Treatment of landfill leachate: Removal of ammonia by struvite formation

This paper presents a study of ammoniacal nitrogen removal by chemical precipitation resulting in the formation of ammonium and magnesium phosphat (MgNH4PO4·6H2O), known as struvite, from the leachate in the Delta A landfill, located in the city of Campinas, São Paulo, Brazil. After the addition of a magnesium source (MgCl2·6H2O), and phosphorus  (Na2HPO4·12H2O), ammoniacal nitrogen was precipitated as highly insoluble salt. The removal of ammoniacal nitrogen from the leachate exceeded 85% when the reaction was performed at an initial pH of 10.0. The highest  efficiencies were achieved when the molar ratio between the ions involved in the reaction, i.e., Mg2+:PO43-:NH4+, was 1.2:1.0:1.0, respectively.Keywords: landfill, leachate, ammonia, nitrogen remova

The Impact of Enzymatic Hydrolysis of Sewage Sludge as a Pre-treatment for Dark Fermentation

For many years, sewage sludge has been processed for methane production in anaerobic digestion reactors at wastewater treatment plants around the world. Sewage sludge is produced in large quantities and is rich in biodegradable organic materials, from which sugars (e.g., glucose) can be produced, recovered and used as a substrate to support hydrogen production through the Dark Fermentation (DF) process. DF is one of several methods used for bio-hydrogen production, whereby fermentative bacteria are used to hydrolyse organic substrates to produce hydrogen gas. Carbohydrates (sugars) is one of the main fermentable substrates for hydrogen production, and they are considered the most favourable substrate for fermentative bacteria (e.g., Clostridium bacteria). Although sewage sludge is rich in organic materials, still the complexity of its structure and low carbon/nitrogen ratio limits the bio-hydrogen production via DF processes. Therefore, this paper addresses the impact of Enzymatic Hydrolysis (EH) as a pre-treatment of sewage sludge on enhancing the biodegradability and glucose content in sewage sludge. The result shows that using the EH process as pre-treatment for sewage sludge, enhanced the glucose content in sewage sludge and converted some of the macro sewage flocs to easy digestible micro flocs (glucose). Therefore, the substrate being more favourable and easier to digest by bacteria in the DF reactor, enhanced the production of hydrogen and VFAs. More research needs to be done to find the optimum enzyme dosage, initial substrate concentration and operation temperature (especially when the enzyme is used inside the DF reactor)

Influence of acute pancreatitis on the in vitro responsiveness of rat mesenteric and pulmonary arteries

<p>Abstract</p> <p>Background</p> <p>Acute pancreatitis is an inflammatory disease characterized by local tissue injury and systemic inflammatory response leading to massive nitric oxide (NO) production and haemodynamic disturbances. Therefore, the aim of this work was to evaluate the vascular reactivity of pulmonary and mesenteric artery rings from rats submitted to experimental pancreatitis.</p> <p>Male Wistar rats were divided into three groups: saline (SAL); tauracholate (TAU) and phospholipase A₂(PLA₂). Pancreatitis was induced by administration of TAU or PLA₂from <it>Naja mocambique mocambique </it>into the common bile duct of rats, and after 4 h of duct injection the animals were sacrificed. Concentration-response curves to acetylcholine (ACh), sodium nitroprusside (SNP) and phenylephrine (PHE) in isolated mesenteric and pulmonary arteries were obtained. Potency (pEC₅₀) and maximal responses (E_MAX) were determined. Blood samples were collected for biochemical analysis.</p> <p>Results</p> <p>In mesenteric rings, the potency for ACh was significantly decreased from animals treated with TAU (about 4.2-fold) or PLA₂(about 6.9-fold) compared to saline group without changes in the maximal responses. Neither pEC₅₀nor E_MAXvalues for Ach were altered in pulmonary rings in any group. Similarly, the pEC₅₀and the E_MAXvalues for SNP were not changed in both preparations in any group. The potency for PHE was significantly decreased in rat mesenteric and pulmonary rings from TAU group compared to SAL group (about 2.2- and 2.69-fold, for mesenteric and pulmonary rings, respectively). No changes were seen in the E_MAXfor PHE. The nitrite/nitrate (NO_x^-) levels were markedly increased in animals submitted to acute pancreatitis as compared to SAL group, approximately 76 and 68% in TAU and PLA₂protocol, respectively.</p> <p>Conclusion</p> <p>Acute pancreatitis provoked deleterious effects in endothelium-dependent relaxing response for ACh in mesenteric rings that were strongly associated with high plasma NO_x^-levels as consequence of intense inflammatory responses. Furthermore, the subsensitivity of contractile response to PHE in both mesenteric and pulmonary rings might be due to the complications of this pathological condition in the early stage of pancreatitis.</p

Assessing Different Inoculum Treatments for Improved Production of Hydrogen through Dark Fermentation

Hydrogen gas (H2) is an energy carrier that does not generate carbon dioxide emissions during combustion, but several processes in use for its production demand high energy inputs associated with fossil fuels and greenhouse emissions. Biological processes, such as dark fermentation (DF), have the potential to remove the dependency on fossil fuels in H2 production. DF is a process that encourages fermentative bacteria to ferment organic substrates to produce H2 as a truly clean energy carrier, but its success depends on removing the presence of competing H2−consuming microorganisms in the inoculum consortia. This paper addresses a strategy to enhance H2 production from different types of substrates by testing inoculum pre-treatment processes to inactivate H2−consuming bacteria, including acid-shock (pH 3), basic-shock (pH 10) and heat-shock (115 °C) methods. Digestate from anaerobic digesters processing sewage sludge was used to produce pre-treated inocula, which were subsequently tested in a batch bio-H2 potential (BHP) test using glucose as a substrate. The results show that heat-shock pre-treatment was the best method, reporting a H2 yield of 191.8 mL-H2/gVS added (the untreated inoculum reported 170.91 mL-H2/gVS added). Glucose conversion data show a high concentration of butyric acid in both treated and untreated inocula during BHP tests, which indicate that the butyrate pathway for H2 production was dominant; shifting this to the formate route could further enhance net H2 production. A standardised inoculum-conditioning method can help to consistently assess the biohydrogen potential of suitable feedstock for DF and maximise H2 yields

Elastic Scattering and Total Reaction Cross Section for the 6He + 27Al System

The elastic scattering of the radioactive halo nucleus 6He on 27Al target was measured at four energies close to the Coulomb barrier using the RIBRAS (Radioactive Ion Beams in Brazil) facility. The Sao Paulo Potential(SPP) was used and its diffuseness and imaginary strength were adjusted to fit the elastic scattering angular distributions. Reaction cross-sections were extracted from the optical model fits. The reduced reaction cross-sections of 6He on 27Al are similar to those for stable, weakly bound projectiles as {6,7}Li, 9Be and larger than stable, tightly bound projectile as 16O on 27Al.Comment: 7 pages, 1 table, 3 figure

MFV Reductions of MSSM Parameter Space

The 100+ free parameters of the minimal supersymmetric standard model (MSSM) make it computationally difficult to compare systematically with data, motivating the study of specific parameter reductions such as the cMSSM and pMSSM. Here we instead study the reductions of parameter space implied by using minimal flavour violation (MFV) to organise the R-parity conserving MSSM, with a view towards systematically building in constraints on flavour-violating physics. Within this framework the space of parameters is reduced by expanding soft supersymmetry-breaking terms in powers of the Cabibbo angle, leading to a 24-, 30- or 42-parameter framework (which we call MSSM-24, MSSM-30, and MSSM-42 respectively), depending on the order kept in the expansion. We provide a Bayesian global fit to data of the MSSM-30 parameter set to show that this is manageable with current tools. We compare the MFV reductions to the 19-parameter pMSSM choice and show that the pMSSM is not contained as a subset. The MSSM-30 analysis favours a relatively lighter TeV-scale pseudoscalar Higgs boson and $\tan \beta \sim 10$ with multi-TeV sparticles.Comment: 2nd version, minor comments and references added, accepted for publication in JHE

Vitamin D and antimicrobial peptide levels in patients with atopic dermatitis and atopic dermatitis complicated by eczema herpeticum: A pilot study.

In this study, Vitamin D supplementation results in improved clinical severity of atopic dermatitis and increased skin surface LL-37 levels, analyzed by a novel, non-invasive method. Vitamin D supplementation could be a therapeutic option in AD

Association between Vitamin Intake during Pregnancy and Risk of Small for Gestational Age

Pregnancy increases the requirements of certain nutrients, such as vitamins, to provide nutrition for the newborn. The aim was to analyze the association between dietary intake of vitamins during pregnancy and risk of having a small for gestational age (SGA) newborn. A matched case-control study was conducted (518 cases and 518 controls of pregnant women) in Spain. Dietary vitamin intake during pregnancy was assessed using a validated food frequency questionnaire, categorized into quintiles. Odds ratios (ORs) and their 95% confidence intervals (CI) were estimated with conditional regression logistic models. A protective association was observed between maternal dietary intake of vitamins A and D and SGA. For vitamin B3 and B6, the observed protective effect was maintained after adjusting for potential confounding factors. For vitamin B9, we found only an effect in quintiles 3 and 4 (OR = 0.64; 95% CI, 0.41–1.00; OR = 0.58; 95% CI, 0.37–0.91). Protective effect for vitamin B12 was observed in 4th and 5th quintiles (OR = 0.61; 95% CI, 0.39–0.95; OR = 0.68; 95% CI, 0.43–1.04). No associations were detected between dietary intake of vitamins B2, E and C intake and SGA. Our results suggest a positive association between dietary vitamin intake during pregnancy and the weight of the newborn, although more studies are necessary and there could be a ceiling effect for higher intakes of some vitamins cannot be discarded.This work was supported by a grant from the National Institute of Health Carlos III (PI11/02199)