Fermentation-Basel
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2023
·Vol. 9
·期 5
·465
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IF 3.7
Bei Li,Chiqian Zhang,Cong Jin,Jinhua Wu,Ping Li
The leachate from municipal solid waste transfer stations has a complex composition of pollutants, contains high concentrations of organic matter, and produces odors. The anaerobic digestion of leachate generates excessive volatile organic acids (VFAs), acidifying the digestate and destabilizing or even collapsing the anaerobic process. To solve these issues, we set up a facultative anaerobic system with air exposure and an obligate anaerobic system without air exposure to explore the impact of anaerobic degree on intermediate accumulation and anaerobic process stability. When the organic loading raised from 0.6 to 6.0 kg COD/(m3·d), VFA accumulation in the facultative system peaked at 3.30 g COD/L, and the chemical oxygen demand (COD) removal rate dropped from 95% to 60%. By contrast, the obligate system remained stable, with VFA concentrations below 0.50 g COD/L and COD removal rates between 85% and 99%. Microbial sequencing shows that VFA-oxidizing bacteria enhanced VFA degradation, such asSyntrophomonasandSmithella, which increased from 4.62% and 0.76% in the facultative system to 17.64% and 0.88% in the obligate system, respectively. Coenzyme F420 concentration as an indicator of methanogenic activity was 50% higher in the obligate system. Therefore, an obligate anaerobic system is promising to alleviate acidification for stable anaerobic digestion of leachate.Keywords:anaerobic digestion;anaerobic degree;loading fluctuation;VFA accumulation;fresh leachate
研究领域:
环境工程
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废物管理
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微生物学
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产品关联
DOI
高影响因子
WATER RESEARCH
·
2020
·
IF 9.13
Da Kang,Yiyu Li,Dongdong Xu,Wenji Li,Wei Li,Aqiang Ding,Ru Wang,Ping Zheng
The red color is the most striking character of anaerobic ammonium-oxidizing bacteria (AnAOB) which has been used to estimate the anammox activity roughly. However, the quantitative relationship between the color and activity of anammox sludge still remains unknown. In this study, the chromaticity, activity and their correlation were systematically investigated at different steady-state nitrogen loading rates. The chromaticity of anammox sludge was digitalized by the CIE L*a*b* color space. The results revealed that the average chroma value was found to be significantly correlated with specific anammox activity ( r = 0.940, p < 0.01) and the cluster centers of chromaticity coordinates (a*, b*) of anammox sludge were established to define the typical working states of anammox system. The visible spectra of anammox sludge were proved to originate from the cytochrome c. The correlation between chroma and heme c concentration of anammox sludge was consistent with the fully-reduced cytochrome c and the chroma was determined by both content and redox ratio of cytochrome c. The chromaticity of anammox sludge was able to be linked with the anammox activity via reduced cytochrome c content. The gene abundance of cytochrome c synthetase linked the chromaticity with AnAOB quantity via total cytochrome c content, while the enzyme activity of octaheme hydrazine dehydrogenase linked the chromaticity with AnAOB activity via reduced cytochrome c ratio. Moreover, the redundancy analysis proved that heme c, as the key component of cytochrome c, was the most important explanatory variable accounting for the maximum 69.6% of the total variation of the anammox community, which correlated positively with the relative abundance of dominant AnAOB ( Candidatus Kuenenia). This work aimed at demonstrating the chromaticity of anammox sludge could be developed as an alternative intuitive anammox activity indicator which will promote the monitoring and optimization of anammox process.
研究领域:
环境工程
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微生物学
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生物技术
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2024
·
IF 8
Xun Weng,Meng-Jiao Gao,Zheng Mao,Hui-Min Fu,Shi-Jun Li,Peng Yan,You-Peng Chen
Iron nanoparticles (FeNPs) generated from industrial activities could end up into the sewer system, and potentially affect wastewater treatment processes. The impact of FeNPs on anammox process is getting increasing attention. However, the resistance mechanism of anammox granular sludge (AnGS) to FeNPs has not been fully elucidated. The current study investigated the metabolic and morphological response of AnGS to acute and chronic FeNPs exposure. Results showed that nitrogen removal efficiencies were elevated at 1–4 mM FeNPs concentrations compared to 0–0.5 mM FeNPs. Extracellular protein and tyrosine-like and tryptophan-like fluorophore secretions of AnGS were stimulated by FeNPs, which largely contributed to the adsorption of FeNPs on AnGS surface. FeNPs exposure triggered higher necrotic fraction of AnGS compared with no FeNPs condition. Highly absorbed particles appeared inside the bacterial cells of AnGS, soft X-ray imaging illustrated that anammox bacteria maintained intact cellular and anammoxosome structures whereas non-anammox bacterial structures were damaged under FeNPs exposure. Anammox bacterial abundance increased from 4.84% to 20.64%, when FeNPs concentrations increased from 0 mM to 4 mM, and anammoxosome membrane ensured anammox bacterial metabolism under FeNPs exposure. This study extended fundamental understanding of AnGS resistance mechanisms to FeNPs.
研究领域:
环境科学
·
微生物学
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DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2024
·
IF 9.7
Yu Feng,Xingyu Zhang,Caiwei Zhang,Haozhe Xu,Xiaoming Ji,Jianfang Wang,Peng Wu,Feiyue Qian,Chongjun Chen,Yaoliang Shen,Wenru Liu
In this study, waste iron scraps (WIS) were exerted to alleviate sulfide inhibition on anammox bacteria and promote anammox nitrogen removal from sulfide-containing wastewater. Short-term batch experiments showed that WIS-addition led to the anammox bacteria activity increasing by 124.8 % at an initial sulfide concentration of 40 mgS/L. During the long-term experiments, the nitrogen removal rate (NRR) reached to 8.76 kg/(m 3 ·d) in the WIS-added reactor, while the maximum NRR was only 3.77 ± 0.31 kg/(m 3 ·d) in the non-WIS reactor. In contrast to anammox bacteria development in the non-WIS reactor, the relative abundance of Candidatus Kuenenia (1.4–3.7 %) declined significantly in the WIS-added reactor, but novel potential anammox bacteria Brocadiaceae_unclassified (60.1 %-78.6 %) were highly enriched. Overall, the experimental evidence suggested that WIS-addition not only mitigated the sulfide inhibition on anammox bacteria, but also promoted novel anammox bacteria proliferation. The findings of this work provide a promising solution for wide engineering applications of anammox treating sulfide-containing wastewater.
研究领域:
环境工程
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2023
·
IF 8.6
Xuran Liu,Xianli Yang,Jingnan Yang,Yanxin Wu,Dongbo Wang
The quality and quantity of short chain fatty acids (SCFAs) production from anaerobic fermentation of sewage sludge is generally constrained by low organics solubilization and poor substrate-availability. This study provided an environmentally friendly strategy with zero valent iron (ZVI) activating sulfite pretreatment to overcome this limitation and advance the sludge anaerobic fermentation. Experimental results showed that the maximal SCFAs production and acetate proportion promoted by 5.7 and 2.75 times respectively at 500 mg S/L and the ZVI/sulfite ratio of 1.25. Mechanism analysis elucidated that the free radicals of S O 4 - · and ·OH produced from ZVI-sulfite pretreatment accelerated the disintegration of sludge-flocs and decreased the value of α-helix and ratio of α-helix/ (β-sheet + random coil) from 21.64 % and 44.23 % to 17.80 % and 38.67 %, respectively, which provided more easily- and bio- available substance for functional anaerobes. The ZVI-sulfite pretreatment enhanced the ability of functional anaerobes for SCFAs production processes as hydrolysis, acidogenesis and acetogenesis and reduced the SCFAs consumption as methanogenesis, which ultimately promoted SCFAs accumulation. Microbial community illustrated that ZVI-sulfite pretreatment enriched the relative abundance of functional anaerobes related to hydrolysis, acidogenesis and acetogenesis bioprocesses. PICRUSt analysis demonstrated that the pretreatment boosted the functional genes abundance involved in pathway of butyrate and acetate formation. Moreover, the enrichment genes of acetate formation were consistent with the increase of acetate proportion.
研究领域:
环境工程
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微生物学
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生物技术
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污水处理
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2023
·
IF 13.6
Jiaohui Xia,Yan Li,Xinbai Jiang,Dan Chen,Jinyou Shen
Electricity-stimulated anaerobic system (ESAS) has shown great potential for halogenated organic pollutants removal. Exogenous redox mediators can improve electron transfer efficiency to enhance pollutants removal in ESAS. In this study, humic acid (HA), a low-cost electron mediator, was added into ESAS to enhance the simultaneous reductive debromination and mineralization of 4-bromophenol (4-BP). Results showed that the highest 4-BP removal efficiency at 48 h was 95.43 % with HA dosage of 30 mg/L at − 700 mV, which was 34.67 % higher than that without HA. The addition of HA decreased the requirement for electron donors and enriched Petrimonas and Rhodococcus for humus respiratory. HA addition regulated microbial interactions, and enhanced species cooperation between Petrimonas and dehalogenation species ( Thauera and Desulfovibrio ), phenol degradation-related species ( Rhodococcus ) as well as fermentative species ( Desulfobulbus ). Functional genes related to 4-BP degradation ( dhaA/hemE/xylC/chnB/dmpN ) and electron transfer ( etfB/nuoA/qor/ccoN/coxA ) were increased in abundance by HA addition. The enhanced microbial functions, as well as species cooperation and facilitation, all contributed to the improved 4-BP biodegradation in HA-added ESAS. This study provided a deep insight into microbial mechanism driven by HA and offered a promising strategy for improving halogenated organic pollutants removal from wastewater.
研究领域:
环境工程
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微生物学
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生物修复
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DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2022
·
IF 11.889
Yidi Wang,Wei Li,Yongkang Wang,Yusan Turap,Zhentong Wang,Zhe Zhang,Zhou Xia,Wei Wang
The effect of pretreatment technologies and reactor types on conversion efficiency and operating costs of anaerobic co-digestion of food waste and sewage sludge were investigated by 300-day continuous experiments. The volatile solids (VS) removal efficiency increased from 61% to 77% with the application of co-hydrothermal pretreatment of sewage sludge and biogas residue. Deep dewatering reduced the volume of hydrothermally pretreated biogas residue by 85%. When continuous stirred tank reactors (CSTRs) were converted to anaerobic sequencing batch reactors (ASBRs), vS removal efficiencies increased by 6%, attributed to a 1.4–1.6-fold increase in solids retention time (SRT). The bottom drainage of mineralized sludge every 40 days increased ASBR stability. Firmicutes and Methanosphaera dominated the bacterial and archaeal communities, respectively. Operating costs decreased by 14.9 US$/metric ton feedstock by applying ASBRs. Compared to CSTRs, ASBRs achieved higher organic matter conversion efficiency, smaller volume of biogas residue, and lower operating costs.
研究领域:
环境工程
·
废物管理
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生物技术
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Zhuo Zeng,Ping Zheng,Da Kang,Yiyu Li,Wenji Li,Dongdong Xu,Wenda Chen,Chao Pan
Copper and zinc are often used as feed additives and frequently detected in swine wastewater. Anaerobic granular sludge (AnGS) plays an important role in high-rate anaerobic methanation biotechnologies which are widely applied to treat swine wastewater. The removal of Cu 2+ and Zn 2+ by AnGS was investigated in the batch and continuous systems. The results of batch experiments showed the adsorption by AnGS could be a significant method for Cu 2+ and Zn 2+ removal with efficiencies of 99 % and 49 % respectively. The sulfide precipitation mediated by AnGS could be another significant pathway for Zn 2+ removal with efficiency of 18–27 % in Protein/M 2+ experiments and 16–46 % in SO 4 2− /M 2+ experiments (M 2+ represents the total concentration of Cu 2+ and Zn 2+ ). The results of continuous experiment showed, with SO 4 2− /M 2+ larger than 1.5, the influent Cu 2+ and Zn 2+ could be effectively removed in an anaerobic methanation bioreactor and its effluent Cu 2+ and Zn 2+ concentrations were below 1 mg/L and 2 mg/L separately. The main removal mechanism of Cu 2+ and Zn 2+ in the anaerobic methanation system was that the biological production of sulfide from sulfate was followed by chemical precipitation and reduction. It is helpful for the removal of Cu 2+ and Zn 2+ with organic pollutants simultaneously to eliminate environmental risk of swine wastewater.
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Water Research X
·
2024
·
IF 7.2
Dongdong Xu,Aqiang Ding,Yang Yu,Ping Zheng,Meng Zhang,Zhetai Hu
Magnetite (Fe 3 O 4 ) particles have been widely reported to enhance the anammox's activity in anammox granular sludge (AnGS), yet the underlying mechanisms remain unclear. This study demonstrates that both Fe 3 O 4 microparticles (MPs) and nanoparticles (NPs) at a dosage of 200 mg Fe 3 O 4 /L significantly increased the specific anammox activity (SAA) of AnGS. Additionally, the transcriptional activities of the hzs and hdh genes involved in the anammox process, as well as the heme c content in AnGS, were also notably enhanced. Notably, Fe 3 O 4 NPs were more effective than MPs in boosting anammox activity within AnGS. Mechanistically, Fe 3 O 4 MPs released free iron, which anammox bacteria utilized to promote the synthesis of key enzymes, thereby enhancing their activity. Compared to MPs, Fe 3 O 4 NPs not only elevated the synthesis of these key enzymes to a higher level but also induced a nanofluids effect on the surface of AnGS, improving substrate permeability and accessibility to intragranular anammox bacteria. Moreover, the nanofluids effect was identified as the primary mechanism through which Fe 3 O 4 NPs enhanced anammox activity within AnGS. These findings provide new insights into the effects of nanoparticles on granular sludge systems, extending beyond AnGS.
研究领域:
环境工程
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微生物学
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生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Yanjuan Gao,Zhihong Liu,Shaobo Wang,Aijuan Zhou,Xvfeng Lv,Xiuping Yue
Indole and pyridine, which are highly produced refractory compounds in the industrial wastewater, exhibit poor degradation capabilities in natural environments. In this study, we developed an anaerobic digestion system coupled with weak electric mediation (ED), and investigated the promoting effect of weak electricity on indole and pyridine biodegradation. The degradation characteristics were systematically explored, and the results showed that the degradation rate and mineralization of indole and pyridine were significantly enhanced, the production of CH 4 was increased 1.4-fold, and the optimal voltages were 1.0 V and 0.8 V in the ED, respectively. Moreover, simultaneous removal of carbon and nitrogen was achieved. Gas chromatography–mass spectrometry analysis verified the transformation products, and possible pathways were proposed. Several byproducts of indole and pyridine were identified, with oxindole and glutaric dialdehyde being the main metabolites, respectively. Additionally, density functional theory (DFT) analysis was performed to investigated the radical indices and stabilities of the molecules to further confirm the degradation pathway. Microbial structure analysis demonstrated that the electrically mediated enhanced metabolism and activity of functional microbes, led to the promotion of indole and pyridine mineralization. Moreover, such species as degrading bacteria ( Alicycliphilus , Shinella ) and electroactive bacteria ( Achromobacter ), anaerobic ammonia-oxidizing bacteria ( SM1A02 ), and denitrifying bacteria ( Thiobacillus ) coexisted. This study demonstrates that weak electric mediation is a promising methodology for enhancing the removal of indole and pyridine from wastewater under anaerobic conditions.
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2024
·
IF 7.7
Xingyao Ye,Xiaojun Niu,Ling Li,Mengyu Lv,Dongqing Zhang,Deye Chen,Yu Line,Zhiquan Yang
N-(1,3-Dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD) is an antioxidant commonly used in tire manufacturing, and its release into the environment has significantly increased due to rapid urbanization. When subjected to ozonation, 6PPD converts into the harmful pollutant 6PPD quinone (6PPDQ). These substances enter wastewater treatment plants (WWTPs) via stormwater runoff and pipelines, posing significant risks to the functional microorganisms. Anammox, a strictly controlled and sensitive microbial nitrogen removal process, is especially susceptible to the effects of the pollutants. This study investigates the comprehensive impact of 6PPD-Q and 6PPD on anammox communities based on characterization analysis and metagenomics. At environmental concentrations, 6PPD-Q at 200 ng/L-1000 ng/L led to the disintegration of anammox granules. Extended exposure to both 6PPD-Q and 6PPD significantly reduces the population of anammox bacteria (AnAOB). By utilizing organic matter from dead cells and incoming carbonate as a carbon source, the system evolved into a nitrogen metabolism network primarily focused on denitrification and dissimilatory nitrate reduction to ammonium (DNRA). This transformation was accompanied by a reshuffling of the microbial community and associated genes, resulting in an accumulation of NH 4 + -N. These findings underscore the toxicity of 6PPD-Q and 6PPD to anammox and stress the importance of incorporating 6PPD into regulatory and preventive strategies.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
ENERGY CONVERSION AND MANAGEMENT
·
2022
·
IF 11.533
Weizhong Zhao,Xianbo Su,Yifeng Zhang,Daping Xia,Shihui Hou,Yixuan Zhou,Haijiao Fu,Lufei Wang,Xiangju Yin
Coal seams are considered occurrence sites for coalbed methane (CBM) accumulation and bio-methanation and sequestration of CO 2 . Biological approaches for the enhancement of the methanation rate of CO 2 for CBM production have attracted increasing attention. The microbial electrolysis cell (MEC) is a technology with strong potential to improve the performance of the traditional anaerobic digestion (AD) system. In this study, AD and MEC-AD systems were developed to produce biomethane from coal. The results showed that the cumulative methane production of MEC-AD was 6.05 mL/g coal, 39.08% higher compared to AD alone (4.35 mL/g coal). The CO 2 concentration was lower in the MEC-AD reactor, suggesting that the CO 2 from coal degradation was further converted to biomethane. Metagenomics sequencing results showed that Geobacter.sp and Methanosarcina.sp were enriched in the anodic biofilm to the greatest extent, implying that direct interspecies electron transfer at the anode may promote biomethanation. Moreover, there was significant upregulation in the gene abundances of key enzymes involved in the degradation of aromatic compounds and methanogenic metabolism in hydrolytic bacteria. In particular, the gene pilA , which controls conductive pili, was significantly upregulated. The key intermediate metabolites (benzoic acid, phenol, pentadecane, etc.) showed a higher concentration and conversion rate in MEC-AD hydrolysis compared to AD. These results suggest that the efficiency of hydrolysis and interspecies electron transfer during coal digestion are facilitated by MEC technology, achieving a significant increase in biomethane production. This study provides insights into the development of efficient and low or negative carbon technologies for enhancing biomethane production and CO 2 emission reduction.
研究领域:
环境生物学
·
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）