In drinking water, high concentrations of fluoride and arsenic can have adverse effects on human health. Waste deriving from the rice industry (rice husk, rice straw, rice bran) can be promising adsorbent materials, because they are (i) produced in large quantities in many parts of the world, (ii) recoverable in a circular economy perspective, (iii) at low cost if compared to expensive conventional activated carbon, and (iv) easily manageable even in developing countries. For the removal of fluoride, rice husk and rice straw allowed to obtain adsorption capacities in the range of 7.9–15.2 mg/g. Using rice husk for arsenic adsorption, excellent results were achieved with adsorption capacities above 19 mg/g. The best results both for fluorides and arsenic (>50 mg/g) were found with metal- or chemical-modified rice straw and rice husk. Identifying the next steps of future research to ensure the upscaling of biochar from recovered by-products, it is fundamental to perform: (i) tests on real waters for multicomponent adsorption; (ii) experiments with pilot plants in continuous operation; (iii) cost analysis/real applicability of modification treatments such as metal coupling or chemical synthesis; (iv) more studies on the biochar stability and on its regeneration or recovery after use.

This work evaluates the efficiency of three biochar samples toward the adsorption of manganese, iron, and selenium present in a sample of urban wastewater. The biochar was produced from the pyrolysis of rice husks at 350 °C for 6 h (RHB) and subsequently modified using HCl (RHB_HCl) or NaOH (RHB_NaOH) to increase its surface area. The RHB_NaOH sample exhibited the highest removal efficiency for the three metals. The metals’ adsorption removal efficiency for RHB_NaOH was in the order Mn (76%), Se (66%), and Fe (66%), while for RHB_HCl, it was Fe (59%), Mn (30%), and Se (26%). The results show that the as-prepared RHB can remove the metals, even if in low amounts (Fe (48%), Mn (3%), and Se (39%)). The adsorption removal for the three types of adsorbents follows the Langmuir isotherm model. Pseudo-first-order and pseudo-second-order models were used to determine the adsorption mechanism for each of the three adsorbents. Both models showed a good fit with R² (>0.9) for the RHB_NaOH and RHB sorption of Fe, Mn, and Se. Overall, this work demonstrates the potential of biochar for the removal of metals from real wastewater.

Per- and polyfluoroalkyl substances (PFAS) constitute a group of organofluorine chemical synthetic compounds widely used in industries and manufacturing due to their hydrophobic properties. However, PFAS have been found to cause negative human health outcomes. Therefore, a strong interest in the possible removal of these compounds from wastewater (WW) has been shown. This work aims to present a systematic analysis of the scientific literature related to the innovative and alternative adsorbent materials that can be used for treating PFAS-contaminated WW. Moreover, the adsorption processes are considered, focusing the attention on virgin adsorbent materials and biochar as adsorbents. Virgin adsorbent materials comprise conventional adsorbent materials, functional clays, metal–organic frameworks, and functionalized organic polymers. Biochar includes materials obtained from agricultural or food residues and from sewage sludge. The review shows that conventional treatment units using virgin adsorbent materials are characterized by high adsorption capacity, but also high costs. In addition, the refunctionalization of adsorbent materials is difficult to obtain. On the contrary, biochar, which is a residual product of other production processes, appears to be a cost-effective solution.

The interest in research on up-flow anaerobic sludge blanket (UASB) reactors is growing. The meta-analysis of bibliometric data highlighted the growing interest in four diverse topics: (i) energy recovery production; (ii) combination with other treatments; (iii) the study of processes for the removal of specific pollutants and, (iv) characterization of microbial community and granular sludge composition. In particular, the papers published in the first 6 months of 2021 on this process were selected and critically reviewed to highlight and discuss the results, the gaps in the literature and possible ideas for future research. Although the state of research on UASB is to be considered advanced, there are still several points that will be developed in future research such as the consolidation of the results obtained on a semi-industrial or real scale, the use of real matrices instead of synthetic ones and a more in-depth study of the effect of substances such as antibiotics on the microbiota and microbiome of UASB granular biomass. To date, few and conflicting data about the environmental footprint of UASB are available and therefore other studies on this topic are strongly suggested.

In this study, the rheological properties of thermophilic biological sludge (TBS) have been investigated evaluating the influence of non-volatile solids (NVS). Calcium carbonate, sand, and sodium bentonite were separately added to the sludge to evaluate the effect of concentration and type of NVS. Results show that TBS consistency coefficient significantly enhanced increasing sodium bentonite concentration. On the contrary, calcium carbonate and sand showed relatively small influence on the rheological properties of TBS. Thixotropic behaviour of TBS has also been investigated and is more pronounced at higher shear rate (1000 s⁻¹). Double exponential fitting model was the best choice to represent thixotropic behaviour in case of low (100 s⁻¹) and high shear rate (1000 s⁻¹), while a single-exponential model represents the best option in case of medium shear rate (400 s⁻¹).

Bcl-2/IgH rearrangement is the molecular hallmark of follicular lymphoma which is present in 70 - 90% of cases at diagnosis. The significance of the bcl-2 rearrangement at onset of disease and of its clearing after treatment (molecular response) is still controversial. The aims of the present analysis are: to evaluate the incidence of bcl-2 rearrangement in blood and marrow in a cohort of patients systematically investigated at diagnosis, to describe the correlation between bcl-2 and presenting features, to clarify the correlation of molecular response with outcome. Of 98 patients studied at initial staging for the presence of bcl-2 rearrangement, 64 (65%) showed bcl-2/IgH rearrangement in peripheral blood (PB) and/or bone marrow (BM) (58 at Major Breakpoint Region, MBR, and 6 at minor cluster region, mcr) while no bcl-2/IgH rearrangement was detected in the remaining 34 (35%) (germline status). No statistically significant differences were found between bcl-2 positive and bcl-2 negative cases as concerns presenting clinical features and response to first-line therapy. The median event-free survival, EFS, was not reached for the bcl-2 negative patients in PB and was 11 months for bcl-2 positive patients (statistically significant, P = 0.01) and, similarly, the median EFS was not reached for the bcl-2 negative patients in BM and was 11 months for bcl-2 positive patients (statistically significant, P = 0.04). Of the 64 bcl-2 positive cases, patients were analysed for molecular response (48 in BM and 40 in PB): 16 were molecular responders in BM and 20 were molecular responders in PB. The median EFS was 19 months for molecular responders in PB and 9 months for non-responders; 1-year-EFS was 68% (95% CI; 49 - 88), for responders in PB and 42% (95% CI; 22 - 61) for non-responders (P = 0.05). The median EFS was 11 months both for molecular responders and non-responders in BM; 1-year-EFS was 52% for responders in BM (CI; 30 - 73), and 43% (CI 33 - 71) for non-responders (P = 0.7). No clinical feature showed significant correlation with PB and BM molecular responses. This analysis shows that bcl-2 rearrangement in blood and bone marrow is frequently detected at staging, even in stage I disease. Absence of the bcl-2 rearrangement is related to a better EFS and the achievement of a molecular response in peripheral blood after therapy is associated with a better EFS.