In recent years, the frequent outbreaks of cyanobacterial blooms have caused severe water pollution in many rivers and lakes at home and abroad, endangering drinking water safety and human health. How to remove cyanobacteria from water bodies safely, quickly, and economically has attracted the attention of many scientists. Currently, the typical treatment methods for algae in algae-bearing water bodies are physical, biological, and chemical methods. The physical method of algae removal is for both the symptoms and the root cause, but the workload is extensive, with high input costs, and should not be used on a large scale. The biological method is low-cost, but the removal efficiency is slow and unsuitable for the treatment of sudden water bloom. The chemical method can kill algae quickly, but it is easy to cause secondary pollution. These methods are relatively independent of each other, so the choice of a practical combination of technologies is essential for algal bloom removal and eutrophication management. This paper reviews the current application status and advantages and disadvantages of algae removal technologies at home and abroad; classifies them from physical, chemical, biological, and combined methods; and provides an outlook on the future development direction of algae removal technologies.

The aim of this paper was to effectively reduce environmental pollution and further improve the enzymatic hydrolysis rate of corn straw. Thus, a pretreatment method for activating cellulose by using ionic liquid to treat metal ion solution was developed. By investigating the effects of the three factors of substrate mass fraction, reaction temperature, and reaction time, and the interaction between the factors on the pretreatment effect, the response surface design method was used to optimize the conditions of ionic liquid (1-butyl-3-methylimidazolium chloride) treatment of corn straw after activation, and the physicochemical structure and enzymatic hydrolysis efficiency before and after treatment were compared and analyzed. The experimental results showed that the yield of reducing sugar was increased by 157.85% and 150.41%, respectively, compared with the untreated corn straw. The analysis of chemical composition and structure showed that the cellulose content of the material increased significantly by 68.11% and 60.54%, respectively, after ionic liquid treatment. The results of the scanning electron microscope (SEM) observation and X-ray diffraction (XRD) showed that the relative crystallinity of the material decreased after ionic liquid treatment, which was more conducive to the enzymatic hydrolysis of cellulose.