
Abstract The present study was designed to assess the effects of elemental chlorine free (ECF) and totally chlorine free (TCF) pulp and paper mill effluents on the immune defence of the roach ( Rutilus rutilus ). Fish were exposed for 5 weeks to concentrations of 0, 0.6, 2, 6 and 20% of untreated effluents from ECF or TCF bleaching processes. In order to study the capability to respond to foreign antigens the fish were immunised with bovine γ-globulin (BGG) 3 weeks before sampling. The numbers of anti-BGG antibody-secreting cells and immunoglobulin-secreting cells in the spleen and blood, as well as the levels of the anti-BGG antibodies and concentrations of immunoglobulin in plasma and the…