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Bleached kraft pulp mills generate large volumes of effluents usually treated by biological processes that don´t remove recalcitrant organic constituents. The present study was undertaken to evaluate the potential of electrocoagulation of acid (AcF) and alkaline (AlF) kraft pulp bleaching filtrates with Al and Fe electrodes to improve their biotreatability. Response surface methodology was used to predict the effects of initial pH, current density, and electrolysis time on biodegradability (BOD/COD). Biodegradability increases of 1.7–2.1-fold were obtained using optimized experimental conditions for each electrode-filtrate combination: AcF-Al (pH 7.9, 128 A/m², 49 min), AcF-Fe (pH 4.6, 104 A/m², 40 min), AlF-Al (pH 3.8, 150 A/m², 52 min) and AlF-Fe (pH 6.3, 101 A/m², 42 min). Electrocoagulation with Al electrodes was more efficient in removing color, phenols and estrogenic activity, but required longer reaction time and higher current density, while treatment with Fe electrodes resulted in lower toxicity to Daphnia similis. Electrocoagulation of both filtrates before combining them for biological treatment led to 88 % dissolved organic carbon (DOC) removal in a five-day biodegradability test, compared to only 27 % DOC removal from combined raw filtrates. The potential to increase overall pulp mill wastewater treatment efficiency using electrocoagulation prior to biological treatment was demonstrated.

Wastewater from two (A and B) small-scale hair care product manufacturers located in the state of Minas Gerais were characterized, with regard to physical, chemical and ecotoxicological parameters. Wastewater characteristics typical for this industrial sector were found in three samples collected at each manufacturing plant, with high levels of both particulate and dissolved organic matter (soluble and total COD), oils and grease and acute toxicity to the microcrustacean Daphnia similis (EC50 Ceriodaphnia dubia is indicated for use in routine monitoring, since it exhibited the highest sensitivities to hair care products wastewaters, for both acute and chronic effects.

The contamination of water sources by pharmaceutically active compounds (PhACs) and their effect on aquatic communities and human health have become an environmental concern worldwide. Membrane bioreactors (MBRs) are an alternative to improve biological removal of recalcitrant organic compounds from municipal sewage. Their efficiency can be increased by using high retention membranes such as forward osmosis (FO) and membrane distillation (MD). Thus, this research aimed to evaluate the performance of an anaerobic osmotic MBR coupled with MD (OMBR-MD) in the treatment of municipal sewage containing PhACs and estrogenic activity. A submerged hybrid FO-MD module was integrated into the bioreactor. PhACs removal was higher than 96% due to biological degradation, biosorption and membrane retention. Biological removal of the PhACs was affected by the salinity build-up in the bioreactor, with reduction in biodegradation after 32 d. However, salinity increment had little or no effect on biosorption removal. The anaerobic OMBR-MD removed99.9% of estrogenic activity, resulting in a distillate with 0.14 ng L

This study was undertaken to assess the capacity of the upflow anaerobic sludge blanket (UASB) reactor, one of the most commonly used systems in Brazilian sewage treatment plants, to remove municipal sewage toxicity using different Danio rerio life stages (embryo, embryo-larval, larval, adult), and estrogenicity using in vitro (yeast Saccharomyces cerevisiae) and in vivo (vitellogenin induction in D. rerio) assays. Sensitivity of chronic fish assays were compared to the chronic Ceriodaphnia dubia assay. UASB-treated sewage met Brazilian legal limits for BOD and COD removals, but did not remove toxicity, and treated sewage remained extremely toxic to D. rerio larvae and C. dubia, and highly toxic to D. rerio embryos. The 4-day embryo assay had the same sensitivity as the adult acute toxicity assay, and could safely replace it, avoiding the need to sacrifice adult fish. No significant differences were identified in vitellogenin induction among organisms exposed to sewage or control. However, the in vitro test showed that anaerobic treatment increased sample estrogenicity from 27 to 40 ng equivalents of 17-β estradiol per liter, a result corroborated by the greater induction of vitellogenin in male fish exposed to 5% (2.73 μg/g) and 20% (2.12 μg/g) treated sewage compared to the same concentrations of raw sewage (0.174 μg/g at 5% and 0.188 μg/g at 20%). Thus, UASB reactor should be followed by post-treatment to reduce risks of sewage discharge to receiving waters.

Dissolving pulps could be considered as the future biorefineries, which normally generate liquor during the wood chip pre-hydrolysis (PHL). PHL has high chemical oxygen demand (COD) and biochemical oxygen demand (BOD). Mills do not have efficient means for disposal of PHL, being in general burned in the recovery boiler with a high cost due to its low consistency. The objectives of this work were to evaluate i) the biotreatability of PHL and the effects it would have on a kraft mill effluent biological treatment plant and ii) the use of ultrafiltration (UF) membrane to treat the PHL prior to biological treatment. PHL was generated into lab with a hydrothermal process and was mixed with kraft pulp mill effluent in different proportions and added to sequencing batch reactors (SBRs). The SBRs achieved high rates of COD removal (>75 %). However, treated effluent COD increased with the increase in PHL dose. This treatment using UF membranes reduced the COD load. Biotreatability of the UF permeate was higher than that of PHL. UF retentate, with 28 % of the volume and a much higher solids content than the initial PHL, would have a significantly lower evaporation energy demand if sent to the black liquor evaporators.

Pharmaceutically active compounds (PhACs) may cause harmful effects in living beings, and advanced treatment is required to improve wastewater treatment plant efficiency. In this context, this study aimed to assess the performance of a hybrid anaerobic osmotic membrane bioreactor coupled with a membrane distillation system (AnOMBR-MD) for removing PhACs and estrogenic activity from municipal sewage. Human health and environmental risks of produced water were also assessed. The removal efficiency of dissolved organic carbon and P-PO43- reached 97.2% and 98.0%, respectively. N-NH4+ accumulated in the bioreactor since anaerobic treatment can not remove it. Salinity increase in the bioreactor caused a great change in the microbial community, with Chao 1 and Shannon indexes higher in the sludge after 50 days of operation than in the sludge used as inoculum. Estrogenic activity of municipal sewage spiked with PhACs was >3 times higher than the expected value calculated by the additive model (2 µg L−1E2-eq.), which indicates that some of the PhACs effects increased in the presence of others. Estrogenicity was not detected in distillate samples, which greatly reduced human health risks to acceptable values. Of the 7 PhACs selected in this study, only betamethasone, fluconazole, and prednisone were detected in the distillate. However, the overall removal of PhACs by the AnOMBR-MD system was higher than 96.4%. The chronic environmental risk considering the estrogenic activity was classified as high because of the detection limit in the yeast estrogen screen (YES), which supports the need for improving bioassay sensibility. The results demonstrated that the use of the YES assay combined with detection and identification of micropollutants allowed an effective assessment of the overall treatment performance.

The integrated forward osmosis membrane bioreactor and membrane distillation (OMBR-MD) is an emerging technique for wastewater reclamation and trace organic compound (TrOC) removal. The selection of draw solution (DS) for this system should consider the particularities of both forward osmosis and membrane distillation. The effect of five different draw solutions on forward osmosis and TrOC rejection in a hybrid submerged forward osmosis – membrane distillation (FO-MD) module was investigated in this study. The roles of each solution on FO and MD water flux, FO reverse salt flux, temperature, concentration polarization and rejection of 7 TrOCs were explored. The salt used in the draw solution influenced both FO water flux (NaCl = MgOAc2 (4.8 L.m−2.h−1) > NaOAc (4.6 L.m−2.h−1) > MgCl2 (3.6 L.m−2.h−1) > EDTA-Na2 (2.8 L.m−2.h−1)) and MD water flux (NaOAc (4.0 L.m−2.h−1) > NaCl (3.8 L.m−2.h−1) > MgCl2 (3.3 L.m−2.h−1) > MgOAc2 (3.1 L.m−2.h−1 > EDTA-Na2 (3.0 L.m−2.h−1)). MgCl2 draw solution produced the lowest FO reverse salt flux, demonstrating its potential to prevent salinity build-up when applied in OMBR-MD. MgCl2 and NaCl were the only salts completely rejected by the distillation membrane, which salt losses during draw solution reconcentration. Regardless of the draw solution salt, the integrated FO-MD module could effectively remove 6 of the 7 TrOCs. MgCl2 and NaOAc afforded the highest TrOC rejections, while the lowest rejections were observed when MgAOc2 was used. MgCl2 was selected as the best DS salt for OMBR-MD by using the technique for order preference by similarity to ideal solution (TOPSIS) tool.

In this work, Fe/Ni bimetallic nanoparticles (BN-Fe/Ni) were synthesized and supported on chitosan beads (BN-Fe/Ni-CSs). The physical-chemical properties of BN-Fe/Ni-CSs were determined as density, mass, diameter, the degree of deacetylation, and relative humidity of the chitosan beads (CSs) were determined. BN-Fe/Ni and BN-Fe/Ni-CSs have applied color removal of raw effluent (RE) from a textile mill, obtaining 100 % color removal in 10 and 20 min, respectively, in batch experiments. A fixed bed reactor (FBR) with BN-Fe/Ni-CSs was constructed and the treatment of RE in this reactor resulted in approximately 70 % removal (time: 11 h, volume: 5 L). Contaminants removal from RE in the BN-Fe/Ni-CSs FBR occurs through adsorption and degradation processes. Removals of ADMI color and chemical oxygen demand were observed. The treated effluent showed reduced acute toxicity, 87 % less when compared to the RE before treatment. These results showed that the BN-Fe/Ni-CSs applied in the reactor proved to be efficient for treating the effluent in terms of the studied parameters.

Encontrados em diferentes matrizes ambientais devido à ineficiência de remoção em estações de tratamento de esgoto, os denominados micropoluentes são alvos de estudos por causarem diversos efeitos adversos à saúde do ser humano, mesmo em baixas concentrações. São exemplos os hormônios, destacando-se o 17-β-estradiol (E2), o qual tem elevado potencial estrogênico e foi encontrado em mananciais superficiais no Brasil. Dessa maneira, o presente estudo tem como objetivo avaliar a cloração como modo de remoção da atividade estrogênica do E2 em diferentes condições de dose de cloro e tempo de contato previstos em norma, bem como quantificar a atividade estrogênica remanescente através do ensaio Yeast Estrogen Screen (YES). Para a dose de cloro de 0,5 mg.L‑1 e tempo de contato de 30 minutos, a remoção da atividade estrogênica foi de 98,6 ± 1,1%; e para a maior dose, de 5 mg.L-1, obteve-se 99,5 ± 0,1% de remoção no mesmo tempo. Avalia-se que tanto a dose quanto o tempo de contato foram significativos na remoção da atividade estrogênica. Mais estudos em busca de condições ótimas de cloração, identificação de subprodutos da reação e avaliação da remoção em diferentes tecnologias de tratamento são necessários.

Full-scale application of heterogeneous photocatalysis for industrial wastewater treatment remains a challenge because of the complex nature of these matrices and the potential to form toxic by-products during treatment. A recent unsuccessful attempt to find adequate conditions for TiO2/UV treatment of a cotton dyeing textile mill led to this study on the treatability of mixtures of the dyes used in the greatest amounts at the mill and therefore most likely to be present in mill effluent. Four reactive and three vat dyes were mixed in different combinations and treated (10 mg/L of each dye, 0.5 mg/L TiO2, pH 4) to evaluate the influence of the different dyes on ADMI color, chemical oxygen demand (COD), and acute toxicity. While ADMI color removal was similar in all dye mixtures, COD removal was higher when vat dyes were absent. When treated individually, vat dyes exhibited greater recalcitrance, with no ADMI color removal and COD removals of less than 30%. Toxicity to Daphnia similis was decreased or eliminated from dye mixtures that exhibited the highest COD removals and corresponded to those in which reactive dyes were partially degraded. For raw textile mill effluent, photocatalysis reduced but did not eliminate treated effluent toxicity (EC50 = 26.8%).

A series of TiO 2 /MgZnAl photocatalysts were successfully synthesized from ternary (Mg, Zn and Al) layered double hydroxides impregnated with TiO 2 nanoparticles by the co-precipitation method at variable pH with different Zn 2+ /Mg 2+ molar ratios. The composite photocatalysts were calcined at 500 °C resulting in the incorporation of oxide zinc, in the calcined MgZnAl LDH structure. Synergistic effect between ZnO and TiO 2 lead to significant enhancement of TiO 2 /MgZnAl photocatalytic activity. Composite photocatalysts were characterized by ICP-MS, N 2 adsorption-desorption, XRD, SEM, EDS, IR and UV–vis DRS. Phenol in aqueous solution (50 mg/L) was used as a model compound for evaluation of UV–vis (filter cut-off for λ > 300 nm) photocatalytic activity. The most efficient photocatalyst composite was obtained at a 5% Zn 2+ /Mg 2+ molar ratio, in the catalyst identified as TiO 2 /MgZnAl-5. This composite catalyst had high photocatalytic activity, completely destroying phenol and removing 80% of total organic carbon in solution after 360 min. The TiO 2 /MgZnAl-5 catalyst remained relatively stable, presenting a 15% decrease in phenol degradation efficiency after five consecutive photocatalytic cycles.

To investigate possible morphological changes to the liver tissue of lambaris, Astyanax bimaculatus (Linnaeus, 1758), females were exposed to treatments of sublethal concentrations of the insecticide Thiodan® for 96 hr. Treatments included three sublethal concentrations of 1.15, 2.3, and 5.6 μg L−1 of Thiodan® and a control group without insecticide. The action of Thiodan® at sublethal concentrations did not affect the morphological structure of the liver as a whole, but changes in isolated locations of the hepatic parenchyma were observed. Glycogen depletion, nuclear and cytoplasmic deformation, nuclear and cytoplasmic hypertrophy, hyperemia, and cellular degeneration in liver cells at the different concentrations studied were recorded. These observed changes in the livers were greater in groups exposed to Thiodan® in comparison to the control group. Furthermore, there was a change in the diameter of the nuclei and cytoplasm of hepatocytes in the different treatments. The groups exposed to Thiodan® also exhibited a larger number of hepatocyte nuclei and a reduction in the amount of cytoplasm. We conclude that for the exposure period and concentrations of Thiodan® analyzed, the morphology of hepatic tissue had a cellular adaptive response. Anat Rec, 298:1754–1764, 2015. © 2015 Wiley Periodicals, Inc.

The new magnetic photocatalysts HT/TiO2/Fe and HT-DS/TiO2/Fe, modified with the anionic surfactant sodium dodecylsulfate (DS) were successfully synthesized in this work. Titanium dioxide (anatase) followed by iron oxide were deposited on the hydrotalcite support. Several catalyst samples were prepared with different amounts of titanium and iron. The photocatalysts were characterized by infrared and Raman spectroscopy, X-ray diffraction, scanning electron microscopy. Photocatalytic performance was analyzed by UV–visible radiation (filter cutoff, λ > 300 nm) of an aqueous solution (24 mg/L) of methylene blue (MB). The most efficient catalyst was obtained at an iron oxide:TiO2 molar ratio of 2:3. This catalyst showed high photocatalytic activity, removing 96% of the color and 61% of total organic carbon from the MB solution after 120 min. It was easily removed from solution after use because of its magnetic properties. The reuse of the HT-DS/TiO2/Fe23 catalyst was viable and the catalyst was structurally stable for at least four consecutive photocatalytic cycles.

The objective of this study was to evaluate ADMI color removal from a biologically treated textile mill effluent by heterogeneous photocatalysis with UVevisible irradiation (UVevis) using a novel catalyst composed of TiO 2 supported on hydrotalcite and doped with iron oxide (HT/Fe/TiO 2 ). Simulated biological treatment of solutions of the dyes (50 mg/L) used in the greatest amounts at the mill where the textile effluent was collected resulted in no color removal in reactive dye solutions and about 50% color removal in vat dye solutions, after 96 h, indicating that the secondary effluent still contained a large proportion of anionic reactive dyes. Photocatalytic treatments were carried out with TiO 2 and HT/Fe/TiO 2 of Fe:Ti molar ratios of 0.25, 0.5, 0.75 and 1, with varying catalyst doses (0e3 mg/L), initial pH values (4 e10) and UVevis times (0e6 h). The highest ADMI color removal with unmodified TiO 2 was found at a dose of 2 g/L and pH 4, an impractical pH value for industrial application. The most efficient composite was HT/Fe/TiO 2 1 at pH 10, also at a dose of 2 g/L, which provided more complete ADMI color removal, from 303 to 9 ADMI color units (96%), than unmodified TiO 2 , from 303 to 37 ADMI color units (88%), under the same conditions. Hydroxyl radicals were responsible for the color reduction, since when 2- propanol, an OH scavenger, was added color removal was very low. For this reason, the HT/Fe/TiO 2 1 composite performed better at pH 10, because the higher concentration of hydroxide ions present at higher pH favored hydroxyl radical formation. COD reductions were relatively low and similar, approximately 20% for both catalysts after 6 h under UVevis, because of the low initial COD (78 mg/L). Secondary effluent toxicity to Daphnia similis (EC 50 1⁄4 70.7%) was reduced by photocatalysis with TiO 2 (EC 50 1⁄4 95.0%) and the HT/Fe/TiO 2 1 composite (EC 50 1⁄4 78.6%). HT/Fe/TiO 2 1 was reused five times and still lowered secondary effluent ADMI color below local discharge limits. Benefits of the HT/Fe/TiO 2 1 catalyst compared to TiO 2 include its lower bandgap energy (2.34 eV vs 3.25 eV), higher ADMI color removal and its magnetic nature that facilitated its recovery and would reduce treatment costs.

Thiodan® is an insecticide which can cause morphological changes in fish tissues, dependent on the concentration. To investigate possible morphological changes, this study evaluated the number and diameter of ovarian follicles in lambaris Astyanax bimaculatus exposed to Thiodan® for 96 h in different treatments at three sub-lethal concentrations: 1.15, 2.3 and 5.6 μg L−1 and a control group without Thiodan®. Females exposed to Thiodan® were divided into four treatments: (i) without acclimation and without food, (ii) without acclimation and with food, (iii) with acclimation for 10 days and without food; (iv) with acclimation for 10 days and with food. In this study, it was noted that the action of Thiodan® at sub-lethal concentrations in a static system did not affect the morphology of follicular development. However, the treatments with acclimation showed lower numbers of primary and secondary follicles when compared to fish from treatments without acclimation. For the groups exposed to Thiodan®, a greater number of atretic follicles were observed compared to the control groups. The follicular diameter of secondary follicles in fish exposed to Thiodan® in the treatment with acclimation and with food was highest in the control group (P

Full-scale application of heterogeneous photocatalysis for industrial wastewater treatment remains a challenge because of the complex nature of these matrices and the potential to form toxic by-products during treatment. A recent unsuccessful attempt to find adequate conditions for TiO

Toxicity reduction in wastewaters from small hair care products manufacturing companies using coagulation/flocculation/sedimentation or flotation, membrane separation and powdered activated charcoal adsorption was evaluated. Raw wastewater composition varied widely within and especially between companies, but all exhibited high acute toxicity to Daphnia similis (EC(I)50; 48 h 0.02-0.33%). Coagulation with aluminum sulfate and polyaluminum chloride aided by cationic or anionic polymers, as well as filtration on ultra (UF) and nanofiltration (NF) membranes efficiently removed turbidity (99%) and oil and grease (99%) and all treated samples exhibited similar dissolved organic matter contents. However, elimination of acute toxicity was only achieved after UF on submerged hollow fiber membrane, while other membrane modules (tubular UF and NF) produced filtrates with residual toxicities equal to or higher than the wastewater samples treated by coagulation processes. Adsorption removed up to 90% of the soluble COD remaining after coagulation or membrane processes, but did not eliminate acute toxicity, possibly because of the presence of activated charcoal or substances leached from it in the treated samples. The results indicate the need for further studies to develop treatment strategies that can guarantee non-toxic effluents at costs compatible with those of the simple manufacturing processes used at small-scale cosmetics manufacturing plants.

The objective of this study was to evaluate ADMI color removal from a biologically treated textile mill effluent by heterogeneous photocatalysis with UV-visible irradiation (UV-vis) using a novel catalyst composed of TiO

Thiodan® is an organochlorine insecticide used in agriculture that can reach aquatic ecosystems where it can affect fish reproduction. This research aimed to evaluate follicular development and the expression of integrin β1, collagen type IV and caspase 3 by morphological, histometrical and immunohistochemical analyses of Astyanax bimaculatus exposed to Thiodan®. Treatments included three sublethal concentrations of Thiodan® (1.15, 2.30, and 5.60 μg L−1) for 96 h and a control without the insecticide. Mature females with ovaries in advanced follicular development were chosen for study (average weight: 11.52 ± 2.0 g; average total length: 9.12 ± 0.64 cm). The follicles of A. bimaculatus exhibited normal morphology, while the diameters of secondary follicles showed an increase (P< 0.05) in all concentrations when compared to the control group; a characteristic of follicles undergoing the initial stages of intoxication. Immunohistochemical analysis revealed secondary follicles with greater expression of integrin β1 and collagen type IV in cytoplasm of follicular cells than in the primary follicles in all treatments and in the control. Immunolocalization of caspase 3 was detected in follicular cells during secondary development in all tested concentrations of Thiodan® and the control. These analyses demonstrate positive immunolocalization throughout the course of follicular development, even in fish exposed to varying concentrations of Thiodan® for 96 h, demonstrating that follicular cells retain their physiological integrity.

Economic and environmental stimuli for biodiesel production have also increased production of glycerol, a byproduct present in biodiesel industry wastewater (BIW). The objective of the present study was to analyze which factors influenced glycerol biodegradation in anaerobic sequencing batch reactors (AnSBR) in the attempt to optimize chemical oxygen demand (COD) removal efficiency. Six factors were analyzed: pH, temperature, mixing speed, influent COD, inoculum mass, and reaction time. The results indicated that mixing speed, temperature, mass of inoculum, and reaction time had direct influence on COD removal efficiency in BIW. The reactor used in the experiments operated with efficiencies and applied loads above those mentioned in the literature. The mathematical model generated in this study can be used for estimating efficiency, process control and scale up of AnSBR.

Biodiesel is an important source of renewable energy, whose production generates wastewater (BWW) comprised mainly of glycerol as the source of organic matter (COD). Anaerobic digestion of BWW is a promising technique for the remediation of this environmental hazard. Anaerobic biodegradation of glycerol present in BWW is influenced by parameters such as reaction time, amount of biomass inoculum and operating temperature. The objective of this work was the optimization and mathematical modeling of these parameters to maximize the performance of an anaerobic sequencing batch reactor (AnSBR) for treating BWW. The amount of biomass inoculum had the greatest influence on COD removal efficiency. Temperature and reaction time had greater influence on behavior of the parameters responsible for AnSBR buffering, including total volatile acids and total, partial, intermediate and bicarbonate alkalinities. Even when operated under loading rates above the values reported in the literature, the AnSBR presented satisfactory performance. The mathematical model generated in this work can be used for forecasting, process control and reactor scaleup.

Interest in rational use and reuse of water has increased in recent years, especially in forest nurseries. However, before water can be reused in nurseries, it must be properly treated to eradicate plant pathogens to reduce risks of pathogen dispersal and losses to disease. In the present study, the efficacy of irrigation water treatment by ultrafiltration and conventional physical-chemical treatment was studied to eliminate Botrytis cinerea, Cylindrocladium candelabrum, Ralstonia solanacearum, and Xanthomonas axonopodis, the pathogens most commonly found in Brazilian forest nurseries. Ultrafiltration eradicated over 99% of R. solanacearum, X. axonopodis, and B. cinerea and 100% of C. candelabrum. The few remaining cells or conidia of R. solanacearum and B. cinerea did not induce disease in irrigated rooted cuttings. Flocculation and fast sand filtration used in physical-chemical treatment completely eliminated C. candelabrum but the other pathogens were only removed after chlorination of the filtered water. Both forms of treatment are viable, practical, and safe methods for plant pathogen removal from irrigation water.

Eucalyptus bleached kraft pulp production, an important sector of the Brazilian national economy, is responsible for generating large volume, high pollutant load effluents, containing a considerable fraction of recalcitrant organic matter. The objectives of this study were to quantify the biological activity of the effluent from a eucalyptus bleached kraft pulp mill, characterize the nature of compounds responsible for biological activity and assess the effect of ozone treatment on its removal. Primary and secondary effluents were collected bimonthly over the course of one year at a Brazilian bleached eucalypt kraft pulp mill and their pollutant loads (biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), adsorbable organic halogen (AOX), lignin, extractives) and biological activity (acute and chronic toxicity and estrogenic activity) quantified. The effluent studied did not present acute toxicity to Daphnia, but presented the chronic toxicity effects of algal growth inhibition and reduced survival and reproduction in Ceriodaphnia, as well as estrogenic activity. Chronic toxicity and estrogenic activity were reduced but not eliminated during activated sludge biological treatment. The toxicity identification evaluation revealed that lipophilic organic compounds (such as residual lignin, extractives and their byproducts) were responsible for the toxicity and estrogenic activity. Ozone treatment (50 mg/L O3) of the secondary effluent eliminated the chronic toxicity and significantly reduced estrogen activity.

The cosmetics industry has shown steady growth in many developing countries over the past several years, yet little research exists on toxicity of wastewaters it generates. This study describes a toxicity identification evaluation conducted on wastewater from a small Brazilian hair care products manufacturing plant. Physicochemical and ecotoxicological analyses of three wastewater treatment plant inlet and outlet samples collected over a six month period revealed inefficient operation of the treatment system and thus treated wastewater organic matter, suspended solids and surfactants contents consistently exceeded discharge limits. Treated wastewater also presented high acute toxicity to Daphnia similis and chronic toxicity to Ceriodaphnia dubia and Pseudokirchneriella subcapitata. This toxicity was associated with suspended solids, volatile or sublatable and non-polar to moderately polar organic compounds that could be recovered in filtration and aeration residues. Seven surfactants used in the largest quantities in the production process were highly toxic to P. subcapitata and D. similis. These results indicated that surfactants, important production raw materials, are a probable source of toxicity, although other possible sources, such as fragrances, should not be discarded. Improved treatment plant operational control may reduce toxicity and lower impact of wastewater discharge to receiving waters.

Female individuals of Hyphessobrycon eques were exposed to Diflubenzuron (Dimilin ® ) in order to determine whether exposure to sublethal levels of this insecticide causes changes in gill morphology. Fish were exposed to 0.01, 0.1 and 1.0 mg L −1 for 96 h and 17 days and then submitted to pathological and histometric evaluation. Pathological lesions, such as hyperplasia, lamellar fusion, vascular congestion, secondary lamellar disarray, vasodilatation, hemorrhage and increased lamellar epithelium, were significantly more common in the gills of fish exposed to Dimilin ® than the control. Histometric analysis documented significant changes in blood vessel diameter, primary lamellae width and secondary lamellae length, and the appearance of hemorrhage foci in all concentrations tested. Even at low Dimilin ® concentrations, the histopathological alteration index was mild to moderate, thereby indicating that the function of this tissue was compromised. These findings indicate that indiscriminate use of Dimilin ® can adversely affect the structural integrity of the gills of H. eques , which can cause numerous problems for fish farming systems.

Paper mills consume large quantities of water and consequently produce large volume of effluent. Direct water reuse is not always possible because of poor effluent quality. Membrane biological reactor (MBR) treatment of paper machine white water is a technology that could allow for water reuse. This study examined the technical viability of thermophilic treatment of paper machine effluents (white water) in a MBR. The research was divided into two experiments. The objective of Experiment I was to compare performance of MBR t reatment under mesophilic (35°C), thermotolerant (45°C) and thermophilic (55°C) conditions. The results showed that the increase in temperature led to a reduction in COD removal efficiency. No filamentous bacteria were found at 55°C and fl occulation was defi cient. The objective of Experiment II was to evaluate sludge microbial diversity in aerobic MBRs operating under mesophilic and thermophilic conditions. Microbial community composition and structure was analyzed by polymerase chai...

Acid hydrogen peroxide catalyzed with molybdenum (PMo stage) is effective to decrease pulp kappa number and potentially minimize chlorine dioxide demand in subsequent ECF bleaching. This study aimed at developing cost-effective methods for applying PMo as the first stage bleaching for eucalyptus kraft pulp and evaluating their impact on pulp properties and effluent quality in relation to current ECF bleaching techniques. The PMo(EP)DP and A/PMo(EP)DP sequences proved to be most cost-effective for PMo stage application. The pulp properties and effluent quality derived from bleaching with these two sequences were compared with those of the conventional bleaching with the DHT(EP)DP sequence. The PMo(EP)DP sequence produced pulp of refinability and physical properties similar to that of the reference but the A/PMo(EP)DP one resulted in pulp of 20% lower refinability and 10% lower tearing strength. Untreated effluents of the PMo(EP)DP and A/PMo(EP)DP sequences presented similar COD, but lower AOX and color than the DHT(EP)DP effluents. None of the effluents exhibited acute toxicity. The effluents from the PMo(EP)DP sequence showed much lower BOD and BOD/COD ratio than that of the A/PMo(EP)DP one. All effluents were readily treated in bench-scale reactors, and achieved COD removal efficiencies of greater than 70%.

In order to meet increasingly strict Brazilian COD emissions limits, mills must understand the components that contribute to effluent COD, how these vary between normal mill operation and maintenance shutdowns, and how this variation affects treatment efficiency. To this end, primary and secondary effluents from a Brazilian bleached eucalypt kraft pulp mill activated sludge system were analyzed for COD, lignin, extractives, carbohydrates and AOX over a sixth month period that included two general maintenance shutdowns and four months of normal operation. Primary effluent presented significantly different compositions during periods of normal operation and mill shutdowns. During normal operation, the main components of effluent COD (909 mg/l average) were carbohydrates, followed by lignin. However, the lignin fraction was the main component of secondary effluent COD during both normal operation and mill shutdowns. Higher removal efficiencies for COD carbohydrates and AOX were observed during normal operation compared to shutdowns, while no difference in removal efficiencies of lignin and extractives was observed. Carbohydrate removal efficiency was significantly lower in one of the parallel treatment lines. The different removal efficiencies reflect not only variations in effluent composition, but possibly differences in system operational control which should be explored in greater detail

Efluentes de fábrica têxtil têm composição complexa e, mesmo após o tratamento biológico, ainda apresentamelevada concentração de corantes e pigmentos. A adsorção em carvão ativado tem sido extensivamenteinvestigada para a remoção de corantes, porém a maioria dos trabalhos utilizam efluentes sintéticos ao invés de efluente têxtil real. O objetivo deste trabalho foi avaliar a eficiência de remoção de cor e DQO de um efluente têxtil real com a adsorção em carvão ativado em pó (PAC). Para a caracterização do PAC, foi medido o número de iodo. A cor do efluente foi medida pelo método de cor ADMI. A máxima eficiência de remoção alcançada foi de 60% para DQO e 93% para cor, com 20 g.L-1 de PAC. Ainda, com uma concentração de adsorvente de 4 g.L-1, pode-se alcançar o limite de cor estabelecido pela legislação de Minas Gerais, Brasil. Os resultados mostraram a viabilidade do uso de PAC para remoção de cor e DQO de efluente têxteis.

The potential of the H 2 O 2 /UV process for improving quality of an industrial textile effluent before biological treatment was evaluated in the laboratory using a multivariate experimental design to determine the effects of pH, H 2 O 2 dose and reaction time on colour, COD and toxicity removal efficiencies. Increasing reaction time (from 10 to 120 min) and H 2 O 2 dose (from 0 to 5 mmol L −1 ) significantly improved removal efficiencies, while increasing pH (from 4 to 10) had a negative effect on colour and toxicity removals. Laboratory H 2 O 2 /UV treatment of the mill effluent under optimum conditions (pH 7, 5 mmol L −1 H 2 O 2 , 120 min) resulted in decreases in colour (70%), COD (21%) and toxicity (67%), without lowering BOD. H 2 O 2 was consumed within the first 30–60 min, while the effluent average oxidation state stabilized after 60 min. Decreasing reaction time to 60 min resulted in similar colour (63%) and COD (20%) removals but lower toxicity removal (44%). Spectrophotometric monitoring of the optimized reaction indicated partial destruction of residual aromatic azo dyes. H 2 O 2 and residual peroxide and average oxidation state of the effluent Effluent biodegradability (BOD/COD) increased by 28% after the H 2 O 2 /UV treatment. Improvements observed in effluent quality are expected to enhance combined AOP-biological treatment efficiency of the mill effluent.

Eucalypt leaf spot caused by Quambalaria eucalypti is currently one of the main diseases occurring in mini-clonal hedges cultivated in sand beds with drip fert-irrigation or hydroponic tanks. Given the lack of studies on the effectiveness of fungicides for control of this pathogen, the protective, curative and antisporulating effects of systemic fungicides and their influence on production and rooting of eucalypt mini-cuttings were evaluated. Among the nine active ingredients tested, azoxystrobin, epoxiconazole, epoxiconazole+pyraclostrobin, pyraclostrobin and tebuconazole were the most effective against Q. eucalypti. Epoxiconazole, epoxiconazole+pyraclostrobin and tebuconazole presented protective, curative and antisporulating effects against the pathogen. In mini-clonal hedges, only epoxiconazole+pyraclostrobin negatively affected the production of mini-cuttings.

A total of 107 rhizobacterial isolates, obtained from the rhizosphere of eucalypt clones were tested as rooting inducers of cuttings and mini-cuttings planted in substrate composed of carbonized rice husk and vermiculite (1:1). Cuttings and mini-cuttings were planted in conical plastic tubes containing treated and untreated (control) substrate and kept under intermittent mist irrigation at 26-28ºC. After 35 days, rooting percentage and dry root matter of cuttings were evaluated. Ten isolates capable of providing gains of up to 110% in root formation and up to 250% in root biomass over non-inoculated control cuttings were selected. Gains in rooting varied according to clone and isolate tested. The greatest gains were obtained for the mini-cuttings exhibiting the lowest rooting efficiency. Among the ten isolates tested, only 3918 (code R98) and MF4 (code R87), produced 3-indole-acetic acid in vitro, at concentrations of 0.7 and 0.67 µg ml-1, respectively. Significant increases in rooting and root dry matter of cuttings grown on rhizobacteria-inoculated substrate were found when compared to untreated or indole-butyric acid (IBA) treated mini-cuttings. Neste trabalho, testaram-se 107 rizobactérias, isoladas da rizosfera de mudas de clones de eucalipto, quanto ao seu potencial como promotoras de enraizamento de estacas e miniestacas de eucalipto, em substrato à base de casca de arroz carbonizada e vermiculita (1:1). Estacas e miniestacas foram plantadas em tubetes cônicos contendo substrato tratado e não tratado (testemunha) e foram mantidas sob nebulização intermitente de água a 26-28ºC. Aos 35 dias, avaliou-se a porcentagem média de estacas enraizadas e a massa seca do sistema radicular. Dez isolados destacaram-se como indutores de enraizamento e crescimento, propiciando ganhos de até 110% e de 250%, respectivamente. Esses isolados também foram eficientes no enraizamento de miniestacas, cujos ganhos variaram de acordo com o clone e isolado testado. Os maiores incrementos obtidos no enraizamento de estacas foram superiores aos observados para miniestacas. Em geral, quanto menor o índice de enraizamento do clone, maior foi o ganho médio obtido com a inoculação. Apenas os isolados 3918 (código R98) e MF4 (código R87) foram capazes de produzir ácido indol-acético (AIA) in vitro, em quantidades equivalentes a 0,7 e 0,67 µg/ml de suspensão, respectivamente. Quando comparados ao tratamento de miniestacas em ácido indol butírico (AIB), estes isolados promoveram incrementos significativos na porcentagem de enraizamento e na massa seca do sistema radicular de miniestacas.

A total of 107 rhizobacterial isolates, obtained from the rhizosphere of eucalypt clones were tested as rooting inducers of cuttings and mini-cuttings planted in substrate composed of carbonized rice husk and vermiculite (1:1). Cuttings and mini-cuttings were planted in conical plastic tubes containing treated and untreated (control) substrate and kept under intermittent mist irrigation at 26-28ºC. After 35 days, rooting percentage and dry root matter of cuttings were evaluated. Ten isolates capable of providing gains of up to 110% in root formation and up to 250% in root biomass over non-inoculated control cuttings were selected. Gains in rooting varied according to clone and isolate tested. The greatest gains were obtained for the mini-cuttings exhibiting the lowest rooting efficiency. Among the ten isolates tested, only 3918 (code R98) and MF4 (code R87), produced 3-indole-acetic acid in vitro, at concentrations of 0.7 and 0.67 µg ml-1, respectively. Significant increases in rooting and root dry matter of cuttings grown on rhizobacteria-inoculated substrate were found when compared to untreated or indole-butyric acid (IBA) treated mini-cuttings.Neste trabalho, testaram-se 107 rizobactérias, isoladas da rizosfera de mudas de clones de eucalipto, quanto ao seu potencial como promotoras de enraizamento de estacas e miniestacas de eucalipto, em substrato à base de casca de arroz carbonizada e vermiculita (1:1). Estacas e miniestacas foram plantadas em tubetes cônicos contendo substrato tratado e não tratado (testemunha) e foram mantidas sob nebulização intermitente de água a 26-28ºC. Aos 35 dias, avaliou-se a porcentagem média de estacas enraizadas e a massa seca do sistema radicular. Dez isolados destacaram-se como indutores de enraizamento e crescimento, propiciando ganhos de até 110% e de 250%, respectivamente. Esses isolados também foram eficientes no enraizamento de miniestacas, cujos ganhos variaram de acordo com o clone e isolado testado. Os maiores incrementos obtidos no enraizamento de estacas foram superiores aos observados para miniestacas. Em geral, quanto menor o índice de enraizamento do clone, maior foi o ganho médio obtido com a inoculação. Apenas os isolados 3918 (código R98) e MF4 (código R87) foram capazes de produzir ácido indol-acético (AIA) in vitro, em quantidades equivalentes a 0,7 e 0,67 µg/ml de suspensão, respectivamente. Quando comparados ao tratamento de miniestacas em ácido indol butírico (AIB), estes isolados promoveram incrementos significativos na porcentagem de enraizamento e na massa seca do sistema radicular de miniestacas.

A study was performed in Vicosa, Minas Gerais, Brazil, to determine the feasibility of using solar radiation to disinfect treated domestic wastewater (TDWW). The effluent from a residential development, after passing through a pre-treatment unit (bar screen and grit channel) and a septic tank, was used as supply. After the septic tank, the TDWW had mean values of 286 mg L -1 COD, 54 mg L -1 TSS, and 65 NTU turbidity. A square cement block reactor was constructed (located at 20° 45' 14" S, 42° ° 52 ' 53 " W) and used to disinfect the reclaimed TDWW Fixed depths of water (0.05, 0.10, 0.15, and 0.20 m) were tested at different exposure times from November 2004 to May 2005. Solar UV disinfection (SODIS) was effective in reducing mean concentration of indicator microorganisms, i.e., total coliform (TC) and Escherichia coli (E. coli), after 8 h of exposure to direct sunlight. Statistical analysis showed that the inactivation rates of E. coli did not significantly vary due to turbidity or dissolved oxygen. A model was developed to estimate the surviving E. coli population after SODIS from its initial population, depth of water treated, and solar energy received. The model indicated that, for a fluence accumulated of 32.91 MJ m -2 , a 4 log reduction of E. coli population was achieved with a wastewater depth of 0.05 m in the SODIS reactor.

The ability of a rhizobacterium to protect tomato plants against naturally occurring diseases as well as to improve crop yield under field conditions was studied. The rhizobacterium was introduced to the plants through seed microbiolization. Treatments consisted of different frequencies of fungicide (Chlorothalonyl) sprayings (5, 10 or 20 applications) of tomato plants grown from either microbiolized or non-microbiolized seeds over a 90-day evaluation period. Treatment of non-microbiolized seeds without fungicide application was included as a control. The progress of the following three naturally occurring diseases was evaluated in the field and quantified: early blight (Alternaria solani), late blight (Phytophthora infestans), and septoria leaf spot (Septoria lycopersici). All treatments resulted in reduced disease severity when compared with the control treatment. Highest final fruit yields were found after treatment of plants grown from non-microbiolized seeds and sprayed with fungicide 20 times over 90 days, and for treatment of plants from microbiolized seeds that received 10 fungicide spray applications, although all treatments increased yield over that obtained in the control treatment. The results demonstrate that combined rhizobacterial and chemical treatments in the field may permit reducing fungicidal spraying frequency while at the same time increasing crop yields.

Rhizobacteria B101R, B212R, and A068R, selected as inducers of systemic resistance against Pseudomonas syringae pv. tomato, were tested individually for biological control of multiple pathogens causing foliar diseases in tomato plants. Greenhouse bioassays were carried with five pathogens—Alternaria solani (early blight), Corynespora cassiicola (foliar blight), Oidium lycopersici (powdery mildew), Stemphilium solani (leaf spot), and Xanthomonas campestris pv. vesicatoria (bacterial spot). The level of control achieved by each rhizobacterium varied with the pathosystem studied. Isolate B101R afforded reduced disease intensity in terms of average number of leaf lesions as compared to the treatment control, protection against A. solani, S. solani, and O. lycopersici. Lipoxygenase, phenylalanine amonia-lyase, and peroxidase activities were estimated spectrophotometrically in extracts of plants grown from seeds that were microbiolized with rhizobacterium B101R, and inoculated with P. syringae pv. tomato. Increases in peroxidase and lipoxygenase activities were detected in foliar extracts from plants whose seeds had been microbiolized, while no increase in phenylalanine amonia-lyase activity was observed.

The ability to colonize roots is a sine qua non condition for a rhizobacteria to be considered a true plant growth-promoting rhizobacteria (PGPR). A simple screening method to detect such a potential ability of PGPR is described. Tomato seeds were surface sterilized for 30 s in 50% ethanol and this is followed by 3–5min dipping in 2% NaClO. They were then washed three times in sterile water, left immersed in a propagules suspension of the rhizobacteria for 24 h, and transferred onto sterile 0.8% water-agar in tubes. The young, developing root system shows a tendency to grow downwards in the agar-gel column. When the rhizobacteria has a potential ability to colonize roots it is possible to visualize, by transparency, bacterial growth (turbid, milky and narrow zone) along and around roots. Testing 500 rhizobacteria isolated from tomato rhizosphere for their ability to induce systemic resistance against Pseudomonas syringae pv. tomato ,2 8 of them did reduce infection to less than 40% and all 28 colonized roots according to the described bioassay. Therefore the bioassay may turn into an important auxiliary tool for helping in selecting rhizobacteria with PGPR potentiality.

The ability to differentiate functional and structural diversity of bacterial communities present in activated sludges adapted to elementally (ECF) and totally (TCF) chlorine-free bleaching effluents was evaluated. Community function was evaluated through substrate utilization patterns in BiologGN®microplates, and taxonomic structure was evaluated by fluorescent in situ hybridization using probes targeting the Eubacteria; the alpha, beta, and gamma subclasses of the Proteobacteria; and gram-positive bacteria with high GC content. Over 6-week sampling periods, ECF- and TCF-adapted sludge bacterial communities presented reproducible substrate utilization patterns that through principal components (PCs) analysis, separated the ECF samples from the TCF samples. Application of the fluorescent in situ hybridization technique was complicated by the intense autofluorescence of the bleaching effluent sludge samples that interfered with detection of specific hybridization signals. The most notable difference in community structure detected using the chosen set of probes was the relatively greater proportion of cells of the alpha subclass in TCF sludge (27%) than in ECF sludge (6%). Nonspecific hybridization with beta and gamma probes was relatively high, but both sludges appeared to have similar proportions of cells of the beta (20–22%) and gamma (11–12%) subclasses. The two sludges presented relatively few gram-positive cells with high GC content (

Esta faltando um resumo. O Thiodan ® é um organoclorado a base de endosulfan que pode causar alterações morfológicas nos tecidos de peixes, dependendo da concentração e tempo de exposição. Este estudo teve como objetivo determinar a CL 50 -96h do Thiodan ® (endosulfan 350g L -1 ) para fêmeas de lambaris Astyanax bimaculatus em período de reprodução e analisar a morfologia do desenvolvimento folicular em diferentes concentrações do agrotóxico. Foram feitos quatro experimentos: 1) sem aclimatação e sem alimentação; 2) sem aclimatação e alimentados; 3) com aclimatação de 10 dias e sem alimentação; 4) com aclimatação de 10 dias e alimentados. A CL 50 -96h determinada foi de 13,6μg L -1 , com intervalo de confi ança de 10,1 a 18,4μg L -1 (P

Contaminated irrigation water constitutes one of the main sources of plant pathogens that can cause disease and lead to potentially significant production losses in forest nurseries. Recycling of contaminated irrigation water increases the risk of spreading diseases. The objective of this study was to evaluate a simple slow sand filtration treatment of irrigation water as a method for eradicating fungal and bacterial pathogens in eucalypt cutting nurseries. Pilot filter units were constructed from PVC pipes containing a 80 cm high layer of sand with grain size varying from 0.50 to 0.75 mm, drainage layers of 10 cm of fine gravel (4 mm) followed by a 15 cm layer of coarse gravel (8 mm), connected to a water outlet. The PVC pipe had space for a 150 mm water column above the sand layer and the filter had a flow rate of 100 to 300 L m-2 h-1. Eradication of the bacterial pathogen Ralstonia solanacearum, and the fungal pathogens Cylindrocladium candelabrum and Botrytis cinerea through the use of the filter was evaluated. Detection of bacteria in filter-treated irrigation water was performed through the micro drop method followed by PCR of colonies, while fungal pathogens were detected using a castorbean leaf biological bait method. Evaluations were performed daily 35 times for R. solanacearum, 25 times for C. candelabrum and 18 times for B. cinerea during a period of 12 months. After the last evaluation period, samples from various depths of the sand layer in the filters were taken and analyzed for the presence of the plant pathogens. The slow sand filters were able to remove B. cinerea and C. candelabrum spores with 100% efficiency while eradication of R. solanacearum colonies reached up to 99.6%. Colonies of Trichoderma sp. were found predominantly on the all filter layers. The results of this study show that slow sand filters are efficient for recycled water in eucalypt nurseries, especially in eradicating fungal pathogens.

The petroleum industry generates large amounts of solid and semisolid wastes known as oily sludges. The composition of oily sludge varies due to the large diversity in the quality of crude oils, differences in the processes used for oil-water separation, leakages during industrial processes, and also mixing with the existing oily sludge. Usually, the oily sludge contains water, sand, oils, grease, organic compounds, chemical elements, and metals. Those sludges can be generated in several steps of the petroleum production and refining, such as in oil/water separation steps and in the bottom of tanks. The accumulation of oily residues in petroleum industry poses a serious environmental problem. The purpose of this work was evaluate an alternative process to removal of oily sludges through the use of biosurfactants to reduce the viscosity and promote formation of oil/water emulsions making sludge pumping easier and permitting crude oil recovery after breaking the emulsion. Five bacterial isolates were selected for their biosurfactant production potential after screening microorganisms recovered from oil-contaminated sites. Supernatants obtained from autoclave cell suspensions (hereby referred to as autoclaved-supernatant) were mixed with oily sludge collected from fuel oil storage tanks to a final concentration of 0.01%, in order to separate the oil from the inert material. The process proved to be highly efficient for oil recovery, and resulted in up to 95% reduction in sludge volume. The use of cell-free supernatant medium obtained from biosurfactant-producing bacterial strains to treat oily sludges may be an economically and environmentally viable technology, considering the small volume of microbial culture required for the treatment.

O mercúrio, elemento químico considerado não essencial a qualquer processo metabólico, é facilmente acumulado na maioria dos organismos. Ocorre naturalmente em formas orgânicas e inorgânicas, nos estados sólido, dissolvido e gasoso. Seu ciclo biogeoquímico envolve processos que ocorrem no solo, na água e na atmosfera. Em 2002, descobriu-se mercúrio elementar na zona rural do município de Descoberto, Minas Gerais, onde moram cerca de 70 famílias, e sua origem parece estar associada à exploração de ouro, que existiu na região no século 19. Neste trabalho, foram escolhidas três áreas para identificar possível contaminação da água, solo, sedimento e peixes por mercúrio, bem como para estabelecer valores de referência local e contraprova de resultados obtidos anteriormente. Verificaram-se elevadas concentrações no solo (0,26 a 0,55 mg.kg -1 ), sedimentos (0,13 a 0,61 mg.kg -1 ) e água (< 0,2 a 2,10 μg.L -1 ). Mercury is a chemical element considered unessential to any metabolic process; however, it is easily accumulated in most organisms. It is naturally found in both organic and inorganic forms in solid, liquid and vapor states. Its biogeochemical cycle involves processes occurring in the soil, water and the atmosphere. In 2002, elementary mercury was found in the city of Descoberto, Minas Gerais, Brazil, where 70 families live, and its origin may be related to gold exploration that happened in this region in the 19 th century. In this work, three areas were chosen to identify a possible mercury contamination of water, soil, sediment and fish samples and to establish local reference values and counter-evidence of the data previously obtained. Based on the results, high mercury concentrations in soil (0.26 to 0.55 mg.kg -1 ), sediments (0.13 to 0.61 mg.kg -1 ) and water (< 0.2 to 2,10 μg.L -1 ) were verified.

In this study a poorly biodegradable (BOD/COD = 0.3) industrial alkaline ECF bleaching filtrate was treated using different advanced oxidation processes to evaluate their use in combined chemical–biological treatment aimed at increasing recalcitrant COD removal and improving final effluent quality. Oxidative treatments included ozonation combined with hydrogen peroxide (2, 5, 10, 20 mmol L −1 O 3 /0.7, 2, 5, 10 mmol L −1 H 2 O 2 ) and photocatalysis with hydrogen peroxide (UV/2, 4 and 8 mmol L −1 H 2 O 2 ) and with TiO 2 (UV/TiO 2 /0.7 and 4 mmol L −1 H 2 O 2 ). The O 3 /H 2 O 2 process increased effluent biodegradability by up to 68% as a result of increasing BOD and decreasing COD. Increasing the O 3 dose had a greater effect on biodegradability improvement and lignin and colour removal efficiencies than increasing the H 2 O 2 dose. A combined oxidant dose of 5 mmol L −1 O 3 and 2 mmol L −1 H 2 O 2 resulted in 75% lignin removal, 40% colour removal and 6% carbohydrate loss without mineralizing the organic carbon. The photocatalytic processes led to a decrease in effluent biodegradability through combined decrease in BOD and increase in COD and did not result in efficient lignin or colour removal. Photocatalytic oxidation was apparently inhibited by the high chloride and COD levels in the alkaline filtrate, and may be more efficient in recalcitrant COD removal if performed after biological.