Tracer studies at a full-scale lagoon used as pre-treatment facility for a water treatment plant

The water treatment plant (WTP) of Turin (Italy), fed by water of river, has a lagoon as pre-treatment facility. Since the effectiveness of the lagoon treatment towards the removal of contaminants from water depends on the residence time of the system, and the mixing aspects for the limitation of peak concentration are also very important, this led to an investigation of the internal hydraulics of the lagoon. A tracer study using sodium fluoride (NaF) was performed to determine the stimulus response output and an extensive internal sampling of the tracer was also performed to better understand the movement of the tracer through the system. The lagoon investigated in the study had a surface of 151600 m2, a volume of about 1.8•106 m3 and a nominal residence time of 18 d at average daily flow (1150 L/s). An amount of NaF equal to 180 kg was diluted with about 50000 m3 of the lagoon water and introduced in the lagoon in 12 hours, in order to simulate a pulse injection. The amount of tracer added was fixed in order not to exceed the threshold concentration of 1.5 mg/L (maximum concentration value allowed in drinking water) under the hypothesis that the lagoon was not mixed at all (plug flow modality). Samples were taken from the outlet channel every 45 minutes and analyzed using a fluoride selective probe. The sampling campaign at the outlet channel was stopped after 29 days from the introduction of the tracer, when the outlet concentration dropped under the detection limit of the fluoride selective probe. Samples were also taken at 15 points (over 3 depth values, for a total of 45 sampling points) throughout the lagoon, 1, 7 and 14 days after the tracer introduction. From the interpretation of the tracer response and the tracer distribution in the lagoon in the three days of sampling, it appears that the system was efficiently mixed without relevant short circuits. In fact the first detection of the tracer at the outlet channel occurred after very few hours from the beginning of the test and the mean residence time of the lagoon, determined using the Levenspiel formula, in the presence of the flow rate used for the test, was about 13 days compared with a theoretical hydraulic residence time of 18 days. This assured that dissolved contaminants, like fluoride, from the river were efficiently diluted by the lagoon before entering the WT

Long-Term Monitoring of a Lagooning Basin Used as Pretreatment Facility for a WTP: Effect on Water Quality and Description of Hydrological and Biological Cycles Using Chemometric Approaches

The drinking water treatment plant (WTP) of the city of Turin (NW Italy), with a treatment capacity of 40•106 m3/y, has a basin, that is employed as a lagooning pre-treatment facility. This study aims to: • assess the effect of the basin on several environmental parameters (temperature, dissolved oxygen (DO), turbidity, pH, chloride, nitrite and total chlorophyll) of the river water before entering the WTP and • monitor the changes inside the basin caused by the seasonal hydrological and biological cycles. Sampling was carried out on 16 dates over three years at the inlet and outlet channel of the basin and in five locations along three depth values (1; 6 and 12 m, i.e. at the bottom). The results of the three-year monitoring campaign demonstrated that the basin had an effect on pH (p = 6.6•10-9), DO (p = 0.000072), turbidity (p = 0.011) and chlorophyll (p = 0.033). No significant changes regarding nitrite (p = 0.11), chloride (p = 0.94) and temperature (p = 0.66) were detected. The results gathered from the sampling campaign inside the basin demonstrated that, during the year, the basin experienced: • two states of complete mixing in early spring and fall, when the differences in temperature between the surface and the bottom of the basin were less than 1°C; • a condition of late spring / summer stratification, with a temperature difference between surface and bottom of 4-5°C and a difference in DO, pH and total chlorophyll concentration that increased throughout the spring season; • one or more states of summer circulation due to the weak stability of the warm season stratification. During the states of circulation, the persistent algae photosynthetic activity tended to cause a quick change in the concentration of DO, total chlorophyll and pH value in the most superficial layer of the basin. The results of the Principal Component Analysis (PCA) showed a strong direct relationship between the weight of the first component and the hydrodynamic states of the basin (stratification / circulation) and an inverse relationship between the weight of the second component and the intensity of photosynthetic activity of algae species

Chlorate as disinfection by-product in Turin drinking water treatment plant: formation, monitoring, solution possibilities

Chlorine dioxide application in drinking water disinfection avoids trihalomethanes, but it can generate other disinfection by-products (DBPs): chlorite and chlorate. This paper concerns chlorate ion formation during chlorine dioxide generation and oxidation reactions, in relation with the use of sodium hypochlorite solutions. This aspect is very important taking into account that current WHO Drinking water Guidelines suggest a limit of 700 µg/L for chlorate ion. SMAT (the drinking water supplier of the town of Turin, northern Italy) uses both chlorine dioxide and sodium hypochlorite in its three surface water treatment plants, having a whole potentiality of about 40 M m3/y. This research considered the following issues: chlorate neo-formation processes, potential precursors and influencing conditions, and process and plant minimization intervents. The three treatment lines were analyzed by monitoring for nine months chlorate concentration in significant phases of the potabilization process and in the outflow, in order to detect the most critical conditions. Chlorate formation can be bound both to the natural degradation of hypochlorite, and to different dismutation phenomena occurring during disinfection. The first contribution can be more easily controlled: a refrigerated storage of hypochlorite was evaluated on laboratory and pilot scale, and taking into account its effectiveness to comply with WHO guidelines, this improvement will be shortly adopted in full scal

Chlorate as disinfection by-product in Turin drinking water treatment plant: formation, monitoring, solution possibilities

Chlorine dioxide application in drinking water disinfection avoids trihalomethanes, but it can generate other disinfection by-products (DBPs): chlorite and chlorate. This paper concerns chlorate ion formation during chlorine dioxide generation and oxidation reactions, in relation with the use of sodium hypochlorite solutions. This aspect is very important taking into account that current WHO Drinking water Guidelines suggest a limit of 700 µg/L for chlorate ion. SMAT (the drinking water supplier of the town of Turin, northern Italy) uses both chlorine dioxide and sodium hypochlorite in its three surface water treatment plants, having a whole potentiality of about 40 M m3/y. This research considered the following issues: chlorate neo-formation processes, potential precursors and influencing conditions, and process and plant minimization intervents. The three treatment lines were analyzed by monitoring for nine months chlorate concentration in significant phases of the potabilization process and in the outflow, in order to detect the most critical conditions. Chlorate formation can be bound both to the natural degradation of hypochlorite, and to different dismutation phenomena occurring during disinfection. The first contribution can be more easily controlled: a refrigerated storage of hypochlorite was evaluated on laboratory and pilot scale, and taking into account its effectiveness to comply with WHO guidelines, this improvement will be shortly adopted in full scale

Circulating extracellular vesicles derived from tumor endothelial cells hijack the local and systemic anti-tumor immune response: Role of mTOR/G-CSF pathway

Circulating tumour-derived extracellular vesicles are supposed to contribute to the spreading of distant metastasis. In this study, we investigated the impact of circulating extracellular vesicles derived from tumour-endothelial cells (TEVs) in the expansion of the metastatic bulk. We focus on the role of immune cells in controlling this process using the 4T1 triple negative breast cancer (TNBC) syngeneic model.4T1 cells were intravenously injected and exposed to circulating TEVs from day 7. The lung, spleen, and bone marrow (BM) were recovered and analysed. We demonstrated that circulating TEVs boost lung metastasis and angiogenesis. FACS and immunohistochemically analyses revealed a significant enrichment of Ly6G+/F4/80+/CD11b+ cells and Ly6G+/F4/80-/CD11b+ in the lung and in the spleen, while Ly6G+/F4/80-/CD11b+ in the BM, indicating the occurrence of a systemic and local immune suppression. TEV immune suppressive properties were further supported by the increased expression of PD-L1, PD-1, and iNOS in the tumour mass. In addition, in vitro experiments demonstrated an increase of CD11+ cells, PD-L1+ myeloid and cancer cells, upregulation of LAG3, CTLA4 and PD-1 in T-cells, release of ROS and NOS, and impaired T-cell-mediated cytotoxic effect in co-culture of TEVs-preconditioned PBMCs and cancer cells. Granulocyte-colony stimulating factor (G-CSF) level was increased in vivo, and was involved in reshaping the immune response. Mechanistically, we also found that mTOR enriched TEVs support G-CSF release and trigger the phosphorylation of the S6 (Ser235/236) mTOR downstream target. Overall, we provided evidence that circulating TEVs enriched in mTOR supported G-CSF release thereby granting tumour immune suppression and metastasis outgrowth

Interleukin-3-Receptor-α in Triple-Negative Breast Cancer (TNBC): An Additional Novel Biomarker of TNBC Aggressiveness and a Therapeutic Target

SIMPLE SUMMARY: Molecular and histological profiling is crucial for biomarker and therapeutic target discovery, for example, in TNBC. We demonstrated that IL-3Rα expression led to the identification of a subgroup of TNBC patients displaying a poor overall survival. Moreover, we refined TNBC molecular annotation and drew a model including IL-3Rα, PD-L1, and genes related to EMT, which finely discriminates cancer aggressiveness. Finally, we first demonstrated that IL-3Rα is instrumental in granting tumour adaptation and progression by reprogramming TNBC cells to form large dysfunctional vessels and reshaping PD-L1 expression in primary tumours and metastases. Therefore, the IL-3/IL-3Rα axis may be proposed as a marker of TNBC aggressiveness, as a novel TNBC therapeutic challenge. ABSTRACT: Tumour molecular annotation is mandatory for biomarker discovery and personalised approaches, particularly in triple-negative breast cancer (TNBC) lacking effective treatment options. In this study, the interleukin-3 receptor α (IL-3Rα) was investigated as a prognostic biomarker and therapeutic target in TNBC. IL-3Rα expression and patients’ clinical and pathological features were retrospectively analysed in 421 TNBC patients. IL-3Rα was expressed in 69% human TNBC samples, and its expression was associated with nodal metastases (p = 0.026) and poor overall survival (hazard ratio = 1.50; 95% CI = 1.01–2.2; p = 0.04). The bioinformatics analysis on the Breast Invasive Carcinoma dataset of The Cancer Genome Atlas (TCGA) proved that IL-3Rα was highly expressed in TNBC compared with luminal breast cancers (p = 0.017, padj = 0.026). Functional studies demonstrated that IL-3Rα activation induced epithelial-to-endothelial and epithelial-to-mesenchymal transition, promoted large blood lacunae and lung metastasis formation, and increased programmed-cell death ligand-1 (PD-L1) in primary tumours and metastases. Based on the TCGA data, IL-3Rα, PD-L1, and EMT coding genes were proposed to discriminate against TNBC aggressiveness (AUC = 0.86 95% CI = 0.82–0.89). Overall, this study identified IL-3Rα as an additional novel biomarker of TNBC aggressiveness and provided the rationale to further investigate its relevance as a therapeutic target