Global Rate of Willingness to Volunteer Among Medical and Health Students During Pandemic: Systemic Review and Meta-Analysis.

BACKGROUND: During health crises such as the COVID-19 pandemic, shortages of health care workers often occur. Recruiting students as volunteers could be an option, but it is uncertain whether the idea is well-accepted. OBJECTIVE: This study aims to estimate the global rate of willingness to volunteer among medical and health students in response to the COVID-19 pandemic. METHODS: A systematic search was conducted on PubMed, Embase, Scopus, and Google Scholar for studies reporting the number of health students willing to volunteer during COVID-19 from 2019 to November 17, 2023. The meta-analysis was performed using a restricted maximum-likelihood model with logit transformation. RESULTS: A total of 21 studies involving 26,056 health students were included in the meta-analysis. The pooled estimate of the willingness-to-volunteer rate among health students across multiple countries was 66.13%, with an I2 of 98.99% and P value of heterogeneity (P-Het)<.001. Removing a study with the highest influence led to the rate being 64.34%. Our stratified analyses indicated that those with older age, being first-year students, and being female were more willing to volunteer (P<.001). From highest to lowest, the rates were 77.38%, 77.03%, 65.48%, 64.11%, 62.71%, and 55.23% in Africa, Western Europe, East and Southeast Asia, Middle East, and Eastern Europe, respectively. Because of the high heterogeneity, the evidence from this study has moderate strength. CONCLUSIONS: The majority of students are willing to volunteer during COVID-19, suggesting that volunteer recruitment is well-accepted.

Integration of copperas and calcium hydroxide as a chemical coagulant and coagulant aid for efficient treatment of palm oil mill effluent.

Palm oil mill effluent (POME) is highly polluted wastewater that is to the environment if discharged directly to water source without proper treatment. Thus, a highly efficient treatment with reasonable cost is needed. This study reports the coagulation treatment of POME using integrated copperas and calcium hydroxide. The properties of copperas were determined using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and X-ray fluorescence (XRF). Coagulation was conducted using jar test experiments for various coagulant formulations and dosages (1000-5000 mg/L), initial pH (4-10), stirring speed (100-300 rpm), and sedimentation time (30-180 min). The characterisation results show that copperas has a compact gel network structure with strong O-H stretching and monoclinic crystal structure. The effectiveness of integrated copperas and calcium hydroxide (Ca(OH)2) with the formulation of 80:20 removed 77.6%, 73.4%, and 57.0% of turbidity, colour, and chemical oxygen demand (COD), respectively. Furthermore, the integration of copperas and Ca(OH)2 produced heavier flocs (ferric hydroxide), which improved gravity settling. The coagulation equilibrium analysis shows that the Langmuir model best described the anaerobic POME sample as the process exhibited monolayer adsorption. The results of this study show that copperas with the aid of Ca(OH)2 demonstrated high potential in the removal of those parameters from POME with acceptable final pH for discharge. The utilisation of this by-product as a coagulant in effluent treatment can unlock the potential of copperas for wider applications, improve its marketability, and reduce gypsum waste generation from the TiO2 industry.