Frontiers in Materials
·
2022
·
IF 3.985
Tan Wei,Zhu Songxiang,Kong Lingyun,Peng Yi,Xu Lei,Fu Yaoguo
Efficient demulsification is vital for the application of emulsified asphalt in road construction. In this paper, the effects of the main chemical components of the aggregates (CaCO3, MgO, Fe2O3, SiO2, Al2O3) on the demulsification process of emulsified asphalt were studied by experiment and simulation using a Gompertz model. The findings indicate that the surface energy, specific surface area, and pH of the chemical components of the aggregates are the most important factors influencing the demulsification speed of the emulsified asphalt. The choice of the aggregate’s main chemical components can accelerate demulsification speed, with the acceleration effect of Al2O3 on anionic (SDBS) emulsified asphalt and MgO on cationic (STAC) emulsified asphalt both reaching 60%. The fit between the Gompertz model and the experimental viscosity curve is greater than 0.93, which verifies the utility of using the Gompertz approach for studying emulsified asphalt-aggregate mortar viscosity changes. A demulsification evaluation function φ(t) of emulsified asphalt is proposed based on the parameters of the Gompertz model. When φ(t) is close to 1, the emulsified asphalt-aggregate mortar is fully demulsified, and setting φ(t)=1 allows the demulsification time of the emulsified asphalt-aggregate mortar to be calculated from the Gompertz model parameters.
研究领域:
材料科学
·
土木工程
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Huaxin Lei,Jiayu Zhang,Jin Huang,Dengjin Shen,Yin Li,Rui Jiao,Renxin Zhao,Xiaoyan Li,Lin Lin,Bing Li
The aerobic, lincomycin-degrading bacterial strain Conexibacter sp . LD01, belonging to the phylum Actinobacteria, was isolated from activated sludge . Both second- and third-generation sequencing technologies were applied to uncover the genomic characterization and high-quality genome with 99.2% completeness and 2.2% contamination was obtained. The biodegradation kinetics of lincomycin fit well with the modified Gompertz model ( R 2 > 0.97). Conexibacter sp . LD01 could subsist with lincomycin as the sole source of carbon, nitrogen, and energy. When 500 mg/L of glucose was added as a co-substrate, the biodegradation rate improved significantly, whereas the addition of 500 mg/L sodium pyruvate had a slight inhibitory effect. Ammonia nitrogen was the best nitrogen source for Conexibacter sp . LD01 when growing and degrading lincomycin. In total, 17 metabolic products consisting of nine novel products were detected, and five biodegradation pathways, including N-demethylation, breakage of the amido bond, sulfoxidation, and oxidation of the pyrrolidine ring and propylamino chain, were proposed. This study significantly expands our understanding of the functional microorganisms and mechanism involved in lincomycin biodegradation at the phylum level.
研究领域:
微生物学
·
环境科学
·
基因组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2024
·
IF 8
Huanying Ge,Zhaoxia Peng,Denglong Lu,Zhaoguang Yang,Haipu Li
Polycyclic aromatic hydrocarbons (PAHs) were frequently found in sediment and were primarily treated through microbial degradation. Thus, efficient management of PAH pollution requires exploring the molecular degradation mechanisms of PAHs and expanding the pool of available microbial resources. A fungus (identified as Sarocladium terricola strain RCEF778 ) with the remarkable ability to degrade pyrene was screened from sediment near a petrochemical plant, and its growth and pyrene degradation characteristics were comprehensively investigated. The results showed that the fungus exhibited great effectiveness in pyrene degradation, with a degradation ratio of 88.97% at 21 days at the conditions: 35 °C, pH 7, 10 mg L −1 initially pyrene concentration, 3% supplementary salt, and glucose supplementation. The generation and concentration variation of the intermediate products were identified, and the results revealed that the fungus degraded pyrene through two pathways: by salicylic acid and by phthalic acid. Three sediments (M1, M2, M3), each exhibiting different levels of PAH pollution, were employed to examine the effectiveness of fungal degradation of PAHs in practical sediment samples. These data showed that with the fungus, the degradation ratios ranged from 13.64% to 23.50% for 2–3 rings PAHs, 40.93%–49.41% for 4 rings PAHs, and 39.59%–48.07% for 5–6 rings PAHs, which were significantly higher than those for the sediment without the fungus and confirmed the excellent performance of the fungal. Moreover, the Gompertz model was employed to analyze the degradation kinetics of 4-rings and 5–6 rings PAHs in these sediments, and the results demonstrated that the addition of the fungus could significantly increase the maximum degradation ratio, degradation start-up rate and maximum degradation rate of 4-rings and 5–6 rings PAHs and shorten the time required to reach the maximum degradation rate. This study not only supplied fungal materials but also established crucial theoretical foundations for the development of bioremediation technologies aimed at high molecular weight PAH-contaminated sediments.
研究领域:
环境微生物学
·
生物修复
·
环境科学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENT INTERNATIONAL
·
2019
·
IF 7.943
Lijia Cao,Jiayu Zhang,Renxin Zhao,Yu Deng,Jie Liu,Wenjie Fu,Yusha Lei,Tong Zhang,Xiaoyan Li,Bing Li
Biodegradation is an important route for the removal of sulfamethazine (SMZ), one of the most commonly used sulfonamide antibiotics, in the environment. However, little information is known about the kinetics, products, and pathways of SMZ biodegradation owing to the complexity of its enzyme-based biotransformation processes. In this study, the SMZ-degrading strain A01 belonging to the genus Paenarthrobacter was isolated from SMZ-enriched activated sludge reactors. The bacterial cells were rod-shaped with transient branches 2.50–4.00 μm in length with most forming in a V-shaped arrangement. The genome size of Paenarthrobacter sp. A01 had a total length of 4,885,005 bp with a GC content of 63.5%, and it contained 104 contigs and 55 RNAs. The effects of pH, temperature, initial substrate concentration and additional carbon source on the biodegradation of SMZ were investigated. The results indicated that pH 6.0–7.8, 25 °C and the addition of 0.2 g/L sodium acetate favored the biodegradation, whereas a high concentration of SMZ, 500 mg/L, had an inhibitory effect. The biodegradation kinetics with SMZ as the sole carbon source or 0.2 g/L sodium acetate as the co-substrate fit the modified Gompertz model well with a correlation coefficient (R 2 ) of 0.99. Three biodegradation pathways were proposed involving nine biodegradation products, among which C 6 H 9 N 3 O 2 S and C 12 H 12 N 2 were two novel biodegradation products that have not been reported previously. Approximately 90.7% of SMZ was transformed to 2-amino-4, 6-dimethylpyrimidine. Furthermore, sad genes responsible for catabolizing sulfonamides were characterized in A01 with high similarities of 96.0%–100.0%. This study will fill the knowledge gap in the biodegradation of this ubiquitous micropollutant in the aquatic environment.
研究领域:
环境科学
·
微生物学
·
基因组学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）