Wood vinegar enhances humic acid-based remediation material to solidify Pb(II) for metal-contaminated soil

Mechanistic Investigation of the Pyrolysis Temperature of Reed Wood Vinegar for Maximising the Antibacterial Activity of Escherichia coli and Its Inhibitory Activity

To solve the problem of large-scale growth of wetland reeds, wood vinegar, a by-product of pyrolysed reed wood vinegar, can be used as a natural antimicrobial agent. In this study, we compare the changes in growth and bacterial morphology of Escherichia coli (E. coli) treated with reed wood vinegar at different pyrolysis temperatures (300 °C, 500 °C and 700 °C) and reveal the bacterial inhibition mechanism of reed wood vinegar by RNA-Seq. The results of bacteria inhibitory activity showed that 1/2MIC 500 °C wood vinegar had the most prominent bacteria inhibitory activity. qPCR results showed that reed wood vinegar was able to significantly inhibit the expression of E. coli biofilm and genes related to the cell membrane transporter proteins. Electron microscopy observed that the wood vinegar disrupted the cellular morphology of E. coli, resulting in the crumpling of E. coli cell membranes. RNA-Seq showed the multifaceted antimicrobial effects of wood vinegar and demonstrated that the inhibitory effect of wood vinegar on E. coli was mainly realized through the inhibition of the expression of malE, which is an ATP-binding cassette (ABC) transporter complex of E. coli. In conclusion, our study provides an effective method and a theoretical basis for the mechanism of reed wood vinegar as a natural antimicrobial agent and its pathway of bacterial inhibition.

Biochar and wood vinegar altered the composition of inorganic phosphorus bacteria community in saline-alkali soils and promoted the bioavailability of phosphorus

As an important part of the ecosystem, saline-alkali soils are in urgent need of efficient and environmentally friendly soil conditioners. Biochar and wood vinegar are regarded as organic soil improvement and plant growth regulators to improve soil physicochemical properties and promote crop growth. However, the mechanism of how inorganic phosphorus bacteria increase phosphorus when biochar and wood vinegar applied to saline-alkali soils is not clear. Herein, the present study was designed to investigate the effects of biochar and wood vinegar with different rates on physicochemical properties of saline-alkali soils and inorganic phosphorus bacteria diversities and to discuss the mechanism of biochar and wood vinegar on available phosphorus by pot experiments. The application of biochar and wood vinegar exhibited an effect on the decrease in pH and salt contents and the increase in soil porosity, soil nutrients, and hundred-grain weight of rice. The 600 kg ha-1 biochar and 1800 kg ha-1 wood vinegar group showed the most significant increment in available phosphorus, alkaline phosphatase, acid phosphatase, and neutral phosphatase activities, with the increases of 49.24%, 40.35%, 48%, and 149%, respectively. The 600 kg ha-1 biochar and 1200 kg ha-1 wood vinegar group significantly enhanced microbial biomass phosphorus concentrations by 41.29%. Moreover, biochar and wood vinegar shifted inorganic phosphorus bacteria composition structure and promoted its diversities, more so at a higher rate of wood vinegar application. The dominant species of inorganic phosphorus bacteria were Proteobacteria, Gammaproteobacteria, Alphaproteobacteria, Pseudomonas, and Rhizobium in saline-alkali soils. The Alphaproteobacteria and Hydrogenophaga were the key microorganisms reducing pH and salt contents and increasing available phosphorus contents in saline-alkali soils. In conclusion, the application of biochar and wood vinegar was a useful strategy to improve saline-alkali soils.

Removal mechanism of Pb(ii) from soil by biochar-supported nanoscale zero-valent iron composite materials

As an adsorbent, biochar has a highly porous structure and strong adsorption capacity, and can effectively purify the environment. In response to the increasingly serious problem of heavy metal pollution in water, this study used nano zero valent iron and rice husk biochar to prepare a new type of magnetic sheet-like biochar loaded nano zero valent iron (BC-nZVI) composite material through rheological phase reaction, showing remarkable advantages such as low cost, easy preparation, and superior environmental remediation effect. The physical and chemical properties and structure of the material were extensively characterized using various methods such as HRTEM, XPS, FESEM, EDS, XRD, FTIR, and RAMAN. Concurrently, batch experiments were undertaken to assess the removal efficiency of Pb(ii) by BC-nZVI, with investigations into the influence of pH value, temperature, soil water ratio, and initial concentration of heavy metal ion solution on its removal efficiency. The results indicate that the removal of Pb(ii) by BC-nZVI reaches an equilibrium state after around 120 minutes. Under the conditions of pH 6, temperature 20 °C, soil water ratio 1 : 5, and BC-nZVI dosage of 1 g L-1, BC-nZVI can reduce the Pb(ii) content in wastewater with an initial concentration of 30 mg L-1 to trace levels, and the treatment time is about 120 minutes. The analysis of adsorption kinetics and isotherms indicates that the adsorption process of Pb(ii) by BC-nZVI adheres to the quasi-second-order kinetic model and Langmuir model, suggesting a chemical adsorption process. Thermodynamic findings reveal that the adsorption of Pb(ii) by BC-nZVI is spontaneous. Furthermore, BC-nZVI primarily accumulates Pb(ii) through adsorption co-precipitation. BC-nZVI serves as an eco-friendly, cost-effective, and highly efficient adsorbent, showing promising capabilities in mitigating Pb(ii) heavy metal pollution. Its recoverability and reusability facilitated by an external magnetic field make it advantageous for remediating and treating lead-contaminated sites.

The Potential of Wood Vinegar to Replace Antimicrobials Used in Animal Husbandry-A Review

The indiscriminate use of antimicrobials in animal husbandry can result in various types of environmental contamination. Part of the dose of these products is excreted, still active, in the animals' feces and urine. These excreta are widely used as organic fertilizers, which results in contamination with antimicrobial molecules. The impacts can occur in several compartments, such as soil, groundwater, and surface watercourses. Also, contamination by antimicrobials fed or administrated to pigs, chickens, and cattle can reach the meat, milk, and other animal products, which calls into question the sustainability of using these products as part of eco-friendly practices. Therefore, a search for alternative natural products is required to replace the conventional antimicrobials currently used in animal husbandry, aiming to mitigate environmental contamination. We thus carried out a review addressing this issue, highlighting wood vinegar (WV), also known as pyroligneous acid, as an alternative antimicrobial with good potential to replace conventional products. In this regard, many studies have demonstrated that WV is a promising product. WV is a nontoxic additive widely employed in the food industry to impart a smoked flavor to foods. Studies have shown that, depending on the WV concentration, good results can be achieved using it as an antimicrobial against pathogenic bacteria and fungi and a valuable growth promoter for poultry and pigs.