Search Results (6)

Occupational exposure to commercial formic and acetic acids through dermal contact and inhalation during rubber sheet processing poses significant health risks to workers. Additionally, the use of these acids contributes to environmental pollution by contaminating water sources and soil. This study investigates the potential of three types of wood vinegar—derived from para-rubber wood, bamboo, and eucalyptus—obtained through biomass pyrolysis under anaerobic conditions, as sustainable alternatives to formic and acetic acids in the production of ribbed smoked sheets (RSSs). The organic constituents of each wood vinegar were characterized using gas chromatography and subsequently mixed with fresh natural latex to produce coagulated rubber sheets. The physical and chemical properties, equilibrium moisture content, and drying kinetics of the resulting sheets were then evaluated. The results indicated that wood vinegar derived from para-rubber wood contained a higher concentration of acetic acid compared to that obtained from bamboo and eucalyptus. As a result, rubber sheets coagulated with para-rubber wood and bamboo vinegars exhibited moisture sorption isotherms comparable to those of sheets coagulated with acetic acid, best described by the modified Henderson model. In contrast, sheets coagulated with eucalyptus-derived vinegar and formic acid followed the Oswin model. In terms of physical and chemical properties, extended drying times led to improved tensile strength in all samples. No statistically significant differences in tensile strength were observed between the experimental and reference samples. The concentration of acid was found to influence Mooney viscosity, the plasticity retention index (PRI), the thermogravimetric curve, and the overall coagulation process more significantly than the acid type. The drying kinetics of all five rubber sheet samples displayed similar trends, with the drying time decreasing in response to increases in drying temperature and airflow velocity. Full article

To explore the phytoremediation effect of ornamental chrysanthemums on cadmium (Cd)-contaminated farmland soil, a 2-year field trial was conducted on 23 chrysanthemum cultivars in Cd-contaminated soil in Zhejiang Province, China. The biomass yields, Cd content of the plants, Cd enrichment coefficient, and remediation efficiency were evaluated. The aboveground biomass of the tested chrysanthemums was 67.10–166.08 g/plant, the aboveground Cd content was 1.97–5.92 mg kg⁻¹, and the Cd enrichment coefficient was 2.98–9.84. In a screening test of twenty-three chrysanthemum cultivars, six cultivars, such as marigolds, were characterized by high cadmium accumulation, with the average cadmium accumulation of chrysanthemums exceeding 0.6 mg per plant, and the remediation of rhizosphere-contaminated soils took only 4–5 years. Fourteen chrysanthemum cultivars have good multiple-cropping characteristics, and five multiple-cropping chrysanthemum cultivars, such as QX-yz, have high heavy metal tolerance. The multiple-cropping JL-yg cultivars with higher Cd accumulation could be recommended for the remediation of Cd-contaminated farmland. The application of bamboo vinegar to the chrysanthemum rhizosphere effectively promoted Cd absorption. After estimating the economic benefits of artificially planting five dominant varieties of chrysanthemums for polluted farmland remediation, it is concluded that the annual income of a worker can be slightly higher than the average annual income level of local residents. Full article

Currently, workers in the ribbed smoked sheet (RSS) rubber production industry face increasing health risks, primarily due to their direct involvement in converting fresh latex into raw rubber sheets. This process involves the manual addition of appropriately diluted commercial formic acid and acetic acid to induce coagulation, resulting in a tofu-like consistency, which is subsequently processed into rubber sheets. Previous studies have indicated that the use of commercial formic and acetic acids poses significant health hazards to workers and contributes to environmental pollution. Therefore, this study explores the feasibility of replacing commercial formic and acetic acids with wood vinegar derived from para-rubber wood, bamboo, and eucalyptus in the RSS production process. Wood vinegar samples from the three biomass sources were analyzed for their organic compound compositions using gas chromatography and subsequently used as coagulants in the preparation of raw rubber sheets. The drying kinetics and antifungal properties of the resulting sheets were then evaluated. The results revealed that wood vinegar derived from para-rubber wood contained the highest concentration of acetic acid (41.34%), followed by bamboo (38.19%) and eucalyptus (31.25%). Rubber sheets coagulated with wood vinegar from para-rubber wood and bamboo exhibited drying kinetics comparable to those obtained using acetic acid, with the two-term exponential model providing the best fit. Conversely, rubber sheets coagulated with eucalyptus-derived wood vinegar, which had a relatively high concentration of phenolic derivatives (22.08%), followed drying behavior consistent with the Midilli et al. model, similar to sheets treated with formic acid. In terms of antifungal properties, five fungal genera—Aspergillus, Penicillium, Fusarium, Trichoderma, and Paecilomyces—were identified on the rubber sheets. Fungal growth was most pronounced in the control samples (untreated with wood vinegar), whereas samples treated with wood vinegar exhibited significantly reduced fungal colonization. These findings indicate that wood vinegar is effective in inhibiting fungal growth on the surface of rubber sheets and may serve as a safer and more environmentally friendly alternative to commercial acid coagulants. Full article

Bamboo vinegar is a liquid biomass with a huge yield and complex chemical composition. At present, the relative quantification of bamboo vinegar has been investigated in most studies. To analyze twelve compounds from bamboo vinegar simultaneously, gas chromatography-mass spectrometry and an external standard method were used to develop an analytical method. In this method, chromatographic separations of all compounds were above 1.5. The linear range was between 0.100 and 10.000 mg/L, and the coefficient of determination (R²) was between 0.9981 and 0.9997, indicating a good linear relationship. The limit of detection (LOD) was between 0.004 and 0.780 mg/L; the limit of quantitation (LOQ) was between 0.016 and 3.120 mg/L; the relative standard deviations (RSDs) of instrument precision and method stability were less than 8%; the recovery rate was between 89.25% and 113.77%, and its RSD was between 0.44% and 5.70%. Using this method, fourteen bamboo vinegars and six wood vinegars were analyzed, and it was found that the content of propionic acid, phenol, and 2-methoxyphenol was higher in most samples. In addition, the differences in physicochemical properties between distilled bamboo vinegar and its original solution after atmospheric distillation were investigated. Full article

The large-scale generation of vegetable waste in China has become a significant environmental concern. The traditional method of composting results in high nitrogen losses during the process and in the final product. To address this issue and shorten the composting period, this study investigated the effects of bamboo vinegar (BV) and a microbial inoculant (MI) on the physical and chemical properties of the compost and bacterial community composition during the composting process. The results revealed that the addition of BV and BV + MI decreased the time required to reach thermophilic temperatures and conserved nitrogen in the final product. Furthermore, it was found that the dominant nitrifying and denitrifying bacteria, as identified through 16S rDNA analysis, belonged to Nitrosomonas and Proteobacteria, respectively. BV and BV + MI reduced NH₃ and N₂O emissions, which suggested that BV is a beneficial composting agent that preserves nitrogen during the composting process. Full article

The coagulating properties of wood vinegar from para rubber wood, bamboo, and coconut shell used as a substitute for acetic acid in the production process of natural rubber (NR) sheets were investigated and considered. For the dirt and volatile content, the tensile strength at break, the percentage of elongation at break, and the 300% modulus, the results showed that the types of wood vinegar coagulants were not significantly different from acetic acid. However, the Mooney viscosity and plasticity retention index (PRI) properties were significantly different from those of acetic acid. The NR sheet temperature increased rapidly during the first hour after the drying process started due to heat transfer from the hot air. Afterward, the temperature of the NR sheet samples began to stabilize. When the drying process started, the drying temperature was increased, so the trend was reducing the drying time. For the yellowness index (YI) value, the increase in the YI value was related to the type of coagulating material, the increase in the airspeed, and the drying temperature. The dried sheet samples using para rubber wood vinegar as the coagulating material had a color value at the same level as acetic acid and the referent. However, the bamboo and coconut shell wood vinegars were at a lower level. In comparing the YI value data between the experimental results and prediction values, the second-degree model had a better fit in prediction than the zero-degree and first-degree models. This result was confirmed by the higher mean of the coefficient of determination. The dried sheet product coagulated by using wood vinegar had fungus growth prior to supplying it to the customer. Full article