Salinity Reduction of Real Produced Waters via Assisted Reverse Electrodialysis

Produced waters (PWs) are waste streams generated during the crude oil extraction processes. The management of these wastewaters is complicated by the large volumes extracted during the oil recovery operations: these depends on the life of the oil-well: typically, 3 barrels of PWs on average are produced for each barrel of oil extracted. After oil separation, PWs are usually re-injected into the well, but this approach is not always possible without a preliminary and suitable treatment. Bioremediation techniques might be a good option, but they fail due to the PWs high salinity, which inhibit bacteria growth and metabolism. Thus, reducing their salinity upstream a bioremediation unit is a matter of crucial importance. To this aim, Assisted Reverse electrodialysis (ARED) along with the use of a dilute stream typically available on site is here proposed as a novel solution. In ARED an additional voltage is applied in the same direction of the salinity gradient through the membranes in order to enhance the passage of ions from the PW to the diluted solution, thus significantly reducing the required membrane area. An experimental campaign was carried out in order to assess the process feasibility. A fixed volume of real PWs was fed to a laboratory scale ARED unit. Each experimental test lasted for three days to reduce the salinity down to about 20 g l-1, a value compatible with the biomass metabolism for a downstream bioremediation step. Two different types of commercial membranes were tested and relevant energy consumptions were calculated. The long-runs performed did not show a significant loss of efficiency due to fouling, thus suggesting that ARED might a suitable technology for a pre-dilution of produced water

Economic Analysis of an Innovative Scheme for the Treatment of Produced Waters

During the crude oil extraction processes, for each barrel of oil turns out an equivalent of 3 barrels of wastewaters on average. These wastes are known as Produced Waters (PWs) and their dramatic impact on the environment has attracted the attention of researchers in order to find an economic and efficient method for their treatment. Dealing with PWs is not easy: the long exposure with oil increases their hydrocarbon fraction, while the contact with the underground wells increases their concentration in salts and minerals. The direct discharge of PWs into the sea is obviously not allowed by law and PWs are usually re-injected into the well. The present work deals with a novel and innovative treatment chain (including assisted reverse electrodialysis (ARED) as dilution step) able to reduce both the salinity and organic content of PWs. The innovative scheme includes an ultrafiltration unit as pre-treatment, upstream an ARED unit for the PW dilution. Once the salinity level has been reduced down to a value affordable for a bioremediation step, PWs are sent to a bio-reactor, where the organic compounds are digested. Finally, a reverse osmosis unit is used to recover water from the treated PWs and to recycle it as diluted stream in the ARED unit. A techno-economic model was purposely developed in the present work to assess the economic feasibility of the proposed scheme. Preliminary results suggest that the treatment costs are lower than 5 € m-3 PW and fully competitive with current PWs treatment technologies

Microalgae in the Mediterranean area: A geographical survey outlining the diversity and technological potential

Microalgal diversity enables the possibility to employ them in technological applications, as widely shown by the modern literature. While there exists an extensive body of literature concerning the technological applications of microalgae, the scientific knowledge of microalgal species remains relatively limited. Therefore, there is still potential for unlocking new opportunities through the study of the microalgal biodiversity, particularly in the Mediterranean region, which is unique because of its sub regional diversity. While some studies have assessed microalgae distribution in the Mediterranean area, and others have focused on specific aspects of their technical exploitation, this review seeks to offer a comprehensive overview of isolated microalgal species and their technological applications. Microalgae from the Mediterranean area share common characteristics, such as low half-saturation constants and acclimation to high light intensity, making them ideal for specific technological applications. While the search for new microalgae for technological purposes can help in biodiversity conservation, numerous species still remain underexplored, offering potential for innovative applications. However, the key finding from the critical analysis of the literature is that the diversity of microalgae in the Mediterranean region is its true richness, allowing for their versatile applications across various processes. The work focuses on the Mediterranean area, i.e., having coastlines along the Mediterranean Sea and on aquatic microalgae, coming from water with different salinity levels. This review offers an intrinsic ecological and technological perspective and provides a fresh outlook on the microalgal sector, promoting its expansion in the Mediterranean area and the development of sustainable bio-industrie

Rectus Femoris Characteristics in Post Stroke Spasticity: Clinical Implications from Ultrasonographic Evaluation

In stroke survivors, rectus femoris (RF) spasticity is often implicated in gait pattern alterations such as stiff knee gait (SKG). Botulinum toxin type A (BoNT-A) is considered the gold standard for focal spasticity treatment. However—even if the accuracy of injection is crucial for BoNT-A efficacy—instrumented guidance for BoNT-A injection is not routinely applied in clinical settings. In order to investigate the possible implications of an inadequate BoNT-A injection on patients' clinical outcome, we evaluated the ultrasound-derived RF characteristics (muscle depth, muscle thickness, cross-sectional area and mean echo intensity) in 47 stroke survivors. In our sample, we observed wide variability of RF depth in both hemiparetic and unaffected side of included patients (0.44 and 3.54 cm and between 0.25 and 3.16 cm, respectively). Moreover, our analysis did not show significant differences between treated and non-treated RF in stroke survivors. These results suggest that considering the inter-individual variability in RF muscle depth and thickness, injection guidance should be considered for BoNT-A treatment in order to optimize the clinical outcome of treated patients. In particular, ultrasound guidance may help the clinicians in the long-term follow-up of muscle quality

Economic Analysis of an Innovative Scheme for the Treatment of Produced Waters

During the crude oil extraction processes, for each barrel of oil turns out an equivalent of 3 barrels of wastewaters on average. These wastes are known as Produced Waters (PWs) and their dramatic impact on the environment has attracted the attention of researchers in order to find an economic and efficient method for their treatment. Dealing with PWs is not easy: the long exposure with oil increases their hydrocarbon fraction, while the contact with the underground wells increases their concentration in salts and minerals. The direct discharge of PWs into the sea is obviously not allowed by law and PWs are usually re-injected into the well. The present work deals with a novel and innovative treatment chain (including assisted reverse electrodialysis (ARED) as dilution step) able to reduce both the salinity and organic content of PWs. The innovative scheme includes an ultrafiltration unit as pre-treatment, upstream an ARED unit for the PW dilution. Once the salinity level has been reduced down to a value affordable for a bioremediation step, PWs are sent to a bio-reactor, where the organic compounds are digested. Finally, a reverse osmosis unit is used to recover water from the treated PWs and to recycle it as diluted stream in the ARED unit. A techno-economic model was purposely developed in the present work to assess the economic feasibility of the proposed scheme. Preliminary results suggest that the treatment costs are lower than 5 € m-3PW and fully competitive with current PWs treatment technologies

Salinity Reduction of Real Produced Waters via Assisted Reverse Electrodialysis

Produced waters (PWs) are waste streams generated during the crude oil extraction processes. The management of these wastewaters is complicated by the large volumes extracted during the oil recovery operations: these depends on the life of the oil-well: typically, 3 barrels of PWs on average are produced for each barrel of oil extracted. After oil separation, PWs are usually re-injected into the well, but this approach is not always possible without a preliminary and suitable treatment. Bioremediation techniques might be a good option, but they fail due to the PWs high salinity, which inhibit bacteria growth and metabolism. Thus, reducing their salinity upstream a bioremediation unit is a matter of crucial importance. To this aim, Assisted Reverse electrodialysis (ARED) along with the use of a dilute stream typically available on site is here proposed as a novel solution. In ARED an additional voltage is applied in the same direction of the salinity gradient through the membranes in order to enhance the passage of ions from the PW to the diluted solution, thus significantly reducing the required membrane area. An experimental campaign was carried out in order to assess the process feasibility. A fixed volume of real PWs was fed to a laboratory scale ARED unit. Each experimental test lasted for three days to reduce the salinity down to about 20 g l-1, a value compatible with the biomass metabolism for a downstream bioremediation step. Two different types of commercial membranes were tested and relevant energy consumptions were calculated. The long-runs performed did not show a significant loss of efficiency due to fouling, thus suggesting that ARED might a suitable technology for a pre-dilution of produced waters

Development of an Electrochemical Sensor for Nitrate Analysis in Municipal Wastewaters Treated by Microalgae

Microalgae are photosynthetic microorganisms which may be employed in several fields. Amongst them, an emerging but promising sector of application is their usage for the remediation of wastewaters. They result particularly effective in treating municipal wastewaters, often resulting in nitrate concentrations exceeding the requirements for discharging treated wastewater into the sea. Furthermore, another advantage of using microalgae in civil wastewater treatment is the cooperation with heterotrophic bacteria which may naturally occur in the water or be introduced through sewage sludge in wastewater treatment plants (WTPs). Microalgae, in fact, produce oxygen which may be used by these bacteria reducing the overall operational costs of the WTP. The assessment of nitrogen compound concentrations in wastewater involves various techniques, with ionic chromatography (IC) and spectrometric methods being commonly used in laboratory settings. However, these methods have drawbacks such as the need for skilled personnel, time-consuming processes, and impracticality for in situ and real-time analysis. To address these issues, electrochemical sensors present a viable alternative. These sensors require portable instruments with low power requirements and can be miniaturized using nanotechnology. Electrochemical sensors operate by reducing/oxidizing the target analyte on the working electrode surface. The choice of electrode material is crucial for sensor sensitivity, and copper is found to exhibit excellent electrocatalytic properties for reducing nitrate ions in acidic media. In this study, a cost-effective electrochemical sensor made of copper was developed for quantifying nitrate in wastewater. The entire electrochemical cell was constructed from a common substrate used in Printed Circuit Boards (PCB). The whole fabrication procedure was optimized in order to obtain a reproducible fabrication procedure. The reference and counter electrodes were modified with graphite and Ag/AgCl paste, respectively. The results demonstrated that the sensor can effectively quantify nitrate ions in wastewater. Moreover, it can be employed during microalgal treatment to assess the in vivo reduction of nitrate, offering a practical and efficient solution for real-time monitoring of nitrogen compounds in wastewater treatment processes

The Lack of Systemic and Subclinical Side Effects of Botulinum Neurotoxin Type-A in Patients Affected by Post-Stroke Spasticity: A Longitudinal Cohort Study

Botulinum Neurotoxin type-A (BoNT-A) is the treatment of choice for focal post-stroke spasticity (PSS). Due to its mechanism of action and the administration method, some authors raised concern about its possible systemic diffusion leading to contralateral muscle weakness and autonomic nervous system (ANS) alterations. Stroke itself is a cause of motor disability and ANS impairment; therefore, it is mandatory to prevent any source of additional loss of strength and adjunctive ANS disturbance. We enrolled 15 hemiparetic stroke survivors affected by PSS already addressed to BoNT-A treatment. Contralateral handgrip strength and ANS parameters, such as heart rate variability, impedance cardiography values, and respiratory sinus arrythmia, were measured 24 h before (T0) and 10 days after (T1) the ultrasound (US)-guided BoNT-A injection. At T1, neither strength loss nor modification of the basal ANS patterns were found. These findings support recent literature about the safety profile of BoNT-A, endorsing the importance of the US guide for a precise targeting and the sparing of "critical" structures as vessels and nerves

Vaccination coverage in healthcare workers: a multicenter cross-sectional study in Italy

IntroductionIn recent years, a phenomenon known as "vaccine hesitancy" has spread throughout the world, even among health workers, determining a reduction in vaccination coverage (VC). A study aimed at evaluating VC among healthcare workers (HCWs) in 10 Italian cities (L'Aquila, Genoa, Milan, Palermo, Sassari, Catanzaro, Ferrara, Catania, Naples, Messina) was performed.Materials and methodsAnnex 3 of the Presidential Decree n. 445 of 28 December 2000 was used to collect information on the vaccination status of HCWs. The mean and standard deviation (SD) were calculated with regard to the quantitative variable (age), while absolute and relative frequencies were obtained for categorical data (sex, professional profile, working sector, vaccination status). The connection between VC and the categorical variables was evaluated by chi-square method (statistical significance at p<0.05). The statistical analyses were performed by SPSS and Stata software.ResultsA total of 3,454 HCWs participated in the project: 1,236 males and 2,218 females. The sample comprised: physicians (26.9%), trainee physicians (16.1%), nurses (17.2%) and other professional categories (9.8%). Low VC was generally recorded. Higher VC was found with regard to polio, hepatitis B, tetanus and diphtheria, while coverage was very low for measles, mumps, rubella, pertussis, chickenpox and influenza (20-30%). ConclusionsThis study revealed low VC rates among HCWs for all the vaccinations. Measures to increase VC are therefore necessary in order to prevent HCWs from becoming a source of transmission of infections with high morbidity and/or mortality both within hospitals and outside