The widespread industrial use of chromium has exacerbated water contamination issues globally. In this study, a nitrogen-doped wheat straw biochar loaded with nanoscale zero-valent iron composite (nZVI/N-KBC) was synthesized via a liquid-phase reduction method, and its adsorption properties for hexavalent chromium (Cr(VI)) in aqueous solutions were systematically investigated. The material was characterized using SEM, XRD, Raman spectroscopy, FTIR, and XPS. Experimental results demonstrated that under optimal conditions (pH 2, 0.05 g adsorbent dosage, and 50 mg/L initial Cr(VI) concentration), the adsorption capacity reached 41.29 mg/g. Isothermal adsorption analysis revealed that the process followed the Langmuir model, indicating monolayer adsorption with a maximum capacity of 100.9 mg/g. Kinetic studies show that the adsorption conforms to the pseudo-second-order kinetic model, and thermodynamic and XPS analyses jointly prove that chemical adsorption is dominant. Thermodynamic analyses confirmed the endothermic and entropy-driven nature of adsorption. Mechanistic studies via XPS and FTIR revealed a dual mechanism: (1) partial adsorption of Cr(VI) onto the nZVI/N-KBC surface, and (2) predominant reduction in Cr(VI) to Cr(III) mediated by Fe⁰ and Fe²⁺. This study highlights the synergistic role of nitrogen doping and nZVI loading in enhancing Cr(VI) removal, offering a promising approach for remediating chromium-contaminated water.

Street food plays a significant role in the economy, where it supports the livelihoods of millions of people living in urban and rural areas while also contributing to tourism industries. As such, the hygiene and safety of street food should not be underestimated, as poor adherence to food hygiene and safety can contribute to foodborne diseases. A good understanding of food safety among consumers can reduce the incidence of foodborne outbreaks. However, comprehensive literature on the safety of street food is still inadequate. Therefore, a cross-sectional online survey was conducted among street food consumers in Kuala Kangsar, Perak Malaysia, to determine the level of food safety knowledge and attitudes, as well as the associated factors. For data analysis, descriptive statistics, Pearson correlation and Chi-square tests were conducted using SPSS version 26. Findings revealed that street food consumers in Kuala Kangsar have a moderate knowledge (59 ± 17) on, and positive attitudes (78 ± 14) towards food safety. Analysis revealed a significant association between participants’ food safety knowledge and attitudes scores, and gender with participants’ knowledge (p < 0.05). Even though the level of food safety knowledge and attitudes among street food consumers were satisfactory, the study suggests that several important factors, including cross-contamination, food pathogens, proper food storage, and time/temperature control, should be stressed when providing food safety education to the general public since these are the topics that the participants could not correctly answer. In addition, to promote hygiene and safety with regard to street food in Malaysia, related agencies such as the Ministry of Health and regulatory authorities must design effective initiatives and implement adequate control.

The incidence of food poisoning in school canteens is increasing and poorly understood. It involves young and vulnerable children. School food handlers must understand food safety knowledge, attitudes, and practices to prevent cross-contamination during food preparation effectively. This study aimed to assess the knowledge, attitudes, and practices related to food safety compliance among food handlers in Islamic schools. A cross-sectional study involving 33 food handlers from 15 schools under the Islamic Education District Office in Tangkak, Johor, was conducted using a structured questionnaire. The findings demonstrate that the school food handlers exhibited sufficient knowledge (85.15%), attitudes (84.55%), and practices (84.85%).