RESUMO
Due to eutrophication, removing phosphate ions from wastewater has received a lot of attention. In order to improve the phosphorus adsorption capacity of the material, this study used biomass pyrolysis to create a series of biochars modified with metal chloride ions. In accordance with adsorption tests, lanthanum-loaded biochar (LCBC) had a significant phosphorus adsorption capacity of approximately 666.67 mg/g, which was 30 times greater than that of pristine biochar. Adsorption kinetic analysis revealed that the LCBC's adsorption process could be fitted to the pseudo-secondary kinetic equation, indicating that chemical processes were primarily responsible for controlling the adsorption process. Zeta potential, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analysis showed that the main adsorption mechanism of LCBC for phosphate removal was electrostatic attraction of protonated H+ with negatively charged mono-hydrogen phosphate and dihydrogen phosphate ions and complexation reaction of the C=O on the carboxyl group and P=O on the phosphate group with the oxygen on the phosphate group and hydroxyl group. According to regeneration performance results, LCBC performed relatively better than as-prepared adsorbents, and the phosphate removal rate was approximately 75.1% after the fifth regeneration cycle. The study provided a potential approach for creating and preparing an adsorbent with high adsorption for phosphate removal.
RESUMO
OBJECTIVE: To investigate the actual condition of the sexual physiological and psychological development of the high school students in Yibin in order to get a reliable basis for sexual education of the teenagers. METHODS: With a proportion of 1% to the whole, 2,770 students were randomly selected from eight high schools in the urban and rural areas of the city. We devised a questionnaire and asked each student to fill in his or her answers presently. RESULTS: So far as sexual physiological and psychological development was concerned, the high school students of Yibin were found rather precocious, with very little sexual knowledge and psychological endurance in sexual affairs and a relative lack of sexual education. CONCLUSION: It is imperative to extend the scope of puberty sexual education in high schools. Teenagers must be taught different kinds of sexual knowledge at different periods of growth as well as how to avoid sexually transmitted diseases and gestation. The sexual knowledge level of the teachers must also be raised. It is a must to establish service or specialist consultation hot lines about sexual knowledge for teenagers. Parents are expected to change their traditional views and assume an active role in the joint efforts of sexual education for their children.
