BIORESOURCE TECHNOLOGY
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2018
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IF 5.807
Yun Huang,Chaoyang Wei,Qiang Liao,Ao Xia,Xun Zhu,Xianqing Zhu
To improve the carbon to nitrogen (C/N) ratio of harvested microalgae biomass for better producing biogas by fermentation, biodegradable cationic starch with high C/N ratio were synthesized to harvest Chlorella vulgaris . The impact of pH was also studied as the zeta potential of both microalgae and cationic starch would change with pH. Results indicated the cationic starch can harvest above 99% of the microalgae and the C/N ratio can rise from 7.50 to 7.90. The zeta potential of microalgae always kept negative and presented a trend of descending firstly and then upgrade. The maximum microalgae biomass flocculation capacity of 1 g cationic starch was 8.62 g with the help of self-flocculation at pH 3. The concentration of flocs formed at pH 11 was 25.74 g L −1 and the diameter was 0.553 mm which was much larger than the flocs formed at pH 3 (0.208 mm).
研究领域:
生物技术
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2025
·
IF 8.4
Zhuocheng Wei,Bin Zhang,Rui Xu,Haoling Li,Acong Chen,Chaohai Wei,Haizhen Wu
Thiocyanate (SCN − ) is a highly toxic reducing inorganic compound commonly found in various nitrogen-rich wastewater and is also a promising electron donor for mixotrophic denitrification. However, its extent of involvement in mixotrophic denitrification under conditions of carbon limitation or excess remains unclear. In this study, five reactors were constructed to investigate the participation and microbial mechanisms of SCN − in mixotrophic denitrification under high C/N and low C/N conditions. The results showed that under low C/N conditions, SCN⁻ synergizes with organic electron donors to enhance denitrification, with mixotrophic systems exhibiting higher electron utilization efficiency and achieving 1.12 times the TN removal rate of autotrophic and heterotrophic systems combined. Under high C/N conditions, an ample supply of electron donors achieve 100% nitrate removal; however, SCN⁻ also participates in denitrification, competing with organic electron donors for NO 3 − -N, which leads to the waste of organic matter. Additionally, high-throughput sequencing revealed that under low C/N mixotrophic conditions, SCN⁻ effectively promoted the growth of SCN⁻-degrading microorganisms such as Thiobacillus , with its abundance increasing from 0% to 8.86%, approximately 1.85 times higher than under autotrophic conditions. This enhancement strengthened the sulfur and nitrogen metabolic capabilities of the microbial community, enabling the system to utilize SCN − more fully for denitrification. This study provides novel insights for reducing the addition of external organic matter to nitrogen-rich wastewater containing SCN − , offering theoretical and technical support for energy-saving and emission reduction in denitrification processes of actual industrial wastewater treatment.
研究领域:
环境科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
·
2021
·Vol. 11
·期 9
·3270-3278
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IF 6.119
Huihui Li,Fuchun Ning,Xiaofei Chen,Anye Shi
Porous carbon nitride nanosheets with carbon and nitrogen double vacancies have been synthesized by a soft template-supported one-pot method. Besides their highly defined and unambiguous structure, they also show minimal thickness and high crystallinity. This porous carbon nitride exhibits great enhancement in photocatalytic hydrogen evolution activity (297.6 μmol h−1), which is 9.6 times higher than 31.2 μmol h−1 of the pristine one. An apparent quantum yield of 12.7% at 420 nm for hydrogen production can be achieved over these porous nanosheets. The detailed investigation suggests that there are carbon vacancies along with nitrogen vacancies. Besides nitrogen vacancies, carbon vacancies also play a positive role in the improvement of hydrogen evolution. In addition, the photocatalytic performance especially hydrogen evolution increases with the increase of the C/N ratio.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2023
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IF 13.1
Zhiyao Chu,Junqi Li,Hong Yong Sohn,Chaoyi Chen,Xiao Huang,Yuanpei Lan,Arun Murali,Junshan Zhang
In this work, novel CeO 2 –C-g-C 3 N 4 S-scheme heterojunctions with significantly enhanced photocatalytic performance were prepared for the first time by a facile one-step molten KCl–LiCl method. The formation mechanism of CeO 2 –C-g-C 3 N 4 was discussed, where g-C 3 N 4 turned to C by carbonizing and the surface C content was adjusted by controlling the synthesis conditions. The photocatalytic property of the ternary composites first increased and then decreased with synthesis temperature and time. The 580 °C 4h CeO 2 –C-g-C 3 N 4 exhibited the best performance towards MB (Methylene blue) and TC (Tetracyclines) degradation with a removal degree of 99.9% and 92.5%, respectively. The surface C/N ratio was a key index that influenced the photocatalytic performance, and was calculated to be 0.918–1.352 for various CeO 2 –C-g-C 3 N 4 catalysts. The 580 °C 4h CeO 2 –C-g-C 3 N 4 had an appropriate C/N ratio of 0.930 and a narrow band gap. The formed S-scheme 2D heterojunctions and generated C clearly promoted the separation of photo-excited e - / h + . Besides, it was indicated that e - and · O 2 − were the main active species for TC photodegradation . The 580 °C 4h CeO 2 –C-g-C 3 N 4 exhibited a large BET surface area, high negative zeta potential , strong π-π electron donor-acceptor interaction, and an excellent MB adsorption ability. It was evident that chemisorption on catalyst surface played an important role for adsorbing MB. The formation mechanism of CeO 2 –C-g-C 3 N 4 and the effects of the surface C/N ratio on photocatalytic performance, determined in this work, offer new insights for preparing and structuring highly effective photocatalysts , which is expected to promote further photocatalytic and adsorption applications.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2020
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IF 6.551
Changwei Li,Zhefeng Gu,Songming Zhu,Dezhao Liu
This study evaluated the contribution of biotic and abiotic routes to the 17 β -estradiol (E2) removal in moving bed biofilm reactors (MBBRs), and uncovered the interrelation between the E2 removal routes and biofilm characteristics, which was not researched in previous literature. Three MBBRs with different C/N ratios (0 for C/N 0 ; 2 for C/N 2 ; and 5 for C/N 5 ) were operated in continuous mode. A 65-day degradation demonstrated that the MBBRs had high potential to remove E2 regardless of the C/N (E2 removal greater than 99% for all MBBRs; P > 0.05). Further batch tests showed that the E2 removal mainly resulted from heterotrophic activities for all MBBRs, accounting for approximately 85% for all MBBRs (P > 0.05), followed by nitrification (10–11%) and adsorption (4–5%). Importantly, lower adhesive force likely led to higher E2 adsorption onto biofilms. Besides, enhanced ammonia oxidizing rate (AOR) was consistent with the high contribution of nitrification to the E2 attenuation. Importantly, heterotrophic activity was positively correlated with its contribution to E2 removal (r = 0.99, P < 0.05). To sum, the results obtained in this study helped to understand the E2 removal routes in nitrifying biofilm systems.
研究领域:
环境科学
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微生物学
✓ 已验证
DOI
高影响因子
SOIL BIOLOGY & BIOCHEMISTRY
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2021
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IF 7.609
Haiyang Liu,Hangwei Hu,Xing Huang,Tida Ge,Yongfu Li,Zhenke Zhu,Xingmei Liu,Wenfeng Tan,Zhongjun Jia,Hongjie Di,Jianming Xu,Yong Li
Chemoautotrophic canonical ammonia-oxidizers and complete ammonia oxidizers (comammox) are responsible for ammonia oxidation, which is the rate-limiting step of nitrification in terrestrial ecosystems. However, the relative importance of autotrophic nitrification and the related active nitrifiers during mineralization of organic substances with different C/N ratios have not been fully elucidated to date. In this study, 15 N tracing and 13 CO 2 -DNA-based stable isotope probing (DNA-SIP) techniques were employed to investigate the responses of soil nitrification processes and the active nitrifying phylotypes in acidic and neutral paddy soils with amendment of glutamine (Gln) or rice straw with low C/N (LS) or high C/N (HS). Acetylene (C 2 H 2 ) was utilized to differentiate autotrophic and heterotrophic nitrification. The results indicated that C 2 H 2 completely blocked the production of 15 NO 3 − in Gln and LS treatments, implying the predominance of autotrophic nitrification with the N derived from the mineralization of Gln and LS. Neither 15 NH 4 + nor 15 NO 3 − was detected in the HS-amended soils, suggesting that NH 4 + derived from organic N mineralization was immobilized immediately by microorganisms. In the DNA-SIP microcosms, the abundance of ammonia-oxidizing bacteria (AOB) in the unamended control (CK), Gln and LS treatments of acidic paddy soil increased by 22.1-, 71.9- and 27.6-fold, respectively. A significantly larger proportion of Nitrosospira -like AOB, rather than ammonia-oxidizing archaea (AOA) and comammox Nitrospira , was labelled by 13 CO 2 , indicating that AOB made a stronger contribution to autotrophic nitrification in acidic paddy soil. The active nitrification of neutral paddy soil was predominated by AOA affiliated with the Nitrososphaera viennensis lineage in the CK and LS microcosms but by Nitrosospira -like AOB in the Gln microcosm. These results suggest the significance of autotrophic nitrification catalysed by canonical ammonia oxidizers, rather than comammox, during the mineralization of organic substances with low C/N in paddy soils.
研究领域:
微生物学
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土壤学
·
生态学
✓ 已验证
DOI
高影响因子
ACS ES&T Water
·
2024
·
IF 4.8
Jianguo Li,Shikan Zheng,Wanli Yan,Chengsong Ye,Xin Yu
The membrane-aerated biofilm reactor (MABR) is emerging as a promising solution for future wastewater treatment owing to its remarkable proficiency in achieving concurrent nitrogen and carbon removal. The research addressed a new type of MABR (R2) equipped with a polytetrafluoroethylene membrane-wrapped hollow nylon rope module that was constructed to improve the carbon and nitrogen removal of conventional MABR (R1). Uninterrupted operation lasting 120 days was conducted to compare the performance of R1 and R2 in treating simulated municipal wastewater with varying chemical oxygen demand (COD)/nitrogen (C/N) ratios. The results showed that R2 outperformed R1, exhibiting over 15.9% and 27.9% higher COD and TIN removal rates, respectively. The nylon fillers promoted biofilm formation, mitigated membrane pore clogging by the extracellular polymeric substances, and maintained a stable transmembrane pressure. R2 consistently maintained stable ammonia removal efficiency across different C/N ratios, while R1 exhibited a notable decrease at a high influent C/N ratio. Utilizing nylon carriers on membranes offered a cost-efficient and convenient method for modifying and preparing membranes for treating wastewater with broader C/N ratios and scaling up MABR applications.
研究领域:
环境工程
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废水处理
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生物技术
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Omega
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2020
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IF 2.87
Xueyu Liu,Hongguang Zhu
The traditional biological denitrification process has the problems of low removal rates and lack of a carbon source when treating wastewater with high ammonia nitrogen concentration and a low carbon–nitrogen ratio. Based on a bio-electrochemical system (BES), a novel carbon cloth bipolar plate multicompartment electroenhanced bioreactor (CBM-EEB) system was constructed. In this study, nitrogen removal efficiency and enrichment of functional bacteria using CBM-EEB under different voltage conditions were investigated. The results from next-generation sequencing indicated that the CBM-EEB included heterotrophic nitrification and aerobic denitrification (HNAD) and was dominated by heterotrophic nitrification aerobic denitrifying bacteria (HNADB). The applied voltage was confirmed as having the ability to regulate the microbial community structure and abundance of functional genes, thereby further enhancing the nitrogen removal efficiency of the system. The total nitrogen removal efficiency was 77.70 ± 1.14, 87.10 ± 0.56, 86.40 ± 0.59, and 89.30 ± 0.53% under applied voltages of 0.4, 0.7, 1.0, and 1.3 V, respectively. All values were significantly higher than the control group (62.86 ± 2.06%). HNADB had the highest abundance among the 17 detected genera related to nitrogen metabolism. Facultative denitrifying bacteria, Pseudoxanthomonas, along with key bacteria of HNADB, such as Flavobacterium, constructed a shortcut simultaneous nitrification–denitrification (SND) process. Poisson analysis and redundancy analysis (RDA) showed that the applied voltage improved the denitrification efficiency by changing the microbial community structure, reducing the abundance of heterotrophic bacteria, and increasing the unit abundance of key functional genes so that less organics were required for the denitrification process. The increased nitrogen removal efficiency in the experimental group was mainly related to simultaneous nitrification–denitrification process and cooperation of microbial communities in the anode and the cathode. This study highlighted the feasibility of CBM-EEB to enhance the HNAD reaction and the response of wastewater with a low C/N ratio to enhance the abundance of microbial bacteria and their functional gene abundance.
研究领域:
环境工程
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生物技术
·
微生物学
·
废水处理
✓ 已验证
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2021
·
IF 4.952
Xi Cao,Yayu Pan,Wei Wei,Tinglan Yuan,Sen Wang,Lingyun Xiang,Yongjun Yuan
Effects of various fermentation conditions on fatty acid composition of single cell oil (SCO) from Trichosporon sp. F1-2 were investigated. Ten carbon sources clustered into two groups using hierarchical clustering algorithm and principal component analysis. Xylose and soluble starch from each group were further studied. SCO using xylose had a high oleic acid content, while the linoleic acid and α-linolenic acid content increased significantly in SCO using soluble starch especially at the sn -2 position. 20 and 31 triacylglycerol (TAG) types were detected, respectively. The increased types were rich in linoleic acid and α-linolenic acid. The effect of C/N ratios was the weakest (distance threshold 3.05), followed by inoculation amounts (3.08), fermentation time (4.30) and nitrogen sources (5.64). The optimum nitrogen source, C/N ratio, inoculation amount and fermentation time for SCO accumulation were ammonium sulfate, 60, 6% and 120 h, respectively. Two different SCOs were produced using xylose and soluble starch under optimum conditions, which were demonstrated to be potential substrates for synthesis of 1,3-distearoyl-2-oleoyl-glycerol (a cocoa butter improver) and MLM-type TAG (the dietary TAG with low caloric value) respectively. Therefore, changing the carbon source can help broaden application fields of SCOs and increase feedstock sources of structured TAG synthesis.
研究领域:
生物技术
·
食品科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）