Impact of pre-treatment in GnRH-antagonist cycles triggered with GnRH agonist on reproductive outcomes.

OBJECTIVE: Pre-treatment (PT) therapies in IVF are known to be used as pre-stimulation modality to improve cycle outcomes. This study aims to assess whether PT in GnRH antagonist cycles triggered with GnRH-agonist impact oocyte maturation response. METHODS: Data were retrospectively collected for patients who underwent GnRH antagonist cycle with agonist triggering with and without PT. The patients were allocated to groups according to their PT status. The primary outcome evaluated was suboptimal maturation response. Suboptimal maturation to trigger was defined as no oocyte upon retrieval when adequate response was expected. RESULTS: The study population included 196 patients who underwent GnRH antagonist cycle with agonist triggering. The study group included 69 patients who received PT. The control group included 127 patients with no PT. In univariate analysis, the PT group significantly displayed suboptimal response compared to the controls (p = 0.008). All the patients in the study group with suboptimal response (with or without hCG re-triggering) were treated with GnRH-agonist as PT. Basal and pre-trigger LH values were significantly lower in the study group compared to controls (p < 0.001). Multivariate regression analysis revealed that PT with GnRH agonist was a significant predictor for suboptimal response. CONCLUSIONS: Pre-treatment, and particularly the use of GnRH-agonist as PT in antagonist cycles triggered with agonist, increases the risk of suboptimal response to GnRH-agonist trigger. This might be explained by prolonged pituitary suppression, which lasts beyond the PT cessation.

Comparison of pre-treatments mediated by endoglucanase and TEMPO oxidation for eco-friendly low-cost energy production of cellulose nanofibrils.

Specific kinds of enzymes have been used as an eco-friendly pre-treatment for mechanical extraction of cellulose nanofibrils (CNFs) from vegetal pulps. Another well-established pre-treatment is the 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)-mediated oxidation, which has gained considerable attention. Pre-treatments assist in fiber swelling, facilitating mechanical fibrillation, and reducing energy consumption; however, some of these methods are extremely expensive. This work aimed to evaluate the influence of enzymatic pre-treatment with endoglucanase on the energy consumption during mechanical fibrillation of cellulose pulps. Bleached pulps from Eucalyptus sp. and Pinus sp. were pre-treated with endoglucanase enzyme compared to TEMPO-meditated oxidation. Average diameters of CNFs pre-treated with enzymes were close to that found for TEMPO-oxidized nanofibrils (TOCNFs). Results showed that enzymatic pre-treatment did not significantly modify the pulp chemical and morphological characteristics with efficient stabilization of the CNFs suspension at higher supernatant turbidity. Energy consumption of pulps treated with endoglucanase enzymes was lower than that shown by pulps treated with TEMPO, reaching up to 58% of energy savings. The enzyme studied in the pulp treatment showed high efficiency in reducing energy consumption during mechanical fibrillation and production of films with high mechanical quality, being an eco-friendly option for pulp treatment.

The effect of the acid pretreatment temperature of natural diatomaceous earth on the Si/Al ratio of ZSM-5 zeolite

La tierra de diatomea boliviana es una fuente de silicio potencialmente más económica en comparación a los reactivos de alta pureza comúnmente utilizados para la síntesis de zeolitas. Dada su composición compleja es necesario realizarle un pretratamiento ácido con el fin de reducir las impurezas y regular el contenido de aluminio. En este artículo se realizaron múltiples experimentos durante la etapa de pretratamiento ácido. La temperatura del pretratamiento ácido fue modificada en un rango entre 50 y 155 °C esto con el fin de determinar su efecto en la relación Si/Al final. Los resultados mostraron que la relación Si/Al puede ser modulada en un rango entre 6,2 y 38,1. Posteriormente, se obtuvieron zeolitas a partir de la tierra de diatomea modificada. Las zeolitas obtenidas presentaron una relación Si/Al entre 9,6 y 40,2. Se aplicaron distintas técnicas de caracterización para la determinación de las propiedades. El grado de cristalinidad y el área superficial específica están directamente relacionadas con la relación Si/Al. Los sitios ácidos están conformados por ácidos fuertes de tipo Brönsted y ácidos fuertes y débiles de tipo Lewis. Para la zeolita con menor relación Si/Al se determinó una elevada acidez total (>0,51 molNH3/Kgzeolita), mientras que para la zeolita con mayor relación Si/Al la acidez total se redujo considerablemente (<0,38 molNH3/Kgzeolita).

Bolivian diatomaceous earth is a potentially lower cost silica source than conventional high purity reagents used in zeolite synthesis. Due to its complex composition, it is necessary to pre-treat it with sulfuric acid in order to reduce impurities and regulate the aluminum content. In the present work several experiments were carried out with natural Bolivian diatomaceous earth in the pre-treatment stage. In order to determine the effect on the final Si/Al ratio, the temperature of the acid pre-treatment was varied between 50 to 155 °C. The results show that the Si/Al ratio can be modulated from 6.2 up to 38.1. These treated diatomaceous earth samples were used to synthetise ZSM-5 zeolite. The obtained ZSM-5 zeolites have a Si/Al ratio in the following range: 9.6 to 40.2. XRD, NH3-TPD and Nitrogen Physisorption techniques were used to characterise the properties of the obtained zeolites. The degree of crystallisation and the specific surface area are directly related to the Si/Al ratio, resulting in high values at high Si/Al ratios. The acid sites are composed of strong Brönsted acid sites and, strong and weak Lewis acid sites. For the zeolite with a low Si/Al ratio a high total acidity was found (>0.51 molNH3/Kgzeolite), while at high Si/Al ratios the total acidity is reduced (<0.38 molNH3/Kgzeolite).

A terra diatomácea boliviana é uma fonte potencialmente mais barata de silício em comparação com os reagentes de alta pureza comumente usados para a síntese de zeólitas. Dada a sua composição complexa, é necessário realizar um pré-tratamento ácido para reduzir as impurezas e regular o teor de alumínio. No presente trabalho, vários experimentos foram realizados durante a etapa de pré-tratamento ácido. A temperatura do pré-tratamento ácido foi modificada em uma faixa entre 50 e 155 °C para determinar seu efeito na relação Si/Al final. Os resultados mostram que a razão Si/Al pode ser modulada em uma faixa entre 6,2 e 38,1. Posteriormente, as zeólitas foram obtidas a partir de terra diatomácea modificada. As zeólitas obtidas possuem uma razão Si/Al entre 9,6 e 40,2. Diferentes técnicas de caracterização foram aplicadas para determinar as propriedades. O grau de cristalinidade e a área superficial específica estão diretamente relacionados com a razão Si/Al. Os sítios ácidos são compostos por ácidos fortes do tipo Brönsted e ácidos fortes e fracos do tipo Lewis. Para a zeólita com menor relação Si/Al, foi determinada uma alta acidez total (>0,51 molNH3/Kgzeólita), enquanto para a zeólita com maior relação Si/Al, a acidez total foi consideravelmente reduzida (<0,38 molNH3/Kgzeolita).

Rotas tecnológicas, desafios e potencial para valoração energética de resíduo sólido urbano por coprocessamento no Brasil / Technological routes, challenges and potential for municipal solid waste energetic valorization by coprocessing in Brazil

RESUMO Mais de dez anos depois da implantação da Política Nacional de Resíduos Sólidos, por meio da Lei federal n° 12.305/2010, a elaboração e a execução de políticas públicas com resultados positivos na gestão dos resíduos sólidos urbanos são precárias. O coprocessamento desses produtos em fornos de clínquer pode ser uma alternativa viável para melhorar esse cenário, mas encontra diversas dificuldades de ordem técnica e econômica. Neste trabalho, estimou-se a composição e a gravimetria dos resíduos no Brasil com base em dados secundários, de forma a estimar o poder calorífico inferior resultante de diferentes formas de pré-tratamento desses produtos: triagem de orgânicos, triagem de orgânicos e inertes, secagem para redução da umidade e combinação das três estratégias. Com base nos valores obtidos de poder calorífico, estima-se a capacidade de coprocessamento de resíduos pré-tratados pelas indústrias nacionais que possuem licenciamento ambiental para essa atividade. O tratamento prévio dos resíduos resultou em aumentos entre 20 e 56% em relação ao cenário-base. Observou-se que, para o cenário sem triagem, mas com secagem térmica do resíduo, até 8% dos resíduos com destinação inadequada no Brasil atualmente podem ser recebidos por indústrias de cimento para o coprocessamento, desde que haja viabilidade técnica para sua substituição e transporte.

ABSTRACT More than ten years after the implementation of the Solid Waste Nacional Policy by Brazilian Federal Law nº 12.305/2010, elaboration and execution of public policies with positive results in Municipal Solid Waste management is precarious. Coprocessing of Municipal Solid Waste in cement kilns can be a viable alternative for improving this scenario, but still encounters many technical and economical challenges. In this study, an estimate of the mean gravimetric composition of Municipal Solid Waste in Brazil is presented, based on secondary data, so as to estimate the resultant lower heating value resultant of different Municipal Solid Waste pre-treatment alternatives; separation of the organic fraction, separation of organic and inert fraction, drying of Municipal Solid Waste and all strategies combined. Based on the obtained lower heating value, an estimate of the yearly potential of Municipal Solid Waste coprocessing in industries already licensed for coprocessing of waste in Brazil is presented. Pre-treatment of Municipal Solid Waste resulted in lower heating value improvements ranging from 20 to 56% when compared to the base scenario. It is observed that, in the scenario where the Municipal Solid Waste is dried but not triaged, up to 8% of the Municipal Solid Waste that is currently disposed inappropriately in Brazil could be received by cement industries for coprocessing, as long as there is technical feasibility for the substitution and transportation.

Formation of Recalcitrant Compounds during Anaerobic Digestion of Thermally Pre-Treated Sludge: A Critical Macromolecular and Structural Study.

Thermal hydrolysis, when used as pre-treatment, enhances the anaerobic digestion of sewage sludge; moreover, due to the high temperature normally applied, undesirable recalcitrant compounds via Maillard reactions may also be formed. However, although the appearance of these recalcitrant compounds is widely reported, more information on the formation, structure, and fate of these compounds is still needed. This study was focused on understanding the amount and whereabouts of such compounds during the anaerobic digestion process with thermal pre-treatment in soluble and total phase and advance in its structural identification by analyzing their infrared (IR) spectra. It was found that, even with the improved methane production and COD degradation, at 165 °C for 30 min, humic-like compounds are formed which could not be degraded at the anaerobic digestion step. These compounds account for 25% of the original sludge. Infrared spectroscopy proved to be a powerful technique, permitting their differentiation from the natural humic-like compounds. This research provides new information about the structure of melanoidins at every stage of the thermal hydrolysis pre-treatment and how they contribute to the dissolved organic nitrogen.

Membrane Distillation: Pre-Treatment Effects on Fouling Dynamics.

In the research reported in this paper, membrane distillation was employed to recover water from a concentrated saline petrochemical effluent. According to the results, the use of membrane distillation is technically feasible when pre-treatments are employed to mitigate fouling. A mathematical model was used to evaluate the fouling mechanism, showing that the deposition of particulate and precipitated material occurred in all tests; however, the fouling dynamic depends on the pre-treatment employed (filtration, or filtration associated with a pH adjustment). The deposit layer formed by particles is not cohesive, allowing its entrainment to the bulk flow. The precipitate fouling showed a minimal tendency to entrainment. Also, precipitate fouling served as a coupling agent among adjacent particles, increasing the fouling layer cohesion.

Efficiency of integrated electrooxidation and anaerobic digestion of waste activated sludge.

BACKGROUND: Most of the organic content of waste activated sludge (WAS) comprises microbial cells hard to degrade, which must be pre-treated for energy recovery by anaerobic digestion (AD). Electrooxidation pre-treatment (EOP) with boron-doped diamond (BDD) electrode have been considered a promising novel technology that increase hydrolysis rate, by the disintegrating cell walls from WAS. Although electrochemical oxidation could efficiently solubilize organic substances of macromolecules, limited reports are available on EOP of WAS for improving AD. In this endeavour, the mathematical optimization study and the energy analysis of the effects of initial total solids concentrations [TS] of WAS and current density (CD) during EOP on the methane production and removal of chemical oxygen demand (COD) and volatile solids (VS) were investigated. Because limited reports are available on EOP of WAS for improving biogas production, it is not well understood; however, it has started to attract interest of scientists and engineers. RESULTS: In the present work, the energy recovery as biogas and WAS conversion were comprehensively affected by CD and [TS], in an integrated EOP and AD system. When working with WAS at 3% of [TS] pre-treated at current density of 24.1 mA/cm2, the highest COD and VS removal were achieved, making it possible to obtain the maximum methane (CH4) production of 305 N-L/kg VS and a positive energy balance of 1.67 kWh/kg VS. Therefore, the current densities used in BDD electrode are adequate to produce the strong oxidant (hydroxyl radical, ·OH) on the electrode surface, allow the oxidation of organic compounds that favours the solubilization of particulate matter and VS from WAS. CONCLUSIONS: The improvement of VS removal and COD solubilization were due to the effects of pre-treatments, which help to break down the microbial cells for faster subsequent degradation; this allows a decomposition reaction that leads to biodegrade more compounds during AD. The balance was positive, suggesting that even without any optimization the energy used as electricity could be recovered from the increased methane production. It is worth noting that this kind of analysis have not been sufficiently studied so far. It is therefore important to understand how operational parameters can influence the pre-treatment and AD performances. The current study highlights that the mathematical optimization and energy analysis can make the whole process more convenient and feasible.

Comparison of the performance of four staging systems in determining the prognosis of breast cancer among women undergoing neoadjuvant chemotherapy.

PURPOSE: Different tumor-related factors have been proposed to assess the risk of disease progression and death in women undergoing neoadjuvant breast cancer chemotherapy. Recently, besides the classical pre-treatment clinical stage (CS) and post-treatment pathologic stage (PS), estrogen receptor status and histologic grade (CPS + EG score) and HER2 results (Neo-Bioscore) have also been added to this suite of staging systems, generating new scores. The present study aims to compare the performance of these four staging systems, namely CS, PS, CPS + EG and Neo-Bioscore, in the prognosis of breast cancer in women undergoing neoadjuvant chemotherapy. METHODS: This study comprises a retrospective cohort study of female breast cancer patients diagnosed at the Brazilian National Cancer Institute, Brazil from January 2013 to December 2015. A descriptive analysis of patient characteristics was conducted, and Kaplan-Meier curves, a Cox proportional hazard analysis and Receiver Operating Characteristic (ROC) curves were developed according to the assessed staging system scores. RESULTS: A total of 803 patients were eligible for this study. Most were under 65 years old (88.0%), presented advanced tumors (clinical stage ≥ IIB 77.1%), with positive estrogen receptor (71.2%) and negative HER2 (75.7%) results. During the follow-up, 172 patients (21.4%) evolved to death. A statistical difference (p < 0.001) was observed between 5 year disease-free survival and 5 year overall survival rates according to the PS, CPS + EG and Neo-Bioscore staging systems. CONCLUSION: The PS, CPS + EG and Neo-Bioscore staging systems were proven to be equivalent to predict the prognosis of patients undergoing neoadjuvant chemotherapy.

Potential benefits of near critical and supercritical pre-treatment of lignocellulosic biomass towards anaerobic digestion.

Vegetable crop residues, such as sugarcane bagasse (SCB), despite their limited biodegradability, are potential materials for anaerobic processes because of their low cost, high availability, and sugar content. The difficulty of biodegrading this type of material is primarily related to its chemical composition and to the complex interactions between its compounds (cellulose, hemicelluloses, and lignin). Thus, the following supercritical and near critical carbon dioxide (CO2) pre-treatments were evaluated with and without the addition of sodium hydroxide (NaOH): (i) 40°C/70 kgf·cm-2; (ii) 60°C/200 kgf·cm-2; and (iii) 80°C/200 kgf·cm-2, aiming to enhance the anaerobic biodegradability of SCB. The methanogenic production of SCB increased in all cases in which the material was pre-treated, except the case in which NaOH was used together with a high temperature. The condition using CO2 at 60°C/200 kgf·cm-2 was highlighted with a lignin removal of 8.07% and an accumulated methane production of 0.6498 ± 0.014 LN (273.15K, 1.01325 × 105 Pa), 23.4% higher than the value obtained with the untreated material. This condition also showed the highest net energy at the energy balance that was calculated for comparison with the tested conditions. The results showed that pre-treatments with near critical and supercritical fluids have the potential to reduce structural obstacles of lignocellulosic materials and to enhance their anaerobic biodegradability.

Thermochemical pretreatment and anaerobic digestion of dairy cow manure: Experimental and economic evaluation.

The aim of this study was to assess technically and economically the application thermochemical pretreatment in the anaerobic digestion of dairy cow manure. After selecting the optimum substrate to inoculum (S/I) ratio in a preliminary BMP test, the following tests compared 20 different pretreatment conditions varying temperature (100 and 37°C), exposure time (5 and 30min and 12 and 24h) and chemical doses (0.5, 2, 6 and 10% of HCl or NaOH). The highest value of maximum production rate was achieved at an S/I ratio of 0.25gVSsgVSi-1. The major improvements of the methane potential were 23.6% with 10% of NaOH at 100°C for 5min and 20.6% with 2% of HCl at 37°C. The technical-economic analysis showed that the implementation of neither thermal alkali nor thermal-acid pretreatment would be feasible and the conventional one-step anaerobic digestion outperforms both alternatives.

FIRST BRAZILIAN CONSENSUS ON MULTIMODAL TREATMENT OF COLORECTAL LIVER METASTASES. MODULE 1: PRE-TREATMENT EVALUATION / I CONSENSO BRASILEIRO DE TRATAMENTO MULTIDISCIPLINAR DE METÁSTASE HEPÁTICA COLORRETAIS. MÓDULO 1: AVALIAÇÃO PRÉ-TRATAMENTO

Background : Liver metastases of colorectal cancer are frequent and potentially fatal event in the evolution of patients with these tumors. Aim : In this module, was contextualized the clinical situations and parameterized epidemiological data and results of the various treatment modalities established. Method: Was realized deep discussion on detecting and staging metastatic colorectal cancer, as well as employment of imaging methods in the evaluation of response to instituted systemic therapy. Results : The next step was based on the definition of which patients would have their metastases considered resectable and how to expand the amount of patients elegible for modalities with curative intent. Conclusion : Were presented clinical, pathological and molecular prognostic factors, validated to be taken into account in clinical practice.

Racional : As metástases hepáticas de câncer colorretal são evento frequente e potencialmente fatal na evolução de pacientes com estas neoplasias. Objetivo : Neste módulo procurou-se contextualizar esta situação clínica, bem como parametrizar dados epidemiológicos e de resultados das diversas modalidades de tratamento estabelecidas. Método : Foi realizada discussão sobre como detectar e estadiar o câncer colorretal metastático, bem como o emprego dos métodos de imagem na avaliação de resposta ao tratamento sistêmico instituído. Resultado : Fundamentou na definição de quais pacientes teriam suas metástases consideradas ressecáveis e de como se poderia ampliar a gama de pacientes submetidos às modalidades de tratamento ditas de intuito curativo. Conclusão : Foram apresentados os fatores prognósticos clínicos, patológicos e moleculares com validação para serem levados em consideração na prática clínica.

GH11 xylanase from Emericella nidulans with low sensitivity to inhibition by ethanol and lignocellulose-derived phenolic compounds.

An endo-ß-1,4-xylanase (X22) was purified from crude extract of Emericella nidulans when cultivated on submerged fermentation using sugarcane bagasse as the carbon source. The purified protein was identified by mass spectrometry and was most active at pH and temperature intervals of 5.0-6.5 and 50-60°C, respectively. The enzyme showed half-lives of 40, 10 and 7 min at 28, 50 and 55°C, respectively, and pH 5.0. Apparent Km and Vmax values on soluble oat spelt xylan were 3.39 mg/mL and 230.8 IU/mg, respectively, while Kcat and Kcat/Km were 84.6 s(-1) and 25.0 s(-1) mg(-1) mL. Incubation with phenolic compounds showed that tannic acid and cinnamic acid had an inhibitory effect on X22 but no time-dependent deactivation. On the other hand, ferulic acid, 4-hydroxybenzoic acid, vanillin and p-coumaric acid did not show any inhibitory effect on X22 activity, although they changed X22 apparent kinetic parameters. Ethanol remarkably increased enzyme thermostability and apparent Vmax and Kcat values, even though the affinity and catalytic efficiency for xylan were lowered.

How endogenous plant cell-wall degradation mechanisms can help achieve higher efficiency in saccharification of biomass.

Cell-wall recalcitrance to hydrolysis still represents one of the major bottlenecks for second-generation bioethanol production. This occurs despite the development of pre-treatments, the prospect of new enzymes, and the production of transgenic plants with less-recalcitrant cell walls. Recalcitrance, which is the intrinsic resistance to breakdown imposed by polymer assembly, is the result of inherent limitations in its three domains. These consist of: (i) porosity, associated with a pectin matrix impairing trafficking through the wall; (ii) the glycomic code, which refers to the fine-structural emergent complexity of cell-wall polymers that are unique to cells, tissues, and species; and (iii) cellulose crystallinity, which refers to the organization in micro- and/or macrofibrils. One way to circumvent recalcitrance could be by following cell-wall hydrolysis strategies underlying plant endogenous mechanisms that are optimized to precisely modify cell walls in planta. Thus, the cell-wall degradation that occurs during fruit ripening, abscission, storage cell-wall mobilization, and aerenchyma formation are reviewed in order to highlight how plants deal with recalcitrance and which are the routes to couple prospective enzymes and cocktail designs with cell-wall features. The manipulation of key enzyme levels in planta can help achieving biologically pre-treated walls (i.e. less recalcitrant) before plants are harvested for bioethanol production. This may be helpful in decreasing the costs associated with producing bioethanol from biomass.

Methane production from marine microalgae Isochrysis galbana.

Methane production from marine microalgae Isochrysis galbana was assessed before and after mechanical and chemical pretreatments. Mechanical pretreatment resulted in a 61.7% increase in soluble Chemical Oxygen Demand. Different hydrolysis conditions were evaluated by varying temperature - T, sulfuric acid concentration - AC and biomass suspension concentration (measured as particulate COD - CODp) using an experimental design. The most significant interaction occurred between AC and T and the hydrolysis condition that showed the best result in the anaerobic digestion step was the condition at 40°C with addition of 0.2% (v/v) acid for 16h (9.27LCH4/kgVS). The low methane yields were attributed to inhibitory sodium concentrations for anaerobic digestion. Eliminating inhibitory sodium in the anaerobic digestion by biomass prewashing, there was a 71.5% increase in methane yield for biomass after acid hydrolysis, demonstrating the need for pretreatment and reduction in sodium concentration in the anaerobic digestion.

Barreira capilar construida com residuo pre-tratado mecanica e biologicamente / Capillary barrier constructed with mechanical biological treatment waste

O controle da entrada de água de chuva no interior do aterro de resíduos sólidos urbanos durante sua construção e após seu fechamento é crucial para manter o controle da geração de lixiviado. Este fator pode contribuir para a elevação de gastos com tratamento e monitoramento e para a instabilidade mecânica do aterro. Por esta razão, o sistema de cobertura final de um aterro de resíduos sólidos urbanos é decisivo ao controle da entrada de água no mesmo. Na maioria dos casos, o sistema de cobertura final é composto por solo compactado. Frequentemente, um solo adequado para a cobertura não é encontrado nos arredores do aterro; portanto, recursos têm que ser despendidos para o transporte do mesmo até o devido local. Uma alternativa seria a utilização de uma barreira capilar construída com resíduos pré-tratados mecânica e biologicamente. No entanto, o uso deste material para esta construção ainda não foi bem estudado, e as diversas variáveis envolvidas no funcionamento de uma barreira capilar construída com resíduos sólidos pré-tratados mecânica e biologicamente são desconhecidas. O objetivo deste trabalho foi analisar os parâmetros envolvidos no funcionamento de uma barreira capilar construída exclusivamente de resíduos sólidos urbanos pré-tratados mecânica e biologicamente. Observou-se que este utilizado como material de uma barreira capilar pode funcionar de maneira equivalente àquela construída com solo, sendo boa a sua capacidade de retenção da água de chuva.

The control of rainwater entry into the municipal solid waste landfill during its construction and after its closure is crucial to keep track of leachate generation. This is a factor that may contribute to the increase of costs on treatment and monitoring and to the mechanical instability of the landfill. For this reason, the final cover system of a municipal solid waste landfill is critical for controling the water entering into the landfill. In most cases, the final cover system is made of compacted soil. Often, suitable soil for landfilling is not found in its surroundings, and resources must be expended in transporting the soil to the landfill site. An alternative would be to use a capillary barrier constructed with mechanical and biologically pretreated waste. However, the use of this material to construct capillary barriers has not been studied and several variables involved in the operation of a capillary barrier constructed with municipal solid mechanical and biologically pretreated waste landfill are unknown. The objective of this study was to analyze the parameters involved in the operation of a capillary barrier built exclusively solid waste pre-treated mechanically and biologically. It was observed that the MSW MBT used as a capillary barrier material may function similarly to that constructed with soil, with a good capacity for rain water retention.

Bioconversion and saccharification of some lignocellulosic wastes by aspergillus oryzae ITCC-4857.01 for fermentable sugar production

The recent interest in bioconversion of agricultural and industrial wastes to chemical feedstock has led to extensive studies on cellulolytic enzymes produced by microorganisms. In the present study three lignocellulosic substrates viz. sugarcane bagasse, sawdust and water hyacinth were pre-treated with alkali and enzyme and their effect on bioconversion has been investigated. The ability of selected substrates for induction of cellulase enzyme by A. oryzae ITCC 4857.01 and for the potentiality of the induced enzyme to saccharify the substrates were also assessed. The maximum degree of conversion of substrate (0.415 percent) and improved specific substrate consumption (0.99 g substrate/g dry biomass) was exhibited in sugarcane bagasse after alkali treatment at 96 hrs. Both alkali-treatment and enzyme-treatment, water hyacinth was the best for cellulase induction and showed maximum endoglucanase activity of 11.42 U/ml. Reducing sugar yield ranged from 1.12 mg/ml for enzyme treated sawdust at 48 hrs to 7.53 mg/ml for alkali treated sugarcane bagasse at 96 hrs. Alkali-treated sugarcane bagasse gave the highest saccharification rate of 9.03 percent after 96 hrs. The most resistant substrate was sawdust which produced 5.92 percent saccharification by alkaline treatment. The saccharification of lignocellulosic substrates by enzyme produced by A. oryzae ITCC 4857.01 indicates the enzymes specificity towards the substrates. The use of such enzyme in lingo-cellulose hydrolysis will lead to efficient conversion of cellulose materials to other important products.

Concepção e avaliação de uma unidade de peneiramento forçado para a redução do tamanho de partículas presentes no esgoto bruto doméstico / Design and evaluation of a forced sieving unit (FSU) for the reduction of the particle size present in raw domestic sewage

Este trabalho teve como objetivo a concepção e o teste de uma unidade de peneiramento forçado, utilizada para o pré-tratamento do esgoto bruto com vistas à redução do tamanho de partículas de matéria orgânica. A unidade de peneiramento forçado (UPF) era constituída de uma peneira metálica (abertura de malha de 1 mm) inserida na tubulação de recalque através da qual o esgoto efluente era bombeado. O peneiramento forçado resultou em maior concentração de partículas com diâmetro entre 1,8 e 30 µm, sem que houvesse retenção de material particulado. Todavia, a UPF não influenciou na redução/retenção de DQO TOTAL do esgoto bruto.

The work focused on the conception and test of a forced sieving unit, used for the pre-treatment of raw sewage aiming at the reduction of organic matter particle size. The pre-treatment unit involved the use of a metallic sieve (1 mm cut-off) assembled inside the pipeline through which the influent sewage was pumped. The results indicated that the forced sieving resulted in a higher concentration of particles with range diameter between 1.8 and 30 µm, without the retention of particulate material. However, the forced sieving unit did not influence the reduction/retention of COD TOTAL of the raw sewage.

Influência da alteração da distribuição do tamanho de partículas no desempenho de reator UASB tratando esgoto doméstico / Influence of alteration of particle size distribution on the performance of UASB reactor treating domestic wastewater

O trabalho consistiu na avaliação do desempenho de um reator UASB tratando esgoto doméstico pré-tratado em uma unidade de peneiramento forçado (UPF), resultando na redução do tamanho médio de partículas da matéria orgânica afluente. Os experimentos foram conduzidos em dois reatores UASB em escala de demonstração idênticos, sendo um precedido da UPF e o outro utilizado como controle. Os resultados apontaram que, após a adaptação da biomassa às novas condições cinéticas e hidráulicas (reduzido TDH seguido de alta carga biológica aplicada), a redução do tamanho das partículas, na faixa de 1,8 a 30 µm, resultou na seleção de uma comunidade microbiana de maior atividade (atividade metanogênica específica de 0,072 g DQO/g STV.dia, quatro vezes superior à do reator controle). Isso propiciou um melhor desempenho do reator UASB precedido da UPF, o qual apresentou uma maior eficiência de remoção de DQO TOTAL (65 versus 54 por cento no reator controle), e um efluente com menor DQO PARTICULADA (48 versus 74 mg/L no reator controle).

The work aimed at evaluating the performance of an UASB reactor treating domestic sewage pre-treated in a Forced Sieving Unit (FSU) which resulted in size reduction of the influent organic matter particles. The experiments were carried out in two identical demonstration-scale UASB reactors, one with a FSU upstream and the other used as control reactor. The results showed that, after biomass adaptation to new kinetic and hydraulic conditions (low hydraulic detention time followed by high sludge load), the particles size reduction, in the range of 1.8 to 30 µm, resulted in a microbial community selection with higher activity (specific methanogenic activity of 0.072 g COD/g VTS.day four times higher than in the control reactor). This enabled a better performance of the UASB reactor with the FSU, which showed a higher removal efficiency in terms of COD TOTAL (65 versus 54 percent in the control reactor), and an effluent with lower concentration of COD PARTICULATE (48 versus 74 mg/L in the control reactor).

Influência da redução do tamanho de partículas na taxa de hidrólise de esgoto bruto doméstico / Influence of particle size reduction on the hydrolisis rate of domestic raw sewage

O trabalho teve por objetivo avaliar as alterações nas taxas de conversão do material particulado do esgoto bruto doméstico, após passar por uma unidade de pré-tratamento que utilizou o peneiramento forçado através de malhas metálicas com aberturas de 1,0 e 0,5 mm como estratégia para reduzir o tamanho médio das partículas. Os resultados mostraram que o peneiramento forçado e a redução do tamanho das partículas presentes no esgoto bruto não foram suficientes para aumentar as taxas de hidrólise do material particulado, uma vez que as constantes de hidrólise para o esgoto bruto e peneirado, estimadas pela relação cinética de primeira ordem, analisando o parâmetro sólidos suspensos voláteis, apresentaram valores semelhantes, da ordem de 0,0492 ± 0,0146 d-1, para o esgoto bruto, e de 0,0472 ± 0,0079 d-1 e 0,0470 ± 0,0117 d-1, para o esgoto bruto peneirado nas malhas de 1 e 0,5 mm, respectivamente.

The work aimed at assessing the changes in the particulate material conversion rates of domestic raw sewage, after passing through a pre-treatment unit that used the forced sieving through metallic sieves with apertures of 1.0 and 0.5 mm as strategy to reduce particles' size. The results indicated that the forced sieving and the reduction of particle size were not enough to increase the particulate material hydrolysis rates, since the hydrolysis constants for the raw and sieved sewage, estimated by the first order relation kinetics, analyzing the volatile suspended solids parameter, had similar values, in order of 0.0492 ± 0.0147 d-1, for the raw sewage, and of 0.0472 ± 0.0079 d-1 and 0.0470 ± 0.00117 d-1, for the raw sewage sieved in metallic sieves with apertures of 1.0 and 0.5 mm, respectively.

Biosorption of hexavalent chromium using tamarind (Tamarindus indica) fruit shell-a comparative study

The adsorption of chromium (VI) ions from aqueous solutions has been investigated on crude tamarind fruit shell, HCl treated and Oxalic acid treated shells at room temperatures. The biosorbents are characterized by FT-IR, EDXRF and porosimetry. The biosorption experiments are conducted through batch system. The influence of different experimental parameters such as pH, effect of initial metal ion concentration and effect of dosage of adsorbent on biosorption are evaluated. The adsorption followed first order kinetics. The data are fitted well to Langmuir and Freundlich isotherm models. A comparison is drawn on the extent of biosorption between untreated and treated forms of the tamarind shells. Due to their outstanding adsorption capacities, tamarind shells are excellent sorbents for the removal of chromium ions.