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Microcystins are a group of heptapeptide hepatotoxins produced by a variety of algae and are frequently detected in aquatic ecosystems, posing a global threat to ecological stability and human health. However, it is difficult to eliminate them completely and innocuously from water by conventional water treatment processes. This study comprehensively evaluated a total of 821 original articles retrieved from the Web of Science (1991–2020) about the removal of microcystins using bibliometric and content analysis to provide a qualitative and quantitative research landscape and a global view of research hotspots and future research directions. Furthermore, the primary and promising treatment technologies for microcystin pollution were also summarized and discussed. The results indicated an urgent practical demand to remediate microcystin pollution according to the increasing number of publications since 2005. China had the highest number of publications, whereas the United States was the core country in the international collaboration network. The Chinese Academy of Sciences and University of Cincinnati showed their leading positions considering article amounts and academic cooperation. Dionysiou DD contributed the most articles, and Carmichael WW had the highest number of co-citations. Three treatment technologies, including biodegradation, chemical oxidation and adsorption, were the major strategies to remediate the pollution of microcystins in water. In addition, the toxicity of toxins/their metabolites, degradation kinetics, and elimination mechanism were also important research contents. Bacterial degradation, photocatalytic degradation, and multiple-technologies approach have been identified with great potential and should be given more attention in future studies. This work summarizes the current research status on microcystin management, provides a valuable reference for researchers to identify potential opportunities for collaboration in related fields, and guides future research directions to inter-disciplinary and multi-perspective approaches. [Display omitted] • Bibliometrics and content analysis are performed on the removal of microcystins. • China ranks first in publication quantity, while USA takes the leader in influence. • Biodegradation, oxidation, and adsorption are the primary treatment technologies. • The visualized research results and future directions in this field are provided. [ABSTRACT FROM AUTHOR]

Nafine Chemical Industry Group Co. Ltd. extracted inorganic salts from the saline lake of Shanxi Yuncheng, China. Because of the complexity of component and the high content of organic matters in the saline lake water, the purity of the inorganic salts was influenced directly. As a result, the organic matters in the saline lake water were needed to be removed. In order to solve this problem, different water treatment processes were utilized to remove the organic matters in saline lake water, but some valuable metal ions would lose, especially the magnesium ion in water treatment processes. The purpose of this paper is to study the treatability of high concentrated organic matters in saline water by O2/H2O2 oxidation, O2/H2O2 oxidation followed coagulation and activated carbon adsorption respectively, and the mechanisms of magnesium ion loss were analyzed. The results showed that O2/H2O2 oxidation can change the structure of organic matter and increase the content of carboxylic groups in organic matters which resulted in the complexation with magnesium ion. So that magnesium ion would be lost along with the removal of organic matters by coagulation or activated carbon adsorption following oxidation. However, it indicated that the magnesium ion loss could be decreased effectively through pH adjusting after oxidation. [ABSTRACT FROM AUTHOR]