Heavy metals are recognized as a growing environmental concern due to their toxicity and long-term stability. In this study, a magnetic composite biochar material (PDFMB) was synthesized using iron-based sludge and Chinese medicine residue, with zinc chloride and polyaniline serving as modifiers, to adsorb and reduce Cr(VI) in water. The optimal preparation conditions were determined through preliminary experiments, and the adsorption performance was evaluated through material characterization and Cr(VI) adsorption tests. The removal of Cr(VI) by PDFMB was highly pH-dependent, with an optimal pH of 2, indicating that acidic conditions favored adsorption. The maximum adsorption capacity for Cr(VI) at 308 K and pH 5 was 111.11 mg/g. The adsorption kinetics followed a pseudo-second-order model, while the Langmuir isotherm provided a good fit to the adsorption isotherm data. Thermodynamic analysis revealed that the removal process was spontaneous and endothermic. The anions Cl‒, SO42‒, and PO43‒ inhibited the removal efficiency of Cr(VI), with inhibition strength following the order Cl‒ < SO42‒ < PO43‒. The key mechanisms involved in Cr(VI) removal included physical and chemical adsorption, chelation, and the reduction of Cr(VI) to Cr(III). The PDFMB composite exhibited high stability and reusability, achieving an 85.25% removal efficiency after six cycles. Owing to its high efficiency, magnetic separability, and excellent recyclability, PDFMB represents a highly promising candidate for addressing Cr(VI) pollution.
Achieving carbon peaking and carbon neutrality requires coordinated action across macro, meso, and micro levels. For Chinese firms, reducing carbon emissions and controlling carbon costs are important challenges. Using Nanjing Iron and Steel Co., Ltd. (NJ Steel) as a case, this study proposes a two-dimensional “carbon flow–value flow” cost control method that traces carbon-containing material and energy inputs, transformation, and emissions through steel production, maps these flows to internal resource transfer costs and external environmental damage costs, and identifies process-level control points and optimization measures. Carbon flow analysis indicated that coking, ironmaking, and steelmaking are high-emission processes. Value flow analysis showed that these processes also incur high carbon costs and are therefore key control points. Within the process-level quantitative boundary and simulated optimization scenarios, internal resource transfer costs and external environmental damage costs were RMB 1,176 million and RMB 1,442 million lower than baseline, respectively. After accounting for technical retrofit investment and key parameter uncertainty, carbon cost reductions ranged from approximately RMB 1,879 million to RMB 3,941 million across the sensitivity scenarios. The findings provide practical guidance for enterprises seeking to strengthen carbon emissions management, optimize carbon cost control, and advance their low-carbon transition.
Environmental exposure to pesticide mixtures is an increasing public health concern, yet their combined effects on DNA conformational integrity and protein structural stability remain insufficiently characterized under controlled in vitro conditions. This study examined the individual and combined effects of two widely used pesticides, imidacloprid and cymoxanil, on plasmid DNA conformational integrity and BSA structural stability. Using plasmid relaxation and SDS-PAGE assays, pBluescript M13+ plasmid DNA and bovine serum albumin (BSA) were exposed to increasing concentrations (50–800 μg/mL) of each pesticide. Both compounds induced detectable plasmid DNA conformational alterations, with co-exposure leading to the complete loss of the supercoiled DNA form, suggesting more pronounced DNA structural alteration under combined exposure. While imidacloprid alone had limited effects on the BSA band pattern, cymoxanil induced mild BSA structural alterations; their combination resulted in more evident changes in BSA band intensity and structural integrity. These findings suggest that pesticide co-exposure may intensify molecular structural alterations under the present in vitro conditions and support the need for mixture-based toxicological assessment.
This research focused on the theoretical reduction of cadmium (Cd) in the above-ground parts of pepper plants. Utilising bioinformatics and transcriptome data, we identified 259 members of the heavy metal transport protein family within pepper. We then selected CaHMA19, CaCAX11, and CaNRAMP8 as candidate genes that may influence Cd levels in pepper fruits, as indicated by RPKM/FPKM analysis and genotype clustering. Following this, we employed molecular simulation techniques to screen candidate small molecules with potential anti-heavy-metal activity. By conducting molecular docking with AutoDock software and evaluating energy scores and affinities using Discovery Studio, we identified three leading compounds, A, B, and C, and thoroughly examined their interactions with the proteins CaHMA19, CaCAX11, and CaNRAMP8. The findings indicated that these compounds were predicted to form interactions with the active sites of the target proteins, with compound A predicted to have broad-spectrum binding potential and compound C predicted to preferentially bind to CaHMA19. All findings in this study are derived from computational virtual screening and molecular docking simulations and require further experimental validation.
To effectively mitigate the free-riding phenomenon prevailing in inter-enterprise collaborative carbon emission reduction behavior, this paper establishes an evolutionary game model for cooperative carbon emission reduction based on the spatial public goods game. By introducing incentive-based environmental regulations, the equilibrium solution of the game model is derived and analyzed. Numerical simulations are conducted to examine the impact of three types of incentive-based environmental regulations on the strategic choices of inter-enterprise cooperative carbon emission reduction in China. The research conclusions are presented as follows: (1) when two enterprises both opt for cooperation in carbon reduction, each party can obtain higher benefits compared with adopting non-cooperative strategies. In addition, when the synergistic benefits of cooperative emission reduction exceed the sum of the benefits from one enterprise cooperating while the other does not, and when this sum surpasses the sum of non-cooperative emission reduction benefits and external effects, the optimal choice for both enterprises is to adopt a cooperative emission reduction pattern; (2) incentive-based environmental regulation acts as an implicit incremental cost. Among these, an increase in carbon tax rates will inhibit enterprises from carrying out collaborative emission reduction activities. On the contrary, an increase in carbon emission trading prices and input subsidy coefficients can effectively incentivize enterprises to implement joint carbon emission reduction. This study reveals the dynamic evolutionary path and degree of influence of enterprises’ cooperative carbon reduction under incentive-based environmental regulation, providing theoretical foundations and practical references for facilitating inter-enterprise collaboration on carbon reduction initiatives.
