155 research outputs found
First Results on the Removal of Emerging Micropollutants from Municipal Centrate by Microalgae
The results of a first campaign of sampling and analyses of emerging micropollutants in the influent (municipal centrate) and effluent of a pilot MBP raceway are reported. The algal population was chiefly made of Chlorella spp. and the pilot worked satisfactorily for the removal of nitrogen. 14 emerging micropollutants were analysed. Average removal efficiencies exceeding 80 % were observed for diclofenac, lamotrigine, ketoprofene, clarithromycin. For such compounds the variability of removal efficiency was also reduced, with respect to the other tested molecules, and was particularly low for diclofenac and lamotrigine. Removal efficiencies over 50 % were measured for azithromycin, metoprolol and irbesartan but with strong variability. Lower removal efficiencies were observed for amisulpride and 5-methylbenzotriazole, while for the remaining compounds the concentrations in the effluent were higher than in the influent
Microalgal cultivation on digestate: Process efficiency and economics
This study aims at evaluating the process efficiency of an outdoor pilot-scale microalgae-based wastewater treatment system. Experimental results from two monitoring campaigns were analysed, showing that the system removed on average 85.1 % and 36.2 % of the influent ammoniacal nitrogen and orthophosphate, respectively, with an associated algal productivity of 9.5 g TSS center dot m(-2)center dot d(-1). Based on pilot-scale results, a comprehensive technoeconomic assessment was performed, allowing to calculate a biomass production cost of 4.3 euro center dot kg TSS-1 and a wastewater treatment cost of 2.7 euro center dot m(-3) (corresponding to a nitrogen removal cost of 12.5 euro center dot kg N-1). These costs turned out to be comparable with conventional wastewater treatment processes, thus recognizing the potential of microalgae cultivation on wastewaters as feasible alternative to conventional energy-demanding bioremediation systems and to expensive algal cultivation processes. A sensitivity and scenario analysis indicated that, under the most optimistic condition (20 % increase in the productivity, and 20 % OPEX and CAPEX reduction), biomass production and nitrogen removal costs could be further reduced of approximately 44 %
LCA of Zero Valent Iron Nanoparticles Encapsulated in Algal Biomass for Polishing Treated Effluents
Research data produced within the CARIPLO IMAP and Perform Water 2030 projects were processed using the SimaPro software to carry out the Life Cycle Assessment according to ISO 14040-44 of an innovative process of treated effluents' polishing. The study aims to evaluate the integration of a microalgae culture as a side-stream process into the baseline layout of a wastewater treatment plant to remove nitrogen from the supernatant of sludge centrifugation from an environmental perspective. In particular, the investigated system focuses on using the algal biomass produced as an organic matrix for encapsulating zero-valent iron nanoparticles to be used for the final refinement of the effluent. Zero-valent iron (ZVI) is a reactive metal and an effective reducing agent. It can be used to remove organic and inorganic pollutants (e.g., chlorinated organics, pharmaceuticals, metals, textile dyestuffs). The encapsulation of ZVI by hydrothermal carbonization (HTC) in a carbonaceous matrix allows for overcoming the problems related to its lack of stability, easy aggregation, and difficulty in separating the ZVI nanoparticles from the treated solution. The case study refers to Bresso wastewater treatment plant (Milan province, Northern Italy). The environmental performances of the study were assessed following the Life Cycle Impact Assessment methods IMPACT 2002+. According to the results, the new process integration does not affect the environmental performance of the WWTP, still implying a significant improvement in the removal of metals and micropollutants. In fact, due to the ability of ZVI nanoparticles to remove organic and inorganic pollutants, the outflowing load will be significantly reduced, which will improve the environmental performance of the entire Bresso wastewater treatment plant
Respirometric assessment of bacterial kinetics in algae-bacteria and activated sludge processes
Algae-bacteria (AB) consortia can be exploited for effective wastewater treatment, based on photosynthetic oxygenation to reduce energy requirements for aeration. While algal kinetics have been extensively evaluated, bacterial kinetics in AB systems are still based on parameters taken from the activated sludge models, lacking an experimental validation for AB consortia. A respirometric procedure was therefore proposed, to estimate bacterial kinetics in both activated sludge and AB, under different conditions of temperature, pH, dissolved oxygen, and substrate availability. Bacterial activities were differently influenced by operational/environmental conditions, suggesting that the adoption of typical activated sludge parameters could be inadequate for AB modelling. Indeed, respirometric results show that bacteria in AB consortia were adapted to a wider range of conditions, compared to activated sludge, confirming that a dedicated calibration of bacterial kinetics is essential for effectively modelling AB systems, and respirometry was proven to be a powerful and reliable tool to this purpose
Gut-dependent inflammation and alterations of the intestinal microbiota in individuals with perinatal HIV exposure and different HIV serostatus
Objective: HIV-exposed infected (HEI) and uninfected (HEU) children represent the two possible outcomes of maternal HIV infection. Modifications of the intestinal microbiome have been linked to clinical vulnerability in both settings, yet whether HEI and HEU differ in terms of gut impairment and peripheral inflammation/activation is unknown. Design: We performed a cross-sectional, pilot study on fecal and plasma microbiome as well as plasma markers of gut damage, microbial translocation, inflammation and immune activation in HIV-infected and uninfected children born from an HIV-infected mother. Methods: Fecal and plasma microbiome were determined by means of 16S rDNA amplification with subsequent qPCR quantification. Plasma markers were quantified via ELISA. Results: Forty-seven HEI and 33 HEU children were consecutively enrolled. The two groups displayed differences in fecal beta-diversity and relative abundance, yet similar microbiome profiles in plasma as well as comparable gut damage and microbial translocation. In contrast, monocyte activation (sCD14) and systemic inflammation (IL-6) were significantly higher in HEI than HEU. Conclusion: In the setting of perinatal HIV infection, enduring immune activation and inflammation do not appear to be linked to alterations within the gut. Given that markers of activation and inflammation are independent predictors of HIV disease progression, future studies are needed to understand the underlying mechanisms of such processes and elaborate adjuvant therapies to reduce the clinical risk in individuals with perinatal HIV infection
IL-3 or IL-7 Increases ex Vivo Gene Transfer Efficiency in ADA-SCID BM CD34 + Cells while Maintaining in Vivo Lymphoid Potential
To improve maintenance and gene transfer of human lymphoid progenitors for clinical use in gene therapy of adenosine deaminase (ADA)-deficient SCID we investigated several gene transfer protocols using various stem cell-enriched sources. The lymphoid differentiation potential was measured by an in vitro clonal assay for B/NK cells and in the in vivo SCID-hu mouse model. Ex vivo culture with the cytokines TPO, FLT3-ligand, and SCF (T/F/S) plus IL-3 or IL-7 substantially increased the yield of transduced bone marrow (BM) CD34+ cells purified from ADA-SCID patients or healthy donors, compared to T/F/S alone. Moreover, the use of IL-3 or IL-7 significantly improved the maintenance of in vitro B cell progenitors from ADA-SCID BM cells and allowed the efficient transduction of B and NK cell progenitors. Under these optimized conditions transduced CD34+ cells were efficiently engrafted into SCID-hu mice and gave rise to B and T cell progeny, demonstrating the maintenance of in vivo lymphoid reconstitution capacity. The protocol based on the T/F/S + IL-3 combination was included in a gene therapy clinical trial for ADA-SCID, resulting in long-term engraftment of stem/progenitor cells. Remarkably, gene-corrected BM CD34+ cells obtained from one patient 4 and 11 months after gene therapy were capable of repopulating the lymphoid compartment of SCID-hu hosts
Computational Integration of Homolog and Pathway Gene Module Expression Reveals General Stemness Signatures
The stemness hypothesis states that all stem cells use common mechanisms to regulate self-renewal and multi-lineage potential. However, gene expression meta-analyses at the single gene level have failed to identify a significant number of genes selectively expressed by a broad range of stem cell types. We hypothesized that stemness may be regulated by modules of homologs. While the expression of any single gene within a module may vary from one stem cell type to the next, it is possible that the expression of the module as a whole is required so that the expression of different, yet functionally-synonymous, homologs is needed in different stem cells. Thus, we developed a computational method to test for stem cell-specific gene expression patterns from a comprehensive collection of 49 murine datasets covering 12 different stem cell types. We identified 40 individual genes and 224 stemness modules with reproducible and specific up-regulation across multiple stem cell types. The stemness modules included families regulating chromatin remodeling, DNA repair, and Wnt signaling. Strikingly, the majority of modules represent evolutionarily related homologs. Moreover, a score based on the discovered modules could accurately distinguish stem cell-like populations from other cell types in both normal and cancer tissues. This scoring system revealed that both mouse and human metastatic populations exhibit higher stemness indices than non-metastatic populations, providing further evidence for a stem cell-driven component underlying the transformation to metastatic disease
Towards a standardization of biomethane potential tests
8 PáginasProduction of biogas from different organic materials is a most interesting source of renewable energy. The biomethane potential (BMP) of these materials has to be determined to get insight in design parameters for anaerobic digesters. A workshop was held in June 2015 in Leysin Switzerland to agree on common solutions to the conundrum of inconsistent BMP test results. A discussion covers actions and criteria that are considered compulsory ito accept and validate a BMP test result; and recommendations concerning the inoculum substrate test setup and data analysis and reporting ito obtain test results that can be validated and reproduced.The workshop in Leysin, Switzerland, has been financed by the Swiss Federal Office for Energy, and co-sponsored by Bioprocess Control Sweden AB, Lund, Sweden. The authors thank Alexandra Maria Murray for editing the English
c-Kit-Mediated Functional Positioning of Stem Cells to Their Niches Is Essential for Maintenance and Regeneration of Adult Hematopoiesis
The mechanism by which hematopoietic stem and progenitor cells (HSPCs) through interaction with their niches maintain and reconstitute adult hematopoietic cells is unknown. To functionally and genetically track localization of HSPCs with their niches, we employed novel mutant loxPs, lox66 and lox71 and Cre-recombinase technology to conditionally delete c-Kit in adult mice, while simultaneously enabling GFP expression in the c-Kit-deficient cells. Conditional deletion of c-Kit resulted in hematopoietic failure and splenic atrophy both at steady state and after marrow ablation leading to the demise of the treated adult mice. Within the marrow, the c-Kit-expressing GFP+ cells were positioned to Kit ligand (KL)-expressing niche cells. This c-Kit-mediated cellular adhesion was essential for long-term maintenance and expansion of HSPCs. These results lay the foundation for delivering KL within specific niches to maintain and restore hematopoiesis
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