Mechanisms of nano zero-valent iron in enhancing dibenzofuran degradation by a Rhodococcus sp.: Trade-offs between ATP production and protection against reactive oxygen species.

Nano zero-valent iron (nZVI) can enhance pollutants biodegradation, but it displays toxicity towards microorganisms. Gram-positive (G) bacteria exhibit greater resistance to nZVI than Gram-negative bacteria. However, mechanisms of nZVI accelerating pollutants degradation by G bacteria remain unclear.

Behaviour of M. aeruginosa-Microplastic composite pollutants in coagulation and sludge storage.

Microcystis aeruginosa (M. aeruginosa) blooms and microplastics pollution have been major global water pollution concern in lakes and reservoirs. In this study, the behaviour of M.

Different Roles of Dioxin-Catabolic Plasmids in Growth, Biofilm Formation, and Metabolism of sp. Strain p52.

Microorganisms harbor catabolic plasmids to tackle refractory organic pollutants, which is crucial for bioremediation and ecosystem health. Understanding the impacts of plasmids on hosts provides insights into the behavior and adaptation of degrading bacteria in the environment. Here, we examined alterations in the physiological properties and gene expression profiles of sp.

Molecular mechanisms underlying sodium percarbonate treatment suppress the recovery and growth of Pseudanabaena sp. in early spring.

Increasing frequency and intensity of cyanobacterial blooms in water sources is a growing global issue. Algicides are usually implemented in summer or autumn when blooms break out, however, the blooms will form again when algicide's concentration declines to a certain extent. Preventing the recovery and growth of cyanobacteria in early spring may be conducive to abatement of the blooms in summer or autumn.

Advances and challenges in the technologies for cyanobacterial cells removal in drinking water treatment.

Harmful cyanobacteria in reservoirs pose a serious threat to drinking water safety due to the intracellular metabolites, such as toxins and unpleasant tastes & odours. Effective removal of harmful cyanobacteria with little to no cell damage is very important to ensure the safety of drinking water. This review first introduced development history of cyanobacterial removal technologies in drinking water treatment.

Is monochloramine pre-oxidation a viable strategy for enhancing the treatment efficiency of algae-laden water with conventional drinking water treatment process?

Algal blooms worldwide pose many challenges to drinking water production. Pre-oxidation with NaClO, KMnO, or ozone is commonly used to enhance algal removal in conventional drinking water treatment processes. However, these currently utilized oxidation methods often result in significant algal cell lysis or impede the operation of the subsequent units.

[Distribution Characteristics and Environmental Driving Factors of Cyanobacteria Community in Impounded Lakes and Reservoirs in Shandong on the East Route of South-to-North Water Diversion Project].

To investigate the distribution characteristics of the cyanobacteria community and the driving factors in impounded lakes and reservoirs in Shandong on the east route of the South-to-North Water Diversion Project, monthly samples of phytoplankton and the aquatic environment from Nansi Lake, Dongping Lake, Datun Reservoir, Donghu Reservoir, and Shuangwangcheng Reservoir were collected from May to November during 2010 to 2019. A total of 44 planktonic cyanobacteria taxa were identified with 23 filamentous cyanobacteria taxa. , and were the dominant harmful cyanobacteria species, with a high detection frequency and abundance in all lakes and reservoirs.

Shift of phytoplankton assemblages in a temperate lake located on the eastern route of the South-to-North Water Diversion Project.

There remains no consensus on the effects of changes in the environment factors under the action of water diversions on phytoplankton communities. Herein the changing rules applying to phytoplankton communities subject to water diversion were unveiled based on long-term (2011-2021) time-series observations on Luoma Lake, located on the eastern route of the South-to-North Water Diversion Project. We found that nitrogen decreased and then increased, while phosphorus increased after operation of the water transfer project.

Changes of phytoplankton and water environment in a highly urbanized subtropical lake during the past ten years.

Phytoplankton and water quality changes in highly urbanized lakes affect the surrounding water safety. However, due to the complexity and variability of natural changes and human disturbances, it is difficult for multi-year research with yearly sampling frequency to cover accurate changes of phytoplankton and water environment or provide constructive suggestions for managers. Based on monthly monitoring data spanning 2011-2020 in a highly urbanized subtropical lake (Hongze Lake, China), Mann-Kendall test, ANOVA analysis and variation partitioning analysis were used to assess the changes of phytoplankton and water environment, and detect dynamic responses of phytoplankton to environmental changes.

Cyanobacterial bloom intensities determine planktonic eukaryote community structure and stability.

The intensity of cyanobacterial blooms that predominate in the world's lakes and reservoirs is variable, which may lead to differing effects on the freshwater ecosystem. Planktonic eukaryotes play key roles in the structure and function of freshwater ecosystems; however, little is known about the influence of cyanobacterial blooms on eukaryotic plankton communities and their function. Herein, the dynamics of eukaryotic plankton communities in Hongze Lake, which is the fourth largest freshwater lake in China, with a range of bloom levels occurred, from low to high, were studied to reveal the effect of cyanobacterial blooms' spatial heterogeneity on planktonic eukaryotes.

Moderate pre-ozonation coupled with a post-peroxone process remove filamentous cyanobacteria and 2-MIB efficiently: From bench to pilot-scale study.

The increasing frequency and intensity of taste- and odour-producing cyanobacteria in water sources is a growing global issue. Odour events caused by 2-methylisoborneol (2-MIB) mainly arising from filamentous cyanobacteria have been a very common problem in water supply. Removal rates of filamentous cyanobacteria and 2-MIB by conventional water treatment, such as coagulation, and disinfection treatment processes is low.

Using sodium percarbonate to suppress vertically distributed filamentous cyanobacteria while maintaining the stability of microeukaryotic communities in drinking water reservoirs.

The increasing frequency and intensity of blooms of toxin- and taste & odour-producing filamentous cyanobacteria in water sources is a growing global issue. Compared to the common spherical Microcystis genus, the removal of filamentous cyanobacteria is more difficult in drinking water treatment plants; hence, abatement and control of the occurrence and proliferation of harmful filamentous cyanobacteria within drinking water sources is important for water supply. In this study, the solid sodium percarbonate (SPC), NaCO·1.

Fe activating sodium percarbonate (SPC) to enhance removal of Microcystis aeruginosa and microcystins with pre-oxidation and in situ coagulation.

The frequent occurrence of cyanobacterial blooms has become a concern for drinking water safety. Common pre-oxidation, which was widely considered to enhance the followed coagulation, can cause the rupture of algae cell, leading to the undesirable release of intracellular organic matter. In this study, the Fe activating sodium percarbonate (SPC/Fe) process for pre-oxidation and in situ coagulation was proved to effectively remove Microcystis aeruginosa without damaging cell integrity at optimal combined doses of SPC (0.

18S rRNA gene sequencing reveals significant influence of anthropogenic effects on microeukaryote diversity and composition along a river-to-estuary gradient ecosystem.

Microeukaryotes play key roles in the structure and functioning of lotic ecosystems; however, little is known about the relative importance of the processes that drive planktonic microeukaryotic biogeography in rivers, especially the effects of anthropogenic inputs (e.g., wastewater discharge and pesticide and fertilizer use) on the taxonomic and functional diversity of microeukaryotes.

Impact of copper sulphate, potassium permanganate, and hydrogen peroxide on Pseudanabaena galeata cell integrity, release and degradation of 2-methylisoborneol.

Frequent off-flavor events caused by geosmin and 2-methylisoborneol have caused concern among consumers about the quality of potable water. Pseudanabaena galeata, a filamentous cyanobacterium, is a known producer of 2-methylisoborneol in lakes and reservoirs. The use of algicides to control cyanobacteria must consider the potential release of contaminants into the water.

Application of N-TiO for visible-light photocatalytic degradation of Cylindrospermopsis raciborskii - More difficult than that for photodegradation of Microcystis aeruginosa ?

Nowadays Cylindrospermopsis raciborskii (C. raciborskii) and the metabolites produced, such as cylindrospermopsin (CYN), pose a serious threat to the ecosystem. Advanced oxidation technologies have been verified as constituting a very promising means to eliminate the risk from harmful algae.

Using photocatalyst powder to enhance the coagulation and sedimentation of cyanobacterial cells and enable the sludge to be self-purified under visible light.

Removing harmful cyanobacteria intact by coagulation can prevent cell lysis and toxin release, which provides many benefits for drinking water production, including reduction of the burden on subsequent processes and guaranteeing the water quality. But the electronegativity and buoyancy of cyanobacterial cells make them settle slowly and their accumulation and concentration in flocs would still have severe adverse effects. In this study, we introduced a photocatalyst powder to act as a ballasting agent in the coagulation process and to degrade the cells and cyanotoxins during sludge storage.

Worse than cell lysis: The resilience of Oscillatoria sp. during sludge storage in drinking water treatment.

Benthic Oscillatoria sp. may form dense surface blooms especially under eutrophic and calm conditions, which poses a threat to drinking water safety because it can produce toxic and odorous metabolites. This is the first study to investigate the effect of the conventional coagulant polyaluminium ferric chloride (PAFC) on removal of Oscillatoria sp.

Use of fluorescence excitation-emission matrices coupled with parallel factor analysis to monitor C- and N-DBPs formation in drinking water recovered from cyanobacteria-laden sludge dewatering.

This is the first time that correlations between the spectroscopic properties of algal organic matter (AOM) and cyanobacteria-related C- and N-disinfection byproduct (DBP) formation have been presented. Three types of coagulants, aluminium chloride (AC), chitosan (CTS) and a composite chitosan-aluminium chloride (CTSAC), were selected to assess and compare the performance of coagulation to control DBPs formation in dewatering water (DW). Fluorescence excitation-emission matrices (EEMs) coupled with parallel factor analysis (PARAFAC) indicated that four components dominated the EEM of the DW samples.

Primary investigation of the antialgal activity of shrimp shell on Microcystis aeruginosa.

This study aimed to explore the application potential of an eco-friendly waste-shrimp shell in Microcystis aeruginosa (M. aeruginosa) control-for the first time. Four treatments with different doses (0.

High-throughput sequencing reveals microbial communities in drinking water treatment sludge from six geographically distributed plants, including potentially toxic cyanobacteria and pathogens.

The microbial community structures of drinking water treatment sludge (DWTS) generated for raw water (RW) from different locations and with different source types - including river water, lake water and reservoir water -were investigated using high-throughput sequencing. Because the unit operations in the six DWTPs were similar, community composition in fresh sludge may be determined by microbial community in the corresponding RW. Although Proteobacteria, Cyanobacteria, Bacteroidetes, Firmicutes, Verrucomicrobia, and Planctomycetes were the dominant phyla among the six DWTS samples, no single phylum exhibited similar abundance across all the samples, owing to differences in total phosphorus, chemical oxygen demand, Al, Fe, and chloride in RW.

Behavior of Cylindrospermopsis raciborskii during coagulation and sludge storage - higher potential risk of toxin release than Microcystis aeruginosa?

Owing to the global warming and its strong adaptability, Cylindrospermopsis raciborskii has spread world-wide. However, as one of toxic cyanobacteria in many drinking water sources, it has not been drawn proper consideration in drinking water treatment plants so far. The investigation aimed at unveiling the fate of C.

Using quartz sand to enhance the removal efficiency of M. aeruginosa by inorganic coagulant and achieve satisfactory settling efficiency.

In this study, low-cost and non-polluting quartz sand was respectively mixed with AlCl, FeCl and PAFC to synergistically remove Microcystis aeruginosa. Results showed that quartz sand could markedly increase the algae removal efficiency and decrease the coagulant doses. The increase of removal efficiency with AlCl and FeCl was only due to the enhancement of floc density by the quartz sand.

16S rRNA Gene Amplicon Sequencing Reveals Significant Changes in Microbial Compositions during Cyanobacteria-Laden Drinking Water Sludge Storage.

This is the first study to systematically investigate the microbial community structure in cyanobacteria-laden drinking water sludge generated by different types of coagulants (including AlCl, FeCl, and polymeric aluminum ferric chloride (PAFC)) using Illumina 16S rRNA gene MiSeq sequencing. Results show that Cyanobacteria, Proteobacteria, Firmicutes, Bacteroidetes, Verrucomicrobia, and Planctomycetes were the most dominant phyla in sludge, and because of the toxicity of high Al and Fe level in AlCl and FeCl sludges, respectively, the PAFC sludge exhibited greater microbial richness than that in AlCl and FeCl sludges. Due to lack of light and oxygen in sludge, relative abundance of the dominant genera Microcystis, Rhodobacter, Phenylobacterium, and Hydrogenophaga clearly decreased, especially after 4 days storage, and the amounts of extracellular microcystin and organic matter rose.

A promising application of chitosan quaternary ammonium salt to removal of Microcystis aeruginosa cells from drinking water.

This work was aimed toward studying the new application of chitosan quaternary ammonium salt (HTCC), a water-soluble chitosan derivative, on removal of Microcystis aeruginosa (M. aeruginosa) cells during HTCC coagulation and floc storage. Results showed that all cells were removed without damage under optimum coagulation conditions: HTCC dosage 1.