Impact of the hydraulic loading rate on the hydrodynamic characteristics of an anaerobic fixed bed reactor treating cattle slaughterhouse wastewater

The hydrodynamic behavior of an anaerobic fixed bed reactor (AFBR) was evaluated in the treatment of cattle slaughterhouse wastewater. The AFBR was operated at hydraulic retention time (HRT) of 14, 11 and 8 h. Stimulus-response assays were carried out with Eosin Y and the experimental data were adjusted to the single-parameter theoretical models of dispersion and N-continuous stirred tank reactors in series (N-CSTR). The experimental results of the residence time distribution curves showed that at lower flow rate, the reactor showed plug flow behavior with correlation coefficient (r) of 0.88 and number of dispersion of 0.2 for high dispersion (HD). However, at higher and intermediate flow rates, the AFBR behave as a complete mixture flow, (r) of 0.94 and 0.96, respectively. Residence time distribution curves in the AFBR showed a good approximation of the complete mixing model at hydraulic residence time of 11 and 8 h, with 5 and 2 N-CSTR reactors in series, respectively. The volume of dead zones corresponding to 43.0, 37.4 and 11.2% of the volume of the reactor for HRT of 14, 11 and 8 h, respectively, was noted, and hydraulic short circuiting were not confirmedinfo:eu-repo/semantics/publishedVersio

Influence of recirculation rate on the performance of a combined anaerobic-aerobic reactor applied to the removal of carbon and nitrogen from poultry slaughterhouse wastewater

The objective of this study was to evaluate a combined anaerobic-aerobic upflow fixed-bed reactor with liquid phase recirculation for the removal of nitrogen and organic matter from poultry slaughterhouse wastewater. The reactor performance was evaluated with a hydraulic retention time (HRT) of 11 h and three different recirculation rates (R=0.5; 1 and 2). The highest nitrogen removal efficiency value was obtained with an HRT of 11 h (6.8 h in the anaerobic zone and 4.2 h in the aerobic zone) and a recirculation rate of 2. In this condition, the total nitrogen removal efficiency was 69%,  with effluent concentrations of 6 mg NH4+ L-1 and 12 mg NO3- L-1. For all tested conditions, there was good chemical oxygen demand (COD) removal, with efficiency above 95%. The effect of dilution and the favoring of mass transfer caused by the increase in the recirculation rate positively influenced reactor performance.Key words: Anaerobic degradation, nitrification, denitrification, combined reactor

Loss of sediments and nutrients through runoff steepness and soybean variety on portuguesa river basin

There is a great concern in areas with intensive agricultural use, such as physical structure of soil, management system, pesticides application schedule and others. Those practices are associated with environmental problems that indirectly affect the life quality as runoff and other nutrients that are carried through it. This trial studied the loss of sediments, phosphorus and total nitrogen through runoff during the cycle of soybean crop, 2007/2008, in a tillage area on  Portuguesa  river basin, Paraná state, Paraná. The experimental design had sixteen plots with four treatments and four replications, two steepness and a green cover. The treatments were represented by T1 (conventional soybean steepness 10 %) and T4 (transgenic soybean steepness > 10 %). During the trial installation, the authors respected the steepness direction. There were eight occurrences of rainfall during the crop cycle. But, the runoff occurred only during the four first ones. The results showed that concentrations varied a lot because of the variability of drained volumes. The behavior of total nitrogen as a parameter got a good correlation with the drained volume. The parameter phosphorus obtained several concentrations despite the drained volume. Volatile solids concentrations were higher than the fixed solids ones. There was no significant effect (p ≤ 0.05) of green cover concerning the obtained results, as well as steepness

Primeiro registro de melanismo no criticamente ameaçado gato-pampeano (Leopardus munoai), uma espécie endêmica das áreas abertas do Pampa

We report the first record of a melanistic individual of the critically endangered Pampa cat (Leopardus munoai), from July 8th, 2021, at 10:45 am (coordinates 30.096288° S; 54.941139° W) in the area of the Brazilian army, known as Campo de Instrução Barão de São Borja (CIBSB), popularly known as Saicã.Este trabalho reporta o primeiro registro de melanismo do criticamente ameaçado de extinção gato-pampeano (Leopardus munoai), realizado em 8 de julho de 2021, às 10:45 da manhã. O registro foi obtido nas coordenadas 30.096288° S; 54.941139° W na área do exército brasileiro Campo de Instrução Barão de São Borja (CIBSB), popularmente conhecida como Saicã

Cassava Wastewater Treatment in Fixed-Bed Reactors: Organic Matter Removal and Biogas Production

The process of cassava starch extraction is associated with the generation of a large volume of liquid wastes from root washing and starch extraction (5 to 7 L.kg−1root). In this context, the aim of this study was to evaluate the treatment of cassava starch wastewater in a horizontal anaerobic fixed bed reactor to the removal of organic matter and generation of biogas. For this purpose, two fixed bed reactors filled with different types of support materials were used: bamboo rings (R1) and flexible PVC rings (R2). The reactors were constructed in polyvinyl chloride (PVC) with 90 cm length and 15 cm diameter. To evaluate the reactors were carried out 13 assays (A1 to A13) with increases in the organic loading rate (OLR, 1.7 to 15.0 g.L−1.d−1) and a decrease in the hydraulic retention time (HRT, 4.0 to 0.8 days). Biogas production followed a similar pattern in both reactors. The highest biogas productions of 1.4 L.L−1.d−1 (R1) and 1.0 L.L−1.d−1 (R2) were verified in the assay A6 in which were applied highest influent concentration (15.1g.L−1), intermediates OLR (5.6 g.L−1.d−1) and HRT (2.7 d). The chemical oxygen demand (COD) removal increased with the OLR increase resulting in COD removal values of up to 99%. Total solids removal efficiencies of 86.2 and 85.5% were achieved in R1 and R2, respectively. In both reactors, the contact surface of bamboo (132 m2.m−3) and PVC (191 m2.m−3) supported biomass attachment even in the highest OLR (15 g.L−1.d−1) and low HRT (0.8 d). Both support material provided conditions to the reactors resist the variations in operating conditions and reestablish the equilibrium after possible hydraulic and organic shocks load, constituting a robust system for the treatment of cassava starch wastewater. In these conditions the COD and solids removal remained satisfactory. After a 450-days reactor running, no changes were observed in the composition and structure of the support material, indicating that bamboo and PVC are possible cheap and efficient alternatives for biomass immobilization

Experimental and computational studies of the interactions between carbon nanotubes and ionic liquids used for detection of acetaminophen

The interactions between multi-walled carbon nanotubes and different amounts of an ionic liquid (IL), as well asthe interactions between this system (used as electrochemical sensor) and acetaminophen (ACOP), were in-vestigated through both experimental and theoretical methodologies. Experiments indicated that there is anoptimal concentration of ionic liquid for ACOP detection. A host of techniques and model systems were em-ployed to investigate the adsorption and oxidation processes. To investigate the source of the increased elec-trochemical current in the presence of an IL, we computed the adsorption energy values of ACOP in the nanotube–IL system via Monte Carlo simulations and Density Functional Theory (DFT). DFT allowed us to explore thechanges in adsorption energy due to oxidation. Our theoretical results support the experimentalfindings thatmoderate amounts of IL modulates ACOP/ACOP+adsorption, pointing to a cooperative effect that tends to wanewith increasing amounts of IL pairs. We observed that the IL favors desorption of the oxidized species andfacilitates charge transfer from the ACOP to the nanotube. Therefore, our studies point towards multifactorialeffects with clear physical basis that modulates binding leading to an optimal ratio to promote ACOP detectionThe authors wish to thank the Brazilian research funding institu-tions Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq) and Fundação de Amparo à Pesquisa do Estado de São Paulo(FAPESP) for theirfinancial support (CNPq proc. 400223/2014-7,303596/2014-7, 306177/2016-1, 302801/2014-6, 154089/2016-8,573925/2008-9 and 573548/2008-0; FAPESP 2017/23416-9) andCAPES (Funcap–2133/2012/proc. 23038.007973/2012-90),PRONEM/FUNCAP/CNPq (PNE-0112-00048.01.00/16), PRONEX/FUNCAP (proc. PR2-0101-00030.01.00/15). This study wasfinanced inpart by the Coordenação de Aperfeiçoamento de Pessoal de NívelSuperior–Brasil (CAPES)–Finance Code 00. Camila P. Sousa thanksCAPES- PNPD for her grantinfo:eu-repo/semantics/publishedVersio

Measurement of the ratio of branching fractions BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma)

The ratio of branching fractions of the radiative B decays B0 -> K*0 gamma and Bs0 -> phi gamma has been measured using 0.37 fb-1 of pp collisions at a centre of mass energy of sqrt(s) = 7 TeV, collected by the LHCb experiment. The value obtained is BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) = 1.12 +/- 0.08 ^{+0.06}_{-0.04} ^{+0.09}_{-0.08}, where the first uncertainty is statistical, the second systematic and the third is associated to the ratio of fragmentation fractions fs/fd. Using the world average for BR(B0 -> K*0 gamma) = (4.33 +/- 0.15) x 10^{-5}, the branching fraction BR(Bs0 -> phi gamma) is measured to be (3.9 +/- 0.5) x 10^{-5}, which is the most precise measurement to date.Comment: 15 pages, 1 figure, 2 table

Measurement of the CKM angle γ from a combination of B±→Dh± analyses

A combination of three LHCb measurements of the CKM angle γ is presented. The decays B±→D K± and B±→Dπ± are used, where D denotes an admixture of D0 and D0 mesons, decaying into K+K−, π+π−, K±π∓, K±π∓π±π∓, K0Sπ+π−, or K0S K+K− final states. All measurements use a dataset corresponding to 1.0 fb−1 of integrated luminosity. Combining results from B±→D K± decays alone a best-fit value of γ =72.0◦ is found, and confidence intervals are set γ ∈ [56.4,86.7]◦ at 68% CL, γ ∈ [42.6,99.6]◦ at 95% CL. The best-fit value of γ found from a combination of results from B±→Dπ± decays alone, is γ =18.9◦, and the confidence intervals γ ∈ [7.4,99.2]◦ ∪ [167.9,176.4]◦ at 68% CL are set, without constraint at 95% CL. The combination of results from B± → D K± and B± → Dπ± decays gives a best-fit value of γ =72.6◦ and the confidence intervals γ ∈ [55.4,82.3]◦ at 68% CL, γ ∈ [40.2,92.7]◦ at 95% CL are set. All values are expressed modulo 180◦, and are obtained taking into account the effect of D0–D0 mixing

Differential branching fraction and angular analysis of the decay B0→K∗0μ+μ−

The angular distribution and differential branching fraction of the decay B 0→ K ∗0 μ + μ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions