Ni-based catalysts have been extensively investigated because of their superior catalytic performance. In this study, the Ni-La/Al₂O₃-CaO-C catalyst was prepared by homogeneous precipitation, employed in the co-pyrolysis of soybean straw with polyethylene to produce hydrogen. The optimal experimental conditions were identified by discussing the carrier synthesis ratio, feedstock ratio, and addition of La. Additionally, the stability of the catalyst was evaluated. It was established that the carrier was produced using a molar ratio, the raw ingredients ratio of 5:5, and that the optimum catalytic action was obtained when La was added. Co-pyrolysis of soybean straw with polyethylene (PE) that was catalyzed by Ni-La/Al₂O₃-CaO-C generated 55.45 vol% of H₂ under ideal experimental circumstances. After six applications, the H₂ yield was 33.89 vol%, compared to 27.5 vol% for the Ni/Al₂O₃-CaO-C catalyst. The experimental results indicate that Ni-La/Al₂O₃-CaO-C exhibits superior catalytic activity and stability than Ni/Al₂O₃-CaO-C.

The ecological environment of urban lakes affected by human activities is deteriorating rapidly. As a source and sink of pollutants in the lake environment, sediments have become the focus of environmental assessments. At present, most of the studies only conduct pollution assessments on surface sediments. In this study, taking the typical urban lakes GanTang Lake and NanMen Lake (G&N Lake) as the background, not only is the planar spatial distribution of their nutrient elements, seven kinds of heavy metals, and As analyzed in detail, but risk assessments are also carried out on the pollution conditions at different depths. The causes of pollution at different depths are analyzed. It is found that in this lake, with the increase in depth, the pollution situation decreases slightly, but the pollution of nutrient elements is severe. There is severe pollution of nutrient elements at a depth of up to 1 m in the whole lake sediment. In the sediments with a depth of up to 1 m, more than 90% of the areas in the whole lake are at or above the moderate pollution level of Hg, and more than 70% of the areas are under slight pollution of Cd, resulting in the ecological risk level of the whole lake being at or above the high-risk level. Urban lake sediment management is inherently complex, driven by multifaceted factors where intensive anthropogenic activities constitute the primary pollution source. This research provides insights to guide restoration strategies and sustainable development policies for lacustrine ecosystems.