Recent Progress on Synthesis and Properties of Black Phosphorus and Phosphorene As New-Age Nanomaterials for Water Decontamination.

Concerted efforts have been made in recent years to find solutions to water and wastewater treatment challenges and eliminate the difficulties associated with treatment methods. Various techniques are used to ensure the recycling and reuse of water resources. Owing to their excellent chemical, physical, and biological properties, nanomaterials play an important role when integrated into water/wastewater treatment technologies. Black phosphorus (BP) is a potential nanomaterial candidate for water and wastewater treatment, especially its monolayer 2D derivative called phosphorene. Phosphorene offers relative adjustability in its direct bandgap, high charge carrier mobility, and improved in-plane anisotropy compared to the most extensively studied 2D nanomaterials. In this study, we examined the physical and chemical characteristics and synthetic processes of BP and phosphorene. We provide an overview of the latest advancements in the main applications of BP and phosphorene in water/wastewater treatment, which are categorized as photocatalytic, adsorption, and membrane filtration processes. Additionally, we explore the existing difficulties in the integration of BP and phosphorene into water/wastewater treatment technologies and prospects for future research in this field. In summary, this review highlights the ongoing necessity for significant research efforts on the integration of BP and phosphorene in water and wastewater applications.

Microbial desalination cell treated spent geothermal brine as a nutrient medium in hydroponic lettuce cultivation: Health risk assessment.

The scarcity and contamination of freshwater resources are extremely critical issues today, and the expansion of water reuse has been considered as an option to decrease its impact. Therefore, the reuse of microbial desalination (MDC)-treated spent geothermal brine for agricultural purposes arises as a good solution to prevent water contamination and provide sustainable water usage. In this study, the potential of treated spent geothermal water from MDC system as a nutrient solution for the hydroponic cultivation of lettuce was evaluated. The effects of different water samples (Hoagland solution (R1) as a control, MDC-treated water (R2), 1:1, v/v mixture of MDC-treated water and Hoagland solution (R3), 4:1, v/v mixture of MDC-treated water and Hoagland solution (R4), and tap water (R5)) on lettuce growth were considered. The application of R3 and R4 samples for hydroponic lettuce cultivation was promising since the lettuce plants uptake sufficient nutrients for their growth and productivity with low toxic metal concentrations. In addition, the chlorophyll-a, chlorophyll-b, and carotene contents of lettuce were in the range of 1.045-2.391 mg/g, 0.761-1.986 mg/g, and 0.296-0.423 mg/g in different water samples, respectively. The content of chlorophyll-a was highest in R1 (2.391 mg/g), followed by R3 (2.371 mg/g). Furthermore, the health risk assessment of heavy metal accumulations in the lettuce plants cultivated in the various water samples was determined. Results showed that heavy metal exposure via lettuce consumption is unlikely to suffer noticeable adverse health problems with values below the permissible limit value.

Comparative environmental sustainability assessment of biohydrogen production methods.

As energy crisis is recognized as an increasingly serious concern, the topic on biohydrogen (bioH2) production, which is renewable and eco-friendly, appears to be a highly-demanding subject. Although bioH2 production technologies are still at the developmental stage, there are many reported works available on lab- and pilot-scale systems with a promising future. This paper presents various potential methods of bioH2 production using biomass resources and comparatively assesses them for environmental impacts with a special emphasis on the specific biological processes. The environmental impact factors are then normalized with the feature scaling and normalization methods to evaluate the environmental sustainability dimensions of each bioH2 production method. The results reveals that the photofermentation (PF) process is more environmentally sustainable than the other investigated biological and thermochemical processes, in terms of emissions, water-fossil-mineral uses, and health issues. The global warming potential (GWP) and acidification potential (AP) for the PF process are then found to be 1.88 kg-CO2 eq. and 3.61 g-SO2 eq., which become the lowest among all processes, including renewable energy-based H2 production processes. However, the dark fermentation-microbial electrolysis cell (DF-MEC) hybrid process is considered the most environmentally harmful technique, with the highest GWP value of 14.6 kg-CO2 eq. due to their superior electricity and heat requirements. The water conception potential (WCP) of 84.5 m3 and water scarcity footprint (WSF) of 3632.9 m3 for the DF-MEC process is also the highest compared to all other processes due to the huge amount of wastewater formation potential of the system. Finally, the overall rankings confirm that biological processes are primarily promising candidates to produce bioH2 from an environmentally friendly point of view.

Insights into engineered graphitic carbon nitride quantum dots for hazardous contaminants degradation in wastewater.

Increased environmental pollution is a critical issue that must be addressed. Photocatalytic, adsorption, and membrane filtration methods are suitable in environmental governance because of their high selectivity, low cost, environment-friendly nature, and excellent treatment efficiency. Graphitic carbon nitride (g-C3N4) quantum dots (QDs) have been considered as photocatalysts, adsorbents, and membrane materials for wastewater treatments, owing to their stability, adsorption capacity, photochemical properties, and low toxicity and cost. This review summarizes g-C3N4 QD synthesis techniques, operating parameters affecting the removal performance in the treatment process, modification effects with other semiconductors, and benefits and drawbacks of g-C3N4 QD-based materials. Furthermore, this review discusses the practical applications of g-C3N4 QDs as adsorbents, photocatalysts, and membrane materials for organic and inorganic contaminant treatments and their value-added product formation potential. Modified g-C3N4 QD-based material adsorbents, photocatalysts, and membranes present potentially applicable effects, such as removal of most waterborne contaminants. Excellent results were obtained for the reduction of methyl orange, bisphenol A, tetracycline, ciprofloxacin, phenol, rhodamine B, E. coli, and Hg. Overall, this paper provides comprehensive background on g-C3N4 QD-based materials and their diverse applications in wastewater treatment, and it presents a foundation for the enhancement of similar unique materials in the future.

A review of boron removal from aqueous solution using carbon-based materials: An assessment of health risks.

Carbon-based compounds have gained attention of researchers for use in boron removal due to their properties, which make them a viable and low cost adsorbent with a high availability, as well as environmental friendliness and high removal efficiency. The removal of boron utilizing carbon-based materials, including activated carbon (AC), graphene oxide (GO), and carbon nanotubes (CNTs), is extensively reviewed in this paper. The effects of the operating conditions, kinetics, isotherm models, and removal methods are also elaborated. The impact of the modification of the lifetime of carbon-based materials has also been explored. Compared to unmodified carbon-based materials, modified materials have a significantly higher boron adsorption capability. It has been observed that adding various elements to carbon-based materials improves their surface area, functional groups, and pore volume. Tartaric acid, one of these doped elements, has been employed to successfully improve the boron removal and adsorption capabilities of materials. An assessment of the health risk posed to humans by boron in treated water utilizing carbon-based materials was performed to better understand the performance of materials in real-world applications. Furthermore, the boron removal effectiveness of carbon-based materials was evaluated, as well as any shortcomings, future perspectives, and gaps in the literature.

Carbonaceous materials for removal and recovery of phosphate species: Limitations, successes and future improvement.

The carbonaceous materials have gained significant interest for the phosphorus species remediation and recovery in the last decade. Carbonaceous materials present many unique features, such as cost effective, availability, environmentally friendly, and high removal efficiency that make them a promising adsorbent. In this review, the recent application of carbonaceous materials including activated carbon (AC), graphene and graphene oxide (GO), lignin, carbon nanotubes (CNTs), and gC3N4 for phosphate removal and recovery were comprehensively summarized. The kinetics and isotherm models, removal mechanisms, and effects of operating parameters are reported. The reusability, lifetime of carbonaceous materials, and impact of modification were also considered. The modified carbonaceous materials have significantly high phosphate adsorption capacity compared to unmodified adsorbents. Namely, MgO-functionalized lignin-based bio-charcoal exhibited a 906.8 mg g-1 of capacity as the highest one among other reviewed materials. The modification of carbonaceous materials with various elements has been presented to improve the surface functional groups, surface area and charge, and pore volume and size. Among these loaded elements, iron has been effectively used to provide a prospect for magnetic recovery of the adsorbent as well as increase phosphate adsorption. Furthermore, the phosphate recovery methods, phosphate removal efficiency of carbonaceous materials, the limitations, important gaps in the literature, and future studies to enhance applicability of carbonaceous materials in real scale are also discussed.

Energy production from treatment of industrial wastewater and boron removal in aqueous solutions using microbial desalination cell.

As a result of a much needed paradigm shift worldwide, treated saline water is being considered as a viable option for replacing freshwater resources in agricultural irrigation. Vastly produced geothermal brine in Turkey may pose a significant environmental risk due to its high ionic strength, specifically due to boron. Boron species, which are generally found uncharged in natural waters, are costly to remove using high-throughput membrane technologies such as reverse osmosis. Recent advances in bioelectrochemical systems (BES) has facilitated development of energetically self-sufficient wastewater treatment and desalination. In this study, removal of boron from synthetic solutions and real geothermal waters, along with simultaneous energy production, using the microbial desalination cell (MDC) were investigated. Optimization studies were conducted by varying boron concentrations (5, 10, and 20 mg L-1), air flow rates (0, 1, and 2 L min-1), electrode areas (18, 24, 36, and 72 cm2), catholyte solutions, and operating modes. Even though the highest concentration decrease was observed for 20 mg-B L-1, 5 mg-B L-1 concentration experiment gave the closest result to the 2.4 mg-B L-1 limit value asserted by WHO. Effect of electrode surface area was proven to be significant on boron removal efficiency. Employing the optimum conditions acquired with synthetic solutions, boron and COD removal efficiencies from real geothermal brine were 44.3% and 90.6%, respectively. MDC, being in its early levels of technology readiness, produced promising desalination and energy production results in removal of boron from geothermal brine.

Early COVID-19 therapy with azithromycin plus nitazoxanide, ivermectin or hydroxychloroquine in outpatient settings significantly improved COVID-19 outcomes compared to known outcomes in untreated patients.

In a prospective observational study (pre-AndroCoV Trial), the use of nitazoxanide, ivermectin and hydroxychloroquine demonstrated unexpected improvements in COVID-19 outcomes when compared to untreated patients. The apparent yet likely positive results raised ethical concerns on the employment of further full placebo controlled studies in early-stage COVID-19. The present analysis aimed to elucidate, through a comparative analysis with two control groups, whether full placebo-control randomized clinical trials (RCTs) on early-stage COVID-19 are still ethically acceptable. The Active group (AG) consisted of patients enrolled in the Pre-AndroCoV-Trial (n = 585). Control Group 1 (CG1) consisted of a retrospectively obtained group of untreated patients of the same population (n = 137), and Control Group 2 (CG2) resulted from a precise prediction of clinical outcomes based on a thorough and structured review of indexed articles and official statements. Patients were matched for sex, age, comorbidities and disease severity at baseline. Compared to CG1 and CG2, AG showed reduction of 31.5-36.5% in viral shedding (p < 0.0001), 70-85% in disease duration (p < 0.0001), and 100% in respiratory complications, hospitalization, mechanical ventilation, deaths and post-COVID manifestations (p < 0.0001 for all). For every 1000 confirmed cases for COVID-19, at least 70 hospitalizations, 50 mechanical ventilations and five deaths were prevented. Benefits from the combination of early COVID-19 detection and early pharmacological approaches were consistent and overwhelming when compared to untreated groups, which, together with the well-established safety profile of the drug combinations tested in the Pre-AndroCoV Trial, precluded our study from continuing employing full placebo in early COVID-19.

Arsenic removal from groundwater using an aerated electrocoagulation reactor with 3D Al electrodes in the presence of anions.

Co-occurrence of arsenic and anions in groundwater causes a severe health problems and combine effects of these pollutants significantly affect performance of treatment process. Thus, this study has been conducted to examine the combine effects of anions on arsenic removal using aerated electrocoagulation (EC) reactor with 3D Al electrodes in groundwater. A 3-level, six factors Box-Behnken experimental design (BBD) was applied to investigate the individual and combine effect of anions and operating time: phosphate (x1: 1-10 mg L-1), silica (x2: 20-80 mg L-1), bicarbonate (x3: 130-670 mg L-1), fluoride (x4: 2-10 mg L-1), boron (x5: 5-10 mg L-1), and operating time (x6: 8-22 min) on desired responses. The specified responses were effluent arsenic concentration (Cf,As), removal efficiency of arsenic (Re), consumptions of energy and electrode (ENC and ELC), operational cost (OC), and adsorption capacity (qe). The optimum operating parameters predicted using BBD were found to be x1: 1.0 mg L-1, x2: 26.0 mg L-1, x3: 651.5 mg L-1, x4: 2.0 mg L-1, x5: 9.9 mg L-1, and x6: 10.5 min considering highest removal efficiency of arsenic and lowest operational cost. Under these operating conditions, the experimental values of Cf,As, Re, ENC, ELC, OC, and qe were found to be 2.82 µg L-1, 98.6%, 0.411 kWh m-3, 0.0124 kg m-3, 0.098 $ m-3, and 17.65 µg As (mg Al)-1, respectively. Furthermore, mathematical modelling was conducted using quadratic regression model and response surface analysis was performed to understand the relationship between independent parameters and responses.

Arsenite removal from groundwater by aerated electrocoagulation reactor with Al ball electrodes: Human health risk assessment.

The application of conventional electrocoagulation (EC) process for removal of As(III) from groundwater suffers from the need of external oxidation agent for oxidation of As(III) to As(V). To tackle this limitation, an aerated EC reactor for the removal of As(III) from groundwater was evaluated in this study. The effect of initial pHi, air flow rate, applied current, and electrode height in the EC reactor was examined. The experimental results showed that removal of arsenic mostly dependent on the applied current, electrode height in EC reactor, and air flow rate. The As(III) removal efficiency (99.2%) was maximum at pHi of 7.5, air flow rate of 6 L min-1, applied current of 0.30 A, and electrode height in EC reactor of 5 cm, with an total operating cost of 0.583 $ m-3. Furthermore, the carcinogenic risk (CR) and non-carcinogenic risk of arsenic (As) was in the range of tolerable limits at all operating conditions except applied current of 0.075 A at the end of the aerated EC process to remove As from groundwater. The present EC reactor process is able to remove As(III) from groundwater to below 10 µg L-1, which is maximum contaminant level of arsenic in drinking water according to the World Health Organization (WHO).

Erosive pustular dermatosis of the scalp: a multicentre study.

BACKGROUND: Erosive pustular dermatosis of the scalp (EPDS) is characterized by crusted erosions or superficial ulcerations that lead to scarring alopecia. OBJECTIVES AND METHODS: We performed a multicentre retrospective clinical study including 56 patients (29 females and 27 males, mean age 62.7) with a confirmed EPDS in order to describe epidemiology, clinical findings and therapeutic choices of this disease. RESULTS: Mechanical/chemical trauma was reported in 28.6%, a previous infection in 10.7%, a previous cryotherapy in 5.4% androgenetic alopecia in 48.2% and severe actinic damage in 25%. Trichoscopy showed absence of follicular ostia, tufted and broken hair, crusts, serous exudate, dilated vessels, pustules and hyperkeratosis. Histopathology revealed three different features, depending on the disease duration. The most prescribed therapy was topical steroids (62.5%), followed by the combination of topical steroids and topical tacrolimus (8.9%), systemic steroids (7.1%) and topical tacrolimus (5.4%). A reduction of inflammatory signs was observed in 28 patients (50%) treated with topical steroids and in all three patients treated with topical tacrolimus. CONCLUSION: The relatively high number of patients collected allowed us to identify a better diagnostic approach, using trichoscopy and a more effective therapeutic strategy, with high-potency steroids or tacrolimus, which should be considered as first-line treatment.