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Vidal,Gladys; Soto,Manuel; Méndez,Ramón; Lema,Juan Manuel. |
Aerobic biodegradability of effluents from different Eucalyptus kraft pulp bleaching processes was studied. Bleaching effluents were obtained from: i) Chlorine Bleaching (CB) processes, with partial substitution of chlorine by chlorine dioxide and ii) Total Chlorine Free (TCF) processes. The overall biodegradability, in terms of Chemical Oxygen Demand (COD) was higher for TCF effluents (96-98%) than for CB ones (82-93%). Taking into account the higher organic load of CB effluents, this fact implied a much higher residual COD for them (100-180 mg/L) than for TCF effluents (10-30 mg/L). Furthermore, a refractory fraction of molecular weight higher than 43,000 Da was found in CB effluent, which implied the necessity of a further specific treatment. The... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Kraft pulp bleaching wastewater; Aerobic biodegradation; Pulp bleaching technology; TCF; CB. |
Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89131999000300009 |
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Junod,Julio; Zagal,Erick; Sandoval,Marco; Barra,Ricardo; Vidal,Gladys; Villarroel,Mario. |
Water flows provided by irrigation systems may be associated with dissolved organic carbon (DOC) content in the soil solution and may modify the mobility of pesticides, such as chlorpyrifos (CHP). These compounds were analyzed under field conditions, evaluating their distribution in the soil profile under excessive irrigation in a Humic Haploxerand soil. The trial was carried out in soil columns located under the canopy of apple trees (Malus domestica Borkh.) in an orchard located in the Bío-Bío Region, Chile. The insecticide CHP was applied 120 g hL-1, and later the natural run off was collected from the foliage to the columns. Surface irrigation was used as a control, the equivalent to 4 L h-1 weekly, plus two treatments over the columns of 6 and 8 L h-1... |
Tipo: Journal article |
Palavras-chave: Pesticides; Organic matter; Volcanic soil. |
Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392009000300017 |
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Reyes-Contreras,Carolina; Vidal,Gladys. |
Background Anaerobic digestion is a technology applied successfully to converting organic matter into biogas. However, the presence of inhibitory compounds such as antibiotics can adversely affect methane production. The aim of this study is to evaluate the toxic effect of chlortetracycline hydrochloride (CLOR) on the methanogenic bacteria. In order to study the methanogenic toxicity of CLOR, different concentrations of CLOR (10, 50, 100, 200 mg L- 1) were evaluated by methanogenic toxicity assays using three feedings. Results Maximum methane production was obtained for the assays with 10 mg CLOR L- 1, the values obtained were 277 ± 4.07; 193 ± 11.31 and 166 ± 7.07 mL for the first, second and third feedings, respectively. The average values for acetic,... |
Tipo: Journal article |
Palavras-chave: Antibiotics; Anaerobic batch assay; Bacterial inhibition; Volatile fatty acids. |
Ano: 2015 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582015000600010 |
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Alarcón,Evelyn; Decap,Jacqueline; Vidal,Gladys. |
Kraft mills are responsible for the massive discharge of highly polluted effluents, and new bleaching processes (i.e. Total Chlorine Free (TCF)) is presented as a feasible option to reduce this environmental impact. However, increased TCF pulp production is accompanied by an increase in chelate use. The most commonly used chelates, ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DPTA), are considered to be relatively persistent substances in water treatment plants, and consequently environmentally critical compounds. The purpose of this work is to investigate DPTA behaviour in an anaerobic system. An Anaerobic Filter (AF) was operated with three different DPTA load rates (LR DPTA = 0.07 - 0.28 gDPTA/L×d), and the... |
Tipo: Journal article |
Palavras-chave: Anaerobic biodegradation; DTPA; Kraft mill effluent. |
Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000300011 |
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Chamorro,Soledad; Xavier,Claudia Regina; Hernández,Victor; Becerra,José; Vidal,Gladys. |
Kraft mill effluent, due to its organic matter content and acute toxicity, must be treated. A primary treatment followed by a secondary treatment is the most common system. Aerated lagoon is also considered an effective biological treatment, although this technology has some drawbacks related with operation parameters and land extension space. Moreover, the recovery efficiency for micropollutants contained in kraft mill effluent is questioned due to the anoxic zone in the system. The goal of this work is to evaluate the performance of the aerated lagoon to remove stigmasterol contained in kraft mill effluents. Kraft mill effluent was treated by an aerated lagoon (AL), which was operated with three different stigmasterol load rates (SLR = 0.2, 0.6 and 1.1... |
Tipo: Journal article |
Palavras-chave: Aerated lagoon; Kraft mill effluent; Stigmasterol. |
Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582009000200001 |
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Junod,Julio; Zagal,Erick; Sandoval,Marco; Venegas,Alejandro; Campos,Jorge; Radrigan,Rudi; Barra,Ricardo; Vidal,Gladys. |
El presente estudio tiene por objetivo probar mediante ensayos supervisados la variabilidad de los residuos de clorpirifos (CHP) asociados a una metodología de muestreo validada en terreno, al aplicar el ingrediente activo (IA) en huerto de manzanos, con dos diferentes metodologías de aspersión y en épocas diferentes de desarrollo vegetativo. Se estudió la persistencia al aplicar 1,8 kg ha -1(Lorsban 50%WP®, Dow AgroScience, USA), mediante nebulizadora con bomba de espalda con motor (NBEM) y con nebulizadora de alto volumen (NAV). Se evaluó el modelo que representa el mejor ajuste de la declinación de los residuos a través de regresión no lineal. Los resultados muestran altos coeficientes de variación (CV) en ambos métodos de aplicación, NBEM (69%) y NAV... |
Tipo: Journal article |
Palavras-chave: Pesticidas; Residuos; Degradación. |
Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912009000300002 |
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Ortiz,Gerardo; Villamar,Cristina Alejandra; Vidal,Gladys. |
Farm slurry management from storage and/or treatment is the main source of odors from swine production, which are determined by factors such as operational variations (organic loading), cleaning of facilities and animal diet (pH) or environmental conditions (temperature). The aim of this study was to evaluate the influence of pH, temperature and organic loading on odor generation during anaerobic digestion of swine slurry. The methodology employed batch experimental units under controlled pH (6.0, 6.5, 7.0 and 8.0) and temperature (20, 35 and 55 °C) conditions. Additionally, an Upflow Anaerobic Sludge Blanket (UASB) system was operated under two Organic Loading Rate (OLR) conditions as Chemical Oxygen Demand (COD) (Phase I: 0.4 g L-1 d-1 of COD, Phase II:... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anaerobic treatment/storage; Odor threshold; Operational factors; Swine slurry. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162014000600001 |
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