Experimental field exposure of brown trout to river water receiving effluent from an integrated newsprint mill.

Effects of effluents from mechanical pulp production on brown trout were studied for 8 weeks at environmentally relevant concentrations. The exposure took place in laboratory-based pools upstream and downstream of the effluent discharge point of an integrated newsprint mill using ground wood/thermomechanical pulp. The mill had no secondary treatment of the wastewater. The pools were supplied with water pumped directly from the river. To determine the relevance of this approach, wild fish were also caught at the respective sites upstream and downstream from the mill. Sublethal effects were assessed using physiological and biochemical parameters including liver histology, hematology, serum biochemistry, and hepatic enzyme assays. Exposure was verified by analyzing water samples, fish bile, and tissues for resin acid concentrations. The downstream experimental fish and captured feral fish displayed responses and changes in physiological parameters similar to those previously observed in laboratory experiments with untreated effluents. The most obvious effects were liver damage and growth inhibition.

Ecotoxicological characterization of industrial wastewater--sulfite pulp mill with bleaching.

Different process wastewaters from a sulfite pulp mill with bleaching were characterized by chemical analysis and toxicity tests. The amount of adsorbable organically bound halogen (AOX) from the bleachery was 3.6 kg per ton pulp. The extractable organically bound chlorine was 15% of AOX. Some identified organochlorine compounds in the effluent could be traced in the receiving water. Effluents from the chlorination and alkaline extraction stages and the condensate were the main contributors to the effluent toxicity. The effluents were particularly toxic to the alga Skeletonema costatum. The EC50 value for growth of the alga was 24-29 ml/liter of the total effluent. The toxicity cannot be ascribed to single chemical components in the effluents. Degradation of toxic components occurs after dilution of the effluents in the receiving water. The toxicity may be reduced to 30-50% of the initial toxicity within 1 week. Predictions of toxic effects in the receiving water, based on results of toxicity tests and estimated dilution, indicate that large areas are affected by the discharges. Som observations of the distribution of organisms in the receiving water indicate that predictions from the toxicity tests may be valid.

Impact of bleached kraft mill effluents on drinking water quality.

Bleaching effluents from kraft pulp mills contain large quantities of chlorinated organic compounds, some of which are mutagenic. Mutagenic chloro-organic compounds are also formed as by-products in chlorination of drinking water. The work reported here was a combined field and laboratory study aimed at comparing the evidence of health risks from pulp mill contaminants in drinking water, with corresponding evidence from normal, chlorine disinfection by-products. The study was performed in a Swedish river basin with a large, public water works located downstream from a bleached kraft mill. Chemical analyses (gas chromatography and determination of adsorbable organic halogen) and bioassays for mutagenic activity (bacterial and mammalian cell bioassays) were performed on samples of river water, drinking water and laboratory produced drinking water. The study showed that the bleached kraft effluents caused a considerable, long-range transport of chloro-organic substances in the receiving waters, and a substantial increase in the total amount of organic chlorine in drinking water produced downstream from the mill. As regards Ames mutagenic compounds, however, chlorination of naturally occurring humic substances during the chlorine disinfection step in drinking water production, proved to be a far more important source. The contribution of volatile chloro-organic compounds from the kraft mill was also much smaller than the contribution from normal disinfection by-products. The chromosome aberration tests gave no clear evidence of a positive response for any of the samples tested.

Mutagenic properties of spent bleaching liquors from sulphite pulps and a comparison with kraft pulp bleaching liquors.

Parameters influencing the mutagenic properties of spent bleaching liquors from sulphite pulps have been studied. In addition a comparison has been made between the properties of spent liquors from sulphite and kraft pulp bleaching. In the sulphite process the cooking base had no influence on the mutagenicity of the chlorination stage. In contrast, removing the extractives before chlorination especially for dissolving pulp resulted in an increase in mutagenic activity. The mutagenicity decreased significantly after substituting 40% of the chlorine with chlorine dioxide. Sequential addition of chlorine and chlorine dioxide resulted in higher activity than simultaneous or premixed chlorination as observed for liquors from kraft pulp. Increasing the pH of the extracts or addition of sulphur dioxide decreased the mutagenicity. Expressed as 10(7) revertants per kappa number and ton pulp the mutagenicity varied between 10 and 40 for sulphite pulp while the corresponding figures for kraft pulp were 100-225.

Analysis of chlorinated styrenes in environmental samples using negative ion chemical ionization mass spectrometry.

A method for the separation and identification of chlorinated styrene isomers with fully chlorinated aromatic nuclei in environmental samples is presented. Gas chromatography combined with negative ion chemical ionization mass spectrometry is used. The method has been applied to a combined fish liver and filét extract. All the possible chlorostyrenes with fully chlorinated aromatic nuclei were detected in the sample.

Identification of chlorinated compounds in the spent chlorination liquor from differently treated sulphite pulps with special emphasis on mutagenic compounds.

About 80 compounds present in the spent chlorination liquor from the bleaching of sulphite pulp have been identified. A comparison has been made between these compounds and those identified in kraft bleaching effluent, with special emphasis on mutagens. The influence of oxygen delignification, before chlorination and alkali treatment of the spent bleach liquor, on the composition of the liquors has also been investigated.

A comparison of methods for concentrating mutagens in drinking water--recovery aspects and their implications for the chemical character of major unidentified mutagens.

A comparison of techniques for concentrating mutagenic compounds in drinking water has shown that XAD-2 adsorption and dichloromethane extraction have acceptable and almost identical enrichment properties, while purging at an elevated temperature is inappropriate in this context. Quantitatively, the most important drinking water mutagens could only be adsorbed (extracted) after acidification of the water, and even then recovery was far from complete. Recovery experiments with known mutagens from pulp mill effluents have shown that none of the major chlorination-stage mutagens identified thus far can explain the mutagenic activity of extracts from neutral or acidified chlorinated drinking water.

Analysis of volatile halogenated organic compounds in fish.

A method for the analysis of volatile halogenated hydrocarbons in biological samples has been developed. Extraction efficiencies for various C1 and C2 halocarbons were found to be in the range of 63--82%, and recoveries were fairly good. The detection limits lie in the sub-ppb range (0.1--1 ppb). The method has been used to analyse fish samples from both unpolluted and polluted areas in Norway. The compounds most frequently found were chloroform, trichloroethylene and tetrachloroethylene in concentrations ranging from 10--1000 ppb. From one area, corresponding water and fish samples were analysed which made it possible to estimate accumulation factors for chloroform and trichloroethylene, which were found to be 200--500 and 1400 respectively.

Determination of halogenated organic compounds and mutagenicity testing of spent bleach liquors.

The content of organohalogenated compounds in spent bleach liquor from different bleaching stages in a sulphate and a sulphite plant has been determined by a combination of glass capillary gas chromatography, gas-liquid chromatography/mass spectrometry and neutron activation analysis. Several compounds which have not been reported before have been identified including halogenated derivatives of dimethyl-propylnaphthalenes and alkylated catechols. The unconcentrated effluents, non-polar and total extracts were tested for mutagenic activity with Ames' Salmonella test. Spent bleach liquors from most bleaching stages as well as the total effluents contained mutagenic compounds. Addition of liver microsomes for metabolic activation reduced the mutagenic activity in all stages except for the first chlorination stage in the sulphate plant. Two isomers of chloro-, bromo-, and dichloro-p-cymene previously determined in effluents from bleaching plants were synthesized from the parent molecule. Both bromo- and dichloro-p-cymene exhibited weak mutagenic activity in the Salmonella test system. Liver microsomes reduced the effect slightly. The chlorinated cymenes were found to account for up to 18% of the total organically-bound chlorine in the non-polar extracts.