Color reduction of black liquor from cotton cellulose industry using ozonation in an alkaline medium

Pulp and paper mills discharge large amounts of wastewater containing high concentrations of lignin, a coloring substance that is dangerous and presents high toxicity to the environment. In this study, ozonation in alkaline ambience was evaluated for color reduction in black liquor, generated in a cotton linter mill. It was observed that the ozonation time to reach 80% color reduction was higher at a lower initial ozone dose (0,4 gO3 L-1 h-1) in comparison to a higher initial ozone dose (4,3 gO3 L-1 h-1). On the other hand, the amount of consumed oxidant was lower at the lower ozone dose. It is suggested that molecular oxygen participates in the oxidation mechanism of colored compounds, which is initiated by hydroxyl radicals ( OH) formed during ozonation in alkaline ambience.As indústrias de papel e celulose descartam no ambiente um grande volume de efluente contendo grande quantidade da substância lignina, que atribui coloração e apresenta considerável potencial de toxicidade. Neste trabalho, foi avaliada a ozonização em meio básico para a redução de cor do licor negro gerado por uma indústria de celulose de algodão. Face aos resultados, foi possível observar que, para menores concentrações iniciais de ozônio (0,4 gO3 L-1 h-1), foi necessário um tempo mais longo de ozonização para se obter a redução desejada de 80% da cor. O consumo específico de ozônio, entretanto, em comparação a experimentos com dosagens mais elevadas (4,3 gO3 L-1 h-1) foi menor. Sugere-se que o oxigênio molecular desempenhe, também, um importante papel na oxidação dos compostos, participando do mecanismo de oxidação iniciado por radical hidroxila, OH, formado na ozonização em meio básico.9398Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Advanced oxidation processes on doxycycline degradation: monitoring of antimicrobial activity and toxicity

Advanced oxidation processes (AOPs) have been highly efficient in degrading contaminants of emerging concern (CEC). This study investigated the efficiency of photolysis, peroxidation, photoperoxidation, and ozonation at different pH values to degrade doxycycline (DC) in three aqueous matrices: fountain, tap, and ultrapure water. More than 99.6% of DC degradation resulted from the UV/H2O2 and ozonation processes. Also, to evaluate the toxicity of the original solution and throughout the degradation time, antimicrobial activity tests were conducted using Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria, and acute toxicity test using the bioluminescent marine bacterium (Vibrio fischeri). Antimicrobial activity reduced as the drug degradation increased in UV/H2O2 and ozonation processes, wherein the first process only 6 min was required to reduce 100% of both bacteria activity. In ozonation, 27.7 mg L-1 of ozone was responsible for reducing 100% of the antimicrobial activity. When applied the photoperoxidation process, an increase in the toxicity occurred as the high levels of degradation were achieved; it means that toxic intermediates were formed. The ozonated solutions did not present toxicity26272760427619CNPQ - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulo479131/2013-9; 459078/2014-32013/07817-2; 2013/04656-8; 2013/09543-

On-line solid phase extraction-ultra high performance liquid chromatography-tandem mass spectrometry as a powerful technique for the determination of sulfonamide residues in soils

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Sulfonamides are antimicrobials used widely as veterinary-drugs, and their residues have been detected in environmental matrices. An analytical method for determining sulfadiazine, sulfathiazole, sulfamethazine, sulfamethoxazole, sulfadimethoxine and sulfaquinoxaline residues in soils employing a solid phase extraction on-line technique coupled with ultra-high performance liquid chromatography and tandem mass spectrometry (SPE-UHPLC-MS/MS) was developed and validated in this study. SPE and chromatographic separation were performed using an Oasis HLB column and an Acquity UPLC BEH C18 analytical column, respectively, at 40 degrees C. Samples were prepared by extracting sulfonamides from soil using a solid-liquid extraction method with water:acetonitrile, 1:1 v/v (recovery of 70.2-99.9%). The following parameters were evaluated to optimize the on-line SPE process: sorbent type (Oasis and C8), sample volume (100-400 mu l), loading solvent (water and different proportions of water:methanol) and washing volume (0.19-0.66 mL). The method produced linear results for all sulfonamides from 0.5 to 12.5 ngg(-1) with a linearity greater than 0.99. The precision of the method was less than 15%, and the matrix effect was -27% to -87%. The accuracy was in the range of 77-112% for all sulfonamides. The limit of quantitation in the two soils (clay and sand) was 0.5 ngg(-1). The SPE column allowed for the analysis of many (more than 2000) samples without decreasing the efficiency. (C) 2016 Elsevier B.V. All rights reserved.Sulfonamides are antimicrobials used widely as veterinary drugs, and their residues have been detected in environmental matrices. An analytical method for determining sulfadiazine, sulfathiazole, sulfamethazine, sulfamethoxazole, sulfadimethoxine and sulf14528997FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)2013/09543-7; 2014/06201-0; 2013/07817-2; 2014/16622-3SEM INFORMAÇÃOThe authors gratefully acknowledge financial support from Fundação de Amparo à Pesquisa do Estado de São Paulo − FAPESP, Brazil (2013/09543-7, 2014/06201-0) and Conselho Nacional de Desenvolvimento Científico e Tecnológico − CNPq, Brazil. In addition, M.

Abamectin degradation by advanced oxidation processes: evaluation of toxicity reduction using daphnia similis

This work evaluated the toxicity reduction of abamectin in an aqueous solution (500 μg L-1) undergoing to photolysis (UV), peroxidation (H2O2), peroxidation with ultraviolet radiation (UV/H2O2), Fenton (Fe(II)/H2O2), and photo-Fenton (Fe(II)/UV/H2O2) processes. Toxicity trials were carried out using the microcrustacean Daphnia similis. Results were based on effective concentration, EC50 48 h. Using 1.0 mmol L-1 Fe (II) and 5.0 mmol L-1 H2O2 and a reaction time of 60 s, the ranking of efficiency for the degradation of abamectin was as follows: photo- Fenton > Fenton > UV = UV/ H2O2 > H2O2. However, after a reaction time of 300 s, similar degradation was obtained for photo-Fenton, UV, and UV/H2O2 (more than 97%), while the Fenton process degraded 80% of the drug. With the exception of peroxidation, all of the processes evaluated were able to eliminate toxicity in 600 s of reaction (1.0 mmol L-1 Fe(II) and 5.0 mmol L-1 H2O2)171COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPPNPD02330802008/06470-0; 2009/12641-

Influence of pH and ozone on Sulfaquinoxaline ozonation

Ozonation was effective to degrade sulfaquinoxaline: more than 99% of efficiency was obtained using an ozone dose of 2.8 mg L-1 and pH 3. A design of experiments with two variables, pH and ozone dose, was used for planning. There was no significant interaction between these variables and ozone doses played the most important role regarding the contaminant degradation. However, regarding toxicity ozone process at pH 3 did not inhibit the luminescence of the bacteria even though different intermediates were formed and identified by mass spectra. At pH 7 inhibition of luminescence remained almost constant (around 30%) throughout ozonation time.Postprint (author's final draft

Influence of pH and ozone on Sulfaquinoxaline ozonation

Ozonation was effective to degrade sulfaquinoxaline: more than 99% of efficiency was obtained using an ozone dose of 2.8 mg L-1 and pH 3. A design of experiments with two variables, pH and ozone dose, was used for planning. There was no significant interaction between these variables and ozone doses played the most important role regarding the contaminant degradation. However, regarding toxicity ozone process at pH 3 did not inhibit the luminescence of the bacteria even though different intermediates were formed and identified by mass spectra. At pH 7 inhibition of luminescence remained almost constant (around 30%) throughout ozonation time

Degradation Of Formaldehyde By Advanced Oxidation Processes.

The degradation of formaldehyde in an aqueous solution (400 mg L(-1)) was studied using photolysis, peroxidation and advanced oxidation processes (UV/H(2)O(2), Fenton and photo-Fenton). Photolysis was the only process tested that did not reduce formaldehyde concentration; however, only advanced oxidation processes (AOPs) significantly decreased dissolved organic carbon (DOC). UV/H(2)O(2) and photo-Fenton AOPs were used to degrade formaldehyde at the highest concentrations (1200-12,000 mg L(-1)); the processes were able to reduce CH(2)O by 98% and DOC by 65%. Peroxidation with ultraviolet light (UV/H(2)O(2)) improved the efficiency of treatment of effluent from an anatomy laboratory. The effluent's CH(2)O content was reduced by 91%, DOC by 48%, COD by 46% and BOD by 53% in 420 min of testing.10796-10

Fate Of Ivermectin In The Terrestrial And Aquatic Environment: Mobility, Degradation, And Toxicity Towards Daphnia Similis.

Ivermectin (IVM) is a broad-spectrum antiparasitic drug that is regularly employed in veterinary medicine. In this work, the sorption and desorption of IVM in two Brazilian soils (N1-sand and S2-clay) as well as its leaching capacity, dissipation under aerobic conditions, and degradation in aqueous solution by photocatalysis with TiO2 in suspension were evaluated. The kinetic sorption curves of IVM were adjusted to a pseudo-second-order model. The sorption and desorption data were well fitted with the Freundlich isotherms in the log form (r > 0.96). The Freundlich sorption coefficient (K F (ads) ) and the Freundlich desorption coefficient (K F (des) ) were 77.7 and 120 μg(1-1/n) (cm(3))(1/n) g(-1) and 74.5 and 138 μg(1-1/n) (cm(3))(1/n) g(-1), for soils N1 and S2, respectively. A greater leaching capacity of IVM was observed for the sandy soil N1 than for the clay soil S2. Under aerobic conditions, the dissipation (DT50) at 19.3 °C was 15.5 days (soil N1) and 11.5 days (soil S2). Photocatalysis with UVC and TiO2 in suspension resulted in the degradation of 98 % of IVM (500 μg L(-1)) in water in 600 s. The toxicity (Daphnia similis) of the solutions submitted to the photocatalytic process was completely eliminated after 10 min.2

Evaluation of amicarbazone toxicity removal through degradation processes based on hydroxyl and sulfate radicals

The herbicide amicarbazone (AMZ), which appeared as a possible alternative to atrazine, presents moderate environmental persistence and is unlikely to be removed by conventional water treatment techniques. Advanced oxidation processes (AOPs) driven by (OH)-O-center dot and/or SO4 center dot- radicals are then promising alternatives to AMZ-contaminated waters remediation, even though, in some cases, they can originate more toxic degradation products than the parent-compound. Therefore, assessing treated solutions toxicity prior to disposal is of extreme importance. In this study, the toxicity of AMZ solutions, before and after treatment with different (OH)-O-center dot-driven and SO4 center dot--driven AOPs, was evaluated for five different microorganisms: Vibrio fischeri, Chlorella vulgaris, Tetrahymena thermophila, Escherichia coli, and Bacillus subtilis. In general, the toxic response of AMZ was greatly affected by the addition of reactants, especially when persulfate (PS) and/or Fe(III)-carboxylate complexes were added. The modifications of this response after treatment were correlated with AMZ intermediates, which were identified by mass spectrometry. Thus, low molecular weight by-products, resulting from fast degradation kinetics, were associated with increased toxicity to bacteria and trophic effects to microalgae. These observations were compared with toxicological predictions given by a Structure-Activity Relationships software, which revealed to be fairly compatible with our empirical findings541111261143CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP479131/ 2013-92013/50218-2; 2013/09543-7; 2013/ 04656-8; 2013/07817-