ABSTRACT
This study investigates the viability of developing chitosan-based hydrogels derived from waste shrimp shells for the removal of methylene blue and methyl orange, thereby transforming food waste into advanced materials for environmental remediation. Despite chitosan-based adsorbents being conventionally considered ideal for the removal of negative pollutants, through targeted functionalization with poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) at varying concentrations, we successfully enhance the hydrogels' efficacy in also adsorbing positively charged adsorbates. Specifically, the incorporation of PEDOT:PSS at a concentration of 10% v/v emerges as a critical factor in facilitating the robust adsorption of dyes. In the case of the anionic dye methyl orange (MO, 10-5 M), the percentage of removed dye passed from 47% (for beads made of only chitosan) to 66% (for beads made of chitosan-PEDOT:PSS 10%), while, in the case of the cationic dye methylene blue (MB, 10-5 M), the percentage of removed dye passed from 52 to 100%. At the basis of this enhancement, there is an adsorption mechanism resulting from the interplay between electrostatic forces and π-π interactions. Furthermore, the synthesized functionalized hydrogels exhibit remarkable stability and reusability (at least five consecutive cycles) in the case of MB, paving the way for the development of cost-effective and sustainable adsorbents. This study highlights the potential of repurposing waste materials for environmental benefits, introducing an innovative approach to address the challenges regarding water pollution.
ABSTRACT
BACKGROUND: The 2020 SARS-CoV-2 pandemic led to community-wide measures affecting parents and children such as school/daycare closures, job losses, and interruptions in medical care for children with chronic diseases. This is the first study to describe the level of stress and mental health of parents of either healthy children or children with chronic conditions, during the 2020 pandemic. METHODS: A representative sample of US parents was recruited from 10-17 April 2020. Parents completed online questionnaires about the past 7 days, including the Perceived Stress Scale, Resilient Coping Scale, Self-Efficacy Scale, Kansas Marital Satisfaction Scale, Parental Stress Scale, PROMIS Anxiety and Depression scales and various other pandemic-related stress questions Results: Levels of stressors (e.g., job loss, school closures, etc.) were high during this time (e.g., 79% of children attended home/online school) and parents reported being moderately to highly stressed. Rates of clinical anxiety (44.6%) and depression (42.2%) were high. Parents of children with chronic conditions reported higher levels of stress and worse mental health, but did not differ from other parents in dealing with stress or interruptions in work, child schooling, and marital satisfaction. DISCUSSION: The COVID-19 pandemic has introduced unprecedented levels of stress for parents, especially those of children with chronic conditions. Mental health effects are expected to continue for months/years and preparation is needed to meet an increasing demand for mental health care.
