Phaeodactylum tricornutum a prominent source of industrial fucoxanthin production, faces challenges in its application due to its tolerance to high-temperature environments. This study investigates the physiological responses of P. tricornutum to high-temperature stress and its impact on fucoxanthin content, with a specific focus on the role of cis -zeatin. The results reveal that high-temperature stress inhibits P. tricornutum ’s growth and photosynthetic activity, leading to a decrease in fucoxanthin content. Transcriptome analysis shows that high temperature suppresses the expression of genes related to photosynthesis (e.g., psbO , psbQ , and OEC ) and fucoxanthin biosynthesis (e.g., PYS , PDS1 , and PSD2 ), underscoring the negative effects of high temperature on P. tricornutum . Interestingly, genes associated with cis -zeatin biosynthesis and cytokinesis signaling pathways exhibited increased expression under high-temperature conditions, indicating a potential role of cis -zeatin signaling in response to elevated temperatures. Content measurements confirm that high temperature enhances cis -zeatin content. Furthermore, the exogenous addition of cytokinesis mimetics or inhibitors significantly affected P. tricornutum ’s high-temperature resistance. Overexpression of the cis-zeatin biosynthetic enzyme gene tRNA DMATase enhanced P. tricornutum ’s resistance to high-temperature stress, while genetic knockout of tRNA DMATas e reduced its resistance to high temperatures. Therefore, this research not only uncovers a novel mechanism for high-temperature resistance in P. tricornutum but also offers a possible alga species that can withstand high temperatures for the industrial production of fucoxanthin, offering valuable insights for practical utilization. IMPORTANCE: This study delves into Phaeodactylum tricornutum ’s response to high-temperature stress, specifically focusing on cis -zeatin. We uncover inhibited growth, reduced fucoxanthin, and significant cis -zeatin-related gene expression under high temperatures, highlighting potential signaling mechanisms. Crucially, genetic engineering and exogenous addition experiments confirm that the change in cis -zeatin levels could influence P. tricornutum ’s resistance to high-temperature stress. This breakthrough deepens our understanding of microalgae adaptation to high temperatures and offers an innovative angle for industrial fucoxanthin production. This research is a pivotal step toward developing heat-resistant microalgae for industrial use.

The necessity to eliminate nickel (Ni) from wastewater stems from its environmental and health hazards. To enhance the Ni adsorption capacity, this research applied a copper sulfate–ammonia complex (tetraamminecopper (II) sulfate monohydrate, [Cu(NH₃)₄]SO₄·H₂O) as a modifying agent for a Phragmites australis-based activated carbon preparation. The physiochemical properties of powdered activated carbon (PAC) and a modified form ([Cu(NH₃)₄]-PAC) were examined by measuring their surface areas, analyzing their elemental composition, and using Boehm’s titration method. Batch experiments were conducted to investigate the impact of various factors, such as Ni(II) concentration, contact time, pH, and ionic strength, on its substance adsorption capabilities. Additionally, the adsorption mechanisms of Ni(II) onto activated carbon were elucidated via Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The findings indicated that modified activated carbon ([Cu(NH₃)₄]-PAC) exhibited a lower surface area and total volume than the original activated carbon (PAC). The modification of PAC enhanced its surface’s relative oxygen and nitrogen content, indicating the incorporation of functional groups containing these elements. Furthermore, the modified activated carbon, [Cu(NH₃)₄]-PAC, exhibited superior adsorption capacity relative to unmodified PAC. Both adsorbents’ adsorption behaviors conformed to the Langmuir model and the pseudo-second-order kinetics model. The Ni(II) removal efficiency of PAC and [Cu(NH₃)₄]-PAC diminished progressively with rising ionic strength. Modified activated carbon [Cu(NH₃)₄]-PAC demonstrated notable pH buffering and adaptability. The adsorption mechanism for Ni(II) on activated carbon involves surface complexation, cation exchange, and electrostatic interaction. This research presents a cost-efficient preparation technique for preparing activated carbon with enhanced Ni(II) removal capabilities from wastewater and elucidates its underlying adsorption mechanisms.

Ampicillin (AMP) poses a significant environmental hazard to aquatic ecosystems, and previous research has been inadequate in addressing the ecological toxicity of its byproducts. A novel photocatalyst, WO₃-BiFeO₃/digestate biochar (DSB), denoted WBD, was synthesized for efficient photocatalytic degradation of AMP. In our study, 150 mg WBD achieved 99.93% AMP degradation in 3 h at a concentration of 100 mg/L. WBD maintained a stable degradation performance under various environmental stressors, including pH, and the presence of Cl⁻, NO₃⁻, and HA. •O₂⁻, h⁺, •OH, and ¹O₂ were identified as primary active oxygen species. WBD effectively targeted the -NH₂, -SH, and β-lactam ring-forming -COOH of AMP, facilitating its transformation into low-toxic or non-toxic degradation products, and establishing a detoxification pathway. Overall, this study introduces a novel environmentally material that demonstrates a high degradation efficiency, long-lasting effectiveness, and low product toxicity, offering a promising approach for the effective management of emerging pollutants.

Dewatering is a crucial stage in the treatment of sludge since it directly increases capacity and lowers the cost of subsequent handling. Enhanced dewatering of printing and dyeing sludge was experimentally investigated with combined conditioners of sludge-derived biochar and ferric chloride (FeCl3) in this study. Results showed that the optimal conditioner dosages were: FeCl3 of 3% dry sludge (DS) and biochar of 60% DS. Compared with raw sludge, the sludge specific resistance to filtration (SRF) decreased by 77.14%, and the moisture content of sludge decreased from 85.38% to 67.08%. In addition, the chemical oxygen demand (COD), turbidity and chromaticity of supernatant decreased by 32.50%, 89.20% and 77.50%, respectively. It was found that the synergistic effect existed between the two conditioners. The possible mechanism was that FeCl3 aggregated small sludge particles to form large flocs and improved the dewatering performance of sludge, while biochar helped to build an incompressible and permeable sludge cake to further improve the sludge dewaterability due to its relatively hydrophobicity and large specific surface area. Therefore, combined addition of FeCl3 and biochar might be a promising conditioning method to enhance textile sludge dewaterability.