Hongjie Wang

Sewage sludge biochar (SSB) is an innovative environmental material with remediation capabilities and significant potential for soil enhancement. This study aimed to accurately assess the dual regulatory effects of SSB on plant growth and soil quality. We conducted potting experiments with ryegrass and cosmos to analyze the impacts of SSB on plant growth, soil quality, and microbial communities. The partial least squares path model (PLS-PM) analysis was employed to elucidate the intrinsic relationships between SSB application and soil environmental factors, microbial communities, and plant growth. The results indicated that the application of SSB significantly enhanced the growth of ryegrass and cosmos, improved the soil quality, and increased the quantity of soil beneficial bacteria in the inter-root soil microbial communities. The addition of 9% and 3% (w w⁻¹) SSB resulted in the most substantial growth of ryegrass and cosmos, with aboveground biomass increasing 68.97% and 68.12%, respectively, and root biomass increasing by 49.87% and 45.14%. PLS path analysis revealed that SSB had a significant effect on the number of bacteria, which also played an important role in soil environmental factors such as pH and conductivity. This study provides a scientific basis for the utilization of sludge resources, green agriculture, and soil improvement. Additionally, it offers technical support for optimizing the application strategy of sludge biochar.

This study systematically investigated the ferrate(VI)–ozone combination process for TBBPA degradation. Firstly, the advantages of a ferrate(VI)–ozone combination process were assessed as compared with a sole ozone and ferrate(VI) oxidation process. Then, the performance of the ferrate(VI)–ozone combination process was investigated under different experimental conditions, including the dosing orders of oxidants, dosing concentrations of oxidants, and the initial solution pH. At the same time, toxicity control (including the acute and chronic toxicity) and mineralization were analyzed after optimization. Finally, a mechanism was proposed about the synergetic effects of the ferrate(VI)–ozone combination process for decontamination. The ferrate(VI)–ozone combination process proved to be an efficient and promising technology for removing TBBPA from water. After being pre-oxidized by ferrate(VI) for 3 min and then co-oxidized by the two oxidants, TBBPA of 1.84 μmol L⁻¹ could be completely degraded by dosing only 0.51 μmol L⁻¹ of ferrate(VI) and 10.42 μmol L⁻¹ of ozone within 10 min in wide ranges of pH (5.0–11.0). Up to 91.3% of debromination rate and 80.5% of mineralization rate were obtained, respectively. In addition, no bromate was detected and the acute and chronic toxicity were effectively controlled. The analysis of the proposed mechanism showed that there might exist a superposition effect of the oxidation pathways. In addition, the interactions between the two oxidants were beneficial for the oxidation efficiency of ferrate(VI) and ozone, including the catalytic effect of ferrate(VI) intermediates on ozone and the oxidation of low-valent iron compounds by ozone and the generated ·OH radical.