Effects of different operating conditions on sediment slurry sequencing batch reactors treating marine port sediments contaminated by PAHs

Due to intensive anthropic activities, marine port sediments are often contaminated by organic pollutants like polycyclic aromatic hydrocarbons (PAHs), which represent a significant environmental threat. In this study, two sediment slurry sequencing batch reactors (SS-SBRs) were used to biologically degrade a mixture of PAHs (namely fluorene, phenanthrene, fluoranthene and pyrene) from marine sediments dredged from Cagliari (Italy) and El Kantaoui (Tunisia) ports. To enhance PAHs removal by biostimulation, nutrients were added in both sediments, acetate was used as co-substrate (El Kantaoui, SS-SBR1), and saponins were used as surfactants (Cagliari, SS-SBR2). Moreover, different levels of contamination (up to 200 mgPAHtot/kgdw in SS-SBR1; up to 400 mgPAHtot/kgdw in SS-SBR2) and solid to liquid ratios (S/L, up to 0.2 in SS-SBR1; up to 0.1 in SS-SBR2) were applied. As to SS-SBR1, the highest removal efficiencies (99-100% and 98-100% for 3- and 4-ring PAHs, respectively) were achieved when the level of contamination and S/L were set at 200 mgPAH-tot/kgdw and 0.1, 150 mgPAH-tot/kgdw and 0.13, and 150 mgPAH-tot/kgdw and 0.20, respectively; as to SS-SBR2, very high removal efficiencies (99÷100% and 98÷100% for 3- and 4-ring PAHs, respectively) were observed during the whole experimental campaign. Such results are promising and provide a useful background for testing other important operating parameters (e.g., the volumetric exchange ratio)

Bioleaching of Valuable Elements from Red Mud: A Study on the Potential of Non-Enriched Biomass

Red mud (RM) is the main residue produced by the alkaline extraction of alumina (Al2O3) from bauxite, and it contains valuable metals such as iron (Fe), aluminium (Al), titanium (Ti), magnesium (Mg), manganese (Mn), rare earth elements, etc. This research aimed to investigate the biologically induced leaching of some valuable elements from raw RM without preliminary biomass enrichment and inoculum, simultaneously reducing RM polluting potential and extracting metals for their subsequent recovery within a circular economy-based approach. In addition to the missing inoculum, such an approach is challenging since high RM alkalinity and pH, as well as the absence of any sulphides, constrain the use of the most common biohydrometallurgical techniques. Red Muds from two European locations were tested (RM-I and RM-II, respectively). Bioleaching tests were performed at different temperatures (T = 22 & DEG;C and 28 & DEG;C; and also 15 & DEG;C for RM-II) and solid-to-liquid ratios (S/L = 2%, 5%). A sudden drop in pH from alkaline to constant neutral/acidic values was observed in almost all tests, and such results were attributed to biological activity since abiotic tests did not show any pH decrease. The best results in terms of extraction were achieved with RM-II, in particular for Al, Mg and Mn (17%, 42% and 47%, respectively). At 2% S/L, the highest temperature allowed for a better metal release, while at 5% S/L, the highest extraction of Al, Mg and Ti was observed at 22 & DEG;C. As expected, iron was less available to leach at the achieved pH values, as it was mostly present as hematite in both RMs. Finally, the first microbiological characterisation of the autochthonous biomass selected during the bioleaching treatment of RM was provided

Ammonium recovery from agro-industrial digestate using bioelectrochemical systems

Abstract Growing food and biomass production at the global scale has determined a corresponding increase in the demand for and use of nutrients. In this study, the possibility of recovering nitrogen from agro-industrial digestate using bioelectrochemical systems was investigated: two microbial electrolysis cells (MECs) were fed with synthetic and real digestate (2.5 gNH4+-N L−1). Carbon felt and granular graphite were used as anodes in MEC-1 and MEC-2, respectively. As to synthetic wastewater, the optimal nitrogen load (NL) for MEC-1 and -2 was 1.25 and 0.75 gNH4+-N d−1, respectively. MEC-1 showed better performance in terms of NH4+-N removal efficiency (39 ± 2.5%) and recovery rate (up to 70 gNH4+-N m−2d−1), compared to MEC-2 (33 ± 4.7% and up to 30 gN m−2d−1, respectively). At the optimal hydraulic retention time, lower NH4+-N removal efficiencies and recovery rates were observed when real digestate was fed to MEC-1 (29 ± 6.6% and 60 ± 13 gNH4+-N m−2d−1, respectively) and MEC-2 (21 ± 7.9% and 10 ± 3.6 gNH4+-N m−2d−1, respectively), likely due to the higher complexity of the influent. The average energy requirements were 3.6–3.7 kWh kgNremoved−1, comparable with values previously reported in the literature and lower than conventional ammonia recovery processes. Results are promising and may reduce the need for costly and polluting processes for nitrogen synthesis

Clinical characteristics, neuroimaging findings, and neuropsychological functioning in attention-deficit hyperactivity disorder: Sex differences

Recent clinical studies, in both children/adolescents and adults, have shown the extreme neuropsychological heterogeneity of attention-deficit hyperactivity disorder (ADHD): specific neuropsychological deficits have been found only in a minority of individuals, with no direct correlation between discrete cognitive performances and the trajectory of clinical symptoms. Deficits in specific neuropsychological functions may be common in ADHD, but nevertheless no cognitive or neuropsychological profile may fully explain the disorder. Sex differences in the ADHD presentation, both at a neuropsychological and clinical level, also contribute to this clinical and neuropsychological heterogeneity. At a neuropsychological level, females with ADHD may show greater working memory problems, poorer vocabulary skills and worse visual spatial reasoning. Structural and functional imaging study also show discrete differences across sex; however, the great majority of clinical studies mainly or exclusively include male participants with insufficient data to draw firm conclusions on sex differences within the disorder. Here, we report the recent literature data, discussing still open research questions about the clinical presentation, neuroimaging findings, and neuropsychological functioning in ADHD with a focus on the impact of sex differences—a deeper insight in these unresolved issues may have relevant clinical and therapeutic implications for tailored, effective, and long-lasting interventions

Industrial Sponsor Perspective On Leveraging Capstone Design Projects To Enhance Their Business

Capstone design projects have become commonplace among engineering and engineering technology programs.  These projects are valuable tools when assessing students, as they require students to work in teams, communicate effectively, and demonstrate technical competency.  The use of industrial sponsors enhances these projects by giving these projects more of a “real world” feel.  Most of the research into capstone design projects focuses on student learning as well as the overall design process.  However, very little research has been performed from the perspective of the industrial sponsor.  In this paper, an industrial sponsor who has sponsored several large-scale capstone design projects presents their perspective on working with students on these projects.  These projects serve as training systems for their existing employees and clients, and offer the sponsor the opportunity to evaluate the students as prospective future employees

Prognostic factors facilitating multiple food allergies and atopiv march occurrence in children with Non-IgE mediated gastrointestinal Food Allergy: results of two years follow up of the NIGEFA project

Objectives and Study: Non-IgE mediated gastrointestinal food allergies (non-IgE-GIFA) are an increasing problem in pediatric gastroenterology clinical practice. These conditions include food protein-induced: enterocolitis syndrome (FPIES), enteropathy (FPE), allergic proctocolitis (FPIAP), and motility disorders (FPIMD). The NIGEFA project is focused on the investigation of main clinical features, prognostic factors (presence atopic dermatitis (AD), multiple food allergies, diagnostic delay, and familial history of allergy), and natural history (atopic march (AM) prevalence and timing of immune tolerance acquisition). Methods: Prospective observational study evaluating children with non-IgE-GIFA diagnosed according to standard criteria observed at a tertiary center for pediatric gastroenterology and allergy (both sexes, aged <36 m, follow up 12 m after diagnosis). Main anamnestic, demographic, and clinical data were collected from all enrolled patients. Immune tolerance acquisition was evaluated by the result of oral food challenge. Results: A total of 100 patients were enrolled: 58% male, mean age at diagnosis (SD) 8.5(8.8) m. Non-IgE-GIFA conditions were: FPE (44%), FPIES (11%), FPIAP (18%), FPIMD (27%). Mean diagnostic delay was 5.3 (7.4) m. Multiple non-IgE-GIFA were observed in 47% at baseline. Familial history of allergy was observed in 64% of subjects. Presence of AD before the onset of non-IgE-GIFA was observed in 40% of subjects. The overall rate of immune tolerance acquisition at 12 m was 27%, with a higher rate in FPIAP (44%) compared with FPIMD (29.6%), FPE (22.7%) and FPIES (9.1%) subjects (p<0.05). The rate of immune tolerance acquisition at 12 m was significantly lower in children with familial history of allergy (-48%, estimated risk ratio (RR)0.52 (95% CI 0.28 to 0.99, p<0.05)) and in those with multiple non-IgE-GIFA (-61%, RR at 12 m 0.39 (95% CI 0.18 to 0.85, p<0.05)). At 12 m follow up, the rate of subjects presenting AM was 24% with no difference among the 4 disease groups. The occurrence of AM was significantly higher in subjects with multiple (38%) vs. mono non-IgE-GIFA (11%) (p<.001) at baseline, with an estimated RR of 3.38 (95% CI 1.47 to 7.81, p<0.01) at 12 m. Moreover, for every 1-month of diagnostic delay there was an increase of 1.04 RR(95% CI 1.01 to 1.07) of AM occurrence at 12 m. No associations with other potential predictors (sex, familial allergy risk, AD before the onset of GIFA, type of non-IgE-GIFA) were found. Conclusions: These data shed lights on prognostic factors and natural history of non-IgE-GIFA suggesting the importance of early diagnosis in preventing the occurrence of AM occurrence in these patients. Contac