Bleached Kraft Mill Effluent Research Articles

Adsorption of phenolic compounds and color from bleached Kraft mill effluent using allophanic compounds

Synthetic and natural allophanic compounds were used to evaluate the phenolic compounds and color removal capacity from a biological treated softwood bleached Kraft mill effluent. Kinetics studies and solid/solution relationship using synthetic allophanic compounds were studied and compared with powder activated carbon adsorption. On the other hand, the pH effect (4 to 9) on allophanic compounds adsorption was studied. The adsorption capacity of three allophanic soil profiles (10–20, 20–40 and 40–60 cm) activated by washing the soil with H 2SO 4, 0.1 M, and by calcination at 550°C was also evaluated. Kinetics studies showed that the adsorption half-time was 2 min in both activated carbon and synthetic allophanic compounds and more than 90 and 70% removal occurred in the first 5 min, respectively. The adsorption of color and phenolic compounds increased with decreasing solid/solution ratio in both activated carbon and synthetic allophanic compounds. pH plays an important role in adsorption phenomena. Phenolic compounds and color removal increased with the decreasing of suspension-effluent pH, obtaining the optimum at pH 5.0 with 87 and 96% removal, respectively. Phenolic compounds and color removal were near 90 and 75% when 20–40 cm acidified and calcinated soil profile was used, respectively. The organic matter content in the 10–20 cm soil profile and the low content of the fine colloidal fraction in the 40–60 cm profile reduced the removal capacity of the allophanic soil.

ISOLATION AND TENTATIVE IDENTIFICATION OF COMPOUND IN BLEACHED-KRAFT MILL EFFLUENT CAPABLE OF CAUSING MIXED-FUNCTION OXYGENASE INDUCTION IN FISH

A substance isolated from a bleached-kraft mill effluent, capable of causing mixed-function oxygenase (MFO) induction in rainbow trout and in a hepatocyte cell line, was tentatively identified. The MFO-inducing chemicals in final pulp-mill effluent were isolated with the use of C18 solid-phase extraction and high-performance liquid chromatography fractionation. Compound identifications for the MFO-inducing fractions were made using gas chromatography with low- and high-resolution mass spec-trometry. In comparing data from each of three fractionation trials, we noted that MFO activity corresponded best with the presence of a compound tentatively identified as a chlorinated pterostilbene. The parent compound belongs to the pinosylvin family, a group of naturally occurring substances that are often present in coniferous trees.

Factors Affecting Oxygen Transfer in Lab-Scale Activated Sludge Reactors Treating Bleached Kraft Mill Effluent

Abstract In aerobic biological wastewater treatment processes, oxygen must be transferred from the gas phase to the liquid phase to support oxidation of dissolved organics and endogenous metabolism by the bacteria. Power required to supply this oxygen in suspended growth systems can represent a significant fraction of the operating costs of such processes. In this study, the interfacial mass transfer coefficient KLa for water was found to be reduced by up to 28% (average 13%) by the addition of antifoaming agent. KLa values were reduced by up to 43% (average 26%) by the dissolved organics in primary treated bleached kraft mill effluent. There was no significant difference between the KLa for water and biologically treated bleached kraft mill effluent.

Using microbial fatty acids to quantify, characterize and compare biofilm and suspended microbial populations in wastewater treatment systems

Spectra of microbial fatty acid methyl esters were used to assess the influence of pH on the biofilm and suspended biomass populations within bench scale moving bed bioreactors treating bleached kraft mill effluent. The fatty acid spectral data were reduced by logcontrast canonical component analysis. The first canonical component differentiated biofilm from suspended populations and the second two appeared to indicate an influence of pH on microbial ecology. Thus, the biofilm and suspended microbial communities were distinct, as were the populations acclimated at pH 6 and pH 8. Experimental data for total organic carbon removal suggested that the more recalcitrant fraction of the influent was consumed by the slower growing, high SRT biofilm fraction of the biomass. Since the biofilm ecology was sensitive to pH within typical pH operating limits of full-scale systems, tighter pH control might improve treatment reliability in the event of process transients.

Molecular analysis of bacterial isolates and total community DNA from kraft pulp mill effluent treatment systems

Chloroaliphatics are major components of bleached kraft mill effluents. Gene probes and oligonucleotide primers were developed to monitor kraft pulp mill effluent treatment systems for the presence of key genes (dehalogenases) responsible for the dehalogenation of chloroaliphatic organics. The primers were used for polymerase chain reaction (PCR) analysis of genomic DNA extracted from dehalogenating bacterial isolates and from total community DNA extracted from water and sediments of mill effluent treatment system. PCR amplification with oligonucleotide primers designed from dhlB, encoding the haloacid dehalogenase from Xanthobacter autotrophicus, revealed the presence of dehalogenase genes in both aerated lagoons and stabilization basins. Similarly, positive results were obtained with mmoX primers designed from the soluble methane monooxygenase gene of Methylococcus capsulatus Bath. The haloacetate dehalogenase encoding gene (dehH2) from Moraxella sp. was typically not detected in mill effluent treatment systems unless the biomass was selectively enriched. DNA sequence analysis of several PCR fragaments revealed significant similarity to known dehalogenase amd methane monooxygenase genes. The results indicated a broad distribution of known dehalogenation genes and bacteria with chloroorganic-degrading potential in the mill effluent treatment systems.

Does annual variation in growth and sexual maturation of white sucker (Catostomus commersoni) confound comparisons between pulp mill contaminated and reference rivers?

A previous study on the effect of pulp and paper effluents on white sucker (Catostomus commersoni), conducted in 1991 and 1992, in both effluent-exposed and reference rivers showed that fish grew faster at downstream sites than at upstream sites. However, in contrast with fish from a reference river, fish exposed to effluent showed no decrease in age or size at first maturity or increase in gonad size or fecundity in response to greater growth. The objective of the present study, conducted in 1993, was to test if differences in measures of growth and sexual maturation between fish populations in exposed and reference rivers would vary from year to year and whether such variation would affect conclusions concerning the effects of pulp mill effluents. Although size at age, fecundity, and age at first maturity varied between the two studies, patterns of demographic responses to pulp mill effluents, relative to reference populations, remained the same, i.e., conclusions about effects of pulp mill effluents did not change despite variation in demographic variables between years and sites. This study reaffirmed the view that only by including the fish populations in a reference river could effects due to bleached kraft mill effluent be separated from effects due to nutrient gradients.

Environmental Assessment of Benthic Impacts Associated with Pulp Mill Discharges. II. Distribution of Sediment EOX in Relation to Environmental Factors

Between 1991 and 1992, comprehensive toxicological, chemical, and benthic community structure surveys were conducted at Jackfish Bay, Lake Superior, Ontario, to assess sediment quality below a bleached kraft mill effluent (BKME) outfall. In this report, we describe the spatial distribution and concentration of extractable organic chlorines (EOX) in sediments below the outfall in relation to effluent discharge patterns, sediment deposition, and bioaccumulation potential. Triplicate sediment samples were collected by Ekman grab from 29 and 44 stations in 1991 and 1992, respectively, and from 15 stations in three reference areas not exposed to the effluent. For each sample, organic carbon content, dry weight, and sediment-associated EOX were determined. In addition, sediment traps were used to determine sediment deposition along two tangents transecting the effluent plume and at a reference station located approximately 4,200 m from the outfall. The spatial distribution of sediment EOX consisted of two distinct concentration gradients, each linked to effluent discharge patterns from Blackbird Creek and dominant circulatory patterns in Jackfish Bay: a north-south gradient, extending along the west shore of Jackfish Bay, and a east-west gradient. Sediment EOX ranged from 7,000 mg/kg organic carbon (oc) (2,050 mg/kg dry solids (ds)) in depositional sediments of Moberley Bay to nondetectable at some stations in eastern and outer Jackfish Bay. Reference (background) concentrations ranged from nondetectable to 3,000 mg/kg oc (1-15 mg/kg ds). The attenuation of EOX was significantly correlated with the rate of sediment deposition (r2 = 0.57; p </= 0.001). Although the concentration of sediment EOX was strongly correlated with toxicity to some invertebrates (Sibley et al. [1997] Arch Environ Contam Toxicol 32:274-284), bioaccumulation factors were typically <2 based on analysis of oligochaete tissues. The results of this study demonstrate that the spatial distribution of sediment-associated contaminants adjacent to pulp mill effluent outfalls are determined primarily by hydrodynamic and depositional characteristics of the receiving waters and that EOX can be used to accurately delineate areas of contamination.

Effects of ECF-Bleached Kraft Mill Effluent on Reproductive Steroids and Liver MFO Activity in Populations of Perch and Roach

Samples of perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) populations were collected in Lake Saimaa in September-October, after the onset of vitellogenesis and deposition of yolk in the eggs. The study area received elemental chlorine-free (ECF)-bleached kraft mill effluent (BKME). The pulp and paper mill studied used chlorine dioxide for bleaching and its effluents were treated in a modern activated sludge plant. The amounts of chlorophenolics in the bile of perch and roach at the mill site, 1 km from the discharge point, were two to four times higher than in fish from the upstream reference site. In the roach population near the mill liver the 7-ethoxyresorufin 0-deethylase (EROD) activity was four times that measured in the reference areas. However, the EROD activity in the perch remained unchanged. The liver 7-pentoxyresorufin 0-dealkylase (PROD) activity was induced to twice the amount only in male roach near the mill, whereas the relative liver size (LSI) was increased in female and male roach and female perch. The plasma concentrations of oestradiol-17β were decreased in female perch and female roach, but increased in male roach at the mill site. Near the mill, vitellogenin gene expression was also reduced in female perch. In addition, the plasma testosterone concentrations were reduced in female and male perch near the mill. No differences were noted in the plasma immunoglobulin concentrations in roach and in the relative gonad size (GSI) in the perch and roach populations. The condition factor was significantly lower only in female roach near the mill.

Interrenal dysfunction in fish from contaminated sites: In vivo and in vitro assessment

AbstractCortisol, synthesized in the interrenal cells of teleost head kidney, has a major role in the physiologic response to physical and chemical stressors. Plasma levels of cortisol increase in physiologically competent fish acutely exposed to stressors such as cadmium or mercury. The effects of chronic low level exposures are less well understood. We have diagnosed an endocrine impairment characterized by a reduced capacity to elevate plasma cortisol levels in response to an acute standardized capture stress in yellow perch (Perca flavescens) and in northern pike (Esox lucius) sampled at sites contaminated by mixtures of pollutants (heavy metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls), by heavy metals, or by bleached kraft mill effluent. Our studies with fish, as well as with amphibians at contaminated sites, demonstrated that low level chronic exposures impair secretion of corticosteroids. We have developed new tests for assessment of the functional integrity of teleost and amphibian interrenal tissue by using an adrenocorticotropic hormone (ACTH) challenge, in vivo and in vitro. The reduced ability to respond to ACTH indicates that the normal neuroendocrine response to stressors may be disrupted and that the ability to cope with biotic and abiotic stressors in the environment may be significantly reduced in the impaired animals.

Using microbial fatty acids to quantify, characterize and compare biofilm and suspended microbial populations in wastewater treatment systems

Spectra of microbial fatty acid methyl esters were used to assess the influence of pH on the biofilm and suspended biomass populations within bench scale moving bed bioreactors treating bleached kraft mill effluent. The fatty acid spectral data were reduced by logcontrast canonical component analysis. The first canonical component differentiated biofilm from suspended populations and the second two appeared to indicate an influence of pH on microbial ecology. Thus, the biofilm and suspended microbial communities were distinct, as were the populations acclimated at pH 6 and pH 8. Experimental data for total organic carbon removal suggested that the more recalcitrant fraction of the influent was consumed by the slower growing, high SRT biofilm fraction of the biomass. Since the biofilm ecology was sensitive to pH within typical pH operating limits of full-scale systems, tighter pH control might improve treatment reliability in the event of process transients.

Immunoreactivity of Roach,Rutilus rutilus,Following Laboratory Exposure to Bleached Pulp and Paper Mill Effluents

In order to study immunomodulation, controlled laboratory experiments were carried out with roach (Rutilus rutilus) exposed to bleached kraft mill effluent (BKME) or spent bleach liquor (SBL) from two pulp and paper mills using elementary chlorine and chlorine dioxide for bleaching. The total number of immunoglobulin-secreting cells (ISC) and the number of specific antibody-secreting cells (ASC) were determined by ELISPOT assay. Exposure to BKME resulted in decreased numbers of ISC in the spleen. To study the capability of response against foreign antigens the fish were immunized with bovine γ-globulin. Exposure to BKME or SBL reduced antigen-specific ASC response in fish. Moreover, the suppression of ASC response did not require exposure prior to immunization. Depuration of fish in clean water reveals that the immunosuppression caused by BKME is reversible. The ASC response in the BKME-pretreated fish returned to the same or even a higher level compared to untreated immunized fish and, in addition, the number of ISC increased greatly. The results of this study verify an earlier finding on poor antibody response due to exposure in a lake contaminated with BKME. Exposure to SBL alone suppresses antibody-mediated immunity, suggesting that compounds formed in bleaching are at least partly responsible for immunotoxic effects.

The effects of tetrachloroguaiacol on the growth, survival, and development of the fathead minnow, Pimephales promelas.

Fathead minnow (Pimephales promelas) larvae were exposed for 7 days to tetrachloroguaiacol (TeCG), within 24 h of hatching, at concentrations of 0, 25, 50, 100, 200, 400 microg/L. No significant difference in growth or larval survival was found among treatments. Embryos, within 24 h of fertilization, were also exposed to TeCG at concentrations of 0 and 100 microg/L for 10 days. No significant difference was found between the control and treatment groups for larval survival, body length, body width, or for yolk size of the eleutheroembryos. However, a significant difference was found in the hatching success of the eggs (p = 0.05). Since fathead minnows have been known to spawn in areas close to sites that discharge bleached kraft mill effluent (BKME) which contains TeCG, into receiving waters, naturally occurring populations will likely be affected by the toxicant.

The fate of resin acids-2. The fate of resin acids and resin acid derived neutral compounds in anaerobic sediments

A sediment, sampled from a hydroelectric lake receiving a bleached kraft mill effluent discharge, was incubated anaerobically for 264 days. Both recipient and sterilised control sediments were periodically sampled and analysed to monitor the changes in resin acid composition with time. Over 264 days of incubation, the concentration of total resin derived compounds decreased by 50%. The total resin acid concentration was reduced by 50% whereas the concentration of resin derived neutrals decreased by 54%. Relative to an incubated sterile control sediment, the pimaranic acid concentration remained constant, 8-pimarenic and 8-isopimarenic acid concentrations slightly increased and pimaric, isopimaric, abietanic and secodehydroabietic acid concentrations decreased. Dehydroabietic acid was transformed to tetrahydroretene simultaneously with the transformation of labelled dehydroabietic acid to a variety of labelled products. Throughout the incubation period, the concentration of fichtelite remained constant. The concentration of retene slightly increased until the final 50 days of incubation, during which time dehydroabietin and tetrahydroretene concentrations decreased. This is the first study reporting the degradation of a variety of resin acids and derived neutrals in an anaerobic sediment.

The effect of pre-hydrolysis of D-stage filtrate on the biotreatability of chlorinated organic compounds in bleached kraft mill effluents

The influence of pre-hydrolysis of D-stage filtrate on the biotreatability of bleached kraft mill effluent was investigated at the bench scale using four continuous aerated “lagoons” operated in parallel. In comparison to non-hydrolyzed effluent, pre-hydrolysis of D-stage filtrate at pH 11 and 60°C for an hour reduced the AOX inlet to the treatment system by 40% and the outlet AOX discharge after biological treatment by 13%. Overall, pre-hydrolysis followed by biological treatment resulted in a 63% AOX removal, which was significantly higher, at the 95% confidence level, than the 58% removal achieved by biological treatment alone. COD and BOD 5 removals for both feeds were 45 and 99%, respectively, and were not significantly affected by the pretreatment. Studies on the pre-hydrolysis effect on known non-biodegradable organochlorine model compounds showed that pre-hydrolysis was effective in improving the biodegradability of a monomeric model, but not the dimeric model compound.

Treatment of chlorinated organics in bleached kraft mill effluents by activated sludge process

Combined effluents from a bleached Kraft pulp mill using annual plants were treated in a lab-scale activated sludge (AS) system. The effects of operating solids retention time (SRT) and concentration of additional carbon source on AOX removal were investigated. Higher AOX removals (30%) were observed with long SRTs, 99% of which was pure metabolization. As SRT was decreased AOX removal efficiency also decreased (4%) and principal AOX removal mechanism changed to adsorption onto wasted biomass. The AOX removal efficiency was lower (10%) on a 20% decrease in the supplemental carbon source, with no apparent effect on the removal mechanism.

Effect of H 2O 2 on characteristics and biological treatment of TCF bleached pulp mill effluent

Totally chlorine-free (TCF) bleaching technologies can result in high concentrations of residual hydrogen peroxide in combined mill effluent. This study was undertaken to determine the effect of hydrogen peroxide on effluent characteristics (biochemical oxygen demand (BOD), toxicity), biological sludge characteristics (oxygen uptake rate (OUR), catalase activity) and the efficiency with which laboratory-scale activated sludge reactors treat TCF bleached kraft mill (BKM) effluents. The presence of over 20 mg/L hydrogen peroxide in TCF-BKM effluent was found to decrease the BOD by up to 25%. The complete decomposition of hydrogen peroxide concentrations of up to 1000 mg/L was not found to have an effect upon the effluent toxicity, as measured by Microtox R. Increasing concentrations (5–1000 mg/L influent) of peroxide were continually added to a reactor treating combined TCF-bleached kraft mill effluent. Treatment efficiency, as measured by removal of BOD, chemical oxygen demand (COD) and toxicity, was found to be unaffected by hydrogen peroxide concentrations of up to 1000 mg/L influent. Several methods of gauging reactor acclimatization to hydrogen peroxide were performed throughout the study. Activated sludge mixed liquor samples from the continuous reactor were shocked with varying concentrations of hydrogen peroxide. Oxygen uptake rate of activated sludge samples, especially when unacclimated, was found to decrease dramatically when subjected to shock loads of increasing concentrations of peroxide. Activated sludge which had been acclimated to hydrogen peroxide in the reactor feed was more resistant to H 2O 2 shock loading. Catalase-equivalent induction in activated sludge was also monitored as a means of gauging reactor acclimatization to the presence of hydrogen peroxide. Catalase-equivalent activity was found to increase with increasing H 2O 2 feed concentration, and appeared to reach a maximum level of 1.3–1.5 (min g biomass) −1. It was concluded that activated sludge is able to treat TCF bleached kraft mill effluent which contained H 2O 2, and that the microorganisms present in the sludge were able to adapt to receiving such an effluent.

Pyrolysis-GC/AED and pyrolysis-GC/MS analysis of chlorinated structures in aquatic fulvic acids and chlorolignins

A study was undertaken to evaluate whether pyrolysis-gas chromatography/atomic emission detection (PyGC/AED) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) can be used to systematically search for halogenated structures in natural organic matter. Two samples of aquatic fulvic acid (FA) and two samples of high molecular weight organic matter isolated from bleached-kraft mill effluents (BKME) were selected to respectively represent naturally and industrially chlorinated organic matter. Mono- and dichlorophenol were found in the pyrolysates of the naturally chlorinated samples, and methyl esters of 2,4-dichlorobenzoic acid, monochloro-4-methoxybenzoic acid and 3,5-dichloro-4-methoxybenzoic acid were the main compounds detected when a methylating agent, tetramethylammonium hydroxide (TMHA), was added to the samples prior to the pyrolysis. These results strongly indicate the presence of chlorinated 4-hydroxyphenyl structures in the original FA samples. For the BKME samples, on the other hand, the main chlorinated pyrolysis products were guaiacyl- and syringyl-derived compounds.

FP 1 Immunomodulation in fish following exposure to bleached kraft mill effluents

FP 1 Immunomodulation in fish following exposure to bleached kraft mill effluents

Inhibition of the sea urchin sperm acrosome reaction by a lignin-derived macromolecule

The major organic components of effluents from commercial pulping processes are lignin-derived macromolecules (LDMs), which have recently been shown to inhibit fertilization and embryonic development in a variety of marine organisms, as well as to exhibit immunostimulating activity in mammalian cells. We conducted studies on the effects of an isolated LDM from bleached kraft mill effluent (BKME), and its sub-components, at the cellular level utilizing the purple sea urchin ( Strongylocentrotus purpuratus) sperm acrosome reaction (AR) as an experimental system. The AR is an event that is induced by the egg's jelly coat and is prerequisite for successful fertilization. Sperm were preincubated with increasing concentrations of isolated LDM or electrophoretically purified LDM sub-components, followed by addition of isolated egg jelly to induce the AR in vitro. These LDM preparations significantly inhibited the AR as assessed by fluorescence (utilizing the rhodamine-conjugated phallicidin) and transmission electron microscopy. Preincubation of sperm with LDM did not have any effect on sperm motility. The level of AR inhibition was comparable to that observed in experiments assessing successful fertilization. The ability of LDM to inhibit jelly induced AR was overcome by the calcium ionophores A23187 and ionomycin. In addition, LDM was shown to inhibit the normal increase in intracellular calcium (Ca ++) associated with induction of the AR. When eggs were preincubated with LDM prior to addition of unexposed sperm, no effect on fertilization was observed, indicating that LDM specifically affects sperm function during fertilization. Fine structural studies, utilizing biotinylated LDM, confirmed LDM's specificity and revealed that its binding was restricted to the plasma membrane domain of the sperm head. The present observations on the inhibition of the AR by LDM is consistent with our hypothesis that this macromolecule inhibits the AR by blocking egg jelly interaction with the sperm surface, thus inhibiting ionic events such as increases in intracellular calcium. Our present approach also demonstrates that echinoderm sperm functions can be used as a model system for the investigation of the mode of action of toxicants at the sub-cellular level.

The effects of oxygen delignification, complete chloride dioxide substitution, and biological treatment on bleached kraft mill effluent quality

The effects of bleaching modifications on the biotreatability of the resulting Adsorbable Organic Halides (AOX) were studied using laboratory-scale bioreactors and mill-scale bleach plant filtrates. Under conventional pulping/bleaching conditions, biological removal of AOX averaged 40 percent. After modification to oxygen delignification and complete ClO2 substitution, the removal efficiency increased to 47 percent. Under the treatment conditions employed, the eight percent increase was found to be statistically significant at a 95 percent confidence level. These results indicate that AOX biotreatability efficiencies following bleaching sequence modifications to oxygen delignification and complete ClO2 substitution remain at least as high as those observed prior to such modifications.