Characteristics of biofilm layer in a bio-doubling reactor and their impact on aerobic denitrifying bacteria enrichment.

Microbial loss significantly affects wastewater treatment efficiency. This study simulated the inoculation area of a self-developed biological doubling reactor (BDR) to evaluate the retention efficiency of seven different fillers for aerobic denitrifying bacteria. Over 90 days of continuous operation, the porous filler R3 demonstrated excellent performance, with OD values consistently exceeding 1.

Research on the application of heterotrophic nitrification-aerobic denitrification bacteria in membrane bioreactor (MBR).

Inoculating heterotrophic nitrification-aerobic denitrification bacteria (HN-AD) to enhance membrane bioreactor (MBR) efficiency may result in the loss of functional bacteria. Therefore, this study compares the application results of enhancing MBR with a self-designed biological amplifier coupled with HN-AD against the performance of conventional MBR. After enhancement, the MBR achieved a removal efficiency of 96.

Efficient and low-energy degradation of chlorobenzene via catA-mediated cleavage and bedC1 docking in a novel Burkholderia stabilis TF-2.

In this study, a novel strain Burkholderia stabilis TF-2 capable of assimilatory and co-metabolic degradation of chlorobenzenes was obtained. The interaction between chlorobenzene (CB) and target enzymes, as well as the metabolic pathways in TF-2, were elucidated using multi-omics and molecular docking techniques. Results of degradation experiments indicated that TF-2 assimilated CB at a rate of 0.

Influence and mechanism of typical transition metal ions on the denitrification performance of heterotrophic nitrification-aerobic denitrification bacteria.

To investigate the inhibitory effects of various transition metal ions on nitrogen removal and their underlying mechanisms, the single and combined effects of Cu Ni and Zn on Heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria Acinetobacter sp. TAC-1 were studied in a batch experiment system. The results revealed that increasing concentrations of Cu and Ni had a detrimental effect on the removal of ammonium nitrogen (NH-N) and total nitrogen (TN).

Genetic response analysis of Beauveria bassiana Z1 under high concentration Cd(II) stress.

Cadmium (Cd(II)) has carcinogenic and teratogenic toxicity, which can be accumulated in the human body through the food chain, endangering human health and life. In this study, a highly Cd(II)-tolerant fungus named Beauveria bassiana Z1 was studied, and its Cd(Ⅱ) removal efficiency was 71.2% when the Cd(II) concentration was 10 mM.

Metabolic diversity shapes vegetation-enhanced methane oxidation in landfill covers: Multi-omics study of rhizosphere microorganisms.

Vegetation root exudates have the ability to shape soil microbial community structures, thereby enhancing CH bio-oxidation capacity in landfill cover systems. In this study, the CH oxidation capacity of indigenous vegetation rhizosphere microorganisms within operational landfill covers in Chongqing, China, was investigated for the first time, with the objective of identifying suitable plant candidates for CH mitigation initiatives within landfill cover systems. Furthermore, a multi-omics methodology was employed to explore microbial community structures and metabolic variances within the rhizospheric environment of diverse vegetation types.

Microecological health assessment of water environment and sediment based on metagenomics: a case study of Guixi River in Chongqing, China.

River sediment is vital in containing water pollution and strengthening water remediation. This paper has conducted a study on the microecological health assessment of the sediment and water body of Guixi River in Dianjiang, Chongqing, China, using metagenomics sequencing and microbial biological integrity index (M-IBI) technology. The analysis of physical and chemical characteristics shows that the concentration of TN varies from 2.

Quantitative analysis of TCE biodegradation pathway in landfill cover utilizing continuous monitoring, droplet digital PCR and multi-omics sequencing technology.

The remediation of volatile chlorinated hydrocarbons in the quasi-vadose zone has become a significant challenge. We applied an integrated approach to assess the biodegradability of trichloroethylene to identify the biotransformation mechanism. The formation of the functional zone biochemical layer was assessed by analyzing the distribution of landfill gas, physical and chemical properties of cover soil, spatial-temporal variations of micro-ecology, biodegradability of landfill cover soil and distributional difference metabolic pathway.

Domestication and pilot-scale culture of mixed bacteria HY-1 capable of heterotrophic nitrification-aerobic denitrification.

To further investigate the potential of heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria for practical applications, the HN-AD mixed bacteria HY-1 were enriched and domesticated in this study. After five generations of domestication, the mixture was able to remove 98% of ammonia nitrogen (400 mg/L) and 81.9% of mixed nitrogen source (nitrate, nitrite).

Synergistic effects of vegetation and microorganisms on enhancing of biodegradation of landfill gas.

The uncontrolled release of landfill gas represents a significant hazard to both human health and ecological well-being. However, the synergistic interactions of vegetation and microorganisms can effectively mitigate this threat by removing pollutants. This study provides a comprehensive review of the current status of controlling landfill gas pollution through the process of revegetation in landfill cover.

Water microecology is affected by seasons but not sediments: A spatiotemporal dynamics survey of bacterial community composition in Lake Changshou-The largest artificial lake in southwest China.

This study aimed to evaluate the correlation between microecology of sediments and water as well as their spatial-temporal variations in Changshou Lake. The results demonstrated that microecology in the lake exhibits spatiotemporal heterogeneity, and microbial diversity of sediments was significantly higher than that of water body. Further, it was found that there was statistically insignificant positive correlation between microecology of sediments and that of water body.

Nitrogen removal and mechanism of an extremely high-ammonia tolerant heterotrophic nitrification-aerobic denitrification bacterium Alcaligenes faecalis TF-1.

A novel heterotrophic nitrifying bacterium with high salt and high ammonia nitrogen tolerance, Alcaligenes faecalis TF-1, was isolated from the leachate of a landfill. The verification of nitrogen removal efficiency of different nitrogen sources and PCR amplification electrophoresis results showed that the HN-AD pathway of the strain TF-1 was NH → NHOH → NO → NO → N. The results of parameter optimization showed that the optimal nitrogen removal conditions were as follows: sodium citrate as carbon source, C/N = 16, pH = 7, and NH-N loading of 808.

Effect mechanism of individual and combined salinity on the nitrogen removal yield of heterotrophic nitrification-aerobic denitrification bacteria.

One of the biggest challenges of applying heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria to treat high salt organic wastewater lies in the inhibitory effect exerted by salinity. To study the inhibition effect and underlying mechanism induced by different ion types and ion composition, the individual and combined effects of NaCl, KCl and NaSO on HN-AD bacteria Acinetobacter sp. TAC-1 were systematically investigated by batch experiments.

[Transformation mechanism of carbon tetrachloride and the associated micro-ecology in landfill cover, a typical functional layer zone].

Landfill is one of the important sources of carbon tetrachloride (CT) pollution, and it is important to understand the degradation mechanism of CT in landfill cover for better control. In this study, a simulated landfill cover system was set up, and the biotransformation mechanism of CT and the associated micro-ecology were investigated. The results showed that three stable functional zones along the depth, i.

Characterization of a novel salt-tolerant strain Sphingopyxis sp. CY-10 capable of heterotrophic nitrification and aerobic denitrification.

A novel heterotrophic nitrification and aerobic denitrification (HN-AD) strain CY-10 was isolated and identified as Sphingopyxis sp. When ammonium, nitrate or nitrite was used as the sole nitrogen source (300 mg/L), the maximum nitrogen removal efficiency of strain CY-10 were 100%, 91.1% and 68.

Direct aerobic oxidation (DAO) of chlorinated aliphatic hydrocarbons: A review of key DAO bacteria, biometabolic pathways and in-situ bioremediation potential.

Contamination of aquifers and vadose zones with chlorinated aliphatic hydrocarbons (CAH) is a world-wide issue. Unlike other reactions, direct aerobic oxidation (DAO) of CAHs does not require growth substrates and avoids the generation of toxic by-products. Here, we critically review the current understanding of chlorinated aliphatic hydrocarbons-DAO and its application in bioreactors and at the field scale.

Cometabolic degradation mechanism and microbial network response of methanotrophic consortia to chlorinated hydrocarbon solvents.

The cometabolism mechanism of chlorinated hydrocarbon solvents (CHSs) in mixed consortia remains largely unknown. CHS biodegradation characteristics and microbial networks in methanotrophic consortia were studied for the first time. The results showed that all CHSs can efficiently be degraded via cometabolism with a maximum degradation rate of 4.

Response of rotating biological contactor started up by heterotrophic nitrification-aerobic denitrification bacteria to various C/N ratios.

To improve the low pollutant removal efficiency of traditional biological methods for treating livestock and poultry breeding wastewater under a relatively low temperature, a rotating biological contactor (RBC) inoculated with heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria was designed. A quick start-up process and a well removal performance had been achieved in the novel RBC. To elucidate the anti-load shock ability of the novel RBC, the effects of C/N ratio on nitrogen removal and microbial assemblage were focused under a low temperature (12 ± 2 °C).

Effect of bacteria-to-algae volume ratio on treatment performance and microbial community of a novel heterotrophic nitrification-aerobic denitrification bacteria-chlorella symbiotic system.

A novel symbiotic system combined by heterotrophic nitrification-aerobic denitrification (HN-AD) mixed bacteria and Chlorella pyrenoidosa was firstly proposed to resolve the poor tolerance and nitrogen removal performance of traditional symbiotic system for treating high ammonia biogas slurry. Results showed that the volume ratio of bacteria to algae had significant effects on nitrogen removal efficiency, microbial community structure, functional bacteria and genes. The optimal ratio was 1/3, and the average removal efficiency of TN and TP increased by 28.

Efficiency and microbial diversity of aeration solid-phase denitrification process bioaugmented with HN-AD bacteria for the treatment of low C/N wastewater.

To evaluate the simultaneous nitrification and denitrification (SND) performance of the aeration solid-phase denitrification (SPD) process and improve the operating efficiency, aeration SPD process using polybutanediol succinate as carbon source was optimized and the process was bioaugmented with heterotrophic nitrification-aerobic denitrification bacteria for the treatment of real wastewater. The results showed that after bioaugmentation, the total nitrogen removal efficiency of the aeration SPD process increased by 50.46 % under condition of dissolved oxygen (DO) 3 mg/L.

Heterotrophic nitrification and aerobic denitrification by a novel Acinetobacter sp. TAC-1 at low temperature and high ammonia nitrogen.

A novel strain was isolated from swinewastewater and identified as Acinetobacter sp. TAC-1 based on its phylogenetic and phenotypic characteristics. The strain TAC-1 was found to have a high ability to metabolize ammonium-N under low temperature condition.

Response of wastewater treatment performance, microbial composition and functional genes to different C/N ratios and carrier types in MBBR inoculated with heterotrophic nitrification-aerobic denitrification bacteria.

To operate the moving bed biofilm reactor inoculated with HN-AD bacteria (B-MBBR) instead of activated sludge for livestock and poultry breeding wastewater (LPBW) disposal in most efficient manner, nitrogen removal (NR) efficiency and microbial composition of two MBBRs with different carrier types under various C/N ratios were explored. Results indicated that the performance on NR greatly various in different carrier types under various C/N ratios. Attributing to the bacterial protection provided by the porous structure of polyvinyl alcohol (PVA) gel, MBBR using PVA gel as the carrier exhibited a more stable NR performance (range from 78.

Progress of carbon-based electrocatalysts for flexible zinc-air batteries in the past 5 years: recent strategies for design, synthesis and performance optimization.

The increasing popularity of wearable electronic devices has led to the rapid development of flexible energy conversion systems. Flexible rechargeable zinc-air batteries (ZABs) with high theoretical energy densities demonstrate significant potential as next-generation flexible energy devices that can be applied in wearable electronic products. The design of highly efficient and air-stable cathodes that can electrochemically catalyze both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are highly desirable but challenging.

Biodegradation of phenol by a highly tolerant strain Rhodococcus ruber C1: Biochemical characterization and comparative genome analysis.

A novel phenol-degrading strain was isolated and identified as Rhodococcus ruber C1. The degradation analysis shows that 1806 mg/L of phenol can be completely degraded by strain C1 within 38 h, and the maximum specific growth rate (μ=1.527 h) and maximum specific phenol degradation rate (q=3.

Removal of CXR-type disinfection by-product precursors from rainwater with conventional drinking water treatment processes.

In addition to surface water and groundwater, rainwater is used as an important drinking water source in many parts of the world, especially in areas with serious water pollution or insufficient water resources. Conventional drinking water treatment technologies can remove dissolved organic matter and therefore reduce the formation of disinfection by-products (DBPs) during subsequent disinfection using surface water or groundwater as drinking water sources. However, little information has been known about the effect of conventional water treatment processes on DBP formation when rainwater is used as drinking water source.