Application of dewatered paper sludge-derived porous solid base catalyst for biodiesel production: Physicochemical properties, reaction kinetics and thermodynamic studies.

A new porous solid base catalyst was prepared using dewatered paper sludge and successfully employed to produce biodiesel from soybean oil. The as-prepared catalyst was characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transforms infrared spectroscopy, X-ray photoelectron spectroscopy, thermal gravity/differential thermal gravity analysis, Brunauer-Emmet-Teller analysis, and CO2-temperature programmed analysis. The results showed that the formation of CaO and uniformly distributed porous structure should account for the high catalytic activity of the as-prepared catalyst. The optimum reaction conditions were observed at 180 ℃, 8 wt.% catalyst/oil weight ratio, 16:1 methanol/oil molar ratio, and 300 min reaction time with 91.6% biodiesel yield. After being used several times and recycled, the regenerated catalyst still exhibited effective catalytic activity without apparent deactivation. The kinetic study confirmed that the experimental data satisfied with Pseudo-first-order kinetic model controlled by reaction temperature and catalyst/oil weight ratio. The reaction activation energy was 24.98 kJ/mol. The change of enthalpy ΔH (14.98 kJ/mol), entropy ΔS (-208.57 J/mol/K), and Gibbs free energy ΔG (109.46 kJ/mol) indicated that the transesterification reaction catalyzed by the dewatered paper sludge-derived catalyst is endothermic, endergonic, and non-spontaneous. Our research finding indicated that the CaO-based catalyst derived from dewatered paper sludge was an economically promising and eco-friendly solid base catalyst for biodiesel production.

A Cross-Sectional, Multicenter Study Examining the Validation and Adaptation of the Chinese ROWAN Foot Pain Assessment Questionnaire.

BACKGROUND: The 39-item ROwan Foot Pain Assessment Questionnaire (ROFPAQ) has affective, cognitive, and sensory dimensions to evaluate chronic foot pain. However, to date, the ROFPAQ has only been validated in English and Spanish versions. A simplified Chinese version of ROFPAQ is still not available, even though China has a large population of patients with foot pain. OBJECTIVE: This study's aim was to translate the ROFPAQ into a Chinese version and assess its reliability and validity in Chinese patients with chronic foot pain. STUDY DESIGN: A cross-sectional, multicenter descriptive study. SETTING: This study took place at the Chinese PLA General Hospital, PLA Strategic Support Force Characteristic Medical Center and Wenzhou integrated traditional Chinese and Western Medicine Hospital Affiliated to Zhejiang traditional Chinese Medicine University. METHODS: The ROFPAQ-C (Chinese) was developed by a forward/backward translation protocol and cross-cultural adaptation from the United Kingdom to China, and from English to Chinese Putonghua. A total of 194 patients from 3 centers with chronic foot pain were recruited for test-retest measures from July 2020 though September 2021. RESULTS: Adequate internal consistencies (Cronbach's Alpha) in 3 domains ranged from 0.875 to 0.799 for the cognitive, from 0.795 to 0.629 for the affective, and from 0.801 to 0.811 for the sensory, as well as for the total score from 0.880 to 0.815. Adequate test-retest reliability by intraclass correlation coefficient (ICC) were shown in the cognitive 0.712 (95% CI 0.636 to 0.775), the affective 0.929 (95% CI 0.906 to 0.946), the sensory 0.753 (95% CI 0.685 to 0.808), and the total score 0.932 (95% CI 0.910 to 0.948). Adequate item-total correlations were shown for the cognitive from 0.848 to 0.825, the affective from 0.918 to 0.908, and the sensory from 0.943 to 0.855. LIMITATIONS: The original ROFPAQ with 39 items was developed from a podiatry department of the health care national service of the United Kingdom. CONCLUSIONS: The ROFPAQ-C can be used as a valid and reliable tool for chronic foot pain in the Chinese population.

Laboratory investigation of phosphorus loss with snowmelt and rainfall runoff from a Steppe wetland catchment.

Phosphorus (P) losses from terrestrial soils contribute to eutrophication of surface waters. As priority non-point source pollution ways, rainfall runoff (RS1) and snowmelt runoff (RS2) are the main carrier of P loss from terrestrial ecosystem. The aim of this study was to investigate the similarities and differences between P loss with RS1 and RS2 of the same soil type. Six types of soil were used in this experiment. Results have shown that 1), Different types of soil have different P loss with RS1 and RS2 under different slope, and the changes ranged from 0.003 to 0.370 mg L-1. 2), The effects of soil type, slope and runoff type on P loss with surface runoff was not independent, both individual effects of all factors and their interaction with the other two factors effected the P loss with runoff. 3), In our experiment, some soils showed no significant difference between P content in RS1 and RS2. In some soils, P loss with RS1 was higher than that with RS2 while the opposite conclusion was showed in Bog soil (BS) which with higher soil water content. 4), The P loss with RS1 and RS2 of different soils were both mainly affected by soil water content (SW), Olsen-P content (OP) and soil organic matter content (OM). These results can help us understand the P loss with different patterns of surface runoff better and are expected to provide pertinent opinions on the analysis of P loss with runoff and its influencing factors of grassland soils.

Analysis of factors controlling sediment phosphorus flux potential of wetlands in Hulun Buir grassland by principal component and path analysis method.

Phosphorus (P) flux potential can predict the trend of phosphorus release from wetland sediments to water and provide scientific parameters for further monitoring and management for phosphorus flux from wetland sediments to overlying water. Many studies have focused on factors affecting sediment P flux potential in sediment-water interface, but rarely on the relationship among these factors. In the present study, experiment on sediment P flux potential in sediment-water interface was conducted in six wetlands in Hulun Buir grassland, China and the relationships among sediment P flux potential in sediment-water interface, sediment physical properties, and sediment chemical characteristics were examined. Principal component analysis and path analysis were used to discuss these data in correlation coefficient, direct, and indirect effects on sediment P flux potential in sediment-water interface. Results indicated that the major factors affecting sediment P flux potential in sediment-water interface were amount of organophosphate-degradation bacterium in sediment, Ca-P content, and total phosphorus concentrations. The factors of direct influence sediment P flux potential were sediment Ca-P content, Olsen-P content, SOC content, and sediment Al-P content. The indirect influence sediment P flux potential in sediment-water interface was sediment Olsen-P content, sediment SOC content, sediment Ca-P content, and sediment Al-P content. And the standard multiple regression describing the relationship between sediment P flux potential in sediment-water interface and its major effect factors was Y = 5.849 - 1.025X 1 - 1.995X 2 + 0.188X 3 - 0.282X 4 (r = 0.9298, p < 0.01, n = 96), where Y is sediment P flux potential in sediment-water interface, X 1 is sediment Ca-P content, X 2 is sediment Olsen-P content, X 3 is sediment SOC content, and X 4 is sediment Al-P content. Therefore, future research will focus on these sediment properties to analyze the interrelation among sediment properties factors, main vegetable factors, and environment factors which influence the sediment P flux potential in sediment-water interface.