With ongoing economic development, the generation of waste vegetable leaves (WVL) has surged, posing significant environmental risks if not properly managed. To address this challenge, our study developed a copper-based catalyst (Cu 2 O@HAK) derived from WVL, which efficiently catalyzed the conversion of these leaves into artificial potassium humate (C-K-Cu-HAK). Notably, the yield of C-K-Cu-HAK increased from 40.18 % to 95.34 % with the addition of this catalyst. Optimization of the hydrothermal degradation process using response surface methodology (RSM) identified the optimal conditions: a catalyst dosage of 5 %, a reaction temperature of 150 °C, a reaction time of 7 h, and a KOH concentration of 0.6 mol/L. Under these conditions, the extraction efficiency reached 95.25 %. The resulting C-K-Cu-HAK product not only exceeded Chinese national standards for soluble humic acid (HA) content (65.42 %) and K 2 O content (15.48 %), but also demonstrated superior performance in hydroponic trials, significantly enhancing seed germination and plant growth compared to commercial potassium humate (HAK). This study tackles the environmental burden of WVL while introducing an efficient copper-based catalyst that significantly enhances HAK yield. These findings have important implications for environmental protection and sustainable resource utilization, offering a novel approach to HAK production with broad application potential.
In this study, a ZrO 2 -based polycrystalline ceramic foam catalyst was prepared and used in catalytic co-pyrolysis of waste vegetable oil and high density polyethylene (HDPE) for hydrocarbon fuel production. The effects of pyrolysis temperature, catalyst dosage, and HDPE to waste vegetable oil ratio on the product distribution and hydrocarbon fuel composition were examined. Experimental results indicate that the maximum hydrocarbon fuel yield of 63.1 wt. % was obtained at 430 °C, and the oxygenates were rarely detected in the hydrocarbon fuel. The hydrocarbon fuel yield increased when the catalyst was used. At the catalyst dosage of 15 wt.%, the proportion of alkanes in the hydrocarbon fuel reached 97.85 wt.%, which greatly simplified the fuel composition and improved the fuel quality. With the augment of HDPE to waste vegetable oil ratio, the hydrocarbon fuel yield monotonously increased. At the HDPE to waste vegetable oil ratio of 1:1, the maximum proportion (97.85 wt.%) of alkanes was obtained. Moreover, the properties of hydrocarbon fuel were superior to biodiesel and 0 # diesel due to higher calorific value, better low-temperature low fluidity, and lower density and viscosity.
Huang Jiaqing,Liu Cenwei,Price Gordon W.,Wang Yixiang
Bacillus cellulasensis Zn-B isolated from vegetable soil was highly adaptable to Zinc (Zn) and Cadmium (Cd). Cd, but not Zn, adversely affected the total protein spectrum and functional groups of Bacillus cellulasensis Zn-B. Up to 31 metabolic pathways and 216 metabolites of Bacillus cellulasensis Zn-B were significantly changed by Zn and Cd (Zn&Cd). Some metabolic pathways and metabolites related to functional groups of sulfhydryl (-SH) and amine (-NH-) metabolism were enhanced by Zn&Cd addition. The cellulase activity of Bacillus cellulasensis Zn-B was up to 8.58 U mL −1 , increased to 10.77 U mL −1 in Bacillus cellulasensis Zn-B + 300 mg L −1 Zn, and maintained at 6.13 U mL −1 in Bacillus cellulasensis Zn-B + 50 mg L −1 Cd. The vegetables’ cellulose content was decreased by 25.05–52.37% and 40.28–70.70% under the action of Bacillus cellulasensis Zn-B and Bacillus cellulasensis Zn-B + 300 mg L −1 Zn. Those results demonstrated that Zn could significantly enhance cellulase activity and biodegradability of Bacillus cellulasensis Zn-B to vegetable cellulose. Bacillus cellulasensis Zn-B can survive in vegetable soil accumulated with Zn&Cd. The tolerance concentration and adsorption capacity of Bacillus cellulasensis Zn-B to Zn were up to 300 mg L −1 and 56.85%, indicating that Bacillus cellulasensis Zn-B acting as a thermostability biological agent had an essential advantage in accelerating the degradation of discarded vegetables by Zn and were beneficial to maintain organic matter content of vegetable soil. Graphical Abstract
危险品化学品经营许可证（带存储）