Evaluating emotional distress and health related quality of life in patients with heart failure and their family caregivers: Testing dyadic dynamics using the Actor-Partner Interdependence Model

Here, Box-Behnken design (BBD) approaches were utilised to optimise synthesis methodology for the chitosan-calcite rich
adsorbent (CCM) made from fishery-food waste material (crab carapace), using low-temperature activation and potassium
hydroxide (KOH). The effect of activation temperature, activation time and impregnation ratio was studied. The final adsorbent
material was evaluated for its phosphorus (P) removal efficiency from liquid phase. Results showed that impregnation ratio was
the most significant individual factor as this acted to increase surface deacetylation of the chitin (to chitosan) and increased the
number of amine groups (–NH2) in the chitosan chain. P removal efficiency approached 75.89% (at initial P concentration of
20 mg/L) under optimised experimental conditions, i.e. where the impregnation ratio for KOH:carapace (g/g) was 1:1, the
activation temperature was 105 °C and the activation time was 150 min. Predicted responses were in good agreement with the
experimental data. Additionally, the pristine and CCM material were further analysed using scanning electron microscopy with
energy dispersive X-ray spectroscopy (SEM/EDX), Brunauer-Emmett-Teller technique (BET), X-ray diffraction (XRD), Fourier
transform infrared spectroscopy (FTIR) and thermal gravimetric analysis (TGA). Characterisation showed enhancements in
surface chemistry (introducing positively charged amine groups), textural properties and thermal stability of the CCM.