Adaptable strategy for reactivation and recycling of spent S-Zorb adsorbents at the laboratory and pilot scale.

The spent S-Zorb adsorbents containing Ni and Zn elements are hazardous wastes. It would generate significant economic and environmental benefits to reactivate and recycle these solid wastes through a reactivation strategy. Furthermore, adaptability investigation of this strategy is also indispensable before its industrial application. Herein, the spent S-Zorb adsorbents (Spent-TJ/MM/QD) from different plants were reactivated at laboratory and pilot scale in 3 m3 reactor via an acid-base coupling reactivation strategy. The spent adsorbents exhibit distinct phase compositions and microstructures of active components. Formation of ZnSi2O4 and ZnS is the primary reason for abandonment of the Spent-TJ (Spent-MM) and Spent-QD, respectively. The nickel species also exhibit different aggregation extent. Fortunately, the inert zinc and nickel species are respectively converted into ZnO and NiO during the reactivation process. Higher surface area (1.7-4.0 times that of the spent adsorbents) and more acid sites are generated over the reactivated adsorbents. Besides, all the reactivated adsorbents possess similar phase compositions and microstructures. Both the adsorbents reactivated at pilot and laboratory scale exhibit comparable desulfurization activity to fresh ones. The sulfur content of the gasoline desulfurized by the reactivated adsorbents is below 10 µg g-1, meeting the Euro V legislations. All the results indicate the excellent adaptability and commercial potential of the reactivation strategy. The possible mechanism for the excellent adaptability of the reactivation method was proposed.

Experiences and Attitudes of Elementary School Students and Their Parents Toward Online Learning in China During the COVID-19 Pandemic: Questionnaire Study.

BACKGROUND: Due to widespread SARS-CoV-2 infection, an emergency homeschooling plan was rigorously implemented throughout China. OBJECTIVE: This study aimed to investigate the experiences and attitudes of elementary school students and their parents (two generations from the same family) toward online learning in China during the pandemic. METHODS: A 16-item questionnaire was distributed at the 10-day and 40-day marks after the start of the first online course to 867 parent-child pairs and 141 parent-child pairs, respectively. The questionnaire was comprised of questions pertaining to course and homework completeness, effectiveness, reliability, and abundance as well as the students' enthusiasm for taking part in online classes and their satisfaction with the courses. RESULTS: Our findings indicate that 90.7% (786/867) of students exhibited high or moderate enthusiasm for participating in online classes. However, most students performed poorly in online learning classes and after-school homework. With regard to satisfaction, parents' and students' average scores were 7.35 and 7.25, respectively (10-point scoring system). During the second stage of this study, parents' positive evaluations for online learning declined, including those for the effectiveness and reliability of the courses. Furthermore, the proportion of students who completed the courses and homework on time decreased; this difference proved statistically significant (P=.047). The parents' and students' overall satisfaction with online learning also declined during the second stage (parents: 7.21; students: 7.23); however, the difference in overall satisfaction between the two stages was not statistically significant (parents: P=.53; students: P=.60). Several of the parents (315/867, 36.2%) indicated that assisting with and supervising the students' online learning resulted in increased stress. Further, 36% of parents expressed dissatisfaction with or provided suggestions for online learning; most parents and students hoped to return to face-to-face classes (parents: 823/867, 94.9%; students: 811/867, 93.5%). Finally, our results presented the following six main issues that parents were the most concerned about: (1) disappointment regarding timely interaction in courses; (2) apprehensiveness about students' understanding of the course; (3) the increased burden of annoying adult responsibilities; (4) concern about children's eyesight; (5) the idea that teachers' explanations were not detailed enough; and (6) concerns about the decline of students' interest in and attention toward online courses. CONCLUSIONS: Online learning can prevent the spread of infectious diseases while still allowing elementary school students to attain knowledge. However, in our study, children's completion of the courses and homework were not satisfactory. Furthermore, their parents often experienced stress and had many concerns and complaints. Measures such as increasing the interactivity of the courses and prohibiting teachers from assigning tasks to parents could improve the effectiveness of these courses and the mental health of parents and students.