Application of anaerobic granular sludge for competitive biosorption of methylene blue and Pb(II): Fluorescence and response surface methodology

© 2015 Elsevier Ltd. This study assessed the biosorption of anaerobic granular sludge (AGS) and its capacity as a biosorbent to remove Pb(II) and methylene blue (MB) from multi-components aqueous solution. It emerged that the biosorption data fitted well to the pseudo-second-order and Langmuir adsorption isotherm models in both single and binary systems. In competitive biosorption systems, Pb(II) and MB will suppress each other's biosorption capacity. Spectroscopic analysis, including Fourier transform infrared spectroscopy (FTIR) and fluorescence spectroscopy were integrated to explain this interaction. Hydroxyl and amine groups in AGS were the key functional groups for sorption. Three-dimensional excitation-emission matrix (3D-EEM) implied that two main protein-like substances were identified and quenched when Pb(II) or MB were present. Response surface methodology (RSM) confirmed that the removal efficiency of Pb(II) and MB reached its peak when the concentration ratios of Pb(II) and MB achieved a constant value of 1

A Fluorescence Approach to Assess the Production of Soluble Microbial Products from Aerobic Granular Sludge under the Stress of 2,4-Dichlorophenol

In this study, a fluorescence approach was used to evaluate the production of soluble microbial products (SMP) in aerobic granular sludge system under the stress of 2,4-dichlorophenol (2,4-DCP). A combined use of three-dimension excitation emission matrix fluorescence spectroscopy (3D-EEM), Parallel factor analysis (PARAFAC), synchronous fluorescence and two-dimensional correlation spectroscopy (2D-COS) were explored to respect the SMP formation in the exposure of different doses of 2,4-DCP. Data implied that the presence of 2,4-DCP had an obvious inhibition on biological nitrogen removal. According to EEM-PARAFAC, two fluorescent components were derived and represented to the presence of fulvic-like substances and humic-like substances in Component 1 and protein-like substances in Component 2. It was found from synchronous fluorescence that protein-like peak presented slightly higher intensity than that of fulvic-like peak. 2D-COS further revealed that fluorescence change took place sequentially in the following order: protein-like fraction > fulvic-like fraction. The obtained results could provide a potential application of fluorescence spectra in the released SMP assessment in the exposure of toxic compound during wastewater treatment

Fabrication of hyperbranched polyamine functionalized graphene for high-efficiency removal of Pb(II) and methylene blue

© 2015 Elsevier B.V. Multifunctional hyperbranched polyamine modified graphene oxide (HPA-GO) was successfully prepared and characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), zeta potential and scanning electron microscope (SEM) analyses. HPA-GO exhibited excellent adsorption performance for the removal of a heavy metal (Pb(II)) and a dye (methylene blue (MB)). The equilibrium adsorption capacity was 819.7 mg g-1 for Pb(II) and 740.7 mg g-1 for MB under the optimal conditions. The pseudo-second order equation and the Langmuir model exhibited good correlation with the adsorption kinetic and isotherm data, respectively, for these two pollutants. The thermodynamic results (ΔG0, ΔS>0) implied that the adsorption process of Pb(II) and MB was feasible, endothermic and spontaneous in nature. A possible adsorption mechanism has been proposed where chelation and electrostatic attraction dominated the adsorption of Pb(II) and π-π stacking interactions and electrostatic attraction dominated the adsorption of MB. In addition, the excellent reproducibility endowed HPA-GO with the potential for application in water treatment

Study of psi(2S) decays to X J/psi

Using J/psi -> mu^+ mu^- decays from a sample of approximately 4 million psi(2S) events collected with the BESI detector, the branching fractions of psi(2S) -> eta J/psi, pi^0 pi^0 J/psi, and anything J/psi normalized to that of psi(2S) -> pi^+ pi^- J/psi are measured. The results are B(psi(2S) -> eta J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 0.098 \pm 0.005 \pm 0.010, B(psi(2S) -> pi^0 pi^0 J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 0.570 \pm 0.009 \pm 0.026, and B(psi(2S) -> anything J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 1.867 \pm 0.026 \pm 0.055.Comment: 13 pages, 8 figure

First observation of psi(2S)-->K_S K_L

The decay psi(2S)-->K_S K_L is observed for the first time using psi(2S) data collected with the Beijing Spectrometer (BESII) at the Beijing Electron Positron Collider (BEPC); the branching ratio is determined to be B(psi(2S)-->K_S K_L) = (5.24\pm 0.47 \pm 0.48)\times 10^{-5}. Compared with J/psi-->K_S K_L, the psi(2S) branching ratio is enhanced relative to the prediction of the perturbative QCD ``12%'' rule. The result, together with the branching ratios of psi(2S) decays to other pseudoscalar meson pairs (\pi^+\pi^- and K^+K^-), is used to investigate the relative phase between the three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.Comment: 5 pages, 4 figures, 2 tables, submitted to Phys. Rev. Let

Diagnostic Accuracy of Bone Turnover Markers and Bone Histology in Patients With CKD Treated by Dialysis

BACKGROUND: The management of chronic kidney disease-mineral and bone disorder requires the assessment of bone turnover, which most often is based on parathyroid hormone (PTH) concentration, the utility of which remains controversial. STUDY DESIGN: Cross-sectional retrospective diagnostic test study. SETTING & PARTICIPANTS: 492 dialysis patients from Brazil, Portugal, Turkey, and Venezuela with prior bone biopsy and stored (-20 °C) serum. INDEX TESTS: Samples were analyzed for PTH (intact [iPTH] and whole PTH), bone-specific alkaline phosphatase (bALP), and amino-terminal propeptide of type 1 procollagen (P1NP). REFERENCE TEST: Bone histomorphometric assessment of turnover (bone formation rate/bone surface [BFR/BS]) and receiver operating characteristic curves for discriminating diagnostic ability. RESULTS: The biomarkers iPTH and bALP or combinations thereof allowed discrimination of low from nonlow and high from nonhigh BFR/BS, with an area under the receiver operating characteristic curve > 0.70 but 323.0 pg/mL. The best cutoff for bALP to discriminate low from nonlow BFR/BS was <33.1 U/L, and for high from nonhigh BFR/BS, 42.1U/L. Using the KDIGO practice guideline PTH values of greater than 2 but less than 9 times the upper limit of normal, sensitivity and specificity of iPTH level to discriminate low from nonlow turnover bone disease were 65.7% and 65.3%, and to discriminate high from nonhigh were 37.0% and 85.8%, respectively. LIMITATIONS: Cross-sectional design without consideration of therapy. Potential limited generalizability with samples from 4 countries. CONCLUSIONS: The serum biomarkers iPTH, whole PTH, and bALP were able to discriminate low from nonlow BFR/BS, whereas iPTH and bALP were able to discriminate high from nonhigh BFR/BS. Prospective studies are required to determine whether evaluating trends in biomarker concentrations could guide therapeutic decisions.info:eu-repo/semantics/publishedVersio

The occurrence and removal of algae (including cyanobacteria) and their related organic compounds from source water in Vaalkop Dam with conventional and advanced drinking water treatment processes

Cyanobacterial bloom formation in freshwaters, such as rivers, lakes and dams, is known to occur throughout the world. The Vaalkop Dam, which serves as source to the Vaalkop drinking water treatment works (DWTW), is no exception. Blooms of cyanobacteria occur annually in Vaalkop Dam as well as in dams from which Vaalkop is replenished during low-rainfall periods. These blooms during the summer months are associated with the production of cyanotoxins and taste and odour compounds such as geosmin and MIB. The Vaalkop DWTW uses a combination of conventional and advanced water treatment processes to deal with the cyanobacteria and their related organic compounds in the source water. The overall objectives of this study were to: (i) investigate the occurrence of algae (including cyanobacteria) and cyanotoxins in the Vaalkop Dam; (ii) establish which environmental variables are responsible for the development and onset of algae, and (iii) determine whether the Vaalkop DWTW is able to eliminate the influence that algae (including cyanobacteria) may have on the drinking water. Multivariate statistical analyses revealed seasonal variation in algal assemblages in the raw water. The risk of cyanobacteria bloom formation proved to be especially high during the summer months as the nutrients needed for cyanobacterial growth are available and the temperature range is optimal, causing the production of geosmin, MIB and microcystin. The presence of Ceratium hirundinella (O.F. Müller) Dujardin, in the source water appears to exacerbate the negative effect that cyanobacteria have on the drinking water treatment process. When Ceratium hirundinella is present, floc formation is inhibited, causing more of the problematic algae to penetrate into the drinking water. Even though advanced treatment options such as ozone and granular activated carbon filters are used at Vaalkop DWTW, the effects of the organic compounds produced by cyanobacteria are not entirely eliminated during the treatment process.Keywords: potable water treatment, geosmin, MIB (2-methylisoborneol), microcystin, granular activated carbon (GAC), ozon

Efficacy of conventional drinking water treatment processes in removing problem-causing phytoplankton and associated organic compounds

Seven phytoplankton groups were recorded in the source water supplied to South Africa’s largest conventional drinking water treatment plant (DWTP). Two phytoplankton genera, Anabaena and Ceratium were identified as the problem-causing phytoplankton due to their ability to interfere with the water treatment process and negatively impact on water quality. The objectives of this study were to identify problem-causing phytoplankton genera and investigate the efficacy of unit processes in removing phytoplankton genera and associated organic compounds. Phytoplankton and organic compound data were obtained from four different sampling localities throughout the treatment plant and statistically analysed to evaluate the removal efficiencies of unit processes. The highest percentage removal for the Cyanophyceae average seasonal concentration (&gt; 1 000 cells/mℓ) was recorded at 98%, while the highest percentage removal for the Dinophyceae average seasonal concentration (± 9 cells/mℓ) was recorded at 100%. Microcystis and Anabaena were removed by the processes of coagulation, flocculation and sedimentation (&gt; 95%), while Ceratium cells were removed by sand filtration (&gt; 80%). Ineffective removal of Ceratium by coagulation, flocculation and sedimentation (and subsequent penetration to the sand filtration step) will negatively impact on filter run times when these phytoplankton genera are present in high concentrations in the source water. Total photosynthetic pigments (TPP) were removed effectively by all the different water treatment processes. Not enough statistical evidence could be displayed to suggest effective removal of geosmin in this conventional water treatment plant. With good removal of intact cyanobacteria cells during coagulation, flocculation and sedimentation, geosmin concentrations in the final water could be kept to accepted organoleptic levels of 5–10 ng/ℓ in the final water. Optimising conventional drinking water treatment processes can effectively remove problem-causing phytoplankton as well as their associated organic compounds and thereby reduce the potential risk to drinking water consumers.Keywords: coagulation, sand filtration, drinking water, Ceratium, Anabaena, Microcystis, geosmi

Application of a basic monitoring strategy for Cryptosporidium and Giardia in drinking water

Despite the health risks associated with exposure to Cryptosporidium and Giardia, there is no uniform approach to monitoring these protozoan parasites across the world. In the present study, a strategy for monitoring Cryptosporidium and Giardia in drinking water was developed in an effort to ensure that the risk of exposure to these organisms and the risks of non-compliance to guidelines are reduced. The methodology developed will be applicable to all water supply systems irrespective of size and complexity of the purification works. It is based on monitoring procedures proposed by the US Environmental Protection Agency, the Drinking Water Inspectorate, Australia and New Zealand, as well as the risk-based procedure followed by Northern Ireland. The monitoring strategy developed represents a preventative approach for proactively monitoring Cryptosporidium and Giardia species in drinking water. The strategy consists of 10 steps: (i) assessment of the monitoring requirements, (ii) description and characterisation of the source water types, (iii) abstraction of source water, (iv) assessment of the water purification plant, (v) water quality monitoring, (vi) cryptosporidiosis and giardiasis outbreak, (vii) risk assessment, (viii) sample collection and laboratory processing, (ix) data evaluation, interpretation and storage, (x) process evaluation and review. Proper implementation of this protocol can contribute to the protection of drinking water consumers by identifying high-risk source water, identifying areas of improvement within the water treatment system, and also preventing further faecal pollution in the catchments. The protocol can also be integrated into the Water Safety Plans to optimise compliance. Furthermore, this methodology has a potential to contribute to Blue Drop certification as it should form part of the incident management protocols which are a requirement of Water Safety Plan implementation.Keywords: Cryptosporidium, Giardia, monitoring, risk score, drinking wate

Identification of the initial molecular changes in response to circulating angiogenic cells-mediated therapy in critical limb ischemia

BackgroundCritical limb ischemia (CLI) constitutes the most aggressive form of peripheral arterial occlusive disease, characterized by the blockade of arteries supplying blood to the lower extremities, significantly diminishing oxygen and nutrient supply. CLI patients usually undergo amputation of fingers, feet, or extremities, with a high risk of mortality due to associated comorbidities.Circulating angiogenic cells (CACs), also known as early endothelial progenitor cells, constitute promising candidates for cell therapy in CLI due to their assigned vascular regenerative properties. Preclinical and clinical assays with CACs have shown promising results. A better understanding of how these cells participate in vascular regeneration would significantly help to potentiate their role in revascularization.Herein, we analyzed the initial molecular mechanisms triggered by human CACs after being administered to a murine model of CLI, in order to understand how these cells promote angiogenesis within the ischemic tissues.MethodsBalb-c nude mice (n:24) were distributed in four different groups: healthy controls (C, n:4), shams (SH, n:4), and ischemic mice (after femoral ligation) that received either 50 mu l physiological serum (SC, n:8) or 5x10(5) human CACs (SE, n:8). Ischemic mice were sacrificed on days 2 and 4 (n:4/group/day), and immunohistochemistry assays and qPCR amplification of Alu-human-specific sequences were carried out for cell detection and vascular density measurements. Additionally, a label-free MS-based quantitative approach was performed to identify protein changes related.ResultsAdministration of CACs induced in the ischemic tissues an increase in the number of blood vessels as well as the diameter size compared to ischemic, non-treated mice, although the number of CACs decreased within time. The initial protein changes taking place in response to ischemia and more importantly, right after administration of CACs to CLI mice, are shown.ConclusionsOur results indicate that CACs migrate to the injured area; moreover, they trigger protein changes correlated with cell migration, cell death, angiogenesis, and arteriogenesis in the host. These changes indicate that CACs promote from the beginning an increase in the number of vessels as well as the development of an appropriate vascular network.Institute of Health Carlos III, ISCIII; Junta de Andaluci