Enhanced Microcystis Aeruginosa removal and novel flocculation mechanisms using a novel continuous co-coagulation flotation (CCF)

Design and application of a polyacrylamide-grafted gelatin/biochar/Fe3O4 magnetic coagulant for microcystin-LR and turbidity co-removal: A case study with Yangtze River water

This study presents a novel composite coagulant composed of polyacrylamide-grafted gelatin (PAM-g-gelatin), oak-derived biochar, and Fe₃O₄ magnetic nanoparticles for the efficient removal of turbidity and microcystin-LR (Mic-LR) from contaminated water. Comprehensive characterization using FTIR, BET, SEM, XRD, and EDX techniques confirmed successful synthesis and functional integration of the components, with a surface area of 27.596 m2/g. Experimental trials on Yangtze River water spiked with 300 μg/L Mic-LR and turbidity ranging from 0 to 30 NTU identified optimal operating conditions: 50 mg/L coagulant dosage, pH 8, and stirring at 400 rpm. Under these parameters, the composite achieved removal efficiencies of 88 % for Mic-LR and 94 % for turbidity. Improved performance in alkaline conditions was attributed to the increased ionization of functional groups such as -COOH and -NH₂, enhancing adsorption and floc formation. The synergistic role of biochar and magnetic particles contributed to better adsorption capacity, floc stability, and overall sustainability. Reusability tests showed high efficiency over four cycles, with slight performance reduction due to active site saturation. The coagulant also effectively removed Mic-RR (85.3 %) and Mic-YR (87.1 %), and maintained stable performance in complex water matrices, showing promise as a robust, cost-effective, and environmentally friendly solution.

Unlocking the potential of bacterioplankton-mediated microcystin degradation and removal: A bibliometric analysis of sustainable water treatment strategies

Microcystins (MCs) constitute a significant threat to human and environmental health, urging the development of effective removal methods for these toxins. In this review, we explore the potential of MC-degrading bacteria as a solution for the removal of MCs from water. The review insights into the mechanisms of action employed by these bacteria, elucidating their ability to degrade and thus remove MCs. After, the review points out the influence of the structural conformation of MCs on their removal, particularly their stability at different water depths within different water bodies. Then, we review the crucial role played by the production of MCs in ensuring the survival and safeguarding of the enzymatic activities of Microcystis cells. This justifies the need for developing effective and sustainable methods for removing MCs from aquatic ecosystems, given their critical ecological function and potential toxicity to humans and animals. Thereafter, challenges and limitations associated with using MC-degrading bacteria in water treatment are discussed, emphasizing the need for further research to optimize the selection of bacterial strains used for MCs biodegradation. The interaction of MCs-degrading bacteria with sediment particles is also crucial for their toxin removal potential and its efficiency. By presenting critical information, this review is a valuable resource for researchers, policymakers, and stakeholders involved in developing sustainable and practical approaches to remove MCs. Our review highlights the potential of various applications of MC-degrading bacteria, including multi-soil-layering (MSL) technologies. It emphasizes the need for ongoing research to optimize the utilization of MC-degrading bacteria in water treatment, ultimately ensuring the safety and quality of water sources. Moreover, this review highlights the value of bibliometric analyses in revealing research gaps and trends, providing detailed insights for further investigations. Specifically, we discuss the importance of employing advanced genomics, especially combining various OMICS approaches to identify and optimize the potential of MCs-degrading bacteria.

Single-atom Mn-embedded carbon nitride as highly efficient peroxymonosulfate catalyst for the harmful algal blooms control

In recent years, water quality deterioration caused by harmful algal blooms (HABs) has become one of the global drinking water safety issues, and sulfate radical driven heterogeneous advanced oxidation technology has been widely used for algae removal. However, the shortages of low active site exposure, metal leaching, and secondary contamination limit its further application. Therefore, the single-atom Mn anchored on inorganic carbon nitride was constructed to enhance the oxidation and coagulation of algal cells while maintaining cell integrity in this study. The removal efficiency of Microcystis aeruginosa was as high as 100 % within 30 min under the optimal conditions of 400 mg/L single-atom Mn-embedded g-C3N4 (SA-MCN) and 0.32 mM peroxymonosulfate (PMS). Importantly, the K+ release, malondialdehyde concentration, floccules morphology and variation of algal organic matters further showed that the algal cells still maintained high integrity without severe rupture during the catalytic reaction. Furthermore, the catalytic mechanisms of algae removal by moderate oxidation and simultaneous coagulation in this system were explored by quenching experiments, EPR analysis, theoretical calculation, and Zeta potential. In brief, this study highlighted the single-atom heterogeneous catalyst with high-efficiency and environmental-friendliness in harmful algal blooms control.