Functionalised electrospun membranes (TETA-PVC) for the removal of lead(ii) from water.

Driven by the need for delivering sustainable water purification solutions for the removal of heavy metals from water, electrospun PVC membranes were functionalised with triethylenetetramine (TETA) and were used to remove lead(ii) ions selectively from water. The membranes were characterised and their adsorption behavior towards the removal of lead from water was investigated. The incorporation of TETA on the membrane's surface significantly improved the removal efficiency of lead(ii) up to 99.8% in 30 minutes and under ambient conditions, with the lowest concentration of 50 ppm. The adsorption mechanism was investigated and kinetic data showed a better correlation with the pseudo-second-order model. Similarly, the equilibrium data best fitted with the Langmuir adsorption isotherm model with a relatively high maximum adsorption capacity of 1250 mg g-1 for lead(ii) ions, larger than recently reported adsorption capacities for similar membranes. The functionalised membrane also showed high selectivity to lead(ii) in a mixed solution containing lead(ii), mercury(ii), cadmium(ii), arsenic(iii), copper(ii), and zinc(ii). The functionalised membrane was regenerated, where desorption of lead(ii) was achieved, under mildly acidic conditions. The removal efficiency of the regenerated membrane after six cycles of adsorption/desorption was maintained at a high level of 98%. The proposed design offers a simple yet effective, sustainable, and environmentally friendly solution for water treatment.

Thiosemicarbazone modified zeolitic imidazolate framework (TSC-ZIF) for mercury(ii) removal from water.

Zeolitic imidazolate frameworks (ZIF-8), and their derivatives, have been drawing increasing attention due to their thermal and chemical stability. The remarkable stability of ZIF-8 in aqueous and high pH environments renders it an ideal candidate for the removal of heavy metals from wastewater. In this study, we present the preparation of novel aldehyde-based zeolitic imidazolate frameworks (Ald-ZIF) through the integration of mixed-linkers: 2-methylimidazole (MIM) and imidazole-4-carbaldehyde (AldIM). The prepared Ald-ZIFs were post-synthetically modified with bisthiosemicarbazide (Bisthio) and thiosemicarbazide (Thio) groups, incorporating thiosemicarbazone (TSC) functionalities to the core of the framework. This modification results in the formation of TSC-functionalized ZIF derivatives (TSC-ZIFs). Thiosemicarbazones are versatile metal chelators, hence, adsorption properties of TSC-ZIFs for the removal of mercury(ii) from water were explored. Removal of mercury(ii) from homoionic aqueous solutions, binary and tertiary systems in competition with lead(ii) and cadmium(ii) under ambient conditions and neutral pH are reported in this study. MIM3.5:Thio1:Zn improved the removal efficiency of mercury(ii) from water, up to 97% in two hours, with an adsorption capacity of 1667 mg g-1. Desorption of mercury(ii) from MIM3.5:Thio1:Zn was achieved under acidic conditions, regenerating MIM3.5:Thio1:Zn for five cycles of mercury(ii) removal. TSC-ZIF derivatives, designed and developed here, represent a new class of dynamically functionalized adsorption material displaying the advantages of simplicity, efficiency, and reusability.

Intracranial Hypertension in Children: Etiologies, Clinical Features, and Outcome.

This retrospective study aimed to describe the clinical presentations, possible causes, and outcomes of children with idiopathic intracranial hypertension who presented to the authors' clinic. The mean age at onset of symptoms in the authors' cohort of 19 children was 6 years (range: 7 months to 12 years). Most patients (90%) were under 11 years old and (84.2%) symptomatic. The probable cause was identified in 7/19 (37.0%) patients. The most common cause was vitamin D deficiency (26.3%). Other associated probably coincidental comorbidities included sinusitis (5/19, 26.3%), hypophosphatasia (1/19), Pyle disease (1/19), and measles vaccine (1/19). Apart from 2 patients who required lumboperitoneal shunt, the cerebrospinal fluid pressure returned to normal in all patients within a period of 6 weeks to 1 year (average, 5 months). Of those who followed up with the authors' ophthalmologist, 30.7% developed optic atrophy or pallor; 75% of these patients had previous ocular comorbidities.