EVALUATION OF ELECTRODE SURFACE TREATMENTS IN SLUDGE ELECTRO-OSMOSIS DEWATERING”

The drying of sludge produced by Wastewater Treatment Plants (WWTPs) is a very hard process due to the presence of the colloid fraction. Electro-osmosis could be a suitable technique to reduce the water content of the final sludge. Electrical fields of 10 V/cm, 15 V/cm and 20 V/cm have been studied for electro-osmosis tests in a static or dynamic apparatus, obtaining a dry solids content up to 40-45%, with respect to 25-30% obtained by mechanical methods. In order to optimise the apparatus, the corrosion behaviour of the anodic material appears the main critical aspect, due to the high circulating current density. Moreover, wear may be detrimental for the surface of rotating electrodes. We then investigated the behaviour of materials used as electrodes mainly by evaluating the efficiency of the process and their surface aspect after treatment. The full understanding of the electrochemical reactions developed at the anode are a key factor for the material choice. We compared the efficiency and the corrosion resistance of anodes made of titanium MMO with respect to bare stainless steel (AISI 304) and stainless steel coated by PVD technique with TiN, AlTiN and DLC. Characterization of the anodes samples by roughness tests and by AFM show that corrosion resistance of the DSA was the most suitable for our application. However, efficiencies of the electro-osmosis process for all the materials used have been found comparable, in terms of developed current densities and total energy consumptions, for low-test duration

Performance of electro-osmotic dewatering on different types of sewage sludge

The feasibility of pressure-driven electro-dewatering (EDW) on sludge samples taken after different biological processes, stabilisation methods or mechanical dewatering techniques was assessed. First, the influence of potential values on EDW of anaerobically and aerobically stabilised, mechanically dewatered, sludge samples was investigated. Preliminary tests carried out by applying a constant potential (10, 15 and 20 V) in a lab-scale device confirmed the possibility to reach a dry solid (DS) content of up to 42.9%, which corresponds to an increase of 15% of the dry content in dewatered sludge without the application of the electrical field. Dewatering increased with the applied potential but at the expense of a higher energy consumption. A potential equal to 15 V was chosen as the best compromise for EDW performance, in terms of DS content and energy consumption. Then, the influence of the mechanical dewatering was studied on aerobically stabilised sludge samples with a lower initial DS content: the higher initial water content led to a lower final DS content but with a considerable reduction of energy consumption. Finally, the biological process, studied by comparing sludge samples from conventional activated sludge and membrane bioreactor processes, didn’t evidence any influence on EDW. Experimental results shown that DS obtained after mechanical dewatering, volatile solids and conductivity are the main factors influencing EDW. Anaerobically digested sludge reached the highest DS content, thanks to lower organic fraction

ELECTRO-OSMOTIC DEWATERING OF SEWAGE SLUDGE: PRELIMINARY RESULTS

About half of the organic pollution load treated by the activated sludge process is oxidised and converted into water and carbon dioxide, while the remaining is converted into biomass, called “excess biological sludge” or “waste sludge”. At present, this technique is the cheapest way to remove colloidal and soluble organic pollutants from sewage, but it produces a huge amount of liquid waste sludge, with a dry solid (DS) content of less than 2%, rich in organic substances, mostly biodegradable. Therefore, it needs further processes to reduce its volume, by reducing its water content, and to reduce its polluting potential, due to its high content of biodegradable organic matter. However, sludge produced by Wastewater Treatment Plants (WWTPs) usually has a poor dewaterability. Industrially, mechanical dewatering is the method employed to increase the dry solids (DS) of sewage sludge. The aim of dewatering is the decrease of transport and disposal costs, but the efficiency of the mechanical dehydration methods is low. Electro-osmosis could be a suitable technique to reduce water content of the final sludge by the application of an electric field. Studies about electro-dewatering reported that the DS could increase to values around 40-45%, with respect to 25-30% obtained by mechanical methods, such as centrifuge, filter press and belt press. Aim Here, we investigated the parameters affecting pressure-driven electro-dewatering, with a static and a dynamic device, starting from types of sludge mechanically pre-dehydrated. We focused on the optimization of operating conditions to achieve the best results in terms of solids percentage at the minimum energy consumption. Methods Experiments have been performed by means of a lab-scale device able to produce both a mechanical pressure and an electric field. The use of both these systems could be efficient to increase the amount of dry solids in the final sludge. This device, as illustrated in Figure 1, consists of: • Cylindrical glass vessel (h=176 mm, Ø=80 mm) • Cooling water-jacket • Compressed air system (1-4.5 bar) • Double effect cylinder (200 mm stroke) SMC-CP96 (piston) • DC power supply (30 V-5 A) • Anode: DSA Ti (MMO), fixed to the piston • Cathode: stainless steel mesh (AISI 304) • Cloth: PTT (polytrimethyleneterephthalate) Figure 1-Equipment schematic of electro-dewatering device. Main Results The applied voltage has been set at 10 V, 15 V and 20 V and pressures at 3 bar. The results confirmed values of final DS around 40%. Initial DS and sludge conductivity, together with the applied electric field, are the key factors of electro-osmosis tests. The rotating piston highlighted that a mixing of sludge during the potential application could slightly increase the sludge conductivity, but cakes must be kept under 1.5 cm of thickness in order to achieve a good dewatering. In conclusion, in this paper we assess the feasibility of the electro-osmosis dewatering. It is a promising technique to remove water from sewage sludge, since it is able to increase DS of 15% on average with respect industrial mechanical dewatering. Moreover, this work proved that the treatment of a high DS cake is more difficult than a non-dewatered sludge due to a lower conductivity during the process

Ex Vivo Gene Therapy Approaches for the Treatment of Globoid Cell Leukodystrophy

Globoid cell leukodystrophy (GLD) is a rare lysosomal storage disorder (LSD) due to the deficiency of the lysosomal enzyme Galactocerebrosidase (GALC). The enzymatic deficiency results in intracellular storage of undegraded metabolites in the nervous system, leading to progressive dysmyelination. We are testing the feasibility and efficacy of a gene therapy strategy based on hematopoietic stem/progenitor cells (HSPC) and lentiviral vectors (LV) in the murine model of GLD. Differently from what observed with other lysosomal enzymes, GALC gene transfer and expression in HSPC causes apoptosis and functional impairment of the transduced cells due to an inbalance of the intracellular content in bioactive sphingolipids consequent to de novo enzyme expression. Differentiated cells of the myeloid and lymphoid lineages are not affected by GALC expression, suggesting a unique sensitivity of HSPC to enzyme toxicity. To overcome this issue, we explored strategies aimed at de-targeting vector expression from HSPC, while permitting GALC over-expression in differentiated cells. The first approach aims at a transcriptional regulation of GALC expression by the microglia/macrophage specific promoter CD11b. The second strategy exploits endogenous microRNAs for post-transcriptional regulation of GALC expression. The use of LV containing the target sequence of miRNA126, expressed only in HSPC, allows expressing GALC only in the differentiated progeny of transduced HSPC. Although these two approaches proved to be very promising in protecting HSPC from enzyme toxicity both in vitro and in vivo in heterozygous GLD mice, gene-corrected HSPC failed to repopulate lethally irradiated homozygous GLD mice. This poor result might be explained by the existence of a niche defect in homozygous GLD mice, which might hamper the engraftment of HSPC

Sewage sludge electro-osmotic dewatering

LAUREA MAGISTRALEIl fango prodotto dagli impianti di trattamento delle acque reflue di solito ha una scarsa disidratabilità. Industrialmente, la disidratazione meccanica è il metodo impiegato per aumentare la sostanza secca (SS) dei fanghi di depurazione. L’obiettivo della disidratazione è la diminuzione dei costi di trasporto e di smaltimento, ma l’efficienza della disidratazione meccanica è bassa. L’elettroosmosi potrebbe essere una tecnica adatta per ridurre la quantità di acqua del fango finale tramite l’applicazione di un campo elettrico. Studi riguardanti l’elettro-disidratazione hanno riportato che la SS potrebbe aumentare fino a valori intorno al 40-45%, rispetto al 25-30% ottenuti con metodi meccanici. Qui, abbiamo analizzato i parametri che influenzano l’elettro-disidratazione a pressione applicata, con un apparato statico e uno dinamico, partendo da fanghi precedentemente disidratati meccanicamente. Il potenziale applicato è stato di 10 V, 15 V e 20 V con l’obiettivo di esaminare l’energia totale consumata e la finale SS. I risultati hanno confermato valori di SS finale intorno al 40% con il pistone statico. La SS iniziale e la conducibilità del fango, insieme al campo elettrico applicato, sono i fattori chiave delle prove di elettroosmosi. Il pistone rotante ha evidenziato che una miscelazione dei fanghi durante l'applicazione del potenziale può aumentare leggermente la conducibilità dei fanghi, ma lo spessore del fango deve essere mantenuto al di sotto di 1,5 cm per ottenere una buona disidratazione. Inoltre, è stata condotta un'analisi preliminare di differenti materiali per gli anodi da utilizzare in questo apparato, al fine di valutare l'influenza della corrosione durante il processo. L’acciaio inossidabile (AISI 304) è stato usato come substrato per rivestimenti ceramici depositati con tecnica PVD (TiN, AlTiN e DLC), ma i campioni hanno evidenziato una bassa resistenza alla corrosione.Sludge produced by Wastewater Treatment Plants (WWTPs) usually has a poor dewaterability. Industrially, mechanical dewatering is the method employed to increase the dry solids (DS) of sewage sludge. The aim of dewatering is the decrease of transport and disposal costs, but the efficiency of the mechanical dehydration methods is low. Electro-osmosis could be a suitable technique to reduce water content of the final sludge by the application of an electric field. Studies about electro-dewatering reported that the DS could increase to values around 40-45%, with respect to 25-30% obtained by mechanical methods. Here, we investigated the parameters affecting pressure-driven electro-dewatering, with a static and a dynamic device, starting from types of sludge mechanically pre-dehydrated. The applied voltage has been set at 10 V, 15 V and 20 V in order to examine total energy consumption and final DS. The results confirmed values of final DS around 40% with the static piston. Initial DS and sludge conductivity, together with the applied electric field, are the key factors of electro-osmosis tests. The rotating piston highlighted that a mixing of sludge during the potential application could slightly increase the sludge conductivity, but cakes must be kept under 1.5 cm of thickness in order to achieve a good dewatering. In addition, a preliminary analysis of different materials for the anodes to be used in this apparatus has been done, in order to evaluate the influence of corrosion during the process. Stainless steel (AISI 304) has been used as a substrate for ceramic PVD coatings (TiN, AlTiN and DLC), but samples evidenced a low corrosion resistance

Electrode surface treatments in sludge electro-osmosis dewatering

open12siThe sewage sludge dewatering produced by wastewater treatment plants (WWTP) is a multifaceted process due to the presence of colloid fractions. Electro-osmosis could be a suitable technique to reduce the water content of the final sludge. Electric fields of 10, 15, and 20 V/cm have been studied for electro-osmosis tests under the pressure of a static or rotating piston, obtaining a dry solids content up to 40–45%, with respect to 25–30% obtained by mechanical methods. In order to optimize the process, the corrosion behavior and the wear of the anodic material appear to be the main critical aspects, due to the high circulating current density and the use of a rotating electrode. We compared the efficiency and the corrosion resistance of dimensionally stable anodes (DSA) with respect to bare stainless steel (AISI 304) and stainless steel coated by PVD technique with TiN, AlTiN, and DLC. Characterization of the anode surfaces by SEM and potentiodynamic tests show that DSA is the most suitable material for our application. However, efficiencies of the electro-osmosis processes have been found comparable, in terms of developed current densities and total energy consumptions, for short-test duration.openGronchi, Paolo; Canziani, Roberto; Brenna, Andrea; Visigalli, Simone; Colominas, Carles; Montalà, Francesc; Cot, Victor; Stradi, Aristide; Ferrari, Giancarlo; Diaz, Cristina; Fuentes, Gonzalo Garcia; Georgiadis, ArgyriosGronchi, Paolo; Canziani, Roberto; Brenna, Andrea; Visigalli, Simone; Colominas, Carles; Montalà, Francesc; Cot, Victor; Stradi, Aristide; Ferrari, Giancarlo; Diaz, Cristina; Fuentes, Gonzalo Garcia; Georgiadis, Argyrio

Clinical trial of laronidase in Hurler syndrome after hematopoietic cell transplantation.

BackgroundMucopolysaccharidosis I (MPS IH) is a lysosomal storage disease treated with hematopoietic cell transplantation (HCT) because it stabilizes cognitive deterioration, but is insufficient to alleviate all somatic manifestations. Intravenous laronidase improves somatic burden in attenuated MPS I. It is unknown whether laronidase can improve somatic disease following HCT in MPS IH. The objective of this study was to evaluate the effects of laronidase on somatic outcomes of patients with MPS IH previously treated with HCT.MethodsThis 2-year open-label pilot study of laronidase included ten patients (age 5-13 years) who were at least 2 years post-HCT and donor engrafted. Outcomes were assessed semi-annually and compared to historic controls.ResultsThe two youngest participants had a statistically significant improvement in growth compared to controls. Development of persistent high-titer anti-drug antibodies (ADA) was associated with poorer 6-min walk test (6MWT) performance; when patients with high ADA titers were excluded, there was a significant improvement in the 6MWT in the remaining seven patients.ConclusionsLaronidase seemed to improve growth in participants <8 years old, and 6MWT performance in participants without ADA. Given the small number of patients treated in this pilot study, additional study is needed before definitive conclusions can be made

Kourou – La Sablière

Le site archéologique dit « La Sablière », à Kourou, est un des plus importants gisements sur cordons côtiers littoraux de la Guyane. La collaboration de deux disciplines (géomorphologie et archéologie) a permis l'obtention de données nouvelles concernant ce type de site littoral. L'environnement physique a été étudié à partir des nombreux documents (cartes, photographies aériennes, télédétection) et des travaux de terrain. Les relations entre les données géologiques, la morphologie et l'évol..

Endothelial cell activation by SARS-CoV-2 spike S1 protein: A crosstalk between endothelium and innate immune cells

Background. Emerging evidences suggest that in severe COVID-19, multi-organ failure is associated with a hyperinflammatory state (the so-called “cytokine storm”) in combination with the development of a prothrombotic state. The central role of endothelial dysfunction in the pathogenesis of the disease is to date accepted, but the precise mechanisms underlying the associated coagulopathy remain unclear. Whether the alterations in vascular homeostasis directly depend upon the SARS-CoV-2 infection of endothelial cells or, rather, occur secondarily to the activation of the inflammatory response is still a matter of debate. Here, we address the effect of the SARS-CoV-2 spike S1 protein on the activation of human lung microvascular endothelial cells (HLMVEC). In particular, the existence of an endothelium-macrophage crosstalk in the response to the spike protein has been explored. Methods and Results. The effect of the spike protein is addressed in human lung microvascular endothelial cells (HLMVEC), either directly or after incubation with a conditioned medium (CM) of human monocyte-derived macrophages (MDM) previously activated by the spike S1 protein (CM-MDM). Both MDM and HLMVEC are activated in response to the S1 protein, with an increased expression of pro-inflammatory mediators. However, when HLMVEC are exposed to CM-MDM, an enhanced cell activation occurs in terms of the expression of adhesion molecules, pro-coagulant markers, and chemokines. Under this experimental condition, ICAM-1 and VCAM-1, the chemokines CXCL8/IL-8, CCL2/MCP1, and CXCL10/IP-10 as well as the protein tissue factor (TF) are markedly induced. Instead, a decrease of thrombomodulin (THBD) is observed. Conclusion. Our data suggest that pro-inflammatory mediators released by spike-activated macrophages amplify the activation of endothelial cells, likely contributing to the impairment of vascular integrity and to the development of a pro-coagulative endothelium