An evaluation of the potential toxicity of treated bleached kraft mill effluent to striped bass (Morone saxatilis walbaum) larvae exposed through metamorphosis to the juvenile stage

Twenty-day-old striped bass (Morone saxatilis) larvae were exposed to a range of treated bleached kraft mill effluent (BKME) concentrations from 0 to 20% effluent by volume (v/v) under continuous flow test conditins. The experimental test concentrations in the 2–20% BKME test aquaria had a BOD₅ which ranged from < 1 to 5 mg l⁻¹, TSS 12–17 mg l⁻¹, and true color 35–416 mg l⁻¹. Bleached kraft mill effluent did not kill larvae exposed to it for 20 days through metamorphosis to the juvenile stage. The BKME did not alter growth in length, weight or condition factor in larvae over the 20-day exposure period as determined by multiple regression analysis. A linear regression analysis on the dry weight data at Day 20 only, however, indicated a trend of decreasing weight with increasing BKME concentration. Effluent-exposed larvae also developed normally during the 20-day study. All individuals examined completed the transformation from postlarvae to juveniles by the age of 40 days.     

Biological treatment of the effluent from a bleached kraft pulp mill using basidiomycete and zygomycete fungi

Three white-rot fungi (Pleurotus sajor caju, Trametes versicolor and Phanerochaete chrysosporium) and one soft-rot fungi (Rhizopus oryzae) species confirmed their potential for future applications in the biological treatment of effluents derived from the secondary treatment of a bleached kraft pulp mill processing Eucalyptus globulus. Among the four species P. sajor caju and R. oryzae were the most effective in the biodegradation of organic compounds present in the effluent, being responsible for the reduction of relative absorbance (25-46% at 250 nm and 72-74% at 465 nm) and of chemical oxygen demand levels (74 to 81%) after 10 days of incubation. Laccase (Lac), lignin (Lip) and manganese peroxidases (MnP) expression varied among fungal species, where Lac and LiP activities were correlated with the degradation of organic compounds in the effluent treated with P. sajor caju. The first two axes of a principal component analysis explained 88.9% of the total variation among sub-samples treated with the four fungus species, after different incubation periods. All the variables measured contributed positively to the first component except for the MnP enzyme activity which was the only variable contributing negatively to the first component. Absorbances at 465 nm, LiP and Lac enzyme activities were the variables with more weight on the second component. P. sajor caju revealed to be the only species able to perform the biological treatment without promoting an increment in the toxicity of the effluent to the Vibrio fischeri, as it was assessed by the Microtox® assay. The opposite was recorded for the treatments with the other three species of fungus. EC_50-5 min values ranging between 28 and 57% (effluent concentrations) were recorded even after 10 to 13 days of treatment with P. chrysosporium, R. oryzae or with T. versicolor.     

The interaction of treated bleached kraft mill effluent and dissolved oxygen concentration on the survival of the developmental stages of the sheepshead minnow (Cyprinodon variegatus)

The interactions of treated bleached kraft mill effluent (BKME) and dissolved oxygen concentration (DO) on the survival of the embryo, fry, juvenile and adult stages of the sheepshead minnow, Cyprinodon variegatus, were studied under continuous-flow 96 h bioassay conditions. Embryo survival was dependent on effluent concentration only and showed no interaction at nominal DO concentrations of 1.0, 3.0 and 5.0 mg l⁻¹. Survival of the fry was related solely to DO concentration with no interaction with BKME concentrations up to 100%. Juvenile sheepshead minnows showed increased sensitivity to BKME at a nominal DO concentration of 1.0 mg l⁻¹. Adult fish were not affected by BKME at any of the DO concentrations tested. This study shows that the acute toxicity of BKME effluent to sheepshead minnows is a function of the developmental stage of the organism and DO concentration in the receiving stream.     

Acute toxicity of unbleached kraft mill effluent (UKME) to the opossum shrimp, Neomysis americana smith

Ninety-six hour TL₅₀ values of unbleached kraft mill effluent (UKME) for Neomysis americana were found to range from concentrations of 3.29–6.85 per cent at 26–28°C and 3.90–7.30 per cent at 16–18°C. Differences between batches of effluent proved insignificant in experiments at each temperature regime. Furthermore, UKME did not lose its toxicity when stored for 5–7 days at 4°C. A concentration of 20 per cent effluent killed 100 per cent of the organisms in 8 of the 12 bioassays. Slope functions and confidence limits of TL₅₀ were calculated. Toxicity did not appear to be correlated with the Biochemical Oxygen Demand (BOD) of individual batches of raw effluent.     

The effectiveness of a biological treatment with Rhizopus oryzae and of a photo-Fenton oxidation in the mitigation of toxicity of a bleached kraft pulp mill effluent

Huge efforts have been made both in adopting more environmental-friendly bleaching processes, and in developing advanced oxidation processes and more effective biological treatments for the reduction of deleterious impacts of paper mill effluents. Even so, the success of such treatments is frequently reported in terms of chemical parameters without a proper evaluation of the effluent's toxicity mitigation. This is the first study reporting an exhaustive evaluation of the toxicity of a secondary bleached kraft pulp mill effluent, after either tertiary treatment with the soft-rot fungi Rhizopus oryzae or with a photo-Fenton oxidation, using a battery of freshwater species. As it has been reported the photo-Fenton/UV treatment has proved to be the most effective in reducing the colour and the COD (chemical oxygen demand) of the effluent. Nevertheless, extremely low EC₅₀ values were reported for almost all species, after this tertiary treatment. The treatment with R. oryzae was less effective in terms of colour removal and COD reduction, but proved to be the most promising in reducing toxicity.     

Influence of kraft mill effluent on the flavor of salmon flesh

In a laboratory study measurable impairment of the flavor of cooked flesh of jack coho salmon resulted from exposure of the fish to untreated kraft pulp and paper mill effluents for 72 to 96 h at concentrations of about 1.0 to 2.0 per cent by volume and above. No flavor impairment was noted when fish were exposed to a concentration of 2.9 per cent by volume, the highest level tested, of biologically treated effluent.     

Effect of pulpmill effluent on dissolved oxygen in a stratified estuary—II. Numerical model

A numerical model is presented which simulates the biological and physical processes of oxygen supply in a stratified inlet. The results of the model show that the introduction of pulpmill effluent into the upper layer of the inlet causes a decrease in the dissolved oxygen concentration of the water due to blockage of photosynthesis in the stratum of water immediately below the halocline. Removal of the biochemical oxygen demand from the effluent has very little effect on the oxygen concentration in the upper layer since the supply of oxygen from the lower layer is blocked by the stain. Removal of 90 per cent of the stain from the effluent restores the oxygen concentrations to near normal.     

Effect of pulpmill effluent on dissolved oxygen in a stratified estuary—I. Empirical observations

Pulpmill effluent discharged at the surface in Alberni Inlet is shown to prevent oxygen production in the stratum immediately beneath the halocline by restricting light penetration. This stratum is the source of marine water for entrainment in the halocline and to the upper mixed zone. This situation cannot be remedied by removal of BOD from the pulpmill effluent, rather the staining properties must be diminished or removed.     

Wastewater reuse and exposure to Legionella organisms

Eight hundred and fifty-two (852) blood sera were drawn in 1980 and 1981 from populations residing in 30 agricultural settlements (having a total population of 16,240). These sera were tested for the presence of antibodies against 15 different antigens of Legionella species (L. pneumophila serogroups 1–8 and seven other Legionella, i.e. bozemanii, gormanii, micdadei, jordanis, dumoffii, longbeacheae and oakridgensis). The results indicate a significant (P < 0.02) excess in the percentage of sera positive for L. pneumophila (serogroups 1–8) among sewage and non-sewage irrigation and fish pond workers as compared to the control group (4.5% vs 1.5%). For the other Legionella species, there was no difference among the above groups. The isolation of L. pneumophila serogroup 4 and five organisms resembling Legionella spp from one oxidation pond used for irrigation strengthens the seroepidemiological findings.     

The growth of cladophora glomerata in a river receiving sewage effluent

A considerable improvement in the natural flora of the River Great Stour has occurred since the mid-1960s when dense growths of Cladophora glomerata dominated sections of the river with the disappearance of some rooted macrophytes. Cladophora growths in the river in response to changing river conditions and sewage treatment operations during a thirty year period are reviewed. A vegetation mapping programme undertaken from 1978 to 1982 to assess the influence of a sewage treatment works discharge on the growth of the filamentous alga has shown that previous recommendations to reduce dissolved phosphorus concentrations in the final effluent need not be implemented.     

Effect of pH on toxicity of kraft pulp and paper mill effluent to salmonid fish in fresh and seawater

In freshwater bioassays with juvenile rainbow trout (Salmo gairdneri), at initial pH values from 4 to 11, kraft mill effluents were considerably less toxic at pH 9–10 than at neutrality. When pH of test solutions was controlled throughout the bioassay period, the least toxic range was 8.5–9.5. Toxicity at typical receiving-water pH values was 50–67% greater.The acute toxicity of effluent samples to yearling coho salmon (Oncorhynchus kisutch) was identical for these effluents in seawater and freshwater respectively, provided that the pH was adjusted and held at the same value, and that test fish were previously acclimated to the dilution water for several months. Thus seawater constituents other than pH did not affect the acute toxicity of pulp and paper mill effluents appreciably.     

The effects of power plant condenser cooling water entrainment on the amphipod. Gammarus sp.

The abundant Hudson River amphipod Gammarus sp. was examined for viability before and during entrainment in the Indian Point cooling water system. The mean per cent survivial of Gammarus sp. sampled during ΔT's of 7.1–8.3°C and ambient temperatures of 24.9–26.0°C was 98.5 and 97.4 per cent for the two intake stations and 90.1 and 96.8 per cent for the discharge canal stations D-1 and D-2 respectively. A statistically significant (α = 0.05) difference was detected between the survival of Gammarus sp. at the intake stations and discharge station D-1. located near the upper end of the discharge canal. Entrained Gammarus sp. experience increased initial and latent mortalities during periods of condenser chlorination. Comparison of the abundances of entrained Gammarus sp. during day and night sampling periods reveals a significantly higher occurrence during darkness. Temperature bioassays indicate that the thermal tolerance of Gammarus sp. is dependent on exposure time and ambient temperature. The temperature resulting in a 50 per cent mortality of Gammarus sp. for 30 min exposure times increased approximately 11 C as ambient temperatures increased from 2.5 to 25.8°C. Consequently, Gammarus sp. was capable of surviving ΔT's of greater magnitude as the ambient temperature to which they were acclimated decreased. Temperature bioassays indicated that Gammarus sp. should be able to tolerate all projected time-temperature exposure combinations encountered during entrainment through the cooling water system.     

Effects of nickel on daphnia magna during chronic exposure and alterations in the toxicity to generations pre-exposed to nickel

Daphnia magna was cultured at sublethal nickel concentrations. The mean life expectancy was significantly less when exposed to 40 ppb Ni. Statistically significant reductions of the number of offspring, maximum body length of adults and of neonates were caused by 80 ppb Ni. The length and brood size of primiparous animals were significantly less when exposed to 120 ppb Ni. The intrinsic rate of population growth (r) was inversely proportional to nickel concentrations. During seven successive generations exposed to 160 ppb Ni, both the mean life span and the length of primiparous animals decreased significantly with increasing time. The progeny of nickel pre-exposed generations exhibited no adaptation towards nickel except an altered reproduction pattern which induced an increase of r. After the transfer into nickel-free water, the progeny of nickel pre-exposed generations showed an increase of body length, mean life span, number of offspring, brood size and brood number as well as the maximum body length of neonates. However, the progeny of pre-exposed generations remained smaller than the progeny of an untreated generation.     

The effects of an industrial waste (cryolite recovery sludge) upon the atlantic Salmon, Salmo Salar (l.) detection thresholds and the effects of exposure to the waste upon detection of an amino acid

Thresholds for detection of cryolite recovery sludge (CRS, an aluminium smelter waste dumped at sea) were determined for salmon. Salmo salar (L.). in sea water using a cardiac conditioning technique. Some effects of exposure of salmon to CRS filtrate (mean concentration 5.5°_D) for up to 1 h were monitored. Oxygen consumption and ventilation rate increased and heart rate decreased after presentation of the filtrate. The effects were transient and the physiological parameters monitored returned to pre-exposure levels within 2 h of ceasing filtrate presentation. Detection levels for an amino acid (glycine) were determined for salmon in sea-water before and after exposure to CRS filtrate (mean concentration 5.5%). Within 24 h of exposure to the CRS filtrate the mean threshold level was significantly different from the pre-exposure detection level. However, 24–48 h after exposure the threshold for detection of glycine was no longer significantly different.     

Some physiological responses of rainbow trout (Salmo gairdneri) to intermittent monochloramine exposure

Rainbow trout (Salmo gairdneri) were exposed for 2.5 h to monochloramine (NH₂Cl) at an average concentration of 0.16 or 0.23 mg l⁻¹ (and with peak concentrations of 0.4 or 0.6 mg l⁻¹) three times daily. This simulates conditions in the outfall area of many electric power plants. Heart rate, opercular movement, cough frequency, arterial PO₂, lactate, hemoglobin and methemoglobin were monitored. The trout responded to chloramine pulses with slight increases in opercular movement, bradycardia, and a large increase in cough rate. These factors approached control rates between periods of exposure to a peak concentration of 0.4 mg l⁻¹, but not when the peak was 0.6 mg l⁻¹. Neither hemoglobin or lactate changed, while arterial PO₂ decreased slightly but not significantly. Methemoglobin concentration increased markedly at the end of each period of exposure with some recovery between them. In contrast to free chlorine, which causes acute hypoxemia due to gill damage, chloramine at these concentrations causes little if any hypoxemia. The elevated methemoglobin levels, not seen following exposure to free chlorine, indicate that perhaps chloramine is entering the blood stream to an extent that does not occur with free chlorine. Methemoglobinemia is probably not the proximate cause of death.     

Survival and distribution of aeromonas hydrophila in near-shore coastal waters of Puerto Rico receiving rum distillery effluent

For a period of 1 year, monthly water samples were taken for estimates of Aeromonas hydrophila density at 6 sites in Ensenada de Boca Vieja near San Juan, Puerto Rico. Five sites were associated with the effluent plume of the world's largest rum distillery, the sixth site was 177 m upcurrent. Fifteen water quality parameters were monitored concurrently with A. hydrophila estimates. The toxic and stimulatory nature of the effluent made correlations with any physicochemical parameter difficult. However, a significant multiple regression was obtained against density of A. hydrophila using temperature, total phosphorus, total organic carbon and orthophosphates. Densities of A. hydrophila were always higher in the effluent plume and usually highest at the site closest to effluent outfall. Suspensions of A. hydrophila placed in diffusion chambers at the effluent point source not only survived, but gradually increased in density, while 500 m upcurrent densities of A. hydrophila in diffusion chambers rapidly declined. Significant differences in A. hydrophila density between the two sites could be detected after only 18 h. The diffusion chamber studies confirm natural correlations with water quality that indicate A. hydrophila densities in marine habitats can become elevated under the appropriate conditions. Higher densities of other potential pathogens e.g. Klebsiella pneumoniae, Vibrio cholerae, were also observed in the rum distillery effluent plume.     

Response of antioxidant enzymes in freshwater fish populations (Leuciscus alburnoides complex) to inorganic pollutants exposure

Evidence is accumulating indicating the importance of antioxidant enzyme activity measurements in eco-toxicological studies, as they may constitute markers for exposure to a large variety of pollutants. Variation of antioxidant enzymes, superoxide dismutase (SOD) and glutathione S-transferases (GST) and the effect of heavy metals and selenium exposure on these enzymes were investigated in the livers of Iberian endemic minnows (Leuciscus alburnoides complex) captured in a copper (Cu) mining area. Higher hepatic levels of copper and selenium were always observed in fish captured at the polluted site relative to the reference area population, reflecting the environmental monitoring results. A seasonal fluctuation in zinc and selenium levels for both populations was also observed which could be related to gonad maturation. The activity of SOD did not show significant regional alterations, but a seasonal variation occurred presumably associated with the Leuciscus life cycle. The GST activity was higher in the fish population from the polluted area (except in spring) and GST variability was associated with selenium and copper levels when both regions were compared. The increased GST activity was probably a metabolic adaptation to the continuous exposure to higher levels of those elements.     

Cardiovascular-respiratory responses of rainbow trout (Salmo gairdneri) during chronic exposure to sublethal concentrations of cadmium

The effects of exposure to 3.6 and 6.4 μg l⁻¹ cadmium for periods up to 178 days on cardiac and ventilatory rates, hematocrit, hemoglobin concentration and erythrocyte adenosine triphosphate concentration in adult rainbow trout, Salmo gairdneri, were investigated. Except for slight transitory responses, 3.6 μg l⁻¹ cadmium had no effect on any of the cardiovascular/respiratory parameters. Significant increases in cardiac and ventilatory rates, blood hematocrit and hemoglobin were observed in fish exposed to 6.4 μg l⁻¹ Cd over the entire exposure period while erythrocyte ATP concentration declined during the last stages of exposure. Further experiments on the responses of fish exposed to 6.4 μg l⁻¹ Cd for 30 days demonstrated an impairment of oxygen transfer across the gill. The results are discussed in terms of possible gill impairment and hyperactivity as toxic responses to cadmium.     

Effect of substructures upon failure behavior of steel reticulated domes subjected to the severe earthquake

This paper presents the study on the influence of substructures on the failure behavior of steel reticulated domes subjected to the severe earthquake. The full-range dynamic response analysis method is applied to investigate the failure characteristics of single-layer steel reticulated domes with substructures subjected to the severe earthquake. The natural vibration properties are studied. Two typical failure modes of steel reticulated domes with substructures are illustrated according to the stiffness of substructures. Failure criterion is proposed to estimate the ultimate load strength for single-layer steel reticulated domes. It is observed that the substructure has great influence on the failure characteristics and the ultimate load strength of steel reticulated domes subjected to the severe earthquake. It is necessary to take substructure into consideration in analysis and design stage.     

The use of Bacillus thuringiensis var. israelensis to control the nuisance fly Sylvicola fenestralis (Anisopodidae) in sewage filter beds

The effectiveness of using the microbial insecticide Bacillus thuringiensis var. israelensis (Bti) to control the nuisance fly Sylvicola fenestralis at Rossendale Sewage Works, Lancashire, was investigated. Following a provisional trial in 1987, the whole Works (28 filter beds) was treated with a two-stage application of Bti in 1988; the first application in late April was separated from the second in late May by about half the length of the Sylvicola life-cycle. The Bti treatment was timed to reduce fly nuisance in June, the month when most complaints (71%) had been received. For each application, 0.161. of the Bti preparation, containing nearly 10¹⁰ spores·cm⁻³, was applied per square metre of bed surface. An 80 and 98% kill of Sylvicola larvae was recorded following the first and second applications respectively. The lower kill achieved by the first application was believed to be due to insufficient mixing of the Bti with the settled sewage prior to dosing. Nuisance caused by the flies was considerably reduced; there were no complaints from the public during June, although a few were received in late July, early August. Sewage purification efficiency was not affected by Bti treatment. The maximum concentration of Bti spores in the Works' effluent was 7 × 10⁴ spores·cm⁻³. This concentration did not appear to affect the already impoverished macro-invertebrate fauna of the receiving river.