Performance of UASB reactors in two stages under different HRT and OLR treating residual waters of swine farming

In this study it was evaluated the effects of hydraulic retention time (HRT) and Organic Loading Rate (OLR) on the performance of UASB (Upflow Anaerobic Sludge Blanket) reactors in two stages treating residual waters of swine farming. The system consisted of two UASB reactors in pilot scale, installed in series, with volumes of 908 and 188 L, for the first and second stages (R1 and R2), respectively. The HRT applied in the system of anaerobic treatment in two stages (R1 + R2) was of 19.3, 29.0 and 57.9 h. The OLR applied in the R1 ranged from 5.5 to 40.1 kg CODtotal (m³ d)-1. The average removal efficiencies of chemical oxygen demand (COD) and total suspended solids (TSS) ranged, respectively, from 66.3 to 88.2% and 62.5 to 89.3% in the R1, and from 85.5 to 95.5% and 76.4 to 96.1% in the system (R1 + R2). The volumetric production of methane in the system (R1 + R2) ranged from 0.295 to 0.721 m³CH4 (m³ reactor d)-1. It was found that the OLR applied were not limiting to obtain high efficiencies of CODtotal and TSS removal and methane production. The inclusion of the UASB reactor in the second stage contributed to increase the efficiencies of CODtotal and TSS removal, especially, when the treatment system was submitted to the lowest HRT and the highest OLR.

Performance of UASB reactors in two stages followed by post-treatment with activated sludge in wastewater batch of wet-processed coffee

In this study it was evaluated the efficiency of the treatment of wet-processed coffee wastewater in upflow anaerobic sludge blanket (UASB) reactors in two stages, in bench scale, followed by post-treatment with activated sludge in batch. The first UASB reactor was submitted to an hydraulic retention time (HRT) of 6.2 d and organic loading rates (OLR) of 2.3 and 4.5g CODtotal (L d)-1, and the second UASB reactor to HRT of 3.1 d with OLR of 0.4 and 1.4g CODtotal (L d)-1. The average values of the affluent CODtotal increased from 13,891 to 27,926mg L-1 and the average efficiencies of removal of the CODtotal decreased from 95 to 91%, respectively, in the UASB reactors in two stages. The volumetric methane production increased from 0.274 to 0.323L CH4 (L reactor d)-1 with increment in the OLR. The average concentrations of total phenols in the affluent were of 48 and 163mg L-1, and the removal efficiencies in the UASB reactors in two stages of 92 and 90%, respectively, and increased to 97% with post-treatment. The average values of the removal efficiencies of total nitrogen and phosphorus were of 57 to 80% and 44 to 60%, respectively, in the UASB reactors in two stages and increased to 91 and 84% with the post-treatment.

Corn productivity in function of surface application of lime in differents management systems and cultural preparation

The evaluation of technologies employed at the agricultural production system such as crop rotation and soil preparation, both associated with crop-livestock integration, is crucial. Therefore, the aim of the present study was to evaluate the incorporation of lime for three no-tillage systems and cultural managements in system of crop-livestock integration, with emphasis on corn grain yield. The experiment was conducted from January 2003 to April 2005 at Selvíria city, MS, in Dystroferric Red Latosol, clay texture. The experimental design was randomized blocks with split plots consisted of three main treatments, aimed the soil physics conditioning and the incorporation of lime: PD - No-no-tillage; CM - minimum no-tillage, and PC - conventional no-tillage; and of two secondary treatments related to the management: rotation and crop succession, with four replications. Data on agronomic traits of maize were analyzed: plant height, stem diameter, height of the first spike insertion, 100 grains weight and grain yield. The results showed that the maize produced under the system of crop-livestock integration is quite feasible, showing that grain yields are comparable to averages in the region and the different soil physical conditioning and incorporation of lime did not influence the corn yield as well as the cultural managements, rotation and succession, did not affect the maize crop behavior after two years of cultivation.

Disentangling the effects of insomnia and night work on cardiovascular diseases: a study in nursing professionals

Cardiovascular diseases (CVDs) are known to be associated with poor sleep quality in general populations, but they have not been consistently associated with specific work schedules. Studies of CVD generally do not simultaneously consider sleep and work schedules, but that approach could help to disentangle their effects. We investigated the association between insomnia and a self-reported physician diagnosis of CVD in day and night workers, considering all sleep episodes during nocturnal and diurnal sleep. A cross-sectional study was conducted in 1307 female nursing professionals from 3 public hospitals, using baseline data from the “Health and Work in Nursing - a Cohort Study.” Participants were divided into two groups: i) day workers with no previous experience in night shifts (n=281) and whose data on insomnia were related to nocturnal sleep and ii) those who worked exclusively at night (n=340) and had data on both nocturnal and diurnal sleep episodes, as they often sleep at daytime. Multiple logistic regression analysis was performed. Among day workers, insomnia complaints increased the odds of CVD 2.79-fold (95% CI=1.01-6.71) compared with workers who had no complaints. Among night workers, reports of insomnia during both nocturnal and diurnal sleep increased the odds of reported CVD 3.07-fold (95% CI=1.30-7.24). Workers with insomnia had similar probabilities of reporting CVD regardless of their work schedule, suggesting a relationship to insomnia and not to night work per se. The results also highlighted the importance of including evaluation of all sleep episodes (diurnal plus nocturnal sleep) for night workers.

A new cultural cleavage in post-modern society

The attitudes towards gender and homosexuality tend to be linked at the micro level (individuals), which explains the political saliency of this newly emerging cleavage. At the macro level (country), the main finding is that the value orientations towards gender and homosexuality are strongly embedded in the basic cultural or civilisation differences among countries. As developing countries modernise and enter post-modernity, they will also experience the gender cleavage, especially when they adhere to an individualistic culture. Cultural cleavages in the post-modern society, whether in rich or developing countries, can only be properly researched by the survey method. It opens up a large area for both micro and macro analyses in the social sciences.